JP2010201742A - Preliminary discharge section and ink jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that setting a porous member for absorbing mist of ink, etc., at a suction route dries and solidifies the ink, which causes clogging and might reduce the suction force, when a mist suction mechanism is provided for performing preliminary discharge operation. <P>SOLUTION: An ink accepting part comprises a top plate part having a suction port and an ink absorbing member. The ink absorbing member is arranged below the top plate part. The suction route, which is a narrow space and has a flow passage changed to have an angle different from an ink discharge angle, is composed by a gap between an inner surface of the top plate part and the ink absorbing member. Accordingly, the porous member having large flow-passage resistance need not be provided in the suction route, and clogging hardly occurs. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a preliminary ejection unit for performing preliminary ejection of an inkjet head for ejecting liquid, and an ink ejection device that includes the preliminary ejection unit and is used in a manufacturing apparatus such as a color filter in a liquid crystal panel.

  As a technology for ejecting minute droplets and depositing the minute droplets on a desired region, an inkjet technology in which minute droplets are ejected and ejected from minute nozzles using a piezoelectric material is known. In recent years, it has attracted attention as an industrial application.

  In this inkjet technology, for example, in a manufacturing process of a liquid crystal display device, a process in which a manufacturing cost can be reduced by eliminating a photolithography process, for example, a process of applying red, blue, and green color inks of a color filter for each minute region In addition, it is expected to be applied to a process of applying a liquid containing beads for the purpose of arranging a spacer that regulates the thickness of the liquid crystal layer to be constant. In addition, in a manufacturing process of an organic EL (electroluminescence) device that is attracting attention as a next-generation display technology, a process of forming a polymer-type light emitting layer or the like by a liquid discharge technique has been proposed.

  As described above, in an inkjet apparatus for industrial use, it is required to use liquids having various properties according to the field of use. For this reason, there is a tendency that the difficulty of maintaining the ink ejection performance by keeping the nozzle surface clean, and maintenance operations such as cleaning the inkjet head are important. For this reason, generally, a maintenance unit for performing a maintenance operation of the inkjet head is arranged in the inkjet apparatus, and various maintenance operations are performed in the maintenance unit.

  Further, in the maintenance section, the ink is dried and solidified along with the steady operation, and the desired maintenance operation and effect cannot be obtained. For this reason, operations such as cleaning or member replacement are also required for the maintenance unit. Although it is desirable that the maintenance section itself operate and complete automatically, it is not always possible to perform perfect processing, and it is often performed manually by a person regularly or irregularly.

  However, on the other hand, since the above-described manual work is performed by a person entering the production apparatus, the time for stopping the production line is lengthened and the operating time of the production line is lowered. As a result, it increases the product cost. Therefore, the maintenance work that is performed manually is as simple as possible, and it is desired to finish it in a short time.

  In addition, in general, in addition to maintenance work (hereinafter referred to as normal maintenance work) performed in a relatively short cycle of about one week in a manufacturing apparatus, thorough cleaning and replacement of parts etc. once a year In many cases, overhaul work is set for the purpose.

  By the way, among the various inks, a problem that becomes particularly prominent when using fast-drying ink is that the ink in the vicinity of the nozzles of the inkjet head is dried and the landing accuracy is deteriorated when the standby state in which ink is not discharged becomes long. Will occur. Further, if the drying further proceeds, the state shifts to a state where ink cannot be discharged (hereinafter referred to as non-discharge).

  For this reason, in the conventional ink jet apparatus, measures are taken to perform preliminary discharge in addition to the main discharge for the desired processing. If preliminary ejection is performed, ink that has been dried in the vicinity of the nozzles can be ejected in advance, and ink that has not been dried during the desired main ejection can be ejected, thereby suppressing the occurrence of non-ejection or landing deterioration. be able to. Therefore, it is desirable to perform preliminary discharge frequently and immediately before a desired discharge operation.

  However, in an ink jet apparatus, finer mist may be generated in addition to main ink droplets. Alternatively, when the distance between the inkjet head and the landing object is as long as, for example, 1 mm or more, the ejected ink droplet may not reach the landing object and may float as a mist. That is, the preliminary ejection operation becomes a cause of mist generation, adheres to the nozzle surface of the ink jet head, and may cause the landing accuracy to deteriorate.

  Therefore, it is necessary to take measures to prevent the mist from scattering, and in Patent Document 1, the suction pump connected to the capping unit is driven and is generated at the time of preliminary discharge through an ink absorbing member formed of a porous material. A technique for sucking mist is disclosed. According to this technique, the mist generated by the preliminary discharge can be effectively sucked into the cap means, and the problem of soiling the nozzle surface or peripheral members can be reduced.

  Further, in Patent Document 2, a mechanism for sucking mist and an immersion part for immersing ink sucked into a preliminary ejection box, more specifically, a member for capturing mist are provided. A technique such as arranging the suction channel so as to meander by the member is disclosed. According to this technique, ink can be effectively drawn into the preliminary ejection box by the suction function, and the ejected ink can be absorbed by the immersion portion, and the mist can be captured by the mist capturing member that forms a meandering suction path.

JP 2002-137415 A JP 2007-244968 A

  However, when a porous ink absorbing member is disposed in the mist suction path as described in Patent Document 1, the ink absorbing member serves as a path for absorbing ink and sucking air into the member. The ink inside tends to dry and solidify, and clogging is likely to occur. When clogging occurs, the suction force is reduced, ink is deposited on the ink absorbing member, and the suction force is accelerated. Therefore, there is a problem that the necessity of maintenance work for frequently replacing the ink absorbing member is increased.

  Moreover, if the mist capturing member like the technique described in Patent Document 2 is used, the shape of the mist capturing member becomes complicated, and maintenance work such as cleaning after removing becomes complicated.

  Patent Document 2 discloses a maintenance method in which cleaning ink is dissolved and washed by sending cleaning liquid into a preliminary discharge box. If the ink jet apparatus can be automatically cleaned in this way, it is one of desirable forms that does not require manual work. However, among the various ink types used in the ink jet technology, there is an ink that does not easily re-dissolve once solidified, and sufficient cleaning is not always realized only by immersing the cleaning liquid.

  The present invention has been made in view of such a problem, and suppresses a rapid deterioration of suction force in a frequently used preliminary discharge operation. Furthermore, although a normal maintenance operation is required for the preliminary discharge unit, the function of capturing the mist is concentrated on the member to be manually operated, and the configuration in which the above manual operation can be easily performed is compatible. Accordingly, a member that is soiled with ink by a normal maintenance operation is quickly updated to maintain the performance, and the operation reliability of the ink jet apparatus is ensured.

  That is, according to the present invention, the ink receiving portion includes a top plate portion having a suction port and an ink absorbing member, and the ink absorbing member is disposed below the top plate portion, and the inner surface of the top plate portion and the ink A suction path in which the flow path is changed to an angle different from the ink discharge angle is formed by the gap with the absorbing member. Thereby, a porous member having a large flow path resistance is not provided in the suction path, and clogging is unlikely to occur.

  Furthermore, the suction path is preferably formed in a polygonal line shape. Accordingly, it is possible to improve the absorption efficiency of the preliminarily ejected ink into the ink absorbing member.

  Furthermore, it is preferable that the top plate portion of the ink receiving portion and the ink absorbing member have a structure in which two plate-like members are laminated, and the top plate portion is detachable. Thereby, it is possible to easily attach and detach the top plate portion and the ink absorbing member located therebelow from above.

  Further, the suction port formed in the top plate portion is formed in a slit shape that matches the shape of the nozzle row of the inkjet head, and suction is performed from the slit suction port by narrowing the cross-sectional area in the middle of the suction path. It is preferable to form a flow rate adjusting unit that makes the speed of the operation uniform. Accordingly, it is possible to suppress a decrease in suction force due to ink adhesion and solidification in the suction path.

  Furthermore, it is preferable that an optical means for detecting the ejection state of the inkjet head is further provided above the top plate portion. Thereby, it is possible to confirm the ejection of the ink from the inkjet head simultaneously with the continuous ejection or continuously.

  Furthermore, it is preferable that the cross-sectional area of the flow path from the flow rate adjusting unit to the suction mechanism for drawing into the ink receiving unit is larger than the cross-sectional area of the flow rate adjusting unit. As a result, the possibility that ink components that could not be captured by the flow rate adjusting unit adhere to the wall surface in the flow path to the suction mechanism and solidify even when solidified will be reduced to the extent that the flow path is blocked. There is no need to clean or replace the channel.

  Furthermore, it is characterized by having a storage part for storing the moisturizing liquid further below the ink absorbing member, and it is preferable that the moisturizing liquid is supplied from the storing part to the ink absorbing member by vapor or suction. Accordingly, drying of the ink captured by the ink absorbing member during the preliminary ejection operation can be suppressed, and the captured ink can be effectively introduced from the surface layer of the ink absorbing member into the ink absorbing member.

  Furthermore, it is preferable that a sucking member that sucks the moisturizing liquid into the ink absorbing member by a capillary phenomenon is disposed in a part of the space of the ink storing portion. Thereby, the moisturizing effect is improved by supplying the moisturizing liquid into the ink absorbing member.

  Furthermore, the inkjet head is provided so as to be movable relative to the object to be processed, and discharges ink to the object to be processed. The first maintenance unit and the second maintenance unit are capable of performing maintenance on the inkjet head. It is preferable that at least one maintenance unit has a preliminary ejection unit that can move while maintaining a relative positional relationship with the inkjet head. As a result, while performing maintenance work such as cleaning or member replacement for one maintenance unit, the other maintenance unit waits for the inkjet head, and the desired maintenance for the inkjet head is performed as necessary. The operation can be performed, and there is no problem caused by leaving the inkjet head for a long time.

  In the present invention, a preliminary discharge portion that does not easily lower the suction force is realized by the structure of the preliminary discharge portion. Thereby, the mist can be effectively sucked into the preliminary ejection part at the time of preliminary ejection, and the performance deterioration due to adhesion to the ink jet head can be suppressed. Furthermore, the efficiency of normal maintenance work is improved by adopting a configuration in which the part that captures most of the sucked ink can be easily replaced.

It is a figure for demonstrating the whole structure of the inkjet apparatus which concerns on this invention. It is a figure for demonstrating that an inkjet head and a 2nd maintenance unit are arrange | positioned in the inkjet unit which concerns on this invention. FIG. 3 is a diagram illustrating an arrangement configuration of an ink receiving unit and a discharge detection device that configure a preliminary discharge unit which is a second maintenance unit described in FIG. 2. It is a figure explaining the attraction | suction path | route of the preliminary discharge part which concerns on this invention. FIG. 4 is a schematic diagram of a cross section of an ink receiving portion of a preliminary discharge portion according to the present invention, and is a view for explaining an internal configuration of the ink receiving portion. It is a figure for demonstrating the shape of the top-plate part which comprises the ink receiving part of the preparation discharge part which concerns on this invention, and forming a suction path by the groove | channel structure of an inner surface.

  Embodiments of the present invention will be described below with reference to the drawings. However, this embodiment is illustrative in all respects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

  First, an ink jet apparatus according to the present invention will be described. FIG. 1 is a perspective view illustrating the overall configuration of an inkjet apparatus 6 according to the present invention. In FIG. 1, an inkjet apparatus 6 includes a stage 1 on which a workpiece 5 is placed, an inkjet unit 2 having an inkjet head that ejects ink onto the workpiece 5, and a drive unit that moves the inkjet unit 2 in the x-axis direction. 3a, a drive unit 3b that moves the inkjet unit 2 in the y-axis direction, and a second maintenance unit 4 that periodically cleans the inkjet head.

  Further, as shown in FIG. 2, the ink jet unit 2 has a basic configuration of an ink jet head 7 and an elevating mechanism 8 that moves the ink jet head 7 up and down. In the present embodiment, the ink receiving unit 9, the ejection detection device 10 a, An ejection detection device 10 b is mounted on the ink receiving unit driving means 12. Furthermore, an ink suction mechanism (not shown) is connected to the ink receiving portion 9 to constitute a preliminary ejection portion. The first maintenance unit 11 is mainly composed of the elevating mechanism 8, the preliminary ejection unit (the ink receiving unit 9, the ejection detection device 10a, and the ejection detection device 10b are illustrated), and the ink reception unit driving means 12. That is, the first maintenance unit 11 is disposed in the inkjet unit 2 and can move while maintaining the relative positional relationship with the inkjet head 7.

  The driving unit 3a that moves in the x-axis direction and the driving unit 3b that moves in the y-axis direction, the inkjet head 7, the ink supply system (not shown), the lifting mechanism 8, the first maintenance unit 11, and the second maintenance unit 4 Are connected to a control unit such as a computer (not shown). This control unit is configured to drive the drive unit 3a that moves in the x-axis direction and the drive unit 3b that moves in the y-axis direction, the ink ejection operation by the inkjet head 7, the ink supply operation to the inkjet head 7 of the ink supply system, and the elevation The lifting / lowering operation of the inkjet head 7 by the mechanism 8 and various maintenance operations of the first maintenance unit 11 and the second maintenance unit 4 are controlled.

  The operation of a typical ink jet process by the ink jet apparatus of this example is as follows. Based on the control signal from the control unit, the drive unit 3a that moves in the x-axis direction and the drive unit 3b that moves in the y-axis direction are driven, and the inkjet head 7 is on the desired processing position on the workpiece 5. The inkjet unit 2 moves so that

  At this time, the ink-jet head 7 is in a standby state and is stored in the ink-jet unit 2 by the elevating mechanism 8 and is disposed immediately above the ink receiving portion 9 to obtain a moisturizing effect and suppress the drying of the ink. is doing. A configuration that can obtain a moisturizing effect by the ink receiving portion 9 will be described later.

  When the inkjet unit 2 completes movement by the drive unit 3a that moves in the x-axis direction and the drive unit 3b that moves in the y-axis direction, the inkjet head 2 uses the first maintenance unit 11 in the inkjet head 2. 7 is performed. After the preliminary ejection operation, the ejection inspection operation and the liquid sag inspection operation are performed, and after confirming that the inkjet head 7 operates normally, the inkjet head 7 is lowered from the opening 13a of the base plate 13 using the lifting mechanism 8 downward. Thus, ink is supplied to the ink jet head 7 by an ink supply system (not shown), and the ink jet head 7 is operated to discharge micro droplets made of ink onto the object 5 to be processed.

  The ejection inspection operation is an operation for inspecting whether ink can be normally ejected from the inkjet head 7 immediately before ink ejection to the object 5 to be processed. The discharge inspection operation is performed by the discharge inspection apparatuses 10a and 10b. More specifically, the discharge inspection apparatus 10a is a light emitting element, and 10b is a light receiving element, which irradiates laser light from the discharge inspection apparatus 10a toward the discharge inspection apparatus 10b and monitors the amount of light received by the discharge inspection apparatus 10b. At this time, as shown in FIG. 3, the path of the laser beam is arranged so as to pass directly above the suction port 9a provided in the ink receiving unit 9, and the laser beam is transmitted while performing the suction operation of the preliminary ejection unit. Ink is ejected from the inkjet head 7 toward the path. When a predetermined amount of ink is normally ejected from the inkjet head 7, the laser light is shielded, so that the amount of light received by the ejection inspection apparatus 10b is reduced. In this case, the result of the discharge inspection is acceptable. On the other hand, when a predetermined amount of ink is not normally ejected from the inkjet head 7, the laser beam is not shielded, and the amount of light received by the ejection inspection device 10b does not decrease. In this case, the result of the discharge inspection is rejected, and a recovery operation is required. Examples of the recovery operation include an operation of sucking ink in the nozzles and the like, and a device that can be implemented may be mounted on the second maintenance unit 4, but the detailed configuration and description of the operation are omitted here.

  Further, the liquid sag inspection operation is an operation for inspecting whether ink is attached near the nozzles of the inkjet head 7. This is because the ejection inspection devices 10a and 10b are mounted in a state where the inkjet head 7 is arranged by the lifting mechanism 8 at an appropriate height so that the laser beam of the ejection inspection device 10a passes through the vicinity of the nozzle of the inkjet head 7. This is made possible by operating the ink receiving portion driving means 12 to move the ink receiving portion 12 relative to the ink jet head 7 and confirming the presence or absence of a change in the amount of light received by the ejection inspection apparatus 10b. That is, when liquid sag occurs, the amount of light received by the ejection inspection apparatus 10b decreases and fails. On the other hand, when liquid dripping has not occurred, the amount of light received by the ejection inspection apparatus 10b does not change, and is determined to be acceptable. When liquid dripping occurs, if the ink-jet head 7 is lowered, the liquid dripped may adhere to the object 5 to be processed, so a recovery operation is necessary. Specifically, an operation such as wiping the nozzle portion of the ink jet head 7 with a wiper made of an elastic body or the like to remove the dripped ink is exemplified, and the second maintenance unit 4 can perform the same operation as described above. A simple device may be installed.

  As described above, the inkjet device 6 includes the first maintenance unit 11, the second maintenance unit 4, and the two maintenance units. The first maintenance unit 11 has a preliminary discharge function, a discharge inspection function, a liquid sag detection function, and a moisturizing function.

  The second maintenance unit provides a maintenance function other than the maintenance operation that can be performed by the first maintenance unit. In particular, in the present invention, the function to be given is not specified, but specifically, the nozzle suction function and the wipe function as described above are given. Alternatively, an ultrasonic cleaner may be mounted to provide a function of cleaning the solidified ink near the nozzle.

  According to this configuration, the inkjet head 7 can be stored in the inkjet unit 2 and kept moisturized while being cleaned or replaced with the second maintenance unit 4 by normal maintenance. The ink can be prevented from drying and solidifying.

  Further, in the present ink jet device 6, after the ink jet unit 2 is moved by the drive unit 3 a that is moved in the x-axis direction and the drive unit 3 b that is moved in the y-axis direction, that is, a book that performs desired ink discharge onto the object 5. Immediately before discharge, preliminary discharge, discharge inspection, and liquid sag inspection can be performed, and the desired main discharge can be reliably performed.

  Next, a detailed description of the preliminary discharge unit constituting the first maintenance unit 11 will be given.

  FIG. 4 shows a suction path formed by the preliminary discharge portion. In FIG. 4A, a flow path is formed from the ink receiving portion 9 to the pump 15 which is a suction mechanism through the electromagnetic valve 14, and further, A waste liquid tank 16 is formed behind the pump 15, and a suction force for drawing ink into the ink receiving portion 9 is generated by operating the pump 15.

  The pump 15 may be a liquid feed type pump, for example, a diaphragm pump or a tube pump. A member having resistance to the ink to be used may be used for the liquid contact portion, and a pump to be employed may be selected according to the ink to be used.

  The waste liquid tank 16 is arranged to collect ink that has not been captured in the ink receiving unit 9 out of the ink sucked into the ink receiving unit 9. It is not necessary to have a tank shape for storing, and a member such as a filter for capturing ink may be used.

  Further, when the amount of ink that has not been captured as described above is small, a negative pressure generator 18 may be connected via a filter 17 as shown in FIG. The negative pressure generator 18 is a vacuum ejector that introduces a gas such as compressed air into the main body and forms a high-speed flow therein to locally form a vacuum state and generate a suction action. The vacuum ejector is relatively small and has an advantage that a large suction force can be generated.

  The filter 17 is a porous member and has a large flow path resistance. However, if a negative pressure generator such as a vacuum ejector is employed, a sufficient suction force can be secured. Furthermore, when the amount of ink that could not be captured is small, clogging of the filter 17 is unlikely to occur, and the suction force is unlikely to decrease.

  Next, the internal configuration of the ink receiving portion 9 will be described with reference to FIG. FIG. 5 schematically shows a cross section of the ink receiving portion 9, and a plate-like top plate portion 19 is disposed on the ink receiving portion main body 20. A suction port 9 a is formed in the top plate portion 19, and an ink absorbing member 21 is disposed below the top plate portion 19 inside the ink receiving portion 9. Further, a storage portion 23 for storing a moisturizing liquid is formed immediately below the ink absorbing member 21. Further, a suction member 24 for sucking up the moisturizing liquid is disposed in a part of the storage portion 23 so as to be in contact with the ink absorbing member 21.

  As shown in FIG. 6, the top plate portion 19 has a groove formed on the inner surface. If the top plate portion 19 is set in a state where the ink absorbing member 21 is placed, the inner surface of the ink absorbing member 21 and the top plate portion 19 is set. A gap can be formed between the two. As a result, the pipe connection port 9b formed on the side surface of the main body 20 through the gap between the ink absorbing member 21 and the inner surface of the top plate portion 19 from the suction port 9a formed in the top plate portion 19. A path that communicates with is formed. Then, by connecting a suction mechanism (not shown) to the pipe connection port 9b, the ink discharged from the inkjet head 7 can be sucked from the suction port 9a of the ink receiving portion 9.

  Further, the groove formed in the inner surface of the top plate portion 19 is formed with a portion having a shallow depth in the width direction, and is in the middle of the suction path formed by the gap between the inner surface of the top plate portion 19 and the ink absorbing member 21. Thus, it is configured to act as a flow rate adjusting unit 22 that equalizes the flow rate in the width direction in the suction path.

  If the suction force is uneven at each part of the suction port, if the entire suction force is set so that the mist can be sucked even at the part where the suction force is small, the ink of the nozzle part facing the part where the suction force is large Another problem is that drying tends to proceed, and if the balance of the suction force is large, the negative pressure at the portion where the suction force is large becomes high, and ink may leak from the nozzle. Needless to say, if the suction force is set to a desired suction force at which the mist can be sucked at a portion having a large suction force, the mist cannot be sucked at a portion having a small suction force. According to the present invention, the suction force in the width direction of the slit-shaped suction port 9a can be made uniform by the flow rate adjusting unit 22.

  Further, since the flow velocity adjusting unit 22 has a configuration in which the path cross-sectional area is narrowed, the sucked ink is more likely to be clogged than other path parts, but is formed by the inner surface of the top plate part 19 and the ink absorbing member 21. By arranging in the middle of the suction path, the flow path can be secured by replacing or cleaning the constituent members during normal maintenance, and the normal maintenance work can be performed easily.

  During preliminary ejection, ink is ejected from the inkjet head 7 to the lower suction port 9a, but the suction path formed by the gap between the inner surface of the top plate portion 19 of the ink receiving portion 9 and the ink absorbing member 21 is in the horizontal direction. The suction path is formed in a polygonal line. For this reason, most of the ejected ink collides and is captured by the ink absorbing member 21 in the vicinity of the bent portion. That is, the ink ejected by the inkjet head 7 is introduced into the suction port 9a of the ink receiving portion 9 by the suction function, and most of the ink is captured by the ink absorbing member 21 of the ink receiving portion 9. Therefore, it is possible to suppress the ink from floating in the vicinity of the inkjet head 7 and being contaminated. In addition, since the amount of ink components adhering to the wall surface after the suction path formed by the gap between the inner surface of the top plate part 19 and the ink absorbing member 21 can be reduced, the suction path at the part is narrowed and the suction force is reduced. The situation where it falls is less likely to occur, and the suction force can be maintained for a long time. Thereby, for example, at the time of overhauling that is less frequently performed, the suction path formed by the inner surface of the top plate portion 19 and the ink absorbing member 21 is replaced or cleaned from then on, thereby performing preliminary ejection. It is possible to maintain the ability of the suction operation.

  That is, since the ink component can be intensively captured by the inner surface of the top plate portion 19 and the ink absorbing member 21, if the ink absorbing member 21 is replaced and the top plate portion 19 is periodically replaced or cleaned, the preliminary ejection portion Most of the ink that has been sucked in can be eliminated, and the preliminary ejection section is unlikely to cause a reduction in suction force. Further, since the top plate portion 19 and the ink absorbing member 21 of the ink receiving portion 9 are configured so as to laminate two plate-like members, the top plate portion 19 and the ink absorbing member 21 below the top plate portion 19 are arranged from above. It can be easily attached and detached. Therefore, manual maintenance work can be simplified and the work can be completed in a short time.

  In addition, the optical means described above with reference to FIG. 3 provides a discharge inspection function that allows the ink discharge state of the ink jet head 7 to be inspected, and is provided above the suction port 9a of the ink receiving portion 9 during preliminary discharge. A laser beam path is formed between the inkjet head 7 and the position. By providing this optical means, it is possible to quickly confirm the discharge operation simultaneously or continuously with the preliminary discharge, that is, without moving the inkjet head in the horizontal direction, so the time from the preliminary discharge to the main discharge can be shortened, The predetermined processing tact can be shortened. In addition, since the time from the preliminary discharge to the main discharge can be shortened, there is an effect of reducing the drying of the ink near the nozzle that proceeds immediately after the preliminary discharge.

  Furthermore, a storage portion 23 for storing the moisturizing liquid is formed below the ink absorbing member 21. A suction member 24 is disposed in the storage unit 23, and the moisturizing liquid in the storage unit 23 can be supplied to the ink absorbing member 21, and the ink absorbing member 21 can be held in a wet state. As a result, the ink trapped in the ink absorbing member 21 can easily soak into the inside from the surface of the ink absorbing member 21, so that the ink is dried, solidified and deposited on the surface of the ink absorbing member 21. There is an effect to suppress. Furthermore, by holding the ink absorbing member 21 in a wet state, the amount of moisturizing liquid that reaches the suction port 9a as a vapor increases. Therefore, in a state where the ink jet head 7 is not operated (standby state), If the inkjet head 7 is disposed immediately above the suction port 9a, the inkjet head 7 can be moisturized and the drying of the ink near the nozzle can be suppressed.

  Here, as the moisturizing liquid, it is desirable to use the main solvent of the ink, and it is sufficient to determine the volume of the storage part to be replenished to the storage part periodically. The ink absorbing member 21 and the sucking member 24 are preferably members that can absorb a large amount of ink or moisturizing liquid, and a porous member such as a PVA (polyvinyl alcohol) sponge can be preferably used. Since the member is porous, it can absorb a large amount of ink or moisturizing liquid, and can easily absorb the liquid droplets inside by capillary action, and can introduce the ink reaching the surface of the ink absorbing member 21 into the inside. The stored moisturizing liquid is introduced into the upper ink absorbing member by the sucking member 24, and a desired moisturizing effect can be obtained.

  For example, in the case where a porous member having the same quality as the ink absorbing member is disposed in the entire storage portion, the capillarity phenomenon occurs in any part, so that the performance of sucking up the moisturizing liquid is deteriorated.

  In the present invention, a storage space in which capillary action does not work is disposed below the ink absorbing member, and sufficient moisturizing liquid is stored, and the moisturizing liquid is applied to the upper ink absorbing member by a suction function provided in part. Sucked up and can provide effective moisturizing function. In addition, since the sucking member is arranged only in a part of the space of the storing portion, the amount of the moisturizing liquid stored is reduced by the volume of the sucking member, and the space saving configuration is achieved.

  In the present embodiment, the cross-sectional area of each part of the flow path from the flow rate adjusting unit 22 to the pump that is the suction mechanism is set larger than the cross-sectional area of the flow rate adjusting unit 22.

  As a result, even if a small amount of ink component that could not be captured by the flow rate adjusting unit 22 of the ink receiving unit 9 adheres to the wall surface of the flow channel from the flow rate adjusting unit 22 to the suction mechanism, it accumulates to the extent that the flow channel is blocked. This eliminates the need for cleaning the flow path over a long period of time.

  According to the above configuration, in the normal maintenance operation, the top plate 19 is cleaned or replaced, the ink absorbing member 21 is replaced, the moisturizing liquid is replenished, and the entire flow path related to the preliminary ejection unit is cleaned or replaced when overhauling. Should be done. By this operation, most of the ink drawn into the ink receiving portion 9 by the preliminary discharge operation or the discharge inspection operation can be easily removed in a short time by the normal maintenance operation. Further, since the possibility that the ink component adheres and blocks the flow path at a portion other than the top plate portion 19 and the ink absorbing member 21 is reduced, cleaning or member replacement work is unnecessary for a long period of time.

  Therefore, for example, if the flow path constituent member is replaced during an overhaul operation, the preliminary discharge performance can be sufficiently maintained.

  In this example, a broken line-shaped suction path bent from the lower side to the horizontal direction is taken as an example. However, if the suction path is not linear but the angle is changed, the ink is absorbed in the ink absorbing member 21 near the bent part. Collision and ink capture is possible. However, since the ratio at which the ink collides with the ink absorbing member 21 varies depending on the change shape of the flow path, a suction path that changes the angle in a polygonal line as in this example is preferable to the angle change by a gentle curve.

  Moreover, since the flow velocity decreases as the space cross-sectional area of the suction path increases, the ratio at which the sucked ink collides with the ink absorbing member 21 when the flow path changes decreases. For this reason, it is preferable that the area in the range in contact with the ink absorbing member 21 from the suction port 9a is a narrow space of the same extent as the suction port 9a area. In this embodiment, the space cross-sectional area of the suction path is 1.5 times the area of the suction port 9a.

DESCRIPTION OF SYMBOLS 1 Stage 2 Inkjet unit 3a The drive part moved to x-axis direction 3b The drive part moved to y-axis direction 4 2nd maintenance unit 5 To-be-processed object 6 Inkjet apparatus 7 Inkjet head 8 Lifting mechanism 9 Ink receiving part 9a Suction port 9b Pipe connection port 10a Discharge detection device 10b Discharge detection device 11 First maintenance unit 12 Ink receiving portion driving means 13 Base plate 13a Opening portion 14 Solenoid valve 15 Pump 16 Waste liquid tank 17 Filter 18 Negative pressure generator 19 Top plate portion 20 Ink Receiving part main body 21 Ink absorbing member 22 Flow rate adjusting part 23 Reserving part 24 Suction member

Claims (9)

An ink receiving portion for receiving the pre-discharged ink of the inkjet head;
A pre-ejection unit connected to the ink receiving unit and having a suction mechanism for drawing the pre-ejected ink into the ink receiving unit;
The ink receiving portion includes a top plate portion having a suction port;
An ink absorbing member,
The ink absorbing member is disposed below the top plate portion,
A preliminary ejection unit, characterized in that a suction path in which the flow path is changed to an angle different from the ink ejection angle is configured by a gap between the inner surface of the top plate part and the ink absorbing member. .   The preliminary discharge unit according to claim 1, wherein the suction path is formed in a polygonal line shape. The top plate portion and the ink absorbing member are configured by laminating two plate-like members,
The preliminary discharge unit according to claim 1, wherein the top plate is detachable.   The suction port formed in the top plate portion is formed in a slit shape that matches the shape of the nozzle row of the inkjet head, and suction is performed from the suction port by narrowing the cross-sectional area of the path in the middle of the suction path. The preliminary discharge unit according to any one of claims 1 to 3, wherein a flow rate adjusting unit that suppresses variation in speed is formed.   5. The preliminary discharge unit according to claim 4, further comprising an optical unit for detecting a discharge state of the inkjet head above the top plate. 6. The preliminary discharge according to claim 4, wherein a cross-sectional area of a flow path from the flow rate adjusting unit to a suction mechanism for drawing into the ink receiving unit is larger than a cross-sectional area of the flow rate adjusting unit. Department.   The preliminary ejection unit according to any one of claims 1 to 6, further comprising a storage unit for storing a moisturizing liquid below the ink absorbing member.   The preliminary ejection unit according to claim 7, wherein a sucking member that sucks the moisturizing liquid into the ink absorbing member by a capillary phenomenon is disposed in a part of the space of the storage unit. An inkjet apparatus that ejects ink to an object to be processed placed on a stage,
An inkjet head that is provided so as to be movable relative to the object to be processed, and that discharges ink to the object to be processed;
A first maintenance unit and a second maintenance unit capable of performing maintenance of the inkjet head;
The preliminary ejection unit according to any one of claims 1 to 8, wherein the preliminary ejection unit is movable to at least one of the first maintenance unit and the second maintenance unit while maintaining a relative positional relationship with the inkjet head. An ink jet apparatus comprising: