JP5440404B2 - INJECTION LIQUID DRY SUPPRESSION DEVICE, LIQUID EJECTION DEVICE, AND INJECTION LIQUID DRY SUPPRESSION METHOD - Google Patents

Description

  The present invention relates to a jet liquid drying suppression apparatus, a liquid jet apparatus, and a jet liquid drying suppression method.

  There is known a liquid ejecting apparatus that ejects ejecting liquid (for example, ink) from a liquid ejecting unit (for example, a print head) onto a medium (for example, paper) to form a predetermined image (including characters and graphics). Such a liquid ejecting apparatus is provided with an ejecting liquid drying inhibiting device that prevents the ejecting liquid in the liquid ejecting means from being dried in order to stably eject the ejecting liquid from the liquid ejecting means. ing. In this apparatus, when an image is not formed, the abutting member is applied to a nozzle forming surface provided in a liquid ejecting unit and provided with a nozzle opening which is an end opening of a nozzle for ejecting a jetting liquid. By covering the nozzle opening in contact, drying of the jetting liquid is suppressed. And when forming an image, it is an apparatus comprised so that the contact member which contact | abutted may be spaced apart from a nozzle formation surface so that the liquid for injection may be ejected to a medium from a nozzle opening part.

  As this type of device, there is known a device (capping device) configured such that a cap-shaped contact member forms a closed space region between the nozzle forming surface and covers the nozzle forming surface. In such an apparatus, since the member does not directly contact the nozzle opening, there is little possibility that the meniscus (interface between the jetting liquid and the atmosphere) formed in the nozzle is broken by the contact member. However, the solvent component may evaporate and the jetting liquid may be dried until the closed space reaches the saturated vapor pressure.

  Therefore, in order to suppress the drying of the jetting liquid, the member directly contacts or adheres closely to the nozzle forming surface without a space so as to cover the nozzle opening, and the meniscus is stably formed. Various devised technologies have been proposed. For example, in Patent Document 1, when the contact member contacts the nozzle forming surface, the nozzle is pressed when the contact member contacts by pressing the liquid for injection in the nozzle and bringing the meniscus closer to the contact member side from the normal position. An ink drying prevention device that prevents air (bubbles) from being pushed into the opening has been proposed. Alternatively, in Patent Document 2, when the contact member abuts on the nozzle forming surface, the meniscus is applied to the contact member by conversely pulling the meniscus from the normal position into the nozzle by setting the jetting liquid in the nozzle to a negative pressure. There has been proposed a liquid ejection device that prevents contact.

JP 2002-292858 A JP 2009-029113 A

  However, although the disclosed technique of Patent Document 1 can suppress the mixing of bubbles, the contact member and the meniscus are easily in contact with each other, and the liquid for jetting is caused by the capillary phenomenon generated between the contact member and the contact opening member at the moment of contact. May ooze out and spread on the nozzle forming surface. Accordingly, when the exuded jetting liquid is thickened or dried and solidified, the jetting liquid is drawn from a large number of nozzle openings to change the position of the meniscus when the contact member separates from the nozzle forming face, or the nozzle forming face. It was easy to cause troubles such as fouling.

  In addition, the disclosed technique of Patent Document 2 is that the negative pressure applied to the jetting liquid in the nozzle is not uniform due to the difference in flow path length from the supply port that supplies the jetting liquid to the nozzle. It was difficult to raise the meniscus uniformly for the nozzles. Therefore, although the oozing of the jetting liquid from the nozzle opening can be suppressed, since the negative pressure of the nozzle that could not pull up the meniscus is large, there was a problem that bubbles are likely to be caught when the contact member abuts. . Further, when the contact member is separated from the nozzle forming surface in a negative pressure state, there is a possibility that the meniscus is attracted with the moving contact member, and the meniscus formation position may be unstable. As a result, a meniscus is formed at a position different from the normal position for correctly ejecting the jetting liquid from the nozzle opening at the time of image formation.

  The present invention has been made in view of the above problems. The object is to provide a liquid drying suppression apparatus for injection, a liquid drying suppression apparatus for injection, and a liquid drying suppression method for injection, which can suppress bubble entrainment in the nozzle and fluctuations in the position of the meniscus, An object of the present invention is to provide a liquid ejecting apparatus including the ejecting liquid drying suppressing apparatus.

  In order to achieve the above object, an ejection liquid drying suppression apparatus according to the present invention includes a liquid ejecting unit having a nozzle for ejecting an ejection liquid from a nozzle opening formed on a nozzle forming surface, and the nozzle forming surface. A contact state having contactable contact surfaces, the contact surface being in close contact with the nozzle forming surface so as to block the nozzle opening, and a separated state spaced apart from the nozzle forming surface; And a pressure control means for controlling the pressure of the jetting liquid in the nozzle, wherein the nozzle touching means comprises the touching means. The contact surface is separated from the nozzle formation surface so that the separation region of the contact surface with respect to the nozzle formation surface gradually expands in the process of changing from the state to the separation state, and the pressure control means The contact surface is Prior to separating from the nozzle formation surface, the pressure of the injection liquid in the nozzle is controlled so as not to at least a negative pressure relative to the pressure at the nozzle opening.

  According to this configuration, the contact surface is separated from the nozzle opening while exhibiting an oblique state, for example, so that a minute gap is formed between the nozzle opening and the contact surface. At the same time, since the negative pressure is released or pressurized with respect to the jetting liquid in the nozzle, the jetting liquid in the nozzle moves toward the nozzle opening. At this time, since the flow resistance of the jetting liquid is reduced by the amount of entrained bubbles, the jetting liquid moves quickly in the nozzle. As a result, the entrained bubbles also move quickly together with the jetting liquid, and are discharged into this minute gap when the jetting liquid jumps out of the nozzle opening. Thus, the meniscus can be formed at a preferred position by discharging the bubbles. On the other hand, since the jetting liquid that has jumped out from the nozzle opening is difficult to pass through a minute gap due to its surface tension and flow resistance, discharge is suppressed. As a result, the amount of the jetting liquid consumed can be suppressed.

  Further, when the contact surface is separated, the ejection liquid in the nozzle is brought into a pressurized state or a negative pressure is released, so that the ejection liquid is pulled between the nozzle and the contact surface. Suppress the match. Accordingly, since the impact applied to the meniscus formed when the jetting liquid is broken can be weakened at the time of separation, it is possible to suppress entrainment of bubbles in the nozzle and fluctuations in the position of the formed meniscus. .

  In the jetting liquid drying suppression apparatus of the present invention, the liquid jetting unit includes a plurality of nozzles whose pressures of the jetting liquid are commonly controlled by the pressure control unit, and the nozzle contact unit includes a plurality of nozzle contact units. The contact surface is separated from the nozzle forming surface so as to simultaneously open the plurality of nozzle openings in the process of changing from the contact state in which the plurality of nozzle openings corresponding to the nozzles are closed to the separated state. To do.

  According to this configuration, for example, the contact surface of the nozzle contact means is separated first, and the nozzle that has passed the formation state of a minute gap in which it is difficult for the ejection liquid to pass between the contact surface and the contact surface. The oozing of the jetting liquid that occurs when the pressure is applied or the negative pressure is released can be suppressed by simultaneously separating the contact surfaces of the plurality of nozzles. As a result, consumption of the jetting liquid can be suppressed, and fluctuations in the position of the formed meniscus can be suppressed.

  In the jetting liquid drying inhibiting device of the present invention, the plurality of nozzle openings are arranged in one direction so as to present a nozzle row on the nozzle forming surface, and the nozzle contact means is separated from the contact state. In the process of becoming a state, the contact surface is separated from the nozzle formation surface so that the separation region gradually expands from one side to the other side in a direction orthogonal to the one direction in which the nozzle rows are arranged.

  According to this configuration, the nozzle contact means can separate the contact surface so that the separation region gradually expands from one side to the other side in the direction orthogonal to the nozzle row. For a plurality of nozzles to be presented, the contact surface can be a contact surface having a minimum width.

  In the jetting liquid drying suppression apparatus of the present invention, the liquid jetting unit has a plurality of the nozzle rows on the nozzle forming surface, and the nozzle abutting unit is configured such that the abutting surface is the nozzle for each nozzle row. The pressure control means separates each of the plurality of nozzle rows from the formation surface before the contact surface separates from the nozzle formation surface. The pressure is controlled so as not to be at least negative with respect to the atmospheric pressure at the nozzle opening.

  According to this configuration, even when there are a plurality of nozzle rows, when the contact surface is separated, the pressure or negative pressure is released for each nozzle row, so the timing at which the contact surface is separated in each nozzle row The pressurization or negative pressure can be released in accordance with. Therefore, consumption of the jetting liquid can be suppressed and fluctuations in the position of the formed meniscus can be suppressed.

  In the jetting liquid drying inhibiting apparatus of the present invention, the plurality of nozzle rows are arranged in parallel, and the nozzle contact means is arranged in the process of changing from the contact state to the separated state. The contact surface is separated from the nozzle formation surface so that the separation region gradually expands from one side to the other side in a direction perpendicular to the one direction.

  According to this configuration, since the contact surfaces are all separated from the plurality of nozzle rows in the same direction, for example, the nozzle openings sequentially from the nozzle row located at the end of the nozzle forming surface with respect to the plurality of nozzle rows. The contact surface can be separated from the nozzle forming surface so as to open the nozzle. Therefore, the nozzle abutting means can be formed with a single continuous plane. As a result, a contact surface having a stable flatness can be easily formed, so that the nozzle openings can be reliably closed and opened, and as a result, separated from each of the plurality of nozzle rows. Variation in the position of the meniscus formed at the time can be suppressed.

  In the jetting liquid drying inhibiting apparatus of the present invention, the nozzle contact means has a plurality of contact surfaces divided in a direction intersecting the nozzle row, and each of the plurality of contact surfaces is the The contact state and the separated state are exhibited with respect to at least one of the plurality of nozzle rows.

  According to this configuration, the contact surfaces can be simultaneously separated from the nozzle openings with respect to the plurality of nozzle rows by the contact surfaces divided into a plurality of portions. As a result, for example, the pressure control unit simultaneously controls the pressure of the ejection liquid in the nozzles with respect to a plurality of nozzle rows, so the timing for controlling the pressure of the ejection liquid in the nozzles. Need not be adjusted for each nozzle row. Therefore, pressure control can be performed easily and appropriately, and thus fluctuations in the position of the meniscus formed at the time of separation can be suppressed.

  In the jetting liquid drying suppression apparatus of the present invention, the nozzle forming surface and the contact surface have liquid repellency with respect to the jetting liquid, and the liquid repellency of the contact surface is determined by the nozzle forming surface. Higher than liquid repellency.

  According to this configuration, since the oozing of the jetting liquid from the nozzle opening to the contact surface side can be suppressed, consumption of the jetting liquid discharged at the same time as the bubbles are discharged can be suppressed and formed. The fluctuation of the position of the meniscus can be suppressed.

  In the jetting liquid drying suppression apparatus of the present invention, the jetting liquid drying suppression apparatus has a supply unit that supplies the jetting liquid to the liquid jetting unit, and the pressure control unit controls the pressure of the jetting liquid in the supply unit. Thus, the pressure of the jetting liquid in the nozzle is controlled.

  According to this configuration, it is possible to easily pressurize or release the negative pressure with respect to the ejection liquid in the nozzle in the liquid ejecting means. Therefore, fluctuations in the position of the formed meniscus can be suppressed.

  In order to achieve the above object, a liquid ejecting apparatus according to the present invention includes a liquid drying inhibiting device for ejecting configured as described above, and a liquid ejecting means provided in the ejecting liquid drying inhibiting device including a medium that is an ejection target of the ejecting liquid. And a moving means that moves relative to each other.

According to this structure, the effect similar to the effect which the liquid drying suppression apparatus for injection of the said structure can show | play can be show | played.
In order to achieve the above object, the method for suppressing drying of a jet liquid according to the present invention is a contact capable of coming into contact with a nozzle forming surface in which a nozzle opening of a nozzle for jetting the jetting liquid in the liquid jetting means is formed. A process in which the nozzle contact means having a surface shifts from a contact state in which the contact surface is in close contact with the nozzle forming surface so as to close the nozzle opening to a separated state separated from the nozzle forming surface The contact surface of the nozzle contact means is separated from the nozzle formation surface so that a separation region of the contact surface with respect to the nozzle formation surface is gradually enlarged, and the contact surface is formed of the nozzle. Prior to separation from the surface, the pressure in the nozzle in the nozzle is such that the pressure of the jetting liquid in the nozzle is at least negative with respect to the pressure in the nozzle opening. Controlling the pressure of the liquid for morphism.

  According to this method, it is possible to achieve the same operational effects as the operational effects that can be exhibited by the jet liquid drying inhibiting apparatus having the above-described configuration.

The perspective view which shows schematic structure of the liquid injection apparatus provided with the liquid drying suppression apparatus for injection in 1st Embodiment. (A) is the top view which looked at the printing head from the upper part, (b) And (c) is explanatory drawing of the liquid drying suppression apparatus for jetting including the BB arrow sectional drawing in (a). (A), (b), (c), and (d) are diagrams for explaining the behavior of ink when the conventional liquid drying suppression device for ejection is separated. (A), (b), (c), (d), and (e) are diagrams for explaining the behavior of ink at the time of separation of the ejection liquid drying suppression apparatus of the first embodiment, and (f) is an illustration of a conventional ejection liquid drying suppression apparatus. Explanatory drawing of the behavior of ink at the time of separation. In 2nd Embodiment, (a) (b) (c) is explanatory drawing explaining the structural example of a nozzle contact means in the case where there are two nozzle rows. In 2nd Embodiment, (a) (b) (c) is explanatory drawing explaining the structural example of a nozzle contact means in the case where there are four nozzle rows.

(First embodiment)
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a printing apparatus 100 as a liquid ejecting apparatus having the ejecting liquid drying inhibiting apparatus (hereinafter simply referred to as “drying inhibiting apparatus”) according to the first embodiment. As illustrated, the printing apparatus 100 includes a print head 10 as a liquid ejecting unit that ejects ink as an ejection liquid, and a medium that is transported and moved relative to the print head 10 from the print head 10. Ink is ejected toward the paper S as an image to form an image. The medium is not particularly limited to paper (paper), and may be formed of ceramic, glass, or other materials such as wood, metal, resin, cloth.

  The paper S is supplied from a paper feed tray (not shown). And between a platen (supporting base for the paper S) 33 that is sandwiched between a paper feed roller 31 and a driven roller 32 that are rotationally driven by a driving means (such as a motor) (not shown) and that is opposed to the print head 10. It is conveyed so that it may pass. The print head 10 is provided with nozzles (not shown) for ejecting ink. Depending on the image to be formed on the paper S being conveyed from the nozzle opening K located at the nozzle end of each nozzle. Ink droplets 16 are ejected. In the present embodiment, the gravity direction is the downward direction, the antigravity direction is the upward direction, and the ink droplets 16 are ejected downward.

  The nozzle opening K is provided on a substantially flat nozzle forming surface 10p provided on the lower side of the print head 10 so as to face the paper S. In the present embodiment, a plurality of nozzles are provided, and the plurality of nozzle openings K exhibit a nozzle row arranged in a line substantially along the X direction that intersects the Y direction, which is the transport direction of the paper S to be transported. It is formed as follows. Further, the nozzle opening K is formed substantially in the width direction of the paper S. Therefore, the present embodiment is a so-called line head type printing apparatus 100.

  Thereafter, the paper S that has passed through the platen 33 is nipped by a paper discharge roller 34 and a driven roller 35 that are rotationally driven by a driving means (such as a motor) (not shown), and is conveyed in the Y direction. The paper is discharged to a paper discharge tray (not shown). Accordingly, at least the paper feed roller 31 and the paper discharge roller 34 function as a moving unit 30 that moves the paper S relative to the print head 10.

  Further, as illustrated, the printing apparatus 100 includes an ink supply unit 20 as a supply unit that supplies ink L to be ejected to the print head 10. The ink supply unit 20 has two supply paths for supplying the ink L to each of the two supply ports 11 and 12 provided in the print head 10. Specifically, ink tanks 21 and 22 that store the ink L to be supplied, and pipes 23 and 24 for carrying the ink L from the ink tanks 21 and 22 are provided, and the ink L is supplied to the supply ports 11 and 12, respectively. Supply.

  In the present embodiment, pressure controllers 25 and 26 that control the pressure of the ink L supplied to the print head 10 are provided in the middle of the pipes 23 and 24. Accordingly, the ink L supplied from the supply port 11 to each nozzle of the print head 10 is supplied from the pressure control unit 25, and the ink L supplied from the supply port 12 to each nozzle of the print head 10 is supplied from the pressure control unit 26. The pressure is controlled by each.

  The pressure control units 25 and 26 include well-known pumps such as a pump that pushes the ink L in the tube in the rotation direction by rotating while the roller presses the flexible tube, and a diaphragm pump. The pressure of the ink L supplied to the print head 10 is controlled. Alternatively, the pressure of the ink L supplied to the print head 10 can be controlled using a water head difference from the print head 10 (nozzles). Furthermore, the pressure of the ink L supplied to the print head 10 may be controlled by combining these with a valve. Of course, other configurations can be employed as long as the pressure of the ink L supplied to the print head 10 can be controlled. The pressure control units 25 and 26 according to the present embodiment control the pressure in a predetermined range from pressurization to depressurization (negative pressure) with respect to the reference pressure (here atmospheric pressure) with respect to the ink L to be supplied. It can be controlled.

  Further, the printing apparatus 100 is provided with a nozzle abutting means 40 as shown in order to suppress drying of the ink L in the nozzle when an image is not formed on the paper S. The nozzle abutting means 40 holds the abutting member 41 having the abutting surface 40p and the abutting member 41, and applies substantially the entire abutting surface 40p of the abutting member 41 to the nozzle forming surface 10p. It has the elastic member 42 for contacting, and the plate 43 holding the elastic member 42.

  The plate 43 is configured to be moved in the vertical direction by the driving device 45. On the other hand, in the present embodiment, the print head 10 is positioned in the X direction between a position facing the paper S from above by a slide mechanism (not shown) and a position facing the contact surface 40p of the nozzle contact means 40 from above. It is configured to slide. Accordingly, the nozzle contact means 40 moves up and down with respect to the print head 10 that has been slid in the X direction so as to face the contact surface 40p, so that the contact surface 40p is brought into contact with the nozzle formation surface 10p of the print head 10. It can be brought into contact or separated.

  In addition, the printing apparatus 100 includes a control device 50. The control device 50 pressurizes or depressurizes the ink L supplied from the supply ports 11 and 12 by controlling the pressure control units 25 and 26. By doing so, the pressure of the ink L in the nozzles in the print head 10 can be adjusted. Therefore, the pressure control units 25 and 26 function as pressure control means by being controlled by the control device 50. Further, the control device 50 controls the driving device 45 to move the nozzle contact means 40 up and down.

  In addition, the control device 50 controls the pressurizing unit 17 (see FIG. 2B) with respect to the print head 10 so that the ink droplet 16 having a liquid amount corresponding to the image to be formed is opened in the nozzle. While ejecting from the portion K, the rotation of the paper feed roller 31 and the paper discharge roller 34 is controlled. Further, various operations (for example, sliding movement of the print head 10) in the printing apparatus 100 are controlled.

  Accordingly, in the printing apparatus 100 according to the present embodiment, the pressure control units 25 and 26, the nozzle contact means 40, the driving device 45, and the control device 50 are controlled to prevent drying of the ink L in the nozzles of the print head 10. It functions as the device KYS. Specifically, when the drying suppression device KYS suppresses drying of the ink L in the nozzles in the printing apparatus 100, first, the print head 10 is moved to the position facing the nozzle contact means 40 by a slide mechanism (not shown) in the X direction. Move to. Then, the nozzle abutting means 40 is raised by the driving device 45, and the abutting surface 40p is in close contact with the entire peripheral area of each nozzle opening K, and each nozzle opening K is individually closed so as not to be opened to the atmosphere. In this manner, the contact surface 40p is brought into contact with the nozzle forming surface 10p. In this way, the ink L in the nozzle is brought into a close contact state that does not come into contact with the atmosphere, so that drying is suppressed.

  Next, in the printing apparatus 100, the operation of the nozzle contact means 40 constituting the drying suppression apparatus KYS that suppresses the drying of the ink L in this way will be specifically described with reference to FIG. 2A is a plan view showing the print head 10 slid to a position facing the nozzle contact means 40 as viewed from above, and FIGS. 2B and 2C are FIG. It is a BB arrow directional cross-sectional view in (a). FIG. 2B shows a state before the nozzle contact means 40 is raised, and shows a separated state in which the contact surface 40p is separated from the nozzle forming surface 10p. FIG. 2C shows the nozzle contact means. 40 shows a contact state in which the contact surface 40p is in close contact with the nozzle forming surface 10p. Therefore, FIGS. 2B and 2C are also explanatory diagrams of the drying suppressing device KYS of the present embodiment.

  In the present embodiment, as shown in FIGS. 2A and 2B, the print head 10 includes nine nozzles NL1 to NL9 that eject the ink L supplied to the supply ports 11 and 12, respectively. The supply ports 11 and 12 are provided. And each nozzle opening K1-K9 used as the edge part opening of each nozzle NL1-NL9 exhibits two nozzle rows NR arranged in parallel to one direction along the X direction, and each nozzle row NR is a nozzle They are provided side by side with a predetermined interval in the Y direction on the formation surface 10p. Of course, this is to facilitate the explanation of the present embodiment, and it is possible to provide one nozzle row or more than two nozzle rows (supply ports). The number of nozzles (number of nozzle openings) may be one or more (usually, for example, tens to thousands) nozzles (nozzle openings) in one nozzle row. . In the description of this embodiment, when the nozzles NL1 to NL9 are not distinguished, they are referred to as nozzles NL. Further, when the nozzle openings K1 to K9 are not distinguished, they are referred to as nozzle openings K.

  In the two nozzle arrays NR, the ink L adjusted to a predetermined pressure by the pressure control units 25 and 26 passes through the ink flow path provided in the print head 10 from the supply ports 11 and 12 to each nozzle NL. To be supplied. The ink flow path is formed for each nozzle NL. Here, of the two nozzle arrays NR provided on the nozzle forming surface 10p, FIG. 2B shows the ink flow path until the ink L supplied to the supply port 12 is ejected from the nozzle opening K1. It explains using. Of course, similar ink flow paths are formed for the other nozzles NL2 to NL9. In addition, an ink flow path similar to that of the supply port 12 is formed for the ink flow path until the ink L supplied to the supply port 11 is ejected from each nozzle opening K.

  As shown in FIG. 2B, the ink L supplied from the supply port 12 via the pressure control unit 26 first flows into the common ink chamber 13 extending in the X direction. The common ink chamber 13 functions as a reservoir for stably supplying the ink L to each nozzle NL. Thereafter, the ink L that has flowed into the common ink chamber 13 flows into the pressure chamber 15 via the communication channel 14 that communicates with the common ink chamber 13, and further, in the nozzle NL that communicates with the pressure chamber 15. To be guided to. Therefore, the pressure (back pressure) of the ink L in each nozzle NL is controlled by the pressure control unit 26 in common. The pressurizing chamber 15 is provided with pressurizing means 17 including an electrostrictive element or a heat generating element, and is configured to pressurize the ink L in the pressurizing chamber 15. The ink L pressurized by the pressurizing unit 17 is ejected from the nozzle opening K1 provided on the nozzle forming surface 10p through the nozzle NL1 formed in communication with the pressurizing chamber 15. ing.

  Now, as shown in FIG. 2B, the nozzle contact means 40 is inclined 1 downward in the Y direction in the separated state before the contact surface 40p contacts the nozzle forming surface 10p. Two planar inclined surfaces are formed. Specifically, in this embodiment, the contact member 41 having the contact surface 40p formed thereon is an elastic member such as a synthetic rubber (for example, CR (chloroprene) rubber or EPDM (ethylene propylene diene) rubber) on a flat plate. It is formed with. In addition, the elastic member 42 has a shape in which the thickness gradually decreases in the Y direction, and is processed into a sponge-like resin (synthetic resin) or rubber that can obtain a larger elastic deformation than the contact member 41. (Synthetic rubber) or the like. The contact member 41 is fixed to the elastic member 42 by bonding or the like, and the elastic member 42 is fixed to the plate 43 by bonding or the like.

  Then, as shown in FIG. 2C, the nozzle abutting means 40 rises to suppress the drying of the ink L, and abuts so that the abutting surface 40p is in close contact with the nozzle forming surface 10p. In other words, the contact member 41 and the elastic member 42 are deformed (elastically deformed) so that substantially the entire contact surface 40p of the contact member 41 is in close contact with the nozzle forming surface 10p. . By closely abutting in this way, each nozzle opening K is individually closed in the entire peripheral area one by one.

  Next, in the printing apparatus 100, when the contact surface 40p of the nozzle contact means 40 is separated from the nozzle formation surface 10p for image formation in the drying suppression device KYS configured as described above, the formation is performed on each nozzle NL. The separation operation is performed so as to stabilize the position of the meniscus. Hereinafter, this operation will be specifically described with reference to FIG. In order to facilitate understanding of the description of this operation, first, referring to FIGS. 3A, 3B, 3C, and 3D, the conventional drying suppression device KYS is changed from the contact state to the separated state. The behavior of the meniscus in the process will be briefly described. FIG. 3 is a diagram showing a partial cross section of one nozzle NL1 as a representative of the nozzles NL, and a contact member 41 (contact surface) with respect to the print head 10 (nozzle formation surface 10p). 40p) is an explanatory diagram showing the behavior of the ink L in the process from the contacted state (FIG. 3A) to the separated state (FIG. 3D).

  In the prior art, in the state where the contact surface 40p is brought into close contact, the nozzle opening K1 with respect to the ink L in the nozzle NL1 and the pressurizing chamber 15 is controlled by the pressure control units 25 and 26. A negative pressure lower than the atmospheric pressure (atmospheric pressure) was applied. In this way, a negative pressure BF is generated for the ink L in the nozzle NL1, the meniscus MS is pulled up in the nozzle NL1 by this negative pressure BF, and bubbles to the nozzle NL1 are brought into contact with the contact surface 40p. It was preventing the entrainment of. However, as described above, actually, the negative pressure applied to the ink L is not uniform in each nozzle NL, and it is difficult to raise the meniscus MS in all the nozzles NL. Therefore, as shown in FIG. 3A, for example, the ink L at the tip of the nozzle NL1 may come into contact with and adhere to the contact member 41 at the nozzle opening K1.

  In this case, conventionally, the contact surface 40p of the contact member 41 is separated from the state where the contact surface 40p is in close contact with the nozzle formation surface 10p while maintaining a substantially parallel state with respect to the nozzle formation surface 10p. It was. In this way, when the contact surfaces 40p are separated in a substantially parallel state, as shown in FIG. 3B, the ink L adhering to the contact surface 40p is applied while the adhering portion resists the negative pressure BF. It will be pulled evenly by the applied force MF, and it will be difficult to generate a large shearing force on the ink L partially. Therefore, the ink L is pulled without being broken by the adhesive force MF.

  The ink L pulled and pulled from the nozzle NL1 increases in the amount of liquid drawn as the contact member 41 moves downward, so that the drawn ink L is drawn into the nozzle NL1. The acting negative pressure BF gradually increases. As a result, the ink L is finally broken as shown in FIG. 3C due to the tension between the increasing negative pressure BF and the adhesion force MF which is the reaction force.

  As a result, the ink L is strongly pulled so as to be pulled back into the nozzle NL1 by the negative pressure BF that exhibits a large value at the time of breakage. The impact will be applied to. Due to the applied impact, the ink L in the nozzle NL1 vibrates, and as shown in FIG. 3D, the position of the formed meniscus is not fixed and unstable. It becomes. Further, since the meniscus MS is largely retracted, bubbles are likely to be caught in the nozzle NL1 at this time. When such a state occurs, the ink L is not correctly ejected from the nozzle opening K1 during image formation, and so-called dot omission may occur.

  Further, as shown in FIG. 3D, the ink L that has broken and adhered remains as the remaining ink 18 on the contact surface 40 p. Then, when the remaining residual ink 18 is thickened or solidified, and the contact surface 40p comes into contact with the nozzle forming surface 10p again, the thickened or solidified residual ink 18 stains the nozzle forming surface 10p. There is also a risk that it may easily cause a problem such as a failure.

  Therefore, in the present embodiment, as described above, the nozzle contact means 40 includes the contact surface 40p that is inclined with respect to the nozzle formation surface 10p in the separated state. By carrying out like this, the drying suppression apparatus KYS can be operated so that said subject may be solved. Hereinafter, the operation of the present embodiment will be described with reference to FIGS.

  In the present embodiment, the nozzle contact means 40 is in a parallel state with the nozzle formation surface 10p so that the contact surface 40p of the contact member 41 is in close contact with the nozzle formation surface 10p in the contact state, and in the separated state. It is formed so as to form an inclined surface that is uniformly inclined in the Y direction. By forming the nozzle openings K in this way, the nozzle openings K in the two nozzle rows NR arranged in parallel along the X direction intersecting with the Y direction are arranged in the respective nozzle rows when the contact surface 40p is separated. In NR, the sealed state of each nozzle opening K is opened almost simultaneously. Therefore, in the following description, the operation of the drying suppression device KYS will be described for the nozzle NL1 in one nozzle row NR as a representative. Of course, the following description is the same for the other nozzles NL2 to NL9 and also for the other nozzle rows NR.

  First, FIG. 4A shows the same state as FIG. 3A of the conventional example, that is, a state where the meniscus MS cannot be drawn in the nozzle NL1 due to the action of the negative pressure BF. In this case, in this embodiment, before the contact member 41 starts to be separated, the negative pressure applied to the ink L is released or reversely applied under the control of the pressure control units 25 and 26. Press. As a result, the ink L in the nozzle NL1 is pressed downward so that the ink L is ejected from the nozzle opening K1 as shown in FIG. PF is applied.

  Next, after the pressure PF is applied as described above, the contact member 41, that is, the contact surface 40p is separated. Since the contact surface 40p is formed to be inclined with respect to the nozzle formation surface 10p in the separated state, the contact surface 40p is in a direction orthogonal to the arrangement direction (X direction) of the nozzle rows NR. Separation starts from one side (here, the Y direction side), and the nozzle is separated from the nozzle forming surface 10p while being inclined obliquely so as to gradually expand the separation region toward the other side.

  In this case, since the pressure PF is applied to the ink L in the nozzle NL1 instead of the negative pressure BF, the above-described tension of the ink L does not occur in the nozzle opening K1. Become. Conversely, a state in which the ink L at the tip of the nozzle NL1 is pushed out from the nozzle opening K1 by the pressure PF occurs. At this time, as shown in FIG. 4B, the abutting contact surface 40p forms a minute gap that is slanted with the nozzle forming surface 10p, and therefore the force generated by the surface tension of the ink L. In principle (the arrow in the figure), a difference occurs in the Y direction. As a result, a force is generated in a direction in which the minute gap is narrowed (in the direction opposite to the Y direction in the drawing), and the pushed ink L is pushed back toward the nozzle NL1 by the generated force.

  Furthermore, in the present embodiment, the contact surface 40p is subjected to a liquid repellent treatment with respect to the ink L so that the surface tension is stably generated in the ink L. Accordingly, the ink L is suppressed from being exuded and is stably positioned in the vicinity of the nozzle forming surface 10p. When the contact member 41 moves and the contact surface 40p is separated from the nozzle formation surface 10p (nozzle opening K1), the ink L is caused by the liquid repellency applied to the nozzle formation surface 10p. It is pushed back into the nozzle NL1. As a result, as shown in FIG. 4E, the meniscus MS to be formed settles at a preferred position in the nozzle NL1 or a position in the vicinity thereof.

  The preferable formation position of the meniscus MS is a position where the ink L of the liquid amount corresponding to the image to be formed can be correctly ejected from the nozzle opening K1 in a standby state where the ink L can be ejected for image formation. is there. Incidentally, in such a standby state, for the ink L in the normal nozzle NL1, the supply amount of the ink L to the supply port 11 is controlled by the valve mechanism provided in the pressure control units 25 and 26. A predetermined negative pressure (back pressure) is applied to the ink L in the nozzle NL1. Therefore, the position of the meniscus MS to be formed when this predetermined negative pressure is applied is also a preferable position.

  On the other hand, FIG. 4C shows a state different from the case of FIG. 3A in the prior art, that is, a state where the meniscus MS can be drawn by the negative pressure BF. At this time, similarly to FIG. 4B, the negative pressure applied to the ink L in the nozzle NL1 is released or vice versa before the contact surface 40p of the contact member 41 is separated. When the pressurizing force PF is generated instead of the negative pressure BF by pressurizing to, the state shown in FIG. In other words, the pressure PF applies a force to push the ink L in the nozzle NL1 from the nozzle NL1. Accordingly, the meniscus MS is lowered in position in the nozzle NL1 so as to approach the nozzle forming surface 10p as shown in the figure, so that the meniscus MS can be positioned in the vicinity of the nozzle opening K1.

  Further, at this time, for example, when a bubble (not shown) is caught in the ink L due to the pulling of the meniscus MS, the flow resistance of the ink L that moves through the nozzle NL1 decreases according to the bubble that is involved. The moving speed in the L nozzle NL1 is increased. As a result, the probability that the entrained bubbles move with the movement of the ink L increases. Therefore, as shown in the figure, the bubbles that have moved together with the ink L are discharged as air that can easily pass through a slanting minute gap between the contact surface 40p and the nozzle forming surface 10p formed in the separated state. The

  Even if the ink L moves quickly in the nozzle NL1, the nozzle opening K1 is opened so that the separation region gradually widens at the time of separation, so that the gap in the nozzle opening K1 is very small. Exudation of L to the nozzle forming surface 10p is suppressed. In the present embodiment, the nozzle forming surface 10p is subjected to the liquid repellent treatment for the ink L, and the ink L is not substantially exuded to the nozzle forming surface 10p by the applied liquid repellent treatment. Located in the vicinity of the opening K1. In this way, a minute gap is formed in which air can pass and ink L is difficult to pass due to its surface tension and flow resistance.

  As a result, when the meniscus MS can be retracted, as shown in FIG. 4 (e), the meniscus MS is separated in a separated state in which the contact surface 40p is separated from the nozzle forming surface 10p (nozzle opening K1). It can be formed at a preferred position in the nozzle NL1.

  By the way, in this embodiment, as described in FIG. 4B, the liquid repellent treatment for the ink L is performed on the contact surface 40p. At this time, when the liquid repellency of the contact surface 40p by the applied liquid repellency treatment is lower than the liquid repellency of the nozzle forming surface 10p, or when the contact surface 40p does not have liquid repellency, The state shown in FIG. 4 (f) may occur. That is, the ink L pushed out from the nozzle NL1 by its own weight or pressure has a pushing force Ls pushed in the direction of the contact surface 40p due to the liquid repellency of the nozzle forming surface 10p, for example, as indicated by an arrow in the figure. May occur. At this time, if the liquid repellency of the contact surface 40p is low, the ink L does not generate surface tension against the pressing force Ls between the contact surface 40p and spreads on the contact surface 40p. Sometimes. In such a case, there is a possibility that the above-described conventional problem occurs.

  Therefore, in the present embodiment, the liquid repellency of the contact surface 40p is higher than the liquid repellency of the nozzle forming surface 10p. By doing so, the contact surface 40p can generate a larger surface tension on the ink L than the nozzle forming surface 10p, so that the ink L pushed out from the nozzle NL1 is reliably pushed back in the nozzle NL1 direction. It will be.

  In the present embodiment, the nozzles NL are opened almost simultaneously in the nozzle row NR. If, for example, only one nozzle NL1 is opened and the other nozzles NL2 to NL9 are closed, the ink L pressurized in the common ink chamber 13 is in communication with the other nozzles communicating with this. It cannot move in NL2 to NL9. For this reason, all the movement amounts of the ink L in the other nozzles NL2 to NL9 are concentrated on the nozzle NL1. As a result, a large amount of ink L moves toward the nozzle opening K side in the nozzle NL1 than the assumed movement amount due to the applied pressure, so that the amount of ink L oozing from the nozzle NL1 increases or the position of the meniscus MS is desired. It may become impossible to form at the position to be. Further, it is assumed that the pushed ink L remains on the contact surface 40p without being pushed back to the nozzle NL1 side. Accordingly, in the present embodiment, the nozzles NL are opened almost simultaneously in the nozzle row NR.

According to the first embodiment described above, the following effects can be obtained.
(1) Since a minute gap is formed in each nozzle opening K, and the negative pressure is released or pressurized against the ink L, air bubbles are discharged from the minute gap. Thus, the meniscus MS can be formed at a preferred position. Further, since it is difficult for the ink L that moves together with the bubbles to pass through this minute gap, the amount of the ink L that is discharged and consumed from each nozzle NL can be suppressed. Further, the tension of the ink L is suppressed between each nozzle NL and the contact surface 40p, and the impact applied to the meniscus MS due to the breakage of the ink L is weakened at the time of separation. And fluctuations in the formation position of the meniscus MS can be suppressed.

  (2) Since each nozzle NL is separated so as to open each nozzle opening K almost simultaneously, for example, the negative pressure is released or pressurized from the previously opened nozzle opening. The bleeding of the ink L can be suppressed. As a result, consumption of the ink L due to bleeding can be suppressed, and fluctuations in the formation position of the meniscus MS in the separated state can be suppressed.

  (3) Since the contact surface 40p can be separated from each nozzle NL so that the separation region gradually increases from one side to the other side in the direction orthogonal to the nozzle row NR, the nozzle row NR The contact surface 40p can be a surface having the minimum width with respect to the plurality of nozzles NL exhibiting the above. Moreover, since the contact surface 40p can be made into one plane, each nozzle opening K can be reliably closed or opened. As a result, a minute gap can be stably formed with respect to each of the nozzle openings K when the abutment surface 40p is separated, so that fluctuations in the position of the meniscus MS formed in each nozzle NL are suppressed. be able to.

  (4) Even if there are a plurality of nozzle rows NR, when the contact surface 40p is separated, the pressure or negative pressure is released for each nozzle row NR, so the contact surface 40p is separated in each nozzle row NR. The pressurization or negative pressure can be released in accordance with the timing to perform. Therefore, consumption of the ink L can be suppressed, and fluctuations in the formation position of the meniscus MS can be suppressed.

  (5) For the plurality of nozzle rows NR arranged in parallel, the contact surface 40p is separated so that the separation region gradually expands from one side orthogonal to the arrangement direction to the other side. The contact surface 40p can be separated from the plurality of nozzle rows NR so that the nozzle openings K are sequentially opened from the nozzle row NR located at the end of the nozzle forming surface 10p. Therefore, since the nozzle contact means 40 can form the contact surface 40p with one continuous inclined surface that is uniformly lowered in the Y direction, the contact surface 40p is suppressed from being uneven in the direction of the nozzle row NR. A flat surface can be easily formed. As a result, each nozzle opening K can be reliably closed or opened, so that variation in the position of the meniscus MS formed at the time of separation for each of the plurality of nozzle rows NR can be suppressed. it can.

  (6) The liquid repellency of the contact surface 40p, which is higher than the liquid repellency of the nozzle forming surface 10p, suppresses the seepage of the ink L from the nozzle openings K toward the contact surface 40p, and makes contact. Residual ink L on the surface 40p can be suppressed. As a result, it is possible to suppress the consumption of the ink L that is discharged at the same time as the bubbles are discharged, and to suppress the influence on the variation of the meniscus MS formation position.

  (7) The pressure control units 25 and 26 can control the pressure of the ink L in each nozzle NL for each nozzle row. Accordingly, the negative pressure is canceled or the pressure is applied to the ink L in each nozzle NL so as not to be applied at a timing prior to the separation of the contact surface 40p. be able to. As a result, fluctuations in the position of the formed meniscus MS can be suppressed.

(8) By providing the drying suppression apparatus KYS of the present embodiment, the printing apparatus 100 that exhibits the effects (1) to (7) is obtained.
(Second Embodiment)
Next, a second embodiment will be described. The second embodiment is a drying suppression device KYS in which the nozzle contact means 40 has a configuration different from that of the first embodiment. Hereinafter, a configuration example of the nozzle contact means 40 in the present embodiment will be described with reference to the drawings.

  First, as one example of the configuration, as shown in FIG. 5A, the contact surface 40p may be a convex surface shape in which the tangent descending direction gradually increases in the Y direction, instead of the surface uniformly descending in the Y direction. . For example, the contact member 41 is formed in a curved plate shape that is a cylindrical curved surface having a side surface in the X direction and has a convex shape on the upper side. In this way, when each nozzle opening K is opened, the contact surfaces 40p that are separated from each other become a curved surface. The contact surface 40p can be separated so that the gap becomes large in a state where the regions of the portions are separated. As a result, it can be expected that the bubbles can be discharged earlier from the separated portion. Of course, the convex surface shape is formed in such a shape that the contact surface 40p can be in close contact with the nozzle forming surface 10p and can be separated from each nozzle opening K at the same time or almost simultaneously. ing. In this case, the elastic member 42 may be shaped according to the shape of the contact member 41.

  Alternatively, as shown in the right side of FIG. 5A, for example, the elastic member 42 is not a sponge-like elastic member 42, but two types of coil springs 46a and 46b having initially different lengths. It may be arranged side by side in the Y direction. Of course, although not shown, a plurality of coil springs 46a and coil springs 46b may be arranged along the nozzle row NR with a predetermined interval.

  As an example of the configuration, as shown in FIG. 5B, different contact surfaces 40p are in close contact with the nozzle openings K corresponding to the supply port 11 and the supply port 12, respectively. You may comprise. Specifically, as shown in the figure, the contact member 41 is divided into two, that is, the contact member 41a and the contact member 41b in the Y direction intersecting the arrangement direction of the nozzle rows NR. In this way, when the two contact surfaces 40p are separated, the timing for opening each nozzle opening K corresponding to the supply port 11 and the timing for opening each nozzle opening K corresponding to the supply port 12 are set. It can be almost simultaneous.

  As an example of the configuration, the contact surface 40p may be formed as a single curved surface having a maximum convex portion at approximately the middle position between the two nozzle rows NR corresponding to the supply port 11 and the supply port 12, respectively. Good. Specifically, as shown on the left side of FIG. 5C, the contact member 41 is formed of a curved curved plate having a side surface in the arrangement direction of the nozzle row NR, and a cylinder serving as the contact surface 40p. The approximate center position of the surface is set to have a maximum convex portion on the upper side. And it forms so that the position of this largest convex part may become a substantially middle position which is equidistant in the Y direction from each nozzle opening K. By doing so, when the contact surface 40p comes into contact with the nozzle forming surface 10p, the force applied from the elastic member 42 to the plate 43 is generated approximately equally on the left and right with the maximum convex portion as the center. In this configuration example, the elastic member 42 may have a shape that matches the shape of the contact member 41.

  At this time, as shown on the right side of FIG. 5 (c), the contact member 41 is made uniform with the contact member 41a having an inclined surface uniformly lowered in the Y direction and in the opposite direction to the Y direction. You may make it comprise with two with the contact member 41b which has the inclined surface which went down. Similarly, at this time, the elastic member 42 is replaced with sponge-like resin (rubber), the coil spring 47a and the coil spring 47b having different lengths with respect to the contact member 41a, and the contact member 41b. May be composed of a coil spring 48a and a coil spring 48b having different lengths.

  Incidentally, as described above, the print head 10 may be provided with a plurality of nozzle arrays NR more than two. Thus, as an example, a configuration example of the second embodiment when four nozzle arrays NR are provided in the print head 10 will be described with reference to FIG.

  As shown in FIG. 6A, in the printing apparatus 100, in addition to the supply ports 11 and 12, two supply ports 11a and a supply port 12a are further provided. Then, for example, four types of color inks (for example, cyan, magenta, yellow, and black inks) are supplied to the supply ports 11, 12, 11a, and 12a, respectively. Of course, the ink supply unit 20 is further provided with two supply paths for supplying the ink L to the supply port 11a and the supply port 12a, and pressure control for controlling the pressure of the ink L supplied to the supply ports 11 and 12, respectively. Parts are provided.

  Even in the case of such four nozzle rows NR, as in the first embodiment, as shown in the drawing, the contact surface 40p having an inclined surface that uniformly falls in the Y direction is brought into contact with the nozzle forming surface 10p. The nozzle openings K of the four nozzle rows NR can be closed. In this case, in the nozzle forming surface 10p, the elasticity between the first nozzle openings K corresponding to the supply ports 11 and the last nozzle openings K corresponding to the supply ports 12a is blocked. The member 42 is continuously compressed and deformed.

  When the number of such nozzle rows NR is large, the nozzle openings K corresponding to the first supply ports 11 are closed until the nozzle openings K corresponding to the supply ports 12a are finally closed. In this case, the elastic member 42 is greatly compressed and deformed. When the elastic member 42 is greatly deformed in this way, the elastic member 42 is likely to vary in the degree of compressive deformation, and therefore, the timing due to the variation in deformation of the elastic member 42 varies with respect to the timing at which the contact surface 40p is separated from each nozzle opening K. It may occur at every separation. Further, even when the moving speed in the downward direction of the nozzle contact means 40 varies, the timing at which the contact surface 40p is separated from each nozzle opening K may vary with each separation. For this reason, for example, the pressure control unit 25 controls the pressure of the ink L supplied from the supply port 11 to release or pressurize the negative pressure on the ink L in each nozzle NL. There is a possibility that the difference occurs every time the contact means 40 is separated.

  Therefore, as in FIG. 5B, as shown in FIG. 6B, the nozzle abutting means 40 is provided for each of the supply port 11, the supply port 12, the supply port 11a, and the supply port 12a. You may comprise so that the contact surface 40p which each differs with respect to the nozzle opening part K closely_contact | adheres. Specifically, as shown in the drawing, the contact member 41 is moved in the Y direction intersecting the arrangement direction of the nozzle rows NR with the contact member 41a, the contact member 41b, the contact member 41c, and the contact member 41d. Divide into four. In this way, the contact surface 40p can make the timings at which the nozzle openings K corresponding to the supply port 11, the supply port 12, the supply port 11a, and the supply port 12a open are almost the same. Similarly to the contact member 41, the elastic member 42 is divided into four members, that is, an elastic member 42a, an elastic member 42b, an elastic member 42c, and an elastic member 42d. Become. Accordingly, variations in timing at which the contact surface 40p is separated at each nozzle opening K are suppressed.

  Alternatively, as in FIG. 5 (c), as shown in FIG. 6 (c), the nozzle abutting means 40 is arranged in the Y direction with two cylindrical curved surface abutments each having a maximum convex portion at approximately the center. It is good also as a shape in which the surface 40p was formed. Specifically, as shown in the drawing, the contact member 41 is divided into two members, a contact member 41e and a contact member 41f. The abutting member 41e is a flat plate formed in a cylindrical curved surface having side surfaces in the arrangement direction of the nozzle rows NR, and the apex position of the cylindrical surface serving as the abutting surface 40p corresponds to each nozzle opening K of the supply port 11. It forms so that it may become a center position between each nozzle opening part K of the supply port 12. FIG. In addition, the contact member 41f is such that the apex position of the cylindrical surface serving as the contact surface 40p is approximately the center position between each nozzle opening K of the supply port 11a and each nozzle opening K of the supply port 12a. To form. In accordance with this, the elastic member 42 is also divided into an elastic member 42e and an elastic member 42f.

  By doing so, the nozzle openings K can be spaced apart from each other so that the nozzle openings K are opened almost simultaneously. Further, as in the case of FIG. 5C, the force applied to the plate 43 from the elastic member 42a and the elastic member 42b is generated in the plate 43 equally on the left and right.

According to the second embodiment described above, in addition to the effects (1) to (7) in the first embodiment, the following effects are achieved.
(9) Since the pressure control unit simultaneously controls the pressure of the ink L in the nozzle NL with respect to the plurality of nozzle rows NR, the timing for controlling the pressure of the ink L in the nozzle NL is set for each nozzle row NR. There is no need to adjust. Therefore, pressure control can be performed easily and appropriately, and as a result, fluctuations in the position of the meniscus MS formed when the contact surface 40p is separated can be suppressed. Further, since no rotational force is generated on the plate 43 in the nozzle abutting means 40, the generation of a force for tilting the plate 43 when the nozzle abutting means 40 moves up and down is suppressed. As a result, the contact member 41 can stably contact (contact) the contact surface 40p with the nozzle forming surface 10p.

(10) By providing the drying suppression apparatus KYS of the present embodiment, the printing apparatus 100 that exhibits the effect (9) can be obtained.
The above embodiment may be changed to another embodiment as described below.

  In the above embodiment, the contact surface 40p may be a surface having an inclined surface that uniformly rises in the direction opposite to the Y direction. With such an inclined surface, each nozzle opening K can be simultaneously opened in each nozzle row NR as in the above embodiment.

  In the drying suppression apparatus KYS of the above embodiment, the print head 10 is moved in the X direction and the nozzle forming surface 10p is positioned above the nozzle contact means 40. However, the present invention is not necessarily limited to such a configuration. . For example, the print head 10 may be rotated in a plane along the transport direction of the paper S so that the nozzle forming surface 10 p is positioned above the nozzle contact means 40. Or you may make it provide the nozzle contact means 40 in the position which remove | deviated from the platen 33 planarly. Further, the print head 10 may be configured to be lowered with respect to the contact member 41.

  In the above embodiment, each nozzle opening K does not necessarily have to be formed so as to exhibit the nozzle row NR. The point is that the contact surface 40p can be separated from each nozzle opening K almost simultaneously so that the separation region gradually expands.

  In the above embodiment, each nozzle NL does not necessarily have a configuration that communicates with the common ink chamber 13. Of course, in this case, the timing of opening the sealed state at each nozzle opening K may not necessarily be the same.

  In the above embodiment, the so-called serial head type in which the nozzle rows NR provided on the nozzle forming surface 10p are formed in almost one row along the Y direction and the print head 10 is configured to reciprocate in the X direction. The printing apparatus 100 may be used. The print head 10 may be fixed to a carriage that reciprocates in the X direction. The ink supply unit 20 may be mounted on the print head 10 or the carriage.

  In the above embodiment, the liquid ejecting apparatus is the printing apparatus 100 that ejects ink as the ejecting liquid, but a printing apparatus that ejects or discharges liquid other than ink may be employed. Good. The present invention can be used in various printing apparatuses including a print head that discharges a minute amount of liquid droplets. In addition, a droplet means the state of the liquid discharged from the said printing apparatus, and shall include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the printing apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. A typical example of the liquid is ink as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. Specific examples of printing apparatuses include, for example, liquids that are dispersed or dissolved in materials such as liquid crystal displays, EL (electroluminescence) displays, surface emitting displays, and electrode materials and color materials used in the manufacture of color filters. There is a printing device to do. Alternatively, a textile printing device or a micro dispenser may be used. The present invention can be applied to any one of these printing apparatuses.

  In the above embodiment, the present invention is described as a printing apparatus as a liquid ejecting apparatus having an ejecting liquid drying suppression apparatus. As is apparent from the above description, the embodiment of the present invention is used for ejecting. It is also possible to use a liquid drying suppression method. According to this method, the same effect as that of the above embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 10 ... Print head, 10p ... Nozzle formation surface, 11, 11a, 12, 12a ... Supply port, 13 ... Common ink chamber, 18 ... Residual ink, 20 ... Ink supply part as supply means, 21, 22 ... Ink tank, 25, 26 ... pressure control section as pressure control means, 30 ... moving means, 40 ... nozzle contact means, 40p ... contact surface, 41, 41a, 41b, 41c, 41d, 41e, 41f ... contact member, 42 , 42a, 42b, 42c, 42d, 42e, 42f ... elastic member, 43 ... plate, 45 ... driving device, 46a, 46b, 47a, 47b, 48a, 48b ... coil spring, 50 ... control device, 100 ... liquid ejecting device L: ink as jetting liquid, S: paper as medium, BF: negative pressure, K, K1 to K9 ... nozzle opening, MS ... meniscus, NL, L1～NL9 ... nozzle, NR ... nozzle array, PF ... pressure, liquid drying suppressor for KYS ... injection.

Claims (10)

A liquid ejecting means having a nozzle for ejecting a liquid for ejection from a nozzle opening formed on a nozzle forming surface;
A contact surface that can contact the nozzle forming surface, the contact surface being in close contact with the nozzle forming surface so as to close the nozzle opening, and the nozzle forming surface; A nozzle contact means exhibiting a separated state separated from
Pressure control means for controlling the pressure of the jetting liquid in the nozzle;
A liquid drying restraining device for injection comprising:
The nozzle contact means separates the contact surface from the nozzle formation surface so that a separation region of the contact surface with respect to the nozzle formation surface gradually expands in the process of changing from the contact state to the separation state. With
The pressure control means controls the pressure of the jetting liquid in the nozzle so as not to be at least negative with respect to the pressure in the nozzle opening before the contact surface is separated from the nozzle forming surface. A liquid drying suppression apparatus for jetting, characterized in that: In the liquid drying suppression apparatus for injection of Claim 1,
The liquid ejecting means has a plurality of the nozzles in which the pressure of the ejection liquid is commonly controlled by the pressure control means,
The nozzle abutting means opens the plurality of nozzle openings at the same time in the process of changing from the abutting state in which the plurality of nozzle openings corresponding to the plurality of nozzles are blocked to the separated state. A liquid drying suppression apparatus for jetting, characterized in that a surface is separated from the nozzle forming surface. The liquid drying suppression apparatus for injection according to claim 2,
The plurality of nozzle openings are arranged in one direction so as to present a nozzle row on the nozzle forming surface,
The nozzle abutting means gradually expands the separation region from one side to the other side in a direction orthogonal to the one direction in which the nozzle rows are arranged in the process of changing from the contact state to the separation state. And the abutting surface is spaced apart from the nozzle forming surface. The liquid drying suppression apparatus for injection according to claim 3,
The liquid ejecting means has a plurality of the nozzle rows on the nozzle forming surface,
In the nozzle contact means, the contact surface is separated from the nozzle formation surface for each nozzle row, and
For each of the plurality of nozzle rows, the pressure control means is configured such that the pressure of the ejection liquid in the nozzle is changed to the pressure in the nozzle opening before the contact surface is separated from the nozzle formation surface. The liquid drying suppression apparatus for injection characterized by controlling so that it may not become a negative pressure at least. The liquid drying suppression apparatus for injection according to claim 4,
The plurality of nozzle rows are arranged in parallel,
The nozzle contact means gradually expands the separation region from one side to the other side in a direction orthogonal to the one direction in which the plurality of nozzle rows are arranged in the process of changing from the contact state to the separation state. Thus, the liquid drying restraining device for jetting is characterized in that the contact surface is separated from the nozzle forming surface. In the liquid drying suppression apparatus for injection according to claim 4 or 5,
The nozzle contact means includes a plurality of the contact surfaces divided in a direction intersecting the nozzle row, and each of the plurality of contact surfaces is at least one of the plurality of nozzle rows. A liquid drying restraining apparatus for jetting, characterized by exhibiting the contact state and the separated state with respect to a row. In the liquid drying suppression apparatus for injection as described in any one of Claims 1 thru | or 6,
The nozzle forming surface and the contact surface have liquid repellency with respect to the jetting liquid,
The liquid drying suppression apparatus for injection according to claim 1, wherein the liquid repellency of the contact surface is higher than the liquid repellency of the nozzle forming surface. In the liquid drying suppression apparatus for injection as described in any one of Claims 1 thru | or 7,
Supply means for supplying the jetting liquid to the liquid jetting means;
The jet liquid drying restraint device, wherein the pressure control means controls the pressure of the jet liquid in the nozzle by controlling the pressure of the jet liquid in the supply means. A liquid drying suppression apparatus for injection according to any one of claims 1 to 8,
Moving means for moving a medium that is an ejection target of the ejection liquid relative to the liquid ejection means included in the ejection liquid drying suppression device;
A liquid ejecting apparatus. Nozzle contact means having an abutment surface capable of abutting against a nozzle forming surface in which a nozzle opening of a nozzle for ejecting a jetting liquid in the liquid ejecting means is formed. On the other hand, in the process of shifting from the contact state in close contact so as to close the nozzle opening, to the separated state separated from the nozzle forming surface,
The contact surface of the nozzle contact means is separated from the nozzle formation surface so that a separation region of the contact surface with respect to the nozzle formation surface gradually increases,
Prior to the abutment surface being separated from the nozzle forming surface, the ejection in the nozzle is performed such that the pressure of the ejection liquid in the nozzle does not become at least negative with respect to the atmospheric pressure in the nozzle opening. Control the pressure of liquid for use,
A liquid drying suppression method for jetting,

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