JP2015063060A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge device which can suppress unevenness of liquid drying on a plurality of discharge ports.SOLUTION: A printer includes a head, a platen, a platen lifting mechanism, a cap mechanism, a humidifying mechanism, and a control device. The cap mechanism can be in a partitioned state of partitioning a discharge space opposite to a discharge surface of the head from an external space, and an opened state of opening the discharge space in the external space. The humidifying mechanism carries out humidification operation of supplying humidified air to either of supply ports 25a, 61 in the partitioned state. The platen lifting mechanism switches a supply destination of the humidified air during the humidification operation to either of the supply ports 25a, 61 by moving the platen. The control device controls the platen lifting mechanism so that the humidified air is supplied from the supply port 61 to the discharge space after the humidified air is supplied from the supply port 25a to the discharge space.

Description

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

  Patent Document 1 describes a liquid discharge device that humidifies a discharge space after isolating the discharge space facing the discharge port from the external space (after capping) when the head is not used (when the head is at rest). ing. 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

  In the liquid discharge device described in Patent Document 1, the air supply port and the air discharge port are arranged at positions sandwiching the head (that is, the discharge surface on which the discharge port is formed) in the longitudinal direction of the head. For this reason, the humidified air supplied from the air supply port moves a long distance along the longitudinal direction and is discharged from the air discharge port. At this time, the humidified air supplies moisture to the liquid in the vicinity of the discharge port in order from the discharge port on the upstream side, so the humidity of the humidified air decreases as it moves downstream. The humidity drop of the humidified air increases as the moving distance of the humidified air increases, and there is a large difference in liquid drying between the upstream side (air supply port side) and the downstream side (air discharge port side) at multiple outlets. Arise.

  An object of the present invention is to provide a liquid ejection apparatus capable of suppressing variations in liquid drying at a plurality of ejection ports.

  The liquid ejection apparatus of the present invention has a ejection surface in which a direction perpendicular to the conveyance direction of the recording medium is a longitudinal direction, and a plurality of ejection ports for ejecting liquid onto the recording medium are arranged at equal intervals along the longitudinal direction. A head, an opposing member that can oppose the ejection surface, and an ejection space between the opposing member and the ejection surface, including the opposing member and the ejection surface, includes the plurality of ejection ports and is partitioned from an external space A cap mechanism capable of taking a partition state in which the partition member partitions the discharge space from the external space and an open state in which the partition member opens the discharge space to the external space, and the partition A first supply port and a discharge port that are disposed across the plurality of discharge ports with respect to the longitudinal direction when viewed from a direction perpendicular to the discharge surface and communicated with the discharge space in a state, and the first Supply port and front A second supply port disposed between the discharge port, a humidification mechanism for performing humidification operation for supplying humidified air to the first supply port or the second supply port in the partitioned state, and humidification in the humidification operation A switching mechanism that switches the air supply destination from one of the first supply port and the second supply port to the other; and the humidification mechanism that controls the humidification operation when the discharge space is in the partitioned state. Control means for controlling the switching mechanism such that humidified air is supplied from one of the first supply port and the second supply port to the discharge space and then supplied from the other to the discharge space. And.

  According to the liquid ejection device of the present invention, when the ejection space is in the partitioned state, humidified air is supplied from one of the first supply port and the second supply port to the ejection space, and then the humidified air is supplied from the other to the ejection space. The The humidified air supplied from the first supply port and the second supply port to the discharge space flows toward the discharge port. At this time, since the second supply port is disposed at a position closer to the discharge port than the first supply port in the longitudinal direction, liquid drying of the discharge port near the discharge port is suppressed by humidified air from the second supply port. It becomes possible to do. For this reason, it is possible to suppress variations in liquid drying of the plurality of ejection ports.

1 is a schematic side view showing an internal structure of an ink jet printer according to an embodiment of a liquid ejection apparatus of the present invention. FIG. 2 is a plan view showing a head main body and a side cover of a head included in the printer of FIG. 1. FIG. 3A is an enlarged view showing a region surrounded by an alternate long and short dash line in FIG. 2, FIG. 3B is a partial cross-sectional view taken along line IIIb-IIIb in FIG. 3A, and FIG. It is an enlarged view which shows the area | region enclosed with the dashed-dotted line of (b). It is a fragmentary sectional view about the sub scanning direction of a cap mechanism and a head, and shows the situation where a lip member is in a separation position. It is a fragmentary sectional view about the sub-scanning direction of a cap mechanism and a head, (a) shows the situation where a lip member is in the 1st contact position, and (b) shows the situation where a lip member is in the 2nd contact position. . It is a fragmentary sectional view about the main scanning direction of a cap mechanism and a head, (a) shows the situation where a lip member is in a separation position, (b) shows the situation where a lip member is in the 1st contact position, (c ) Shows a situation where the lip member is in the second contact position. It is the schematic which shows the head holder and humidification mechanism which are included in the printer of FIG. It is a plane sectional view of a head, a side cover, and a cap, (a) shows the situation where a lip member is in the 1st contact position, and (b) shows the situation where a lip member is in the 2nd contact position. It is an operation | movement condition diagram for demonstrating operation | movement of a cap mechanism and a platen. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. It is a flowchart figure which shows a series of operation | movement flows regarding the purge operation | movement and humidification operation which the control apparatus of the printer of FIG. 1 performs. It is an operation | movement condition diagram for demonstrating purge operation | movement and wiping operation | movement. The modification of the side cover of the liquid discharge apparatus of this invention is shown, It is a plane sectional view of a head, a side cover, and a cap, (a) shows the situation where a lip member exists in a 1st contact position, (b) The situation where a lip member exists in the 2nd contact position is shown.

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

  First, an overall configuration of an ink jet printer 101 as an embodiment of the liquid ejection apparatus of 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. In the internal space of the housing 101a, there are 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. 7) used for a humidifying operation, a platen 10, and a platen lifting mechanism 30. (See FIG. 10), a head lifting mechanism 70 (see FIG. 10), a wiper unit 80 (see FIG. 12), a control device 100, and the like are accommodated.

  Further, in the internal space of the housing 101a, a transport path for transporting the paper P is formed from the paper feed tray 33 toward the paper discharge unit 31 along the thick black arrow shown in FIG. The printer 101 is of a line type that performs recording with the head 1 fixed.

  In the housing 101a, a cartridge 4 that stores black ink is detachably disposed with respect to the housing 101a. The cartridge 4 is connected to the head 1 via a tube (not shown) and a pump 1P (see FIG. 10). The pump 1P is driven when forcibly sending ink to the head 1 (that is, when purging or initial introduction of ink). Other than these, the pump 1P is in a stopped state, and does not interfere with the supply of ink and water to the head 1.

  The head 1 has a substantially rectangular parallelepiped shape elongated in the main scanning direction, and forms an image by ejecting ink based on a drive signal. The head 1 is supported by the housing 101 a via the head holder 13. The head 1 is a laminated body in which a reservoir unit 12 (see FIG. 4), a flexible printed circuit board (FPC), and the like are laminated in addition to the head main body 3 (see FIG. 2). The reservoir unit 12 as the upstream flow path member is formed with an upstream ink flow path (both not shown) including the reservoir, and ink is supplied from the cartridge 4. The reservoir temporarily stores ink.

  The flow path unit 11 as the downstream flow path member constitutes the head body 3 together with the actuator unit 19, and the ink of the reservoir unit 12 is supplied. The lower surface of the flow path unit 11 is a discharge surface 1a in which a plurality of discharge ports 108 are formed. Ink is ejected from the ejection port 108 by driving the actuator unit 19. The head 1 will be described in detail later.

  A signal from the control device 100 is converted into a drive signal by a driver IC 19a (see FIG. 10) on the FPC, and further output to the actuator unit 19 of the head body 3. When the drive signal is supplied, the actuator unit 19 applies pressure to the ink in the flow path unit 11.

  In addition to the head 1, a cap 41 constituting a cap mechanism 40 is attached to the head holder 13. The cap 41 is an annular member disposed in the head 1 and includes the head 1 in a plan view. The configuration, operation, function, and the like of the cap mechanism 40 will be described in detail later.

  The platen 10 is a flat plate-like member and faces the head 1 in the vertical direction (a direction perpendicular to the main scanning direction and the sub-scanning direction and perpendicular to the ejection surface). A predetermined gap suitable for recording is formed between the upper surface 10a of the platen 10 and the ejection surface 1a. The platen 10 has a plane size that is slightly larger than the ejection surface 1 a and the cap 41. Here, the main scanning direction is a direction orthogonal to the conveyance direction D of the paper P, and the sub-scanning direction is a direction parallel to the horizontal plane and orthogonal to the main scanning direction.

  The platen elevating mechanism (switching mechanism) 30 elevates the platen 10 and moves the platen 10 between the first position and the fourth position. As shown in FIGS. 1 and 9A, the first position is a position where the platen 10 is closest to the ejection surface 1a, and is a position where the platen 10 is disposed during image recording. Further, as shown in FIG. 9B, the first position corresponds to a contact position of a lip member 42 (described later) and is also related to a capping operation. As shown in FIGS. 9B and 9C, the second position has a separation distance between the upper surface 10a and the ejection surface 1a larger than the first position, and corresponds to the contact position of the lip member 42. This relates to the switching operation (described later). In the third position, as shown in FIG. 9C, this separation distance is larger than that in the second position, and is related to the wiping operation by the wiper 81b. In the fourth position, as shown in FIG. 9C, this separation distance is larger than that in the third position, which is related to the return of the base 82 to the standby position. In addition, the 3rd position and the 4th position are shown with the dashed-two dotted line in the figure.

  The paper sensor 32 is disposed upstream of the head 1 in the transport direction. The paper sensor 32 detects the leading edge of the paper P and outputs a detection signal to the control device 100.

  The paper feed tray 33 is a box having an open top surface and is detachable from the housing 101a. The sheet feed tray 33 can accommodate a plurality of sheets P.

  The transport mechanism 8 includes a paper feed roller 34, five feed roller pairs 35 to 39, and four guides 61 to 64. The paper feed roller 34 is rotated by the drive of a paper feed motor 34 </ b> M (see FIG. 10) under the control of the control device 100, and sends the uppermost paper P in the paper feed tray 33. The five feed roller pairs 35 to 39 are arranged in this order from the upstream side in the transport direction along the transport path. One roller of each of the feed roller pairs 35 to 39 is a drive roller that is rotated by the drive of feed motors 35M to 39M (see FIG. 10) under the control of the control device 100. The other roller is a driven roller that rotates as the drive roller rotates. The four guides 61 to 64 are alternately arranged with the feed roller pairs 35 to 39 in this order from the upstream side in the transport direction along the transport path. Each guide 61-64 consists of a pair of board arrange | positioned facing each other.

  The head elevating mechanism 70 moves the head 1 between the recording position and the retracted position by elevating a part of the head holder 13 and the cap mechanism 40 (excluding the platen 10 and the platen elevating mechanism 30). At the recording position, as shown in FIG. 1, the head 1 is positioned at the lower end of the moving range and faces the platen 10 at an interval suitable for image recording. At the retracted position (see FIG. 12C), the head 1 is positioned at the upper end of the moving range and is largely separated from the platen 10. The wiping position (see FIG. 12B) is between the recording position and the retracted position. At the wiping position and the retracted position, wipers 81a and 81b, which will be described later, can move in the space between the head 1 and the platen 10.

  As shown in FIG. 12, the wiper unit (wiping mechanism) 80 wipes the ejection surface 1a and the upper surface 10a of the platen 10 in the main scanning direction. Therefore, the wiper unit 80 includes two wipers 81a and 81b, and includes a base portion 82 and a wiper moving mechanism 83 that support the wipers. The wiper 81a is erected on the upper surface side of the base portion 82 and wipes the ejection surface 1a. The wiper 81b is erected on the lower surface side of the base portion 82 and wipes the upper surface 10a. The wiper moving mechanism 83 includes a pair of guides 84 and a drive motor 80M (see FIG. 10). When the drive motor 80M is driven under the control of the control device 100, the base 82 reciprocates along the guide 84. As shown in FIG. 12A, the left end side of the head 1 is the standby position of the base 82. In the wiping operation, the wipers 81a and 81b wipe the surface while moving rightward in the figure. The return of the base 82 to the standby position is performed after the head 1 is moved to the retracted position and the platen 10 is moved to the fourth position.

  The humidification mechanism 50 supplies humidified air to the discharge space S1 that faces the discharge surface 1a. The ejection port 108 that opens in the ejection space S1 is replenished with moisture in the internal ink, thereby suppressing thickening and drying.

  Next, the control device 100 will be described. The control device 100 controls the operation of each part of the printer and controls the operation of the entire printer 101. The control device 100 controls an image recording operation based on a recording command (image data or the like) supplied from an external device (such as a PC connected to the printer 101) 97. When receiving the recording command, the control device 100 drives the paper feed motor 34M for the paper feed roller 34 and the feed motors 35M to 39M for the feed roller pairs 35 to 39. The paper P delivered from the paper feed tray 33 is transported in the transport direction through the guides 61 to 64 while being sandwiched between the feed roller pairs 35 to 39. When the paper P passes directly under the head 1 while being supported by the upper surface 10a of the platen 10, ink is ejected from the ejection port 108 (see FIG. 2) toward the paper P under the control of the control device 100. The ink ejection operation from the ejection port 108 is performed based on the detection signal output from the paper sensor 32. The paper P on which the image is formed is discharged to the paper discharge unit 31 through an opening formed in the upper portion of the housing 101a.

  In addition, the control device 100 recovers and maintains the ink ejection characteristics of the head 1 through a maintenance operation. The maintenance operation includes, for example, a purge or flushing operation, a wiping operation of the discharge surface 1a and the upper surface 10a of the platen 10, a capping operation, a humidifying operation, and the like.

  In the purge operation, the pump 1P is driven and ink is forcibly discharged from all the ejection ports 108. At this time, the actuator is not driven. In the flushing operation, the actuator is driven and ink is ejected from the ejection port 108. The flushing operation is performed based on flushing data (data different from image data). In the wiping operation, the discharge surface 1a is wiped by the wiper 81a, and the upper surface 10a of the platen 10 is wiped by the wiper 81b (see FIG. 12B). The wiping operation is performed after the purge operation, and residual ink and foreign matter on the ejection surface 1a are removed. The discharge characteristics of the discharge port 108 are restored, and the discharge surface 1a is cleaned. Note that the wiping operation of the upper surface 10a is performed even after the flushing operation is performed.

  In the capping operation, as shown in FIGS. 5 and 7, the discharge space (gap between the discharge surface 1a and the platen 10) S1 is isolated from the external space S2 by the cap 41 (partition state). Capping suppresses drying of the ink meniscus.

  In the humidification operation, as shown in FIG. 7, humidified air is supplied to the discharge space S1 in the partitioned state. At this time, water vapor remains in the ejection space S1, and the drying of the ink is further suppressed. In the humidification operation in the present embodiment, the supply destination of the humidified air is switched from the supply port 25a to the supply port 61 (switching operation) until a predetermined time for supplying the humidified air elapses. This switching operation is performed by the platen elevating mechanism 30 elevating and lowering the platen 10 in the partitioned state.

  Next, the configuration of the head body 3 and the side cover 20 will be described with reference to FIGS. In FIG. 3A, the pressure chamber 110, the aperture 112, and the discharge port 108 that are to be indicated by broken lines below the actuator unit 19 are indicated by solid lines.

  As shown in FIG. 2, the head body 3 is a laminated body in which four actuator units 19 are fixed to the upper surface of the flow path unit 11. A pressure chamber 110 is opened on the upper surface. The actuator unit 19 seals this opening and constitutes the side wall of the pressure chamber 110.

  As shown in FIG. 3B, the flow path unit 11 is a laminated body in which nine stainless steel plates 122 to 130 are laminated. An ink flow path is formed inside the flow path unit 11. The ink flow path includes an upstream common ink flow path and a downstream individual ink flow path 132. The common ink flow path includes a manifold flow path 105 and a sub-manifold flow path 105a branched therefrom. The manifold channel 105 has an upper surface ink supply port 105b at one end. The individual ink channel 132 extends from the outlet of the sub-manifold channel 105a to the ejection port 108 of the ejection surface 1a through the aperture 112 and the pressure chamber 110. The ejection ports 108 are arranged at intervals corresponding to 600 dpi in the main scanning direction on the ejection surface 1a.

  The head 1 has a side cover 20. As shown in FIG. 2, the side cover 20 is an annular member that surrounds the entire circumference of the head body 3. The side cover 20 is a resin molding member, and is fixed across both side surfaces of the flow path unit 11 and the reservoir unit 12 as shown in FIGS. 4 and 6. The side cover 20 has an annular fixing part 23. The fixed portion 23 has a pair of long portions 23a and 23b extending in the main scanning direction and a pair of short portions 24a and 24b extending in the sub-scanning direction.

  The side cover 20 is a protruding portion that extends horizontally toward the outside, and has flange portions 25 and 28 connected to the lower end of the fixing portion 23. As shown in FIGS. 2 and 6, the flange portion 25 (second flange portion) protrudes from the long portions 23 a and 23 b in the sub-scanning direction. As shown in FIGS. 2 and 4, the flange portion 28 (first flange portion) protrudes from each of the short portions 24 a and 24 b in the main scanning direction. Both ends of the flange portion 25 in the main scanning direction and both ends of the flange portion 28 in the sub-scanning direction are connected to each other.

  As shown in FIG. 6, the long portion 23 a and the collar portion 25 constitute an L-shaped cross section. In addition, the elongate part 23b and the collar part 25 comprise the L-shaped cross section similarly. As shown in FIG. 2, each flange 25 has a supply port 25a that is formed at the center in the main scanning direction and penetrates in the thickness direction. The supply port 25a is disposed at a position overlapping the center of the two outermost discharge ports 108 in the main scanning direction. A partition wall 26 is fixed to each of the long portion 23 a and the flange portion 25, and the long portion 23 b and the flange portion 25. The partition wall 26 is disposed in the vicinity of the center of the flange portion 25 in the main scanning direction and above the supply port 25a in FIG. The partition wall 26 has an inclined surface 26a as shown in FIG. The inclined surface 26 a is inclined from the upper portion of the fixed portion 23 toward the tip of the flange portion 25.

  As shown in FIG. 4, each short part 24 a, 24 b has an upper protruding part 29 at the upper end part, and the short parts 24 a, 24 b and the collar part 28 constitute a substantially U-shaped cross section. Each upper protrusion 29 is a protrusion that extends horizontally toward the outside and has a through hole 51. The outward protrusion of the upper protrusion 29 is the same in each of the short portions 24a and 24b. On the other hand, the outward protrusion of the flange portion 28a on the left side in FIG. 4 is larger than the flange portion 28b on the right side in the drawing. The protrusion of the flange portion 28b and the upper protrusion portion 29 to the outside is substantially the same. That is, the protrusion 28 a has a larger outward protrusion than the upper protrusion 29. The protruding amounts of the flange portions 28a and 28b are related to the open states of a supply port 61 and a discharge port 62 which will be described later. On the upper surface of the upper projecting portion 29, a cylindrical connecting portion 29a is erected at the center in the sub-scanning direction, and the hollow portion 29b of the connecting portion 29a communicates with the through hole 51. Thus, the side cover 20 constitutes a part of the side surface of the head 1.

  Next, the actuator unit 19 will be described. As shown in FIG. 2, each of the four actuator units 19 has a trapezoidal planar shape, and is arranged in a staggered manner in the main scanning direction so as to avoid the ink supply ports 105b. Furthermore, the parallel opposing sides of each actuator unit 19 are along the main scanning direction, and the oblique sides of the adjacent actuator units 19 are overlapped along the sub-scanning direction.

  As shown in FIG. 3C, the actuator unit 19 is a lead zirconate titanate (PZT) ceramic having ferroelectricity, and is composed of three piezoelectric layers 141-143. The uppermost piezoelectric layer 141 has a plurality of individual electrodes 135 formed on its upper surface and is polarized in the thickness direction. A common electrode 134 is entirely formed on the upper surface of the piezoelectric layer 142. When an electric field in the polarization direction is generated between the electrodes 134 and 135, the piezoelectric layer 141 (driving active portion) therebetween contracts in the plane direction. Since the piezoelectric layers 142 and 143 are not spontaneously deformed, a strain difference occurs between the piezoelectric layers 141 and 141. Thereby, a portion sandwiched between the individual electrode 135 and the pressure chamber 110 protrudes toward the pressure chamber 110 (unimorph deformation). At this time, the ink in the pressure chamber 110 is pressurized and ejected as ink droplets.

  Thus, the actuator unit 19 has an actuator built for each individual electrode 135, and can independently apply ejection energy to the ink. Here, the common electrode 134 is always at the ground potential. The drive signal is selectively supplied from the individual land 136 to the individual electrode 135. The individual land 136 is at the tip of 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.

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

  The head holder 13 is a rigid frame-like frame made of metal or the like, and supports the side surface of the head 1 over the entire circumference. A cap 41 of a cap mechanism 40 is attached to the head holder 13. The contact portion between the head holder 13 and the head 1 is sealed with a sealant over the entire circumference. The contact portion between the head holder 13 and the cap 41 is also fixed with an adhesive over the entire circumference. As shown in FIG. 4, the head holder 13 is formed with a through hole 13a, and the connection portion 29a is inserted therethrough. The through-hole 13a is slightly larger than the connection portion 29a, and a gap formed with the connection portion 29a is filled with a sealant. Thereby, when the cap 41 isolates the discharge space S1 from the external space S2, the moisture diffusion path in the space S1 is reliably blocked.

  The cap mechanism 40 includes a platen 10 and a platen elevating mechanism 30 in addition to a cap 41 and a cap elevating mechanism 48 that elevates and lowers the cap 41. The cap 41 can include the side cover 20 and the discharge space S1 together with the head 1, and is long in the main scanning direction. As shown in FIGS. 4 and 6, the cap 41 includes a lip member 42 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 20. As shown in FIG. 4, the lip member 42 includes a base portion 42 x and a projecting portion 42 a having a triangular cross section below the base portion 42 x. A biasing portion 46 to be described later is fixed to the upper surface of the base portion 42x.

  The diaphragm 44 is also made of an annular elastic material such as rubber and surrounds the head 1 in a plan view. More specifically, the diaphragm 44 is a thin film member having flexibility, and an outer peripheral end (one end) is connected to an inner peripheral surface of the lip member 42. The lip member 42 and the diaphragm 44 are integral. The inner peripheral end of the diaphragm 44 is a close contact portion 44a. The upper surface of the contact portion 44a is fixed to the head holder 13 with an adhesive. The lower surface of the contact portion 44a is fixed to the upper surface of the fixing portion 33 with an adhesive over the entire length.

  The cap elevating mechanism (lip moving mechanism) 48 includes a movable body 43, an urging portion 46, a plurality of gears 45, and an elevating motor 48M (see FIG. 10). The movable body 43 is connected to a plurality of gears 45 as shown in FIG. The urging portion 46 is made of an elastic member that can expand and contract in the vertical direction, and is connected to the lower end of the movable body 43 and the upper end of the lip member 42. When the lifting motor 48M is driven under the control of the control device 100, the gear 45 rotates and the movable body 43, the urging portion 46, and the base portion 42x are moved 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.

  As the lip member 42 moves up and down the movable body 43 and the urging portion 46, the tip (projecting portion 42a) abuts against the upper surface 10a of the platen 10 (FIGS. 5, 6B and 6). The position shown in (c)) and the separation position (position shown in FIGS. 4 and 6A) separated from the upper surface 10a are selectively taken. The contact position includes a first contact position and a second contact position. The first abutting position is a position where the lip member 42 can abut on the upper surface 10a of the platen 10 at the first position in a state where the urging portion 46 is most contracted. The second contact position is a position where the lip member 42 can contact the upper surface 10a at the second position in a state where the urging portion 46 is extended more than the first contact position. The abutting force of the lip member 42 against the upper surface 10a is larger at the first abutting position than the second abutting position as much as the urging portion 46 is contracted, but at any position, The abutting force is such that the discharge space S1 becomes a sealed space. In the separated position, the protruding portion 42a is positioned above the discharge surface 1a with the urging portion 46 extended to the maximum, and the discharge space S1 is open to the external space S2.

  In the first and second contact positions, the long portion of the lip member 42 along the main scanning direction has an inner peripheral surface as shown in FIGS. 6 (b) and 6 (c). Contact the tip of the portion 25. At this time, a predetermined gap 18 is formed between each of the elongated portion of the diaphragm 44 along the main scanning direction and the fixing portions 23a and 23b and the flange portion 25. The gap 18 is divided into two gaps 18 a and 18 b by contact between the inclined surface 26 a of the partition wall 26 and the diaphragm 44. At this time, the short portion of the lip member 42 along the sub-scanning direction is separated from the front end of the collar portion 28 as shown in FIG. 5, and the supply port 61 and the discharge port 62 are formed therebetween. The supply port 61 and the discharge port 62 are disposed at positions sandwiching the ejection surface 1a and the supply port 25a in the main scanning direction. As shown in FIG. 5A, the short portion of the diaphragm 44 along the sub-scanning direction is curved in a U shape and separated from the side cover 20 at the first contact position, and the supply port 61 and the discharge port 62. Do not close. On the other hand, the short portion of the diaphragm 44 along the sub-scanning direction closes the supply port 61 by contacting the tip of the flange portion 28a at the second contact position as shown in FIG. And the discharge port 62 is maintained.

  Next, the configuration of the humidifying mechanism 50 will be described.

  As shown in FIG. 7, the humidifying mechanism 50 includes tubes 55 and 57, a pump 56, a tank 54 and the like in addition to the cap 41 and the side cover 20. One end of the tube 55 is fitted to the left side connection portion 29 a in the figure, and the other end is connected to the tank 54. On the other hand, one end of the tube 57 is fitted to the right connection portion 29a in the figure, and the other end is connected to the tank 54. Thus, the tubes 55 and 57 make the discharge space S1 and the tank 54 communicate with each other.

  The tank 54 stores water for humidification in the lower space, and stores humidified air in the upper space. The tube 57 communicates with the lower space (underwater) of the tank 54. On the other hand, the tube 55 communicates with the upper space of the tank 54. A pump 56 is provided in the middle of the tube 55. A check valve (not shown) is attached to the vicinity of the tank 54 of the tube 57 so that water in the tank 54 does not flow into the tube 57 side. Further, when the water in the tank 54 becomes low, water is supplied to the tank 54 from a water supply tank (not shown).

  In such a configuration, when the pump 56 is driven under the control of the control device 100, the air in the tank 54 circulates along the white arrow as shown in FIG. The humid air in the upper space of the tank 54 is supplied to the discharge space S1 through the opening 51a and the supply ports 25a and 61. At this time, if the discharge space S1 is in a partitioned state, the air inside flows through the discharge port 62 to the opening 51b while being replaced with humidified air. Since the tube 57 communicates with the tank 54 in water, the air in the discharge space S1 is humidified by the tank 54. The generated humidified air is supplied to the discharge space S1 while the pump 56 continues to be driven.

  In the present embodiment, when the lip member 42 is in the first and second contact positions (that is, in the partitioned state), as shown in FIG. 8 between the side cover 20 and the cap 41, Four air flow paths R1 to R4 are configured. As shown in FIG. 5, the air flow path R1 (second air flow path) is formed by being surrounded by the short portion 24a, the flange portion 28a, and the cap 41, and one end communicates with the opening 51a and is supplied to the other end. It has a mouth 61. Air flow paths R2 and R3 (third air flow paths) are gaps 18a formed between the long portions 23a and 23b and the flange portion 25 and the cap 41, as shown in FIG. Communicates with the air flow path R1 and has a supply port 25a at the other end. As shown in FIG. 5, the air flow path R <b> 4 is formed by being surrounded by the short portion 24 b and the flange portion 28 b and the cap 41, one end communicating with the opening 51 b, and the other end having a discharge port 62. Note that the air flow path R1 communicates with the air flow path (first air flow path) including the tube 55, the hollow portion 29b of the left connection portion 29a in FIG. The air flow path R4 communicates with the air flow path including the tube 57, the hollow portion 29b of the right connection portion 29a in FIG.

  Further, when the lip member 42 is in the first contact position, the supply port 61 and the discharge port 62 are not closed and are in an open state. As shown in FIG. 8A, the supply port 61 extends to both ends of the flange portion 28a in the sub-scanning direction. The discharge port 62 also extends to both ends of the flange portion 28b in the sub-scanning direction. On the other hand, as shown in FIG. 5B, when the lip member 42 is in the second contact position, the supply port 61 is closed and only the discharge port 62 is opened. As shown in FIGS. 5B and 8B, the supply port 61 is closed when the flange portion 28 a and the diaphragm 44 come into contact with each other. Although the opening area of the discharge port 62 is slightly smaller by approaching the flange portion 28b than when the diaphragm 44 is in the first contact position, the opening is maintained.

  Next, the flow of air in the cap 41 will be described. In the sealed state, when the lip member 42 is in the first contact position, when the pump 56 is driven, the humidified air is opened as shown by white arrows in FIGS. 5 (a) and 8 (a). 51a flows into the air flow path R1. At this time, since the opening area of the supply port 61 is larger than that of the supply port 25a, the flow resistance of the air flow path R1 is smaller than that of the air flow paths R2 and R3. For this reason, the humidified air hardly flows into the air flow paths R2 and R3, flows into the discharge space S1 from the entire supply port 61, and moves toward the discharge port 62. More specifically, the humidified air flows from the supply port 61 along the portion on the supply port 61 side of the lip member 42, passes through the region between the discharge surface 1 a and the platen 10, and the discharge port 62 of the lip member 42. Flows along the side edge. And it flows into air flow path R4 via the discharge port 62, and is discharged | emitted from the opening 51b.

  When the lip member 42 is in the second contact position, the supply port 61 is closed, so that the flow path resistance of the air flow path R1 is greater than that of the air flow paths R2 and R3. Therefore, the humidified air flows to the air flow paths R2 and R3 and flows into the discharge space S1 from the supply port 25a as indicated by the white arrows in FIGS. 5B and 8B. The humidified air supplied from the supply port 25a flows along the end of the lip member 42 on the discharge port 62 side through the region between the vicinity of the center of the discharge surface 1a and the platen 10. And it flows into air flow path R4 via the discharge port 62, and is discharged | emitted from the opening 51b.

  Next, the control device 100 will be described with reference to FIG. The control device 100 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, an ASIC (Application Specific Integrated Circuit) 94, and the like. The ROM 92 stores programs executed by the CPU 91, various fixed data, and the like. The RAM 93 temporarily stores data (image data and the like) necessary for executing the program. That is, the RAM 93 includes the image data storage unit 151. The ASIC 94 includes a head control circuit 152, a transport control circuit 153, and a maintenance control circuit 154. The ASIC 94 is connected to an external device 97 such as a PC (Personal Computer) via an input / output I / F (Interface) 96 so that data communication is possible.

  The image data storage unit 151 stores image data (recording command) from the external device 97. The head controller 152 controls the driver IC 19a based on the image data.

  The transport control circuit 153 controls the paper feed motor 34M and the feed motors 35M to 39M so that the paper P is transported at a predetermined speed along the transport direction based on the image data (recording command).

  The maintenance control circuit 154 controls the lifting motor 48M, the drive motor 80M, the head lifting mechanism 70, the platen lifting mechanism 30, and the pumps 1P and 56 in the maintenance operation.

  In the present embodiment, one CPU 91 performs processing related to various controls, but is not limited thereto. For example, a form in which a plurality of CPUs share processes related to various controls, a form in which an ASIC performs processes related to various controls, a process in which one or more CPUs and one or more ASICs cooperate, and processes related to various controls The form to perform etc. may be sufficient.

  Next, the control content of the purge operation and the humidification operation executed by the control device 100 will be described with reference to FIG.

  As shown in FIG. 11, the control device 100 first determines whether or not a purge command has been received (F1). Before receiving the purge command, the platen 10 is in the first position, the head 1 is in the recording position, and the lip member 42 is in the separated position. When receiving the purge command (F1: YES), the control device 100 executes the purge operation. At this time, the maintenance control circuit 154 controls the pump 1P and performs the purge operation of the head 1 as shown in FIG. 12A (F2). In the purge operation, a predetermined amount of ink in the cartridge 4 is forcibly sent to the head 1 by the pump 1P. Ink is discharged from the ejection port 108 toward the platen 10.

  Next, as shown in FIG. 12B, the maintenance control circuit 154 controls the head lifting mechanism 70 to move the head 1 to the wiping position, and controls the platen lifting mechanism 30 to move the platen 10 to the third position. Move to. Thereafter, the maintenance control circuit 154 controls the drive motor 80M to wipe the discharge surface 1a with the wiper 81a and wipe the upper surface 10a of the platen 10 with the wiper 81b (F3: wiping operation). Thereby, foreign matters such as ink adhering to the ejection surface 1a and the upper surface 10a are removed. After wiping, as shown in FIG. 12C, the maintenance control circuit 154 controls the head lifting mechanism 70 to move the head 1 to the retracted position, and controls the platen lifting mechanism 30 to move the platen 10 to the fourth position. The base 82 (wiper 81a, 81b) is returned to the standby position by moving to the position and controlling the drive motor 80M. Next, the maintenance control circuit 154 controls the head lifting mechanism 70 to move the head 1 to the recording position, and controls the platen lifting mechanism 30 to move the platen 10 to the first position.

  Subsequently, the control device 100 determines whether or not a capping command has been received (F4). Before receiving the capping command, the platen 10 is in the first position, the head 1 is in the recording position, and the lip member 42 is in the separated position. When receiving the cap signal (F4: YES), the control device 100 executes capping. At this time, the maintenance control circuit 154 drives the lifting motor 48M to bring the tip of the lip member 42 into contact with the upper surface 10a of the platen 10 (moving from the separation position to the first contact position) (F5). As a result, the discharge space S1 is separated from the external space S2 between the discharge surface 1a and the upper surface 10a (see FIG. 5A). Thereafter, the maintenance control circuit 154 controls the platen lifting mechanism 30 to move the platen 10 to the second position (F6). As the platen 10 moves, the lip member 42 moves downward as shown in FIG. At this time, the urging portion 46 extends from the most contracted state by the amount of movement of the platen 10. At this time, the diaphragm 44 contacts the flange portion 28a, and the supply port 61 is closed. That is, the flow path resistance of the air flow path R1 is greater than that of the air flow paths R2 and R3.

  Next, the maintenance control circuit 154 drives the pump 56 to execute a humidifying operation (F7). At this time, the humidified air from the tank 54 flows into the air flow path R1 from the opening 51a, flows into the air flow paths R2 and R3, and flows into the discharge space S1 from the supply port 25a. Then, the humidified air flows from the discharge port 62 to the opening 51 b and circulates again to the tank 54. At this time, it becomes possible to supply moisture to the ink of all the ejection ports 108 between the supply port 25a and the discharge port 62 in the main scanning direction. At this time, since the humidified air flows through the air flow paths R2 and R3, the ink that has entered the air flow paths R2 and R3 can be discharged from the supply port 25a to the platen 10. Further, moisture can be supplied to the discharged ink by the humidified air. As a result, it is possible to suppress the ink drying of the ejection port 108 caused by drying of the ink remaining in the air flow paths R2 and R3 (gap 18a).

  Before the humidification operation ends (in this embodiment, before the predetermined time has elapsed since the start of the humidification operation and when half of the predetermined time has elapsed since the start), the maintenance control circuit 154 The lifting mechanism 30 is controlled to move the platen 10 to the first position (F8: switching operation). As the platen 10 moves, the lip member 42 moves upward as shown in FIG. At this time, the urging portion 46 is in the most contracted state, and the diaphragm 44 is separated from the flange portion 28a. That is, the closed supply port 61 is opened, and the flow path resistance of the air flow path R1 is smaller than that of the air flow paths R2 and R3. For this reason, the flow of the humidified air to the air flow paths R2, R3 stops, and the humidified air flows into the discharge space S1 from the supply port 61 through the air flow path R1. Then, the humidified air flows from the discharge port 62 to the opening 51 b and circulates again to the tank 54. Thus, the supply destination of humidified air is switched by the rise of the platen 10. By supplying the humidified air from the supply port 61, as shown in FIG. 5A, the humidified air flows from one end (left end in the figure) to the other end (right end in the figure) of the lip member 42 in the main scanning direction. . For this reason, it becomes possible to supply moisture to the ink of all the ejection ports 108 between the supply ports 25a and 61 in the main scanning direction.

  When a predetermined time has elapsed from the start of the humidifying operation, the maintenance control circuit 154 stops driving the pump 56 and ends the humidifying operation (F9). Thereafter, when a signal such as a recording command is received from the external device 97, the control device 100 separates the lip member 42 from the upper surface 10a (moves from the first contact position to the separation position). Then, the head 1 is moved to the retracted position, the platen 10 is moved to the third position, and the wiping operation of the upper surface 10a is executed. Then, the platen 10 is returned to the first position and the head 1 is returned to the recording position, and the image recording operation is performed under the control of the control device 100 as described above.

  As described above, according to the printer 101 according to the present embodiment, when the discharge space S1 is in the partitioned state, humidified air is supplied from the supply port 25a to the discharge space S1, and then humidified from the supply port 61 to the discharge space S1. Air is supplied. The humidified air supplied from the supply ports 25a and 61 to the discharge space S1 flows toward the discharge port 62. At this time, since the supply port 25a is disposed at a position closer to the discharge port 62 than the supply port 61 in the main scanning direction, ink drying of the discharge port 108 in the vicinity of the discharge port 62 is performed by humidified air from the supply port 25a. Can be suppressed. For this reason, it is possible to suppress variations in ink drying of the plurality of ejection openings 108.

  In the partitioned state, the platen lifting mechanism 30 places the platen 10 in the first position, so that the air flow path R1 has a smaller flow resistance than the air flow paths R2 and R3, and the platen 10 is placed in the second position. As a result, the air passage R1 has a larger passage resistance than the air passages R2 and R3. For this reason, switching of the supply destination of the humidified air to the supply port 61 and the supply port 25a can be realized with a simple configuration. Further, the diaphragm 44 is separated from the flange portion 28a when the platen 10 is disposed at the first position, and the supply port 61 is opened, and when the platen 10 is disposed at the second position. The supply port 61 is closed in contact with the portion 28a. As described above, the diaphragm 44 opens and closes the supply port 61 according to the position of the platen 10, thereby realizing switching of the supply destination of the humidified air to the supply port 61 and the supply port 25 a. For this reason, it is not necessary to separately provide a mechanism (for example, a valve mechanism) only for switching the supply destination of the humidified air. Further, the supply port 61 is constituted by a gap between the flange portion 28a and the cap 41, the discharge port 62 is constituted by a gap between the flange portion 28b and the cap 41, and the supply port 25a is formed by each flange portion. It is comprised by the through-hole penetrated in the thickness direction formed in 25. FIG. Thus, by changing the position of the platen 10, the diaphragm 44 can be separated from the flange portion 28 a and the supply destination of the humidified air to the supply port 25 a and the supply port 61 can be switched. For this reason, the switching mechanism of the supply destination of humidified air can be realized with a simple configuration.

  Further, the air flow paths R2 and R3 are constituted by a gap 18a between the diaphragm 44 and the side surface of the head 1 (the fixed portions 23a and 23b and the flange portion 25). Thereby, when supplying humidified air from the supply port 25a to the discharge space S1, the humidified air flows to the supply port 25a through the gap 18a. For this reason, even if ink remains in the gap 18a, the ink can be discharged from the supply port 25a, and moisture can be supplied to the ink itself. Therefore, it is possible to suppress the ink drying of the ejection port 108 that occurs when the ink remaining in the gap 18a is dried.

  Further, the supply port 25a is arranged at a position overlapping with the center from the discharge port 108 on the outermost side (supply port 61 side) to the discharge port 108 on the other side (discharge port 62 side) in the main scanning direction. . As a result, the humidified air from the supply port 25a causes moisture to be applied to ink in the discharge port 108 from the discharge port 108 in the center to the discharge port 108 on the outermost side and on the discharge port 62 side in the main scanning direction. Can be supplied automatically. For this reason, it is possible to further suppress variations in ink drying of the plurality of ejection openings 108.

  In the humidification operation, humidified air is supplied from the supply port 25a to the discharge space S1, and then humidified air is supplied from the supply port 61 to the discharge space S1. As a result, the ink remaining in the air flow paths R2, R3 (gap 18a) is discharged, moisture is supplied to the ink itself, and then humidified air is supplied from the supply port 61 to the discharge space S1. For this reason, it becomes difficult for moisture remaining in the humidified air to be absorbed by the remaining ink, and ink drying at the ejection port 108 can be effectively suppressed.

  As a modification, as shown in FIG. 13, the supply port 25a may be disposed at a position overlapping the end of the discharge surface 1a on the discharge port 62 side in the main scanning direction. In this case, the partition walls 26 are formed at both ends of the fixed portion 24b in the sub-scanning direction. Thus, the gaps 18 formed between the long portion of the diaphragm 44 along the main scanning direction and the fixing portions 23a, 23b and the flange portion 25 are not divided by the partition walls, and each gap 18 is formed in the air flow path R2. , R3.

  In this configuration, similarly to the above-described embodiment, when the platen 10 is moved to the first contact position during the humidifying operation, the humidified air flows from the supply port 61 to the discharge space S1. That is, as shown by the white arrow in FIG. 13A, the humidified air flows from the supply port 61 along the portion of the lip member 42 on the supply port 61 side. Then, it passes through the region between the discharge surface 1 a and the platen 10, flows along the end of the lip member 42 on the discharge port 62 side, and is discharged from the discharge port 62.

  When the humidification operation is performed in a state where the platen 10 is disposed at the second contact position, the humidified air flows to the air flow paths R2 and R3 as shown by white arrows in FIG. It flows into discharge space S1 from 25a. At this time, since the air flow paths R2 and R3 are formed by the gap 18 that is not divided, even ink remaining in the gap 18b in the above-described embodiment can be discharged from the supply port 25a. That is, the remaining ink can be discharged from the entire gap between the side surface along the main scanning direction of the head 1 and the diaphragm 44, and moisture can be supplied to the ink itself. For this reason, it is possible to further suppress the ink drying of the ejection port 108 caused by drying of the ink remaining in the gap 18. The humidified air supplied from the supply port 25a passes through the region between the vicinity of the discharge port 62 of the discharge surface 1a and the platen 10 and flows along the end portion on the discharge port 62 side of the lip member 42 to discharge the discharge port. 62 is discharged.

  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, in the above-described embodiment and modification, the platen 10 is moved so that the diaphragm 44 is moved away from and in contact with the flange portion 28a to switch the supply destination of the humidified air. A switching valve as a switching mechanism may be provided at a connection point between R2 and R3, and humidified air may be supplied from one of the supply port 25a and the supply port 61 to the discharge space S1. In this case, it is desirable that the flow resistance of the air flow paths R2 and R3 is smaller than that of the air flow path R1. Further, the air flow paths R2 and R3 may be configured by a piping member instead of a gap between the side surface of the head 1 and the cap 41. Further, the air flow path R1 may also be configured by a piping member. If the opening area of the supply port 25a is larger than the cross-sectional area of the gap 18, the partition wall 26 may not be formed. Also in this case, the humidified air that has flowed to the gap 18 side is supplied from the supply port 25a to the discharge space S1 side.

  The supply port 61 and the discharge port 62 may be formed on the discharge surface 1a as long as all the discharge ports 108 can be sandwiched in the main scanning direction. The supply port 25a may be disposed between the discharge port 108 and the supply port 61 in the center with respect to the main scanning direction. Also in this case, since the supply port 25a is disposed closer to the discharge port 62 than the supply port 61, the same effects as those of the above-described embodiment can be obtained.

  Further, the lip member 42 may spread outward than at the second contact position by a force that expands outward by the folded portion of the diaphragm 44 that occurs at the first contact position. In other words, the lip member 42 is configured such that the folded portion of the diaphragm 44 generated at the first contact position extends at the second contact position, so that the lip member 42 contracts inward at the second contact position rather than the first contact position. Good. Even if such a cap is employed, the same effect as described above can be obtained.

  The present invention is not limited to a printer, but can be applied to a facsimile machine, a copier, and the like, and can also be applied to a liquid ejecting apparatus that performs recording by ejecting a liquid other than ink. 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 Head 1a Discharge surface 8 Transport mechanism 10 Platen (opposing member)
18, 18a Crevice 23 Fixing part 25 Eaves part (2nd eaves part)
25a supply port (second supply port)
28 buttock (first buttock)
30 Platen lifting mechanism (switching mechanism: opposing member moving mechanism)
40 Cap mechanism 41 Cap (partition member)
42 Lip member 44 Diaphragm 48 Cap lifting mechanism (lip moving mechanism)
50 Humidification mechanism 61 Supply port (first supply port)
62 Discharge port 100 Control device (control means)
101 Printer (Liquid ejection device)
108 Discharge port R1 Air flow path (second air flow path)
R2, R3 air flow path (third air flow path)
S1 Discharge space S2 External space

Claims (8)

A head having a discharge surface in which a plurality of discharge ports for discharging a liquid to the recording medium are arranged at equal intervals along the longitudinal direction, with a direction perpendicular to the conveyance direction of the recording medium as a longitudinal direction,
A facing member that can face the discharge surface, and a partition member that divides the discharge space between the facing member and the discharge surface together with the facing member and the discharge surface from the external space together with the plurality of discharge ports A cap mechanism capable of taking a partition state in which the partition member partitions the discharge space from the external space and an open state in which the partition member opens the discharge space to the external space;
A first supply port and a discharge port which are disposed across the plurality of discharge ports with respect to the longitudinal direction when viewed from a direction perpendicular to the discharge surface and communicated with the discharge space in the partitioned state; and A second supply port disposed between the first supply port and the discharge port;
A humidifying mechanism for performing a humidifying operation for supplying humidified air to the first supply port or the second supply port in the partitioned state;
A switching mechanism for switching the supply destination of the humidified air in the humidification operation from one of the first supply port and the second supply port to the other;
When the discharge space is in the partitioned state, the humidification mechanism is controlled to perform the humidification operation, and humidified air is supplied to the discharge space from one of the first supply port and the second supply port, A liquid ejection apparatus comprising: a control unit that controls the switching mechanism so that humid air is supplied to the ejection space from the other side. The humidifying mechanism is
A first air flow path to which humidified air is supplied, a second air flow path having one end communicating with the first air flow path and having the first supply port at the other end, and one end being the second air flow path And a third air flow path having the second supply port at the other end,
The switching mechanism makes the flow resistance of the second air flow path smaller than that of the third air flow path when supplying humidified air from the first supply port to the discharge space. The liquid ejection apparatus according to claim 1, wherein when humidified air is supplied to the ejection space, the flow resistance of the second air flow path is made larger than that of the third air flow path. 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, an abutting position where the lip member abuts the opposing member, and the lip member A lip moving mechanism for moving the lip member between spaced positions separated from the opposing member;
The switching mechanism is
A counter member moving mechanism that moves the counter member between a first position and a second position that is farther from the discharge surface than the first position in a direction perpendicular to the discharge surface;
The diaphragm closes the first supply port when the opposing member is in the second position and the lip member is in contact with the opposing member, and the diaphragm closes when the opposing member is in the first position. The liquid discharge apparatus according to claim 2, wherein the first supply port is opened.   4. The liquid ejection according to claim 3, wherein at least a part of the third air flow path is configured by a gap formed between a side surface of the head along the longitudinal direction and the diaphragm. apparatus.   5. The liquid according to claim 4, wherein the second supply port is arranged at a position overlapping with a center from one of the outermost discharge ports to the other of the discharge ports in the longitudinal direction. Discharge device.   The liquid discharge apparatus according to claim 4, wherein the second supply port is disposed at a position overlapping with an end portion of the discharge surface closest to the discharge port in the longitudinal direction.   The control means controls the switching mechanism such that humidified air is supplied from the first supply port to the discharge space after the humidified air is supplied from the second supply port to the discharge space. The liquid ejecting apparatus according to claim 4, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The head is
On the outer peripheral side surface of the head, an annular fixed portion to which the diaphragm is connected, and a pair of first flanges protruding outward along the longitudinal direction from below the both end portions in the longitudinal direction of the fixed portion, A pair of second flanges projecting outward along the transport direction from below both ends of the fixed portion in the transport direction, and having tips that contact the lip member when the discharge space is in the partitioned state; And
The first supply port is configured by a gap between one of the pair of first flanges and the partition member,
The discharge port is configured by a gap between the other of the pair of first flanges and the partition member,
8. The liquid ejection according to claim 3, wherein the second supply port is configured by a through portion that is formed in the pair of second flange portions and penetrates in the thickness direction. 9. apparatus.