JP5991022B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a liquid ejection device that ejects liquid.

  Patent Document 1 describes a liquid ejection device that humidifies a space (gap) opposite to an ejection port after the head is not used (when the head is at rest) after isolating the space from the external space (after capping). Has been. In this humidification maintenance, air in the discharge space is discharged from an air discharge port disposed at one end in the longitudinal direction of the head, and humidified air is discharged from the air supply port disposed at the other end in the longitudinal direction of the head into the space. This is done by supplying to

JP 2011-207091 A

  By the way, when the head is not capped, the discharge port is exposed to the external space. For this reason, the liquid at the discharge port is dried. Even when the head is in use (during image recording on a recording medium), the liquid at the ejection port dries out for ejection ports that have not been ejected for a predetermined time. For the purpose of suppressing drying of these discharge ports, a technique for performing flushing for discharging ink from the discharge ports is known. However, when such flushing is performed, there is a problem that the amount of liquid consumption increases. For example, when the recording medium is a center registration system (a system in which the center line extending in the recording medium conveyance direction is conveyed so as to overlap the center in the longitudinal direction of the head), the head is used (image recording on the recording medium). However, depending on the size of the recording medium, ink is not ejected from the ejection ports on both ends in the longitudinal direction of the head. As described above, with respect to the ejection ports with low ink ejection frequency, the liquid at the ejection ports is particularly easy to dry. Accordingly, the amount of liquid consumption due to flushing for suppressing drying of these discharge ports increases.

  An object of the present invention is to provide a liquid ejection device capable of suppressing the drying of the liquid near the ejection port.

  In the liquid discharge apparatus of the present invention, a transport mechanism that transports a recording medium in the transport direction, and a direction perpendicular to the transport direction is a longitudinal direction, and a plurality of ejection ports that eject liquid to the recording medium are along the longitudinal direction. A head having discharge surfaces arranged at equal intervals, a counter member that can face the discharge surface, and a gap between the counter member and the discharge surface are formed together with the counter member and the discharge surface with the plurality of discharge nozzles. A partition member that encloses the outlet and partitions from the external space, the partition member partitioning the gap from the external space, and an open state in which the partition member opens the gap to the external space. And a supply channel having a supply port extending in the longitudinal direction along the upstream side surface of the head with respect to the transport direction, and supplying humidified air from the supply port to the gap Humidification A humidifying mechanism that performs the operation, and a control unit that controls the humidifying mechanism to perform the humidifying operation when the cap mechanism is in the open state and image recording on a recording medium is performed. . The supply flow path is configured such that the humid air supplied from the supply port to the gap is supplied more in the outer side than the center of the gap in the longitudinal direction.

  According to the liquid ejection apparatus of the present invention, the humidification operation is performed when image recording is performed (when the gap is in an open state). As the recording medium is transported, an air flow from the upstream side to the downstream side in the transport direction is generated in the gap, so that the humidified air supplied from the supply port portion effectively flows through the gap and is supplied to the plurality of discharge ports. At this time, the humidified air supplied from the supply port is supplied more on the outer side than the center of the gap in the longitudinal direction. For this reason, it becomes possible to suppress the drying of the discharge outlet in the outer side (longitudinal direction both ends) with a low use frequency. For this reason, the discharge of the liquid by flushing etc. can be suppressed.

1 is a schematic side view showing an internal structure of an ink jet printer according to a first embodiment of a liquid ejection apparatus of the present invention. (A) is a top view of a head body included in the printer of FIG. 1, and (b) is a bottom view of the head. 2 is a schematic diagram illustrating a positional relationship between a position of a sheet stored in a sheet feeding unit and an ejection surface of an inkjet head in the printer of FIG. (A) is the enlarged view which shows area | region IVa enclosed with the dashed-dotted line of Fig.2 (a), (b) is the fragmentary sectional view along the IVb-IVb line of Fig.4 (a), (c ) Is an enlarged view showing a region surrounded by an alternate long and short dash line in FIG. It is the schematic which shows the cap mechanism and humidification mechanism which are included in the printer of FIG. (A) is sectional drawing along the VIa-VIa line | wire of Fig.2 (a), (b) is an enlarged view which shows the area | region enclosed with the dashed-dotted line of Fig.6 (a), (c) is It is sectional drawing along the VIc-VIc line | wire of Fig.2 (a). (A) is the schematic which shows the side cover and cap mechanism based on 2nd Embodiment of this invention, (b) is sectional drawing along the VII-VII line of Fig.7 (a). It is sectional drawing along the VIII-VIII line of Fig.7 (a). It is sectional drawing which shows the modification of the side cover which concerns on 2nd Embodiment of this invention. (A) is schematic which shows the side cover based on 3rd Embodiment of this invention, (b) is sectional drawing along XX of Fig.10 (a). (A) is a partial sectional view showing the state of the humidifying operation during recording, and (b) is a partial sectional view showing the state of the humidifying operation during rest.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, an overall configuration of an inkjet printer 101 as a first embodiment of a liquid ejection apparatus according to the present invention will be described with reference to FIG.

  The printer 101 has a rectangular parallelepiped housing 101a. A paper discharge unit 31 is provided on the top plate of the housing 101a. The internal space of the housing 101a can be divided into spaces A, B, and C in order from the top. In the spaces A and B, a paper conveyance path from the paper supply unit 101c to the paper discharge unit 31 is formed, and the paper P, which is a recording medium, is conveyed along the thick black arrows shown in FIG. In the space A, image recording on the paper P and conveyance of the paper P to the paper discharge unit 31 are performed. In the space B, the paper P is fed to the conveyance path. From the space C, ink is supplied to the inkjet head 1 in the space A (hereinafter referred to as the head 1).

  In the space A, a head 1 for discharging black ink, a transport mechanism 8, a cap mechanism 40, a paper sensor 32, a humidifying mechanism 50 (see FIG. 5) used for a humidifying operation, a control device 100, and the like are arranged. .

  The head 1 has a long, substantially rectangular parallelepiped shape with the main scanning direction as the longitudinal direction (see FIG. 2). The head 1 is supported by the housing 101a via the head holder 13 and faces the platen 6 with a predetermined gap. The head 1 is a laminate in which a reservoir unit, a flexible printed circuit board (FPC), a circuit board, and the like are laminated in addition to the head body 3 (see FIG. 2). An upstream ink flow path (both not shown) including a reservoir is formed in the reservoir unit as the upstream flow path member, and ink is supplied from the cartridge 4.

  The flow path unit 9 as the downstream flow path member constitutes the head main body 3 together with the actuator unit 21, and the ink of the reservoir unit is supplied from the ink supply port 105b on the upper surface. The lower surface of the flow path unit 9 is the discharge surface 1a, and a plurality of discharge ports 108 (see FIG. 4) are formed. Ink is ejected from the ejection port 108 by driving the actuator unit 21.

  The circuit board adjusts a signal from the control device 100. The output signal is converted into a drive signal by a driver IC on the FPC and further output to the actuator unit 21 of the head body 3. When the drive signal is supplied, the actuator unit 21 is deformed and applies pressure to the ink in the flow path unit 9. The head 1 will be described in detail later.

  In addition to the head 1, a partition member 41 constituting the cap mechanism 40 is attached to the head holder 13. The partition member 41 is an annular member disposed in the head 1 and includes the head 1 in a plan view with the main scanning direction as a longitudinal direction. The cap mechanism 40 will be described in detail later.

  The transport mechanism 8 includes two guide portions 5a and 5b that guide the paper P and the platen 6, and constitutes a paper transport path. The two guide portions 5a and 5b are arranged with the platen 6 interposed therebetween. The guide portion 5a on the upstream side in the transport direction includes three guides 18a and three feed roller pairs 22 to 24, and connects the paper feed portion 101c and the platen 6. The image recording paper P is conveyed toward the platen 6. The guide part 5 b on the downstream side in the transport direction has three guides 18 b and four feed roller pairs 25 to 28, and connects the platen 6 and the paper discharge part 31. The paper P after image recording is conveyed toward the paper discharge unit 31.

  The platen 6 supports the conveyed paper P from below during image recording. The platen 6 is a flat plate having a rectangular planar shape that is slightly larger than the partition member 41 in plan view.

  The paper sensor 32 is disposed on the upstream side in the transport direction of the feed roller pair 24 and detects the leading edge of the paper P being transported. The detection signal output at this time is used to drive the synchronized head 1 and the transport mechanism 8, and an image is recorded at a desired resolution and speed.

  The humidifying mechanism 50 supplies humidified air to the discharge port 108 in the cap state (partition state) and the uncapped state (open state). The humidification mechanism 50 includes a humidified air generation unit, a supply unit, and a discharge unit. In the generation unit, humidified air is generated and sent out toward the supply unit. The supply unit receives humidified air and humidifies the discharge port 108. In the discharge part, air is discharged from the vicinity of the discharge port 108. As shown in FIG. 5, the generation unit includes a tank 57 and a pump 58 in addition to the pipes 53 and 54. As shown in FIG. 2, the supply unit includes a supply pipe 60. The discharge part includes a discharge pipe 80. The tank 57 is a generation source of humidified air. During the humidification operation, the pump 58 is driven, humid air is supplied from the supply pipe 60 to the vicinity of the discharge port 108 via the pipes 53 and 54, and air is discharged from the discharge pipe 80.

  As shown in FIG. 2B and FIG. 5, the humidifying mechanism 50 includes a supply port portion 65 and a discharge port portion 85. The supply port portion 65 and the discharge port portion 85 communicate with the discharge space S1 (a gap between the discharge surface 1a and the platen 6), and when viewed from the direction orthogonal to the discharge surface 1a, the sub-scanning direction (head 1). With respect to the short direction). Further, the supply port portion 65 extends in the longitudinal direction along the upstream side surface 1S1 of the head body 3 with respect to the transport direction D (the direction of arrow D in FIG. 1). The discharge port portion 85 extends in the longitudinal direction along the downstream side surface 1S2 of the head body 3 with respect to the transport direction D. The humidification mechanism 50 supplies humidified air to the supply port portion 65 and discharges the air in the discharge space S1 from the discharge port portion 85.

  Returning to FIG. 1, in the space B, the paper feeding unit 101 c is arranged. The paper feed unit 101 c includes a paper feed tray 35 and a paper feed roller 36. Among these, the paper feed tray 35 is detachable from the housing 101a. A plurality of sheets P are stored in the sheet feed tray 35. The paper feed roller 36 feeds the uppermost paper P in the paper feed tray 35.

  A slide type guide (not shown) is attached to the paper feed tray 35 so as to accommodate a plurality of sizes of paper P having different lengths in the main scanning direction. This guide has a pair of paper regulating walls 35a (see FIG. 3) parallel to the conveyance direction of the paper P. When the user displaces one of them in the main scanning direction, the other is interlocked and the same in the reverse direction. Displace by distance. The center position in the main scanning direction of the space separating the pair of sheet regulating walls 35a is the center position in the main scanning direction of the head 1 (ejection surface 1a) (position passing through the center point Q) regardless of the position of the sheet regulating walls 35a. : Refer to FIG. 2B). That is, when the user slides the paper regulating wall 35a, the center of the paper P in the main scanning direction is the same position with respect to the head 1 for any size of paper P as shown in FIG.

  As a modification, a plurality of paper regulation walls are fixed such that the guides are not slidable, the intervals in the main scanning direction are different from each other, and the center of the pair of paper regulation walls coincides with the center position of the head 1 in the main scanning direction. A paper feed tray may be provided.

  Here, the sub-scanning direction is a direction parallel to the conveyance direction D in which the paper P is conveyed by the pair of feed rollers 24 and 25, and the main scanning direction is a direction parallel to the horizontal plane and orthogonal to the sub-scanning direction. is there.

  In the space C, a cartridge 4 that stores black ink is detachably attached to the housing 101a. The cartridge 4 is connected to the head 1 via a tube (not shown) and a pump (not shown). The pump is driven when ink is forcibly sent to the head (that is, when purging or when ink is initially introduced). Other than this, the pump is in a stopped state, and the pump does not disturb the ink supply to the head 1.

  Next, the control device 100 will be described. For example, the control device 100 controls an image recording operation, a maintenance operation, and the like. In the image recording operation, based on a recording command (image data) from an external device (such as a PC connected to the printer 101), the paper feeding unit 101c, guide units 5a and 5b (conveying mechanism 8), the head 1 and the like are driven. To do. Specifically, the paper P is sent out from the paper feed tray 35 and sent to a recording area facing the head 1. In the recording area, the head 1 is driven in synchronization with the detection signal from the paper sensor 32. When the paper P passes directly under the head 1, ink is ejected and a desired image is recorded. The paper P is further conveyed and discharged to the paper discharge unit 31 at the top of the housing 101a.

  In addition, as the maintenance operation, an ink discharging operation (purge operation and flushing operation), a capping operation, a humidifying operation, and the like are executed periodically or in response to a user request. Both are intended to maintain and recover the ink ejection characteristics of the head 1.

  For example, in the ink discharging operation, the thickened ink is discharged from the ejection port 108. In the purge operation, pressure is applied by driving the pump without driving the actuator, and ink is forcibly discharged from the head 1. After the forced discharge, the discharge surface 1a is cleaned (wiping operation). In the flushing operation, the actuator is driven and a predetermined amount of ink droplets are ejected from the head 1. Actuator driving is based on flushing data (data different from image data).

  The capping operation is performed when the head 1 is at rest, and as shown in FIG. 5A, the partition member 41 partitions the discharge space S1 from the external space S2. At this time, the plurality of discharge ports 108 communicate only with the closed discharge space S1. As a result, the path through which moisture is dissipated from the ejection port 108 is closed, so that ink thickening and drying are suppressed.

  The humidifying operation includes a resting humidifying operation during the capping operation and a humidifying operation during recording during the image recording operation. In the humidifying operation during the pause, as shown in FIG. 5A, humidified air is supplied from the supply port 65 to the partitioned discharge space S <b> 1 and internal air is discharged from the discharge port 85. At this time, since the discharge space S1 is filled with water vapor, drying of the discharge port 108 is further suppressed. The humidifying operation during the pause is performed only during a predetermined period of the period during which the capping operation is performed. In the humidifying operation during recording, as shown in FIG. 5 (b), humidified air is supplied from the supply port 65 to the discharge space S1 opened to the external space S2, and the discharge space S1 enters the discharge space S1. Air is exhausted. At this time, the humidified air is supplied to the discharge port 108, so that drying of the discharge port 108 is suppressed.

  Next, the head 1 will be described with reference to FIGS. 2, 4 and 6. In FIG. 4A, for convenience of explanation, the pressure chamber 110 and the discharge port 108 which are to be drawn with a broken line below the actuator unit 21 are drawn with a solid line.

  As shown in FIG. 2A, the head body 3 is a laminated body in which four actuator units 21 are fixed to the upper surface 9 a of the flow path unit 9. On the upper surface 9a, as shown in FIG. 4A, a plurality of pressure chambers 110 are opened and arranged in a matrix. As shown in FIG. 4C, each actuator unit 21 seals these openings and constitutes a side wall of the pressure chamber 110.

  As shown in FIG. 4B, the flow path unit 9 is a laminated body in which nine stainless plates 122 to 130 are laminated. An ink flow path is formed inside the flow path unit 9. As shown in FIGS. 2 and 4, the ink flow path has one end of the ink supply port 105 b on the upper surface 9 a and a pressure from the manifold flow path 105 branched to the sub manifold flow path 105 a and the outlet of the sub manifold flow path 105 a. An individual ink flow path 132 that reaches the discharge port 108 on the lower surface through the chamber 110 is included. On the discharge surface 1a, as shown in FIG. 2B, a plurality of discharge ports 108 are arranged in a matrix corresponding to the pressure chambers 110. The ejection ports 108 are arranged at intervals of 600 dpi, which is the resolution in this direction, with respect to the main scanning direction.

  Next, the actuator unit 21 will be described. As shown in FIG. 2A, each of the four actuator units 21 has a trapezoidal planar shape. These four actuator units 21 are arranged in a staggered manner along the main scanning direction so as to avoid the ink supply port 105b.

  The actuator unit 21 is a lead zirconate titanate (PZT) ceramic having ferroelectricity, and is composed of three piezoelectric layers 141 to 143 as shown in FIG. The uppermost piezoelectric layer 141 has a plurality of individual electrodes 135 formed on its upper surface and is polarized in the thickness direction. As for the piezoelectric layer 142, the common electrode 134 is formed in the upper surface entirely. A portion sandwiched between the individual electrode 135 and the pressure chamber 110 functions as an individual unimorph actuator. When an electric field in the polarization direction is generated between the individual electrode 135 and the common electrode 134, the actuator portion protrudes toward the pressure chamber 110 (unimorph deformation). At this time, the ink in the pressure chamber is pressurized and ink droplets are ejected from the ejection port 108. Here, the common electrode 134 is always at the ground potential. Further, the drive signal is selectively supplied to the individual electrode 135.

  In the present embodiment, a striking method is employed when ink is ejected. The individual electrode 135 is at a predetermined potential in advance, and the actuator is unimorph deformed. When the drive signal is supplied, the individual electrode 135 once has the same potential as the common electrode 134 and returns to the predetermined potential after a predetermined time. At the same potential, the actuator eliminates unimorph deformation and ink is sucked into the pressure chamber 110. At the return timing of the potential, the actuator is deformed again by unimorph, and an ink droplet is ejected from the ejection port 108.

  As shown in FIGS. 2 and 6, a side cover 70 is provided on the outer peripheral side surface of the head body 3. The side cover 70 surrounds the entire circumference of the head body 3 and is a resin-made annular member. The side cover 70 is fixed across both side surfaces of the flow path unit 9 and the reservoir unit. The side cover 70 includes a pair of long portions 71 along the main scanning direction and a pair of short portions 72 along the sub-scanning direction. A pair of short portions 72 connects the pair of long portions 71.

  The pair of long portions 71 has an inlet portion and an outlet portion through which humidified air enters and exits. The inlet portion is provided on the upper side in FIG. Humidified air flows into the discharge space S1 from the inlet. The inlet portion includes a through hole 71a that passes through the upstream long portion 71 vertically (in a direction perpendicular to the discharge surface 1a) and a supply pipe (described later) 60 that is inserted through the through hole 71a. The outlet portion is provided on the lower side in FIG. The air in the discharge space S1 is discharged from the outlet portion. The outlet portion includes a through hole 71b that vertically penetrates the downstream long portion 71, and a discharge pipe (described later) 80 inserted through the through hole 71b. The through holes 71a and 71b are arranged symmetrically with respect to the center point Q of the ejection surface 1a.

  Next, the configuration of the head holder 13 and the cap mechanism 40 will be described with reference to FIG.

  The head holder 13 is a rigid frame-like frame made of metal or the like, and supports the side surface of the head body 3 over the entire circumference. A partition member 41 of a cap mechanism 40 is attached to the head holder 13.

  Here, the contact portion between the head holder 13 and the head main body 3 is sealed with a sealant over the entire circumference. Further, the contact portion between the head holder 13 and the partition member 41 is also fixed with an adhesive over the entire circumference. The head holder 13 has through holes 13a and 13b corresponding to the through holes 71a and 71b. A supply pipe 60 and a discharge pipe 80 are respectively inserted.

  The cap mechanism 40 includes a partition member 41, a cap lifting mechanism 48 that lifts and lowers the partition member 41, and a platen (opposing member) 6. The partition member 41 can include the side cover 70 and the discharge space S1 (discharge port 108) together with the platen 6 and the discharge surface 1a, and is long in the main scanning direction. As shown in FIG. 6, the partition member 41 includes a lip member 42, a movable body 43, and a diaphragm 44.

  The lip member 42 is made of an annular elastic material such as rubber and surrounds the head 1 in a plan view. That is, the lip member 42 is disposed outside the side cover 70. The lip member 42 includes a base portion 42x and a protruding portion 42a protruding from the lower surface of the base portion 42x. Among these, the protrusion 42 a has a triangular cross section, and the tip abuts against the platen 6. A movable body 43 is fixed on the upper surface of the base 42x. The movable body 43 is made of an annular rigid material (for example, stainless steel).

  The diaphragm 44 is also made of a flexible thin film member such as rubber and surrounds the head 1 in a plan view. The diaphragm 44 has an outer peripheral end integrally connected to the lip member 42, and a close contact portion 44a is formed at the inner peripheral end. The inner side surface of the contact portion 44 a is fixed to the outer peripheral side surface of the side cover 70, and the upper surface is fixed to the lower surface of the head holder 13.

  The cap lifting mechanism (lip moving mechanism) 48 includes a plurality of gears 45 and a lifting motor (not shown). The plurality of gears 45 are connected to the movable body 43. When the lifting motor is driven under the control of the control device 100, the gear 45 rotates and the movable body 43 moves up and down. The base 42x also moves up and down. Thereby, the relative position of the front-end | tip of the protrusion part 42a and the discharge surface 1a changes to a perpendicular direction.

  The tip of the lip member 42 (protruding portion 42a) is brought into contact with the surface 6a of the platen 6 as the movable body 43 moves up and down (position shown in FIG. 5A), and is separated from the surface 6a. The position (the position shown in FIGS. 5B and 6) is selectively taken. The contact position is a position where the lip member 42 can contact the platen 6. When the lip member 42 comes into contact with the surface 6a, the partition member 41, the discharge surface 1a, and the platen 6 are in a partition state in which the discharge space S1 is partitioned from the external space S2. Thus, the platen 6 constitutes a part of the cap mechanism 40. Further, at the separation position, the discharge space S1 is opened from the external space S2. In the separated position, the tip of the lip member 42 is located slightly below the ejection surface 1a so as not to prevent the conveyance of the paper P.

  Next, the configuration of the humidifying mechanism 50 will be described. As described above, the humidifying mechanism 50 includes a supply unit (supply pipe 60), a discharge unit (discharge pipe 80), a generation unit (pipes 53 and 54, a tank 57, and a pump 58).

  First, the supply unit (supply pipe 60) will be described. The supply pipe 60 constitutes an inlet for humidified air. As shown in FIG. 6, the supply pipe 60 includes a first supply pipe 61 and a second supply pipe 63 that communicate with each other. The humidified air flows into the first supply pipe 61 and then is supplied to the discharge space S1 through the second supply pipe 63.

  The first supply pipe 61 extends in the vertical direction. The first supply pipe 61 is inserted into the through hole 13a of the head holder 13 in addition to the through hole 71a of the upstream long portion 71, and a pipe 54 is connected to the exposed tip portion. Although there is a slight gap between the first supply pipe 61 and the through holes 13a and 71a, the first supply pipe 61 is filled with a sealing material or the like.

  As shown in FIG. 6C, the second supply pipe 63 has an upper surface bonded to the lower surface of the upstream elongated portion 71 and is disposed between the lip member 42 and the upstream side surface 1S1 of the head 1. ing. As shown in FIG. 6A, the second supply pipe 63 extends in the main scanning direction, one end is connected to the first supply pipe 61, and the other end is a closed portion.

  On the lower surface of the second supply pipe 63, a supply port portion 65 extending along the upstream side surface 1S1 of the head 1 is formed. The supply port portion 65 includes openings (supply ports) of a plurality of supply holes 65 a formed in the second supply pipe 63. These supply holes 65a are arranged along the main scanning direction and communicate with the inside of the second supply pipe 63 to form a supply flow path. The humidified air is uniformly supplied from the supply holes 65a (openings) to the discharge space S1. Further, as shown in FIG. 2B, the two outermost supply holes 65a in the main scanning direction are outside the two outlets 108 at the outermost side of the discharge surface 1a. That is, the supply port portion 65 has a length equal to or longer than the interval between the two outermost discharge ports 108. The second supply pipe 63 is entirely above the platen 6 with respect to the discharge surface 1a and does not hinder the conveyance of the paper P.

  As shown in FIG. 6C, the supply hole 65a is formed in the lower part on the head side of the second supply pipe 63, and its opening faces the discharge space S1 (gap). Thereby, the humidified air supplied from the supply hole 65a effectively flows downstream in the transport direction. For this reason, it is possible to further suppress drying of the plurality of ejection ports 108.

  The flow path resistance with respect to the air in the second supply pipe 63 is made smaller toward the downstream side from the upstream side with respect to the direction of the flow of the humidified air (the right side direction in FIG. 6). In the present embodiment, as shown in FIGS. 2B and 6B, the opening area of the supply hole 65a increases from the upstream side toward the downstream side. Thereby, a substantially equal amount of humidified air flows out from each supply hole 65a. As a modification, the cross-sectional area of the flow path in the second supply pipe 63 may be increased from the upstream side toward the downstream side with respect to the flow direction.

  As shown in FIGS. 2B and 6B, these supply holes 65a are formed as the distance between two adjacent openings (supply ports) in the main scanning direction increases from the center toward the outside. It is arranged to be smaller. As a result, the number of openings of the supply holes 65a is larger on the outer side than the center in the main scanning direction. For this reason, a large amount of humidified air is reliably supplied to the outside of the center of the ejection space S1 in the main scanning direction.

  Next, the discharge unit (discharge pipe 80) will be described. The discharge pipe 80 constitutes an outlet for humidified air. The discharge pipe 80 also includes a first discharge pipe 81 and a second discharge pipe 83 that communicate with each other. The air in the discharge space S <b> 1 flows into the second discharge pipe 83 and then is discharged to the generation unit through the first discharge pipe 81. The first and second discharge pipes 81 and 83 have the same configuration as the first and second supply pipes 61 and 63, and are arranged point-symmetrically with respect to the center point Q of the discharge surface 1a.

  Specifically, the first discharge pipe 81 extends in the vertical direction, is inserted through the through hole 71b and the through hole 13b, and the pipe 53 is connected to the exposed tip portion. The second discharge pipe 83 has an upper surface bonded to the lower surface of the long downstream portion 71 and is disposed between the lip member 42 and the downstream side surface 1S2 of the head 1. The second discharge pipe 83 extends in the main scanning direction, one end is connected to the first discharge pipe 81, and the other end is a closed portion.

  A discharge port portion 85 extending along the downstream side surface 1S2 is formed on the lower surface of the second discharge pipe 83. The discharge port portion 85 is composed of openings (discharge ports) of a plurality of discharge holes 85 a formed in the second discharge pipe 83. These discharge holes 85a are arranged along the main scanning direction, communicate with the inside of the second discharge pipe 83, and form a discharge flow path. The air in the discharge space S1 is discharged from each discharge hole 85a (opening).

  As shown in FIG. 2B, in the main scanning direction, the two outermost discharge holes 85a are located outside the two outermost discharge ports 108 on the discharge surface 1a. That is, the discharge port portion 85 also has a length longer than the interval between the two outermost discharge ports 108. The second discharge pipe 83 is also entirely above the platen 6 with respect to the discharge surface 1a, and does not hinder the conveyance of the paper P.

  As shown in FIG. 6C, the discharge hole 85a is formed in the lower portion on the head side of the second discharge pipe 83, and its opening faces the discharge space S1. As a result, the air in the discharge space S1 can be easily discharged.

  The flow path resistance with respect to the air in the second discharge pipe 83 is increased from the upstream side toward the downstream side in the direction of the flow of the humidified air (the lower direction in FIG. 2B). In the present embodiment, the opening area of the discharge hole 85a is smaller from the upstream side (upper side in the figure) toward the downstream side (lower side in the figure). Thereby, a substantially equal amount of air is discharged from each discharge hole 85a. As a modification, the cross-sectional area of the flow path in the second discharge pipe 83 may be reduced in the flow direction from the upstream side toward the downstream side.

  These discharge holes 85a are also arranged so that the separation distance between two openings (discharge ports) adjacent to each other in the main scanning direction decreases from the center toward the outside. As a result, the number of openings of the discharge holes 85a is larger on the outer side than the center in the main scanning direction. For this reason, air is discharged from the outside of the center of the ejection space S1 in the main scanning direction.

  Next, the generation unit (tank 57, pump 58, etc.) will be described. As a whole, the pipes 53 and 54 constitute a circulation path between the generation source (tank 57) of the humidified air, the supply unit, and the discharge unit. As shown in FIG. 5, the pipe 53 has one end connected to the discharge pipe 80 and the other end connected to the tank 57. A pump 58 is inserted in the middle part. The pipe 54 has one end connected to the tank 57 and the other end connected to the supply pipe 60.

  The tank 57 stores water for humidification in the lower space, and stores humidified humidified air in the upper space. The piping 53 communicates with the lower space (underwater) of the tank 57, and the piping 54 communicates with the upper space of the tank 57. A check valve (not shown) is attached in the vicinity of the tank 57 of the pipe 53 to prevent water from flowing out of the tank 57. When the water in the tank 57 is low, water is supplied to the tank 57 from a water supply tank (not shown).

  Next, a series of flows of the capping operation of the printer 101 and the humidifying operation during suspension will be described. When the image recording operation is paused, the printer 101 performs a humidifying operation in addition to the capping operation.

  When the capping operation is executed, a path of humid air is formed in the partition member 41 in the short direction (sub-scanning direction) of the head 1. Under the control of the control device 100, the lip member 42 is brought into the contact position as shown in FIG. The partition member 41 partitions the discharge space S1 from the external space S2.

  Here, if the partition state (cap state) continues, the ink near the ejection port 108 may dry. Further, when the printer 101 is used for a long period of time, the inner wall of the partition member 41 may be contaminated due to accidental adhesion of ink mist or ink itself. When such residual ink is dried, it functions as a desiccant (moisture absorption source) and promotes drying in the compartment state.

  Therefore, in the present embodiment, the supply port portion 65 and the discharge port portion 85 sandwich all the discharge ports 108 in the short direction of the head 1. Then, in the compartmentalized state of rest, humidified air is supplied and the discharge port 108 is humidified. Hereinafter, the humidifying operation during the pause will be specifically described.

  When the humidifying operation during the pause is executed, the pump 58 is driven under the control of the control device 100. As shown to Fig.5 (a), air flows along the white arrow. The humid air in the upper space of the tank 57 is supplied to the second supply pipe 63 via the pipe 54 and the first supply pipe 61. The humidified air is supplied from the plurality of supply holes 65a of the first supply port 65 to the discharge space S1. The air in the discharge space S1 flows in the sub-scanning direction toward the discharge port 85 while being replaced with humidified air. In addition, the air in the discharge space S <b> 1 is sucked out by the pump 58 through the first discharge pipe 81 and travels from the discharge port portion 85 to the tank 57. The air is humidified in the lower space of the tank 57 and moves to the upper space. The generated humidified air is supplied to the discharge space S1 while the pump 58 continues to be driven.

  Next, a series of flows of the uncapping operation (capping releasing operation) and the humidifying operation during recording of the printer 101 will be described.

  When the uncapping operation is executed, under the control of the control device 100, the lip member 42 is set to the separation position as shown in FIGS. The partition member 41 is in an open state in which the discharge space S1 is opened to the external space S2.

  Next, the above-described image recording operation is performed by the printer 101 based on the received recording command. In the present embodiment, the paper P is conveyed by the center cash register method. That is, the paper P is arranged in the paper feed tray 35 such that the center position in the main scanning direction corresponds to the center position of the ejection surface 1a (position passing through the center point Q) with respect to the main scanning direction. In the recording area, the paper P is conveyed so that the centers in the main scanning direction overlap with the distribution area of the ejection openings 108. At this time, if the size of the paper P is smaller than the distribution area of the discharge ports 108, the discharge ports 108 at both ends in the main scanning direction are only exposed to the atmosphere, and drying proceeds during image recording.

  When this image recording operation is performed, a humidifying operation during recording is executed under the control of the control device 100. In the present embodiment, the plurality of supply holes 65a constituting the supply port portion 65 are arranged more outside the center than in the main scanning direction. Hereinafter, the humidifying operation during recording will be specifically described.

  When the humidifying operation during recording is executed, the pump 58 is driven under the control of the control device 100. As shown in FIG. 5B, the air flows along the white arrow as in the humidifying operation during the pause. The humid air in the upper space of the tank 57 is supplied to the second supply pipe 63 via the pipe 54 and the first supply pipe 61. The humidified air is discharged from the plurality of supply holes 65 a of the first supply port portion 65 to the discharge space S <b> 1 and supplied to the discharge port 108.

  The movement of the humidified air from the supply hole 65a to the discharge port 108 is performed by an air flow accompanying the conveyance of the paper P. On the downstream side in the transport direction, the air in the discharge space S <b> 1 is sucked by the pump 58 and travels from the discharge port portion 85 to the tank 57. In this way, a flow of humidified air from the supply port portion 65 to the discharge port portion 85 is formed. For this reason, even when there is no airflow associated with the conveyance of the sheet in the vicinity of the discharge surface 1a (for example, before the sheet P passes through the discharge surface 1a and when a certain amount of time has passed), the humid air is discharged. It is supplied to the outlet 108. As a result, the discharge port 108 can be prevented from drying even in the uncapped state.

  Moreover, the opening area of the plurality of supply holes 65a is increased from the upstream side toward the downstream side in the direction of the flow of the humidified air. That is, the flow path resistance per unit length with respect to the air in the second supply pipe 63 is smaller toward the downstream side from the upstream side with respect to the direction of the flow of the humidified air. Thereby, the quantity of the humidified air discharged | emitted becomes substantially equal between the some supply holes 65a. Further, at this time, the supply holes 65a are more on the outer side than the center in the main scanning direction. For this reason, much humid air is supplied to the outside of the center of the ejection space S1 in the main scanning direction. That is, in the center registration type conveyance, the discharge ports 108 on the outer side (both ends in the main scanning direction) that are less frequently used tend to dry, but this can be effectively suppressed. Accordingly, it is possible to suppress ink consumption due to a flushing operation or the like. Note that the air sucked from the discharge port portion 85 is humidified in the lower space of the tank 57 and moves to the upper space, as in the humidifying operation during the pause. The generated humidified air is supplied to the discharge space S1 while the pump 58 continues to be driven.

  The tip of the lip member 42 is located slightly below the discharge surface 1a in the separated position. Thereby, the humidified air supplied to the discharge space S1 from the supply hole 65a of the supply port portion 65 is likely to stay in the discharge space S1 (the portion surrounded by the lip member 42 and the discharge surface 1a). For this reason, humidified air is efficiently supplied to the discharge port 108, and drying of the discharge port 108 can be further suppressed.

  As described above, according to the present embodiment, the humidification operation is performed when the image recording operation is performed. In this humidification operation during recording, the humidified air supplied from the supply port 65 rides on the air flow accompanying the conveyance of the paper and crosses the discharge space S1 (gap) on the discharge port 85 side. Thereby, drying of the discharge port 108 is suppressed even during the image recording operation (open state). Further, at this time, more humidified air is supplied outside the center of the ejection space S1 in the main scanning direction. For this reason, even if it is the outer discharge port 108 with low use frequency, drying is suppressed effectively. As a result, ink discharge due to flushing or the like is suppressed.

  Further, the humidifying operation is performed in the partitioned state (capping operation). For this reason, even in the partitioned state, drying of ink is suppressed at the plurality of ejection openings 108.

  In the humidification operation, the air in the discharge space S1 is discharged from the discharge port portion 85. For this reason, the humidified air supplied from the supply port portion 65 is likely to flow along the transport direction D (short direction of the head). That is, it flows to the discharge port portion 85 via the discharge space S1 (gap). As a result, ink drying at the ejection port 108 is effectively suppressed.

  The cap mechanism 40 includes a partition member 41, a cap lifting mechanism 48, and the platen 6. Thereby, the cap mechanism 40 can be made relatively small, and the entire apparatus can be downsized. In addition, each supply hole 65a in the supply port portion 65 and each discharge hole 85a in the discharge port portion 85 are inclined at the center axis of the opening toward the inside of the discharge space S1. Accordingly, the humidified air can be circulated with little waste, contributing to the uniform supply of moisture to each discharge port 108.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment in the configuration of the humidifying mechanism. Below, the same code | symbol is attached | subjected about the location same as 1st Embodiment mentioned above, and the description is abbreviate | omitted suitably.

  In the humidification mechanism 250 according to the present embodiment, the supply unit and the discharge unit each include a partition member 41 in addition to the side cover 270. The side cover 270 surrounds the entire circumference of the head 1 and is a resin-made annular member. The side cover 270 includes a pair of long portions 271 along the main scanning direction and a pair of short portions 272 along the sub scanning direction. The long portion 271 has the same length as the side surfaces 1S1 and 1S2 of the head 1 in the main scanning direction. The pair of short portions 272 connects the pair of long portions 271.

  The upstream long portion 271 (the lower side in FIG. 7B and the left side in FIG. 8) includes an upstream fixing portion 273a and an upstream flange 274a. The upstream side fixing portion 273a extends in the main scanning direction and is fixed to the side surface 1S1 of the head 1. A close contact portion 44a is fixed to the outer side surface of the upstream side fixing portion 273a. The upstream flange 274a is formed integrally with the upstream fixing portion 273a and protrudes from the lower end of the upstream fixing portion 273a toward the upstream side. The upstream flange 274a also extends in the main scanning direction.

  A plurality of notches 275a are formed at the tip of the upstream flange 274a (the surface facing the lip member 42). These notches 275a are formed through the upstream flange 274a with respect to the vertical direction, and are provided with a plurality of openings (supply ports) 265a and a plurality of guide paths 265b connected to the openings 265a by the lip member 42. Defined. A supply port portion 265 is configured by the plurality of openings 265a. These openings 265a are arranged at equal intervals along the main scanning direction. The two outermost openings 265a are on the outer side of the two outlets 108 on the outermost side of the discharge surface 1a. Note that the lower surface of the side cover 270 is entirely above the platen 6 relative to the ejection surface 1a and does not hinder the conveyance of the paper P.

  With respect to the main scanning direction, the mutually facing inner surfaces of the notch 275a are inclined so as to be located on the outer side as they approach the opening 265a. Thereby, the humidified air supplied from the opening 265a to the discharge space S1 is supplied toward the outside in the main scanning direction. For this reason, much humidified air is supplied outside the center of the discharge space S1. Further, the humidified air is supplied to the inner surface of the outermost notch 275a in the main scanning direction toward the position where the lip member 42 of the platen 6 contacts (the tip of the lip member 42 in the contact position). Inclined. Thereby, it becomes possible to supply moisture to the ink stored in the contact portion between the lip member 42 and the platen 6 in the partitioned state.

  The upstream side fixing portion 273a has a protruding portion 276a protruding upward. The protrusion 276a is formed at the center of the upper surface of the upstream fixing portion 273a in the main scanning direction. A channel 277a extending in the vertical direction is formed in the center of the upstream side fixing portion 273a. The flow path 277a passes through the center of the protruding portion 276a and communicates with an opening 278a formed on the side surface of the upstream side fixing portion 273a. The protruding portion 276 a is inserted into the through hole 13 a of the head holder 13 and connected to the pipe 54. There is a slight gap between the protruding portion 276a and the through hole 13a, but a sealing material or the like is filled. The humidified air flows out from the opening 278a through the pipe 54. The tip of the upstream flange 274a is always in contact with the inner peripheral surface of the lip member 42. The pair of short portions 272 are always in contact with the diaphragm 44 at both ends in the sub-scanning direction. For this reason, the space surrounded by the upstream long portion 271 and the partition member 41 constitutes a flow path 279a that is sealed at both ends in the main scanning direction and connected to the flow path 277a. As shown in FIG. 7, the humidified air flows in the flow path 279a from the opening 278a to the left and right in the drawing, and is supplied from each opening 265a to the discharge space S1 through the guide path 265b. The notch 275a (opening 265a and guide path 265b) and the two flow paths 277a and 279a constitute a supply flow path for supplying humidified air to the discharge space S1.

  As shown in FIG. 7, the area of the opening 265a increases in the direction of the flow of humidified air from the upstream side (center in FIG. 7) to the downstream side (outside in FIG. 7). Thereby, a substantially equal amount of humidified air is supplied from each opening 265a.

  The downstream long portion 271 (upper side in FIG. 7B and right side in FIG. 8) includes a downstream fixing portion 273b and a downstream flange 274b. The downstream elongate portion 271 has the same configuration as that in which the upstream elongate portion 271 is arranged in line symmetry with respect to a straight line extending in the main scanning direction passing through the center point Q of the ejection surface 1a. The downstream side fixing portion 273b is fixed to the side surface 1S2 of the head 1. A close contact portion 44a is fixed to the outer side surface of the downstream side fixing portion 273b. The downstream flange 274b protrudes from the lower end of the downstream fixing portion 273b toward the downstream side.

  A plurality of notches 275b are formed at the tip of the downstream flange 274b (the surface facing the lip member 42). These notches 275b are also formed so as to penetrate the downstream flange 274b in the vertical direction, and the lip member 42 defines a plurality of openings (discharge ports) 285a and a plurality of guide paths 285b connected to the openings 285a. Defined. A discharge port portion 285 is configured by the plurality of openings 285a. These openings 285a are also arranged at equal intervals along the main scanning direction, and the two outermost openings 285a are located outside the two outermost discharge ports 108 on the discharge surface 1a. In addition, with respect to the main scanning direction, the mutually facing inner surfaces of the notch 275b are inclined so as to be positioned on the outer side as they approach the opening 285a.

  A channel 277b extending in the vertical direction is formed at the center of the protruding portion 276b of the downstream fixing portion 273b. The flow path 277b passes through the center of the protruding portion 276b and communicates with an opening 278b formed on the side surface of the downstream side fixing portion 273b. The protruding portion 276 b is inserted into the through hole 13 b of the head holder 13 and connected to the pipe 53. There is also a slight gap between the protruding portion 276b and the through hole 13b, but it is filled with a sealing material or the like. The distal end of the downstream flange 274 b is always in contact with the inner peripheral surface of the lip member 42. Further, the space surrounded by the downstream long portion 271 and the partition member 41 constitutes a flow path 279b that is sealed at both ends in the main scanning direction and connected to the flow path 277b. The air in the discharge space S1 is discharged from the opening 285a as indicated by an arrow in FIG. In the flow path 279b, the air sucked through the opening 285a and the guide path 285b flows toward the opening 278b in the center, and is discharged to the tank 57 (outside) through the pipe 53. The notch 275b (opening 285a and guide path 285b) and the two flow paths 277b and 279b constitute a discharge flow path for discharging the air in the discharge space S1 to the outside.

  The opening area of the opening 285a is smaller from the upstream side (left and right side in FIG. 7B) toward the downstream side (center in FIG. 7B) with respect to the direction of the flow of humidified air. As a result, a substantially equal amount of air is discharged from each opening 285a.

  In the printer having the humidification mechanism 250 described above, the humidification operation during recording and the humidification operation during pause are performed in the same manner as in the first embodiment. That is, humidified air is supplied from the plurality of openings 265a to the discharge space S1. In the humidifying operation during recording, the lip member 42 is disposed at the separation position, but the tip thereof is below the flanges 274a and 274b. For this reason, the humidified air released from the opening 265a hits the inner surface of the lip member 42 and tends to stay in the vicinity of the opening 265a. That is, it becomes difficult for the humidified air to flow out upstream in the transport direction D. At this time, the humidified air is supplied from the openings 265a to the outside in the main scanning direction at substantially the same amount. For this reason, much humid air stays outside the main scanning direction. The accumulated humid air effectively flows in the transport direction D by the air flow accompanying the transport of the paper P and the air flow generated by the suction from the discharge port portion 285. For this reason, humidified air is supplied more outside the center of the discharge space S1. Accordingly, similarly to the first embodiment, even in the uncapped state, it is possible to suppress the drying of the ejection ports 108 on the outside that is not frequently used, and thus it is possible to suppress the ink consumption due to the flushing operation or the like.

  In the humidifying operation during the pause, as in the first embodiment, humidified air is supplied from the plurality of openings 265a (supply port portion 265) to the discharge space S1. At this time, the humidified air supplied from the outermost opening 265a in the main scanning direction is supplied toward the place where the lip member 42 of the platen 6 contacts. Thereby, in the partitioned state, it becomes possible to supply moisture directly to the ink stored in the contact portion between the lip member 42 and the platen 6. For this reason, in the partitioned state, the ink in the vicinity of the ejection port is difficult to dry. The air in the discharge space S1 flows in the sub-scanning direction toward the discharge port portion 285 while being replaced with humidified air. The air in the discharge space S1 is sucked out by the pump 58 and travels from the discharge port portion 285 to the tank 57. The air is humidified in the lower space of the tank 57 and moves to the upper space. The generated humidified air is supplied to the discharge space S1 while the pump 58 continues to be driven.

  As described above, also in the present embodiment, as in the first embodiment, in the humidification operation, the humidified air supplied from the supply port portion 65 is supplied more in the outer side than the center of the discharge space S1 in the main scanning direction. Is done. For this reason, it becomes possible to suppress drying of the discharge ports 108 on the outer side (both ends in the main scanning direction) that are less frequently used. Therefore, ink discharge due to flushing or the like can be suppressed.

  In addition, since the supply port portion 265 and the discharge port portion 285 are configured by a plurality of notches 275a and 275b (openings 265a and 285a and guide paths 265b and 285b), the configuration is simplified and formed easily. It becomes possible to do. Note that the same effect can be obtained with the same configuration as in the first embodiment.

  As a modified example, as shown in FIG. 9, a plurality of through holes 295a and 295b may be formed in the flange portions 274a and 274b instead of the notches 275a and 275b. These through holes 295a and 295b are arranged at positions closer to the head 1 than the notches 275a and 275b, and have the same shape. For this reason, the effect similar to 2nd Embodiment can be acquired. In addition, a supply port part and a discharge port part are comprised by opening of these through-holes 295a and 295b.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment differs from the second embodiment in the configuration of a cap mechanism and a humidifying mechanism. Below, the same code | symbol is attached | subjected about the location same as 2nd Embodiment mentioned above, and the description is abbreviate | omitted suitably.

  In the humidification mechanism 350 in the present embodiment, the supply unit and the discharge unit are configured from a side cover 370. The side cover 370 surrounds the entire circumference of the head 1 and is a resin-made annular member. The side cover 370 includes a pair of long portions 371 along the main scanning direction and a pair of short portions 372 along the sub scanning direction. The long portion 371 has the same length as the side surfaces 1S1 and 1S2 of the head 1 in the main scanning direction. The pair of short portions 372 connects the pair of long portions 371.

  The upstream long portion 371 is fixed to the side surface 1S1 of the head 1. The upstream long portion 371 has a protruding portion 376a protruding upward. The protruding portion 376a is formed at the center of the upper surface of the upstream long portion 371 in the main scanning direction. A channel 377 a extending in the vertical direction is formed at the center of the upstream long portion 371. A flow path 378a extending in the main scanning direction is formed at the center in the vertical direction of the upstream long portion 371. The channel 377a passes through the center of the protrusion 376a and communicates with the channel 378a. The protruding portion 376 a is inserted through the through hole 13 a of the head holder 13 and connected to the pipe 54. There is a slight gap between the protruding portion 376a and the through hole 13a, but a sealing material or the like is filled.

  A plurality of supply holes 375a communicating with the flow path 378a are formed on the lower surface of the upstream long portion 371 (the lower side in FIG. 10B and the left side in FIG. 11). These supply holes 375a define a plurality of openings (supply ports) 365a and a plurality of guide paths 365b connected to the openings 365a. A supply port portion 365 is configured by the plurality of openings 365a. The humidified air flows to the flow paths 377a and 378a through the pipe 54. As shown in FIG. 10, the humidified air flows from the center to the left and right in the drawing in the flow path 378a and is supplied to the discharge space S1 from each supply hole 375a. The supply hole 375a (opening 365a and guide path 365b) and the two flow paths 377a and 378a constitute a supply flow path for supplying humidified air to the discharge space S1.

  The plurality of openings 365a are arranged at equal intervals along the main scanning direction. The two outermost openings 365a are on the outer side of the two outlets 108 on the outermost side of the discharge surface 1a. Note that the lower surface of the side cover 370 is entirely above the platen 6 relative to the ejection surface 1a and does not hinder the conveyance of the paper P.

  With respect to the main scanning direction, the mutually opposing inner side surfaces of the guide path 365b are inclined so as to be located on the outer side as they approach the opening 365a. Thereby, the humidified air supplied from the opening 365a to the discharge space S1 is supplied toward the outside in the main scanning direction. For this reason, much humidified air is supplied outside the center of the discharge space S1.

  Further, as shown in FIG. 11A, the guide path 365b of the supply hole 375a is also inclined toward the head 1 side (downstream side in the transport direction) so that the opening 365a faces the discharge space S1 (gap). ing. Thereby, the humidified air supplied from the opening 365a effectively flows downstream in the transport direction. For this reason, it is possible to further suppress drying of the plurality of ejection ports 108.

  The flow path resistance with respect to the air in the flow path 378a is made smaller toward the downstream side from the upstream side with respect to the flow direction of the humidified air (from the center to the outer side in FIG. 10). In the present embodiment, as shown in FIG. 10B, the opening area of the opening 365a increases from the upstream side (center in the figure) toward the downstream side (left and right sides in the figure). Thereby, a substantially equal amount of humidified air is supplied from each opening 365a.

  The downstream long portion 371 (upper side in FIG. 10B and right side in FIG. 11) is relative to a straight line in which the upstream long portion 371 extends in the main scanning direction passing through the center point Q of the ejection surface 1a. The configuration is the same as that arranged in line symmetry. The downstream long portion 371 is fixed to the side surface 1S2 of the head 1 and has a protruding portion 376b. The downstream elongate portion 371 is formed with a flow path 377b extending in the vertical direction and a flow path 378b extending in the main scanning direction and communicating with the flow path 377b. The protruding portion 376 b is inserted into the through hole 13 b of the head holder 13 and connected to the pipe 53. There is a slight gap between the protruding portion 376b and the through hole 13b, but a sealing material or the like is filled.

  A plurality of discharge holes 375 b communicating with the flow path 378 b are formed on the lower surface of the downstream long portion 371. These discharge holes 375b define a plurality of openings (discharge ports) 385a and a plurality of guide paths 385b connected to the openings 385a. The plurality of openings 385a constitute a discharge port portion 385. These openings 385a are arranged at equal intervals along the main scanning direction. The air in the discharge space S1 is discharged from each discharge hole 375b. The discharge hole 375b (opening 385a and guide path 385b) and the two flow paths 377b and 378b constitute a discharge flow path for discharging the air in the discharge space S1 to the outside.

  As shown in FIG. 10B, in the main scanning direction, the two outermost openings 385a are located outside the two outermost ejection ports 108 on the ejection surface 1a. With respect to the main scanning direction, the mutually facing inner surfaces of the guide path 385b are inclined so as to be located on the outer side as they approach the opening 385a.

  Further, as shown in FIG. 11A, the guide path 385b of the discharge hole 375b is inclined toward the head 1 side (upstream side in the transport direction) so that the opening 385a faces the discharge space S1 (gap). ing. As a result, the air in the discharge space S1 can be easily discharged.

  The flow path resistance with respect to the air in the flow path 378b is increased from the upstream side toward the downstream side in the direction of the flow of the humidified air (the direction from the outer side to the center in FIG. 10). In the present embodiment, the opening area of the opening 385a is smaller from the upstream side (outside in the figure) to the downstream side (center in the figure), like the opening 385a of the supply hole 375a. As a result, a substantially equal amount of air flows from each opening 385a.

  The cap mechanism 340 includes a partition member 341, a counter member 345, and a moving mechanism (not shown) that moves the counter member 345. The facing member 345 is a flat plate having a rectangular planar shape, and the outer size is substantially the same as that of the side cover 370. The partition member 341 is made of an annular elastic material such as rubber, and is erected integrally from the peripheral edge portion of the facing member 345.

  The moving mechanism moves the opposing member 345 under the control of the control device 100, and the relative position between the tip of the partition member 341 and the side cover 370 changes in the vertical direction. The tip of the partition member 341 is in contact with the peripheral edge of the lower surface of the side cover 370 as the opposing member 345 moves (position shown in FIG. 11 (b)), and is separated from the side cover 370. And selectively. When the partition member 341 comes into contact with the side cover 370, the discharge space S1 is partitioned from the external space S2 by the partition member 341, the opposing member 345, and the discharge surface 1a. Further, at the separation position, the discharge space S1 is opened from the external space S2.

  In the printer having the humidification mechanism 350 and the cap mechanism 340 described above, the humidification operation during recording and the humidification operation during pause are performed in the same manner as in the first embodiment.

  When the capping operation is performed, a path of humid air is formed in the partition member 341 in the short direction (sub scanning direction) of the head 1. Under the control of the control device 100, as shown in FIG. 11B, the partition member 341 is set to the contact position, and the discharge space S1 is partitioned from the external space S2.

  When the dampening humidifying operation is executed, humidified air is supplied to the discharge space S1 from the supply port 365 (opening 365a) under the control of the control device 100. The air in the discharge space S1 flows in the sub-scanning direction toward the discharge port 385 (opening 385a) while being replaced with humidified air. Air in the discharge space S1 is sucked out by the pump 58 and travels from the discharge port portion 385 to the tank 57. The air is humidified in the lower space of the tank 57 and moves to the upper space. The generated humidified air is supplied to the discharge space S1 while the pump 58 continues to be driven.

  When the uncapping operation is executed, the partition member 341 is set to the separation position under the control of the control device 100. As shown in FIG. 11A, the partition member 341 is in an open state in which the discharge space S1 is opened to the external space S2.

  If the humidifying operation during recording is performed when the image recording operation is performed, air flows in the same manner as in the humidifying operation during pause. That is, the humidified air is discharged from the plurality of openings 365 a of the supply port portion 365 to the discharge space S <b> 1 and supplied to the discharge port 108. Note that the movement of the humidified air from the opening 365a to the discharge port 108 is the same as in the first embodiment. For this reason, similarly to the first embodiment, drying of the discharge port 108 can be suppressed even in the uncapped state.

  Further, the humidified air is supplied from the openings 365a to the outer side in the main scanning direction with substantially the same amount. For this reason, much humid air is supplied to the outside of the center of the ejection space S1 in the main scanning direction. Accordingly, it is possible to effectively suppress drying of the ejection ports 108 on the outside where the frequency of use is low, and it is possible to suppress ink consumption due to a flushing operation or the like.

  As described above, also in the present embodiment, the humidifying operation is performed when the image recording operation is performed, as in the first and second embodiments. In this humidifying operation during recording, the humidified air supplied from the supply port 365 flows along the transport direction D (the short direction of the head) as the paper is transported. That is, it flows to the discharge port portion 85 via the discharge space S1 (gap). Thereby, even during the image recording operation (open state), drying of the plurality of ejection ports 108 can be suppressed. Further, at this time, the humidified air supplied from the supply port portion 365 is supplied more outside the center of the discharge space S1 in the main scanning direction. For this reason, it becomes possible to suppress the drying of the discharge port 108 on the outside where the frequency of use is low. Therefore, ink discharge due to flushing or the like can be suppressed. Note that the same effect can be obtained with the same configuration as in the first and second embodiments.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the first to third embodiments described above may be combined when possible. In the first embodiment, the first supply pipe 61 may be connected to the center of the second supply pipe 63, and the first discharge pipe 81 may be connected to the center of the second discharge pipe 83. In the second and third embodiments, the protrusions 276a, 276b, 376a, and 376b may be connected to the end portions of the upper surfaces of the pair of long portions 271 and 371, respectively.

  In the first to third embodiments, the air in the discharge space S1 is forcibly sucked from the discharge ports 85, 285, and 385. However, the discharge ports 85, 285, and 385 that simply communicate with the outside are provided. Thus, air may be naturally discharged from the space, or the discharge port portions 85, 285, and 385 may not be provided. Further, the plurality of openings constituting the supply ports 65, 265, and 365 are directed from the upstream side to the downstream side with respect to the flow direction of the humidified air if a large amount of humidified air is supplied to the outside of the center in the main scanning direction. It doesn't have to be big.

  In the above-described embodiment, the humidifying operation during recording is performed during the image recording operation. However, if the discharge space S1 is in the open state opened to the external space S2, the image recording operation is not performed. Sometimes it may be done. In other words, the humidifying operation is performed during the standby from when the partition state is set to the open state until the image recording operation is performed and during the standby period after the image recording operation is completed until the partition state is set. May be.

  The present invention can be applied to both a line type and a serial type, and is not limited to a printer, and can also be applied to a facsimile machine, a copier, and the like. Further, recording is performed by discharging a liquid other than ink. The present invention can also be applied to a liquid ejection apparatus that performs the above. The recording medium is not limited to the paper P, and may be various recording media. Furthermore, the present invention can be applied regardless of the ink ejection method. For example, although a piezoelectric element is used in this embodiment, a resistance heating method or a capacitance method may be used.

1 Inkjet head (head)
1a Discharge surface 1S1 Upstream side surface 1S2 Downstream side surface 6 Platen (opposing member)
8 Transport mechanism 40, 340 Cap mechanism 41, 341 Partition member 42 Lip member 44 Diaphragm 48 Cap lifting mechanism (lip moving mechanism)
50, 250, 350 Humidification mechanism 65, 265, 365 Supply port 65a Supply hole (opening and guide path)
85,285,385 Discharge port 100 Control device (control means)
101 Printer (Liquid ejection device)
108 Discharge port 265a, 365a Opening (supply port)
265b, 365b Guide path 273a Upstream fixed portion 273b Downstream fixed portion 274a Upstream flange 274b Downstream flange 275a Notch 345 Opposing member S1 Discharge space (gap)
S2 External space

Claims (11)

A transport mechanism for transporting the recording medium in the transport direction;
A head having a discharge surface in which a direction orthogonal to the transport direction is a longitudinal direction, and a plurality of discharge ports for discharging liquid onto a recording medium are arranged at equal intervals along the longitudinal direction;
A facing member that can face the discharge surface; and a partition member that divides a gap between the facing member and the discharge surface together with the facing member and the discharge surface from the external space including the plurality of discharge ports. A cap mechanism capable of taking a partition state in which the partition member partitions the gap from the external space and an open state in which the partition member opens the gap to the external space;
A humidification operation including a supply flow path having a supply port portion extending in the longitudinal direction along the upstream side surface of the head with respect to the transport direction, and performing a humidification operation for supplying humidified air from the supply port portion to the gap. Mechanism,
Control means for controlling the humidification mechanism to perform the humidification operation when the cap mechanism is in the open state and image recording on a recording medium is performed,
The supply flow path is configured such that humid air supplied to the gap from the supply port is supplied more on the outer side than the center of the gap in the longitudinal direction .
The supply flow path extends along the longitudinal direction;
The supply port portion is composed of a plurality of supply ports arranged along the longitudinal direction,
An opening area of the plurality of supply ports is larger as it goes from the upstream side to the downstream side with respect to the flow direction of the humidified air . 2. The liquid ejection apparatus according to claim 1 , wherein a separation distance between two supply ports adjacent to each other in the longitudinal direction decreases from the center toward the outside.   The supply channel communicates with the supply port and guides the humidified air to the supply port so that the humidified air supplied from the supply port to the gap is supplied toward the outside in the longitudinal direction. The liquid ejecting apparatus according to claim 1, further comprising a plurality of guide paths. A transport mechanism for transporting the recording medium in the transport direction;
A head having a discharge surface in which a direction orthogonal to the transport direction is a longitudinal direction, and a plurality of discharge ports for discharging liquid onto a recording medium are arranged at equal intervals along the longitudinal direction;
A facing member that can face the discharge surface; and a partition member that divides a gap between the facing member and the discharge surface together with the facing member and the discharge surface from the external space including the plurality of discharge ports. A cap mechanism capable of taking a partition state in which the partition member partitions the gap from the external space and an open state in which the partition member opens the gap to the external space;
A humidification operation including a supply flow path having a supply port portion extending in the longitudinal direction along the upstream side surface of the head with respect to the transport direction, and performing a humidification operation for supplying humidified air from the supply port portion to the gap. Mechanism,
Control means for controlling the humidification mechanism to perform the humidification operation when the cap mechanism is in the open state and image recording on a recording medium is performed,
The supply flow path is configured such that humid air supplied to the gap from the supply port is supplied more on the outer side than the center of the gap in the longitudinal direction .
The supply flow path extends along the longitudinal direction;
The supply port portion is composed of a plurality of supply ports arranged at equal intervals along the longitudinal direction,
The opening area of the plurality of supply ports is larger toward the downstream side from the upstream side with respect to the flow direction of the humidified air,
The supply channel communicates with the supply port and guides the humidified air to the supply port so that the humidified air supplied from the supply port to the gap is supplied toward the outside in the longitudinal direction. A liquid discharge apparatus having a plurality of guide paths . The cap mechanism is
An annular lip member surrounding the head, a partition member composed of a flexible diaphragm connecting the lip member and the head, a contact position where the lip member contacts the opposing member, and the lip member A lip moving mechanism for moving the lip member between spaced positions separated from the opposing member;
5. The liquid ejection apparatus according to claim 3 , wherein the control unit controls the humidification mechanism so as to perform the humidification operation when the gap is in the partitioned state. 6.   The humidified air supplied from the supply port arranged on the outermost side with respect to the longitudinal direction is supplied toward the tip of the lip member at the contact position. Liquid ejection device. On the upstream side surface of the head, there is a fixed portion to which the diaphragm is connected, and a flange portion that extends in the longitudinal direction and protrudes from the lower side of the fixed portion toward the upstream side in the transport direction. Provided,
The liquid ejection apparatus according to claim 5, wherein the supply port and the guide path are formed in the collar portion. A plurality of notches that define the supply port and the guide path between the surface and the lip member are formed on a surface of the collar portion facing the lip member,
8. The liquid according to claim 7, wherein inner surfaces of the notches facing each other in the longitudinal direction are inclined so as to be positioned on the outer side in the longitudinal direction as approaching the supply port. Discharge device.   The liquid ejecting apparatus according to claim 5, wherein a tip of the lip member is located below the ejection surface at the separation position. The liquid ejection apparatus according to claim 1 , wherein the supply port opens toward the gap. The humidification mechanism has a discharge port portion that extends in the longitudinal direction along the downstream side surface of the head with respect to the transport direction and has a discharge port portion disposed at a position sandwiching the plurality of discharge ports with the supply port portion. Including a flow path,
The control means controls the humidifying mechanism so as to perform an operation of supplying humidified air from the supply port portion to the gap and discharging air of the gap from the discharge port portion as the humidifying operation. The liquid ejection device according to claim 1.

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