JP5488487B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a liquid ejection apparatus that ejects liquid from ejection ports and records an image on a recording medium.

  Patent Document 1 describes an ink jet recording apparatus including a wiper unit having a wiper for wiping the discharge surface and a sponge provided on the surface of the wiper. In this ink jet recording apparatus, when the ejection surface is wiped with a wiper, ink that has flowed down along the surface of the wiper can be sucked with a sponge.

JP 2010-12739 A

  However, in the technique described in Patent Document 1, when the ejection surface of a head that ejects ink having a relatively high drying speed is wiped with a wiper, the ink attached to the tip of the wiper is thickened by drying, and the wiper May remain at the tip. As described above, in the current wiping of the ejection surface, if thickened ink remains on the tip of the wiper, dust or the like further adheres to the tip of the wiper via the thickened ink until the next time the ejection surface is wiped. . Then, at the next wiping of the discharge surface, foreign matter (thickened ink, dust, etc.) attached to the wiper moves to the discharge surface (that is, foreign matter adheres to or near the discharge port), and from the discharge port. This causes a problem that the ink discharge performance is deteriorated (discharge failure or discharge direction is disturbed).

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection device capable of removing liquid from the tip of a wiper while preventing thickening of the liquid attached to the wiper.

The liquid ejection apparatus of the present invention includes a liquid ejection head having an ejection surface in which an ejection port for ejecting liquid is formed, and a relative movement with respect to the ejection surface while being in contact with the ejection surface. A wiper that performs wiping for wiping, a humidified air supply mechanism that generates humidified air and discharges the humidified air from the discharge port, and a first facing position where the wiper is opposed to the discharge port. A movement mechanism that moves at least one of the wiper and the humidified air supply mechanism; and the movement mechanism is controlled so that the wiper faces the discharge port, and the wiper at the first opposed position and control means for controlling the humidified air supply mechanism to blow the humidified air to the tip, the discharge space facing the ejection surface with the discharge surface from the external space It includes a sealing state is released, and a cap means capable of taking a non-sealing state of opening the discharge space to the external space. The humidified air supply mechanism includes the discharge port for discharging the humidified air into the discharge space in the sealed state, and the suction port for sucking air in the discharge space, The control means controls the humidified air supply mechanism so that the humidified air circulates through the discharge space after controlling the cap means so that the discharge space is in the sealed state.

According to this, since it is possible to blow humid air on the tip of the wiper, it is possible to remove foreign matter (foreign matter such as thickening liquid or dust) adhering to the tip of the wiper without contact. In addition, by blowing humidified air to the wiper, for example, even if a quick-drying liquid adheres to the tip of the wiper, the liquid is removed from the tip of the wiper while preventing the liquid from thickening. It becomes possible. Therefore, it is possible to wipe the ejection surface in a state where no foreign matter is attached to the tip of the wiper, and the liquid ejection performance from the ejection port can be maintained. It is also possible to suppress the thickening of the liquid in the discharge port. Further, the humidified air that is blown to the tip of the wiper and the humidified air that is circulated to the discharge space in the sealed state can be supplied by the same humidified air supply mechanism. For this reason, the configuration of the apparatus can be simplified and downsized.

  In the present invention, it is preferable that the control means controls the moving mechanism so that the wiper faces the discharge port after the wiping is performed. As a result, it is possible to effectively remove foreign matter adhering to the tip of the wiper by wiping from the wiper.

  In the present invention, it is preferable that the control unit controls the moving mechanism so that the wiper faces the discharge port before the wiping is performed. As a result, it is possible to wipe the discharge surface in a state where foreign matter is not further adhered to the tip of the wiper.

  In the present invention, the moving mechanism may be at least one of the wiper and the humidified air supply mechanism so that the first opposed position and a second opposed position where the wiper is opposed to the suction port can be taken. The humidification air supply mechanism moves either one of the humidification air connected to the suction port and the discharge port so that the humidification air can be discharged from the suction port and air can be sucked from the discharge port. A switching mechanism for switching an air path, and with respect to a wiping direction for wiping the discharge surface with the wiper, the discharge port is disposed downstream of all the discharge ports formed on the discharge surface, A suction port is arranged upstream of all the discharge ports formed on the discharge surface, and the control means is in front of the second facing position immediately before the wiping is performed. The moving mechanism, the switching mechanism, and the humidified air are blown to the tip of the wiper, and immediately after the wiping is performed, the humidified air is blown to the tip of the wiper at the first facing position. It is preferable to control the supply mechanism. This makes it possible to discharge the humidified air from the suction port located upstream in the wiping direction, and shorten the time and the moving distance from the time when the humidified air is blown to the wiper until the discharge surface is wiped by the wiper. It becomes possible. And it becomes possible to spray humidified air on a wiper immediately after wiping by discharging humidified air from the discharge port located downstream in the wiping direction. By having such a switching mechanism, it becomes possible to easily blow humidified air onto the wiper immediately before and after wiping.

In the present invention, the suction port and the discharge port are disposed at a position sandwiching the liquid discharge head, and the humidified air is discharged in the same direction as the liquid discharge direction from the discharge port. preferable.
In the present invention, the suction port and the discharge port are disposed at a position sandwiching the liquid discharge head, and the humidified air is discharged in a direction intersecting the liquid discharge direction from the discharge port. Is preferred.
As a result, the wiper can be easily opposed to the suction port, the discharge surface, and the discharge port in this order.

  In the present invention, the cap means includes an opposing member having an opposing surface that opposes the ejection surface, and the discharge port and the suction port. It is preferable to have an annular member that is isolated from the external space. Thereby, a cap means comprises a sealing state by making the front-end | tip of an annular member contact | abut on an opposing surface.

According to the liquid ejection device of the present invention, it is possible to blow humidified air on the tip of the wiper, so it is possible to remove foreign matters (foreign matters such as thickened liquid and dust) adhering to the tip of the wiper without contact. It becomes. In addition, by blowing humidified air to the wiper, for example, even if a quick-drying liquid adheres to the tip of the wiper, the liquid is removed from the tip of the wiper while preventing the liquid from thickening. It becomes possible. Therefore, it is possible to wipe the ejection surface in a state where no foreign matter is attached to the tip of the wiper, and the liquid ejection performance from the ejection port can be maintained. It is also possible to suppress the thickening of the liquid in the discharge port. Further, the humidified air that is blown to the tip of the wiper and the humidified air that is circulated to the discharge space in the sealed state can be supplied by the same humidified air supply mechanism. For this reason, the configuration of the apparatus can be simplified and downsized.

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. It is a top view which shows the flow-path unit and actuator unit of the inkjet head contained in the printer of FIG. FIG. 3 is an enlarged view showing a region III surrounded by an alternate long and short dash line in FIG. 2. FIG. 4 is a partial cross-sectional view taken along line IV-IV in FIG. 3. It is the schematic which shows the head holder and humidified air supply mechanism which are included in the printer of FIG. FIG. 6 is a schematic perspective view of the joint shown in FIG. It is the schematic which shows the modification of the humidified air supply mechanism of the liquid discharge apparatus of this invention. FIG. 6 is a partial cross-sectional view showing a region VI surrounded by a one-dot chain line in FIG. 5, (a) is a diagram showing a situation where the cap is in a separated position, and (b) is a situation showing that the cap is in a contact position. FIG. It is a figure which shows the inkjet head of 1 and the wiper unit etc. corresponding to this, (a) is a fragmentary side view, (b) is a fragmentary sectional view along the VIIB-VIIB line | wire of FIG. ) Is a cross-sectional view of the wiper unit. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. It is a figure which shows the condition of the wiping operation | movement of a printer. It is a flowchart which shows the control content of the wiping operation | movement which the control apparatus of a printer performs. It is a flowchart which shows the control content of the capping and humidification maintenance operation | movement which the control apparatus of a printer performs.

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

  First, an overall configuration of an inkjet printer 1 according to an embodiment of the liquid ejection apparatus of the present invention will be described with reference to FIG.

  The printer 1 has a rectangular parallelepiped casing 1a. A paper discharge unit 31 is provided on the top of the casing 1a. The internal space of the housing 1a can be divided into spaces A, B, and C in order from the top. In the spaces A and B, a paper transport path from the paper feed unit 1b to the paper discharge unit 31 is formed. In the space A, image formation 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. In the space C, ink is supplied to the head 10 in the space A.

  In the space A, a paper sensor 32, four heads 10, a conveyance unit, a guide unit 29 for guiding the paper P, a humidified air supply mechanism 50 used for humidification maintenance (see FIG. 5), and a wiper unit 70 (see FIG. 7). A moving mechanism 80 (see FIG. 7) for moving the wiper unit 70, a control device 1p, and the like are arranged. The transport unit is composed of four platens 7 disposed to face each of the four heads 10 and four feed roller pairs 24 disposed along the paper transport path. Transport in the direction of the arrow (transport direction).

  The heads 10 are arranged at a predetermined pitch in the sub-scanning direction and are supported by the housing 1a via the head holder 3 (see FIG. 5). The head holder 3 holds the head 10 so that a predetermined gap suitable for recording is formed between the lower surface (ejection surface 10a) of the head 10 and the upper surface (opposing surface 7a) of the platen 7. The head holder 3 is provided with an annular cap 40 (annular member) in the vicinity of the lower end of the head 10 for each head 10. The cap 40 includes the head 10 in a plan view and surrounds the ejection surface 10a. A wiper unit 70 (see FIG. 7) is disposed corresponding to each head 10. The configuration, operation, function, and the like of the cap 40 and the wiper unit 70 will be described in detail later.

  A guide unit 29 is disposed across the transport unit. The guide section 29 on the upstream side in the transport direction includes a guide and two feed roller pairs 22 and 23, and connects the paper feed unit 1b (described later) and the transport section. The sheet P for image formation is conveyed toward the conveyance unit. The downstream guide unit 29 includes a guide and three feed roller pairs 25 to 27, and connects the transport unit and the paper discharge unit 31. The paper P after image formation is conveyed toward the paper discharge unit 31.

  In the space B, the paper feeding unit 1b is arranged. The paper feed unit 1 b includes a paper feed tray 20 and a paper feed roller 21. Among these, the paper feed tray 20 is detachable from the housing 1a. The paper feed tray 20 is a box that opens upward, and can store a plurality of papers P. The paper feed roller 21 sends out the uppermost paper P in the paper feed tray 20.

  Here, the sub-scanning direction is a direction parallel to the paper conveyance direction conveyed by the pair of feed rollers 23 and 24, and the main scanning direction is a direction parallel to the horizontal plane and orthogonal to the sub-scanning direction.

  In the space C, the cartridge unit 1c is detachably attached to the housing 1a. The cartridge unit 1 c includes a tray 35 and four cartridges 39 accommodated in the tray 35 side by side. The four cartridges 39 contain magenta, cyan yellow, or black ink. Each cartridge 39 is connected to the head 10 via a tube (not shown), and supplies ink of a color corresponding to the head 10.

  Next, the control device 1p will be described. The control device 1p controls the operation of each part of the printer 1 and controls the operation of the entire printer 1. The control device 1p controls an image forming operation based on image data supplied from an external device (such as a PC connected to the printer 1). Specifically, the control device 1p controls a preparation operation related to recording, a paper P supply / conveyance / discharge operation, an ink ejection operation synchronized with the conveyance of the paper P, and the like. The control device 1p also controls a maintenance operation for the head 10.

  The control device 1p, based on the recording command received from the external device, the paper feed motor 125 for the paper feed roller 21 (see FIG. 8), the feed motor 127 for each of the feed roller pairs 22 to 27 (see FIG. 8), etc. Drive. The paper P sent out from the paper feed tray 20 is guided by the upstream guide unit 29 and sent to the transport unit. In the transport unit, the paper P is sequentially supported and transported by the facing surface 7 a of the platen 7. When the paper P passes directly below each head 10 in the sub-scanning direction (paper transport direction), the control device 1p controls to sequentially eject ink from each ejection surface 10a toward the surface of the paper P. A color image is formed on top. The ink ejection operation is performed based on a detection signal from the paper sensor 32 that detects the leading edge of the paper P. Then, the paper P on which the image is formed is guided by the guide unit 29 on the downstream side, and is discharged to the paper discharge unit 31 from the opening 30 formed in the upper part of the housing 1a.

  The control device 1p prepares for recovery / maintenance of the ink ejection characteristics of the head 10 and recording by a maintenance operation. The maintenance operation includes an ink discharging operation by purging or flushing, a cleaning operation of the ejection surface 10a by wiping, an ink thickening preventing operation by capping or humidification, and the like.

  In purging, the pump is driven and ink is forcibly discharged from all the ejection openings 14a. In flushing, the actuator is driven and ink is ejected (discharged) from all the ejection ports 14a. Ink ejection is performed based on flushing data (data different from image data). In wiping, the discharge surface 10a is wiped by the wiper 71 (see FIG. 9B). The wiping is performed after the ink discharging operation, and residual ink and foreign matters on the ejection surface 10a are removed. In capping, the cap 40 isolates the discharge space (space facing the discharge surface 10a) S1 from the external space S2. In humidification, humidified air is supplied to the isolated discharge space S1.

  The ink discharge operation is accompanied by a cleaning operation, and foreign matter in the head 10 and thickened ink near the discharge port 14a are discharged. The discharge characteristics of the discharge port 14a are restored, and the discharge surface 10a is cleaned. The capping suppresses drying of the meniscus, and the humidification further suppresses drying. The ink discharging operation is performed, for example, immediately after the printer 1 is turned on, after a paper jam (clogging) in the transport path, after image formation that has continued for a predetermined period, or after non-ejection that has continued for a predetermined period of time. The ink discharge operation (particularly flushing) immediately after the power is turned on is a preparatory operation for recording. The ink thickening prevention operation is performed, for example, when the printer 1 is stopped or stopped.

  Next, the configuration of the head 10 will be described with reference to FIGS. In FIG. 3, the pressure chamber 16 and the aperture 15 that are located below the actuator unit 17 and should be indicated by broken lines are indicated by solid lines.

  The head 10 has a substantially rectangular parallelepiped shape, and is a laminated body in which a circuit board, a reservoir unit 11, an actuator unit 17 (see FIG. 2), and a flow path unit 12 (see FIG. 5) are sequentially laminated. The reservoir unit 11 is formed with an upstream ink flow path including a reservoir, and ink is supplied from the outside. The reservoir temporarily stores ink.

  As shown in FIG. 4, the flow path unit 12 is a stacked body in which nine rectangular metal plates 12 a to 12 i are stacked. A downstream ink flow path is formed in the flow path unit 12. The downstream ink flow path is connected to the upstream ink flow path through the opening 12y of the upper surface 12x. As shown in FIGS. 2 to 4, the downstream side ink flow path includes a manifold flow path 13 having an opening 12 y as one end, a sub-manifold flow path 13 a branched from the manifold flow path 13, and many connected to the sub-manifold flow path 13 a. Individual ink flow paths 14. The individual ink flow path 14 includes an aperture (throttle) 15 that adjusts the flow resistance, and extends from the outlet of the sub-manifold flow path 13a through the pressure chamber 16 to the discharge port 14a. In the upper surface 12x, the pressure chambers 16 are opened and arranged in a matrix. The lower surface is a discharge surface 10a on which the discharge port 14a is disposed.

  The actuator units 17 are sandwiched between the reservoir unit 11 and the flow path unit 12 and are arranged in a staggered manner along the main scanning direction. The actuator unit 17 is fixed to the upper surface 12 x of the flow path unit 12 and seals the opening of each pressure chamber 16. The actuator unit 17 is a laminate in which a piezoelectric layer (uppermost layer) polarized in the thickness direction is laminated on a piezoelectric layer that does not spontaneously deform. The uppermost layer is sandwiched between a number of individual electrodes on the surface side and an inner common electrode. When the portion sandwiched between one individual electrode and the common electrode is distorted, the portion sandwiched between the individual electrode and the pressure chamber undergoes unimorph deformation. The portion that undergoes unimorph deformation acts as an individual actuator and is selectively driven by a drive signal.

  The circuit board and the actuator unit 17 are electrically connected by the FPC 19. The FPC 19 has a driver IC mounted in the middle. Under the control of the control device 1p, the FPC 19 transmits various signals (control signals, image signals, etc.) relayed and adjusted on the circuit board to the driver IC, and transmits the drive signals generated by the driver IC to the corresponding individual actuators. To do.

  Next, the configuration of the head holder 3, the cap 40 attached to the head holder 3, and the joint 51 will be described with reference to FIGS.

  The head holder 3 is a frame made of metal or the like, and supports the side surface of the reservoir unit 11 over the entire circumference. The head holder 3 is provided for each head 10, and a cap 40 and a pair of joints 51 are attached thereto. As shown in FIG. 5A, the pair of joints 51 constitute a circulation flow path of the humidified air supply mechanism 50 and are disposed close to one end and the other end of the corresponding head 10 in the main scanning direction. More specifically, in FIG. 5, the pair of joints 51 includes a left joint 51 having a discharge port 51 a and a right joint 51 having a suction port 51 b, and the discharge port 51 a and the suction port 51 b are connected to the head 10. Are arranged at positions sandwiching the main body in the main scanning direction.

  The configuration and arrangement form of the joint 51 is the object on the left and right in FIG. For example, as shown in FIGS. 5B and 6, the left joint 51 includes a base end portion 51 x and a tip end portion 51 y extending from the base end portion 51 x and has a substantially rectangular tube shape. The proximal end portion 51x has a substantially rectangular parallelepiped shape, and when viewed in the Z direction in FIG. 5B, the proximal end portion 51x includes a distal end portion 51y. The distal end portion 51y is composed of an enlarged diameter portion 51m and a cylindrical portion 51n connected to the proximal end portion 51x. The enlarged diameter portion 51m is tapered in the Z direction in FIG. 5B, and a cylindrical portion 51n is connected to the tapered tip. The left joint 51 is long in the X direction in FIG. 5B, and this longitudinal direction is arranged parallel to the sub-scanning direction. As shown in FIG. 6, a slit-like through hole 3 a is formed in the head holder 3 near one end in the main scanning direction of the head 10. The through hole 3a is long in the sub-scanning direction. The left joint 51 is fixed to the head holder 3 with the tip 51y inserted into the through hole 3a. The tip 51y is slightly smaller than the through hole 3a, but the gap between the two is filled with a sealing material or the like and sealed.

  Inside the left joint 51, a hollow space 51z extending from the distal end portion 51y to the proximal end portion 51x is formed. The hollow space 51z connects the circular opening on the cylindrical part 51n side and the rectangular opening (discharge port 51a) on the base end part 51x side. The discharge port 51a is elongated in the sub-scanning direction. Inside, the columnar space on the cylindrical portion 51n side is connected to the funnel-shaped space on the enlarged diameter portion 51m side. The connecting portion between the spaces is closer to the enlarged diameter portion 51m than the joint between the cylindrical portion 51n and the enlarged diameter portion 51m. With respect to the main scanning direction, the size of the hollow space 51z is constant. The columnar space is mainly formed in the columnar portion 51n, and the funnel-shaped space gradually expands from the connecting portion between the spaces toward the opening on the base end portion 51y side. The discharge port 51 a is disposed closer to the reservoir unit 11 than the discharge surface 10 a and is slightly longer than the wiper 71.

  In the humidification of the maintenance operation, humidified air is supplied from the discharge port 51a of the left joint 51 to the discharge space, and air is sucked out from the suction port 51b of the right joint 51 (opening on the base end portion 51x side of the right joint). Further, as will be described later, in the cleaning operation, humidified air is blown from the discharge port 51a and the suction port 51b to the entire tip of the wiper 71. The humidified air is discharged from the discharge port 51a or the suction port 51b in the ink discharge direction.

  The cap 40 is an annular member that surrounds the outer periphery of the head 10 in plan view, and includes an elastic body 41 supported by the head holder 3 and a movable body 42 that can be raised and lowered. Further, the cap 40 includes a discharge port 51a and a suction port 51b as shown in FIG.

  The elastic body 41 is made of an annular elastic material such as rubber and surrounds the head 10 in plan view. As shown in FIG. 6, the elastic body 41 includes a base portion 41x, a protruding portion 41a protruding downward from the base portion 41x, a fixing portion 41c fixed to the head holder 3, and a connection for connecting the base portion 41x and the fixing portion 41c. Part 41d is included. Among these, the protrusion part 41a protrudes from the lower surface of the base part 41x, and a cross section is a triangle. The cross section of the fixed portion 41c is T-shaped. The upper end portion of the fixing portion 41c is fixed to the head holder 3 via an adhesive or the like. The fixing portion 41 c is also sandwiched between the head holder 3 and the base end portion 51 x of each joint 51 in the vicinity of each through hole 3 a. The connection part 41d extends outward (in a direction away from the ejection surface 10a in plan view) while being curved from the lower end of the fixed part 41c, and is connected to the lower end of the base part 41x. The connecting portion 41d can be deformed as the movable body 42 is raised and lowered. A concave portion 41 b is formed on the upper surface of the base portion 41 x and is fitted to the lower end of the movable body 42.

  The movable body 42 is made of an annular rigid material (for example, stainless steel) and is a frame that surrounds the outer periphery of the head 10 in plan view. The movable body 42 is movable relative to the head holder 3 in the vertical direction while being supported by the head holder 3 via the elastic body 41. Specifically, the movable body 42 is connected to a plurality of gears 43. When the lifting motor 44 (see FIG. 8) is driven under the control of the control device 1p, the gear 43 rotates and moves up and down. At this time, the base 41x also moves up and down together with the movable body 42. During this time, the head holder 3 (head 10) does not move. Thereby, the relative position of the front-end | tip 41a1 of the protrusion part 41a and the discharge surface 10a changes to a perpendicular direction. In the printer 1, only one lifting motor 44 is provided. When the lifting motor 44 is driven, the movable body 42 of each cap 40 is lifted and lowered by a transmission mechanism including a plurality of gears 43.

  The protrusion 41a has a contact position where the tip 41a1 contacts the facing surface 7a (position shown in FIG. 6B) and a separation position where the tip 41a1 is separated from the facing surface 7a (position shown in FIG. 6A). And selectively. When the protrusion 41a is in the contact position, the discharge space S1 formed between the discharge surface 10a and the facing surface 7a of the platen 7 is in a sealed state isolated from the external space S2. Moreover, when the protrusion 41a is at the separation position, the discharge space S1 is in an unsealed state opened to the external space S2. Such a cap 40 (annular member), the transmission mechanism, the head holder 3, the lifting motor 44, and the platen (opposing member) 7 constitute a cap means for each head 10.

  Next, the configuration of the humidified air supply mechanism 50 will be described with reference to FIG.

  As shown in FIG. 5A, the humidified air supply mechanism 50 includes a joint 51, tubes 55 and 57, pumps 53 and 56, a water temperature sensor 46, a heater 58, a tank 54, and the like. Each of the tubes 55 and 57 includes main portions 55 a and 57 a common to the four heads 10, and four branch portions 55 b and 57 b branched from the main portions 55 a and 57 a and extending to the joint 51. The pump 53 is provided in the main part 55a, and the pump 56 is provided in the main part 57a. In FIG. 5A, a connection state between one set of branch portions 55b and 57b and one head 10 is shown. Actually, four heads 10 are connected in parallel to one main portion 55a, 57a.

  One end of the tube 55 (the tip of the branching portion 55 b) is fitted to the tip portion 51 y of the left joint 51 provided in the head holder 3, and the other end is connected to the tank 54. On the other hand, one end of the tube 57 (the tip of the branching portion 57 b) is fitted to the tip 51 y of the right joint 51 provided in the head holder 3, and the other end is connected to the tank 54.

  The tank 54 stores water in the lower space, and stores humidified air humidified by the water in the lower space in the upper space. The tubes 55 and 57 communicate with the upper space of the tank 54. Further, a water temperature sensor 46 for measuring the temperature of water is installed in the tank 54, and a heater 58 for heating water in the tank 54 is installed in the vicinity of the tank 54 (lower space). During humidification, the heater 58 is controlled based on the temperature detection result by the water temperature sensor 46 under the control of the control device 1p, and the humidity of the humidified air is adjusted. In the present embodiment, when the printer 1 is turned on, the humidity of the humidified air is automatically adjusted to a desired humidity. When the amount of water stored in the tank 54 is reduced, water is supplied from a supply tank (not shown).

  In this configuration, when the pump 53 is driven under the control of the control device 1p, humidified air or air flows along the white arrow in FIG. The humid air in the upper space flows from the tank 54 toward the discharge port 51a. At this time, a negative pressure is generated in the tank 54, and air is sucked from the suction port 51b. This air flows toward the tank 54. In addition, when the pump 53 is driven, the pump 56 is not driven and is an air path.

  On the other hand, when the pump 56 is driven under the control of the control device 1p, humidified air or air flows along the black arrows in FIG. The humid air in the upper space flows from the tank 54 toward the suction port 51b. At this time, a negative pressure is generated in the tank 54, and air is sucked from the discharge port 51a. This air flows toward the tank 54. In addition, when the pump 56 is driven, the pump 53 is not driven and is a path for humidified air. As described above, the humidified air supply mechanism 50 is a switching mechanism that switches the path (flow direction) of the humidified air so that the humidified air can be discharged from the suction port 51b and the air can be sucked from the discharge port 51a. The pump 56 is provided.

  In the humidified air supply mechanism 50 of the present embodiment, the two pumps 53 and 56 are provided, but the path (flow direction) of the humidified air may be switched by one pump. In this case, the number of pumps is reduced, the configuration of the humidified air supply mechanism is simplified, and the size is reduced.

FIG. 5C shows a humidified air supply mechanism 500 with one pump. Two three-way valves 59 and 60 are used as a path switching mechanism, and the humidified air supply mechanism 50 is different in that the main portion 57a of the tube 57 is opened in water.
The three-way valve 59 has three connection ports a, b, and c, and is inserted into the branching portion 55b. The connection port a is connected to the upstream portion of the branch portion 55b, and the connection port b is connected to the downstream portion thereof. A switching portion 55c is connected to the connection port c and communicates with a downstream portion of the branch portion 57b. For the three-way valve 59, one of the connection port b and the connection port c is selected as a communication destination of the connection port a under the control of the control device 1p. The three-way valve 60 is inserted in the branch part 57b, and the connection form with respect to the path is the same as that of the three-way valve 59.

In this configuration, the pump 53 is driven under the control of the control device 1p.
When the connection port b is selected as the communication destination of the connection port a, humidified air or air flows along the white arrow in FIG. The humid air in the upper space is discharged from the discharge port 51a through the three-way valve 59 and the downstream portion of the branch portion 55b. At this time, a negative pressure is generated in the tank 54, and air is sucked from the suction port 51b. The air is discharged into the water in the tank 54 through the downstream portion of the branch portion 57b and the three-way valve 60.
On the other hand, when the connection port c is selected as the communication destination of the connection port a, humidified air or air flows along the black arrows in FIG. The humid air in the upper space is discharged from the suction port 51b through the three-way valve 59 through the switching unit 55c. At this time, a negative pressure is generated in the tank 54, and air is sucked from the discharge port 51a. The air is discharged into the water in the tank 54 through the switching unit 57c and the three-way valve 60.
In either case, the sucked air once dives in water, so the generation efficiency of humidified air is high.

  Next, the configuration of the platen 7 and the cleaning mechanism will be described with reference to FIG. The cleaning mechanism includes a wiper unit 70 and a moving mechanism 80.

  As shown in FIG. 7A, the platen 7 is a flat plate member arranged for each head 10, and the facing surface 7a facing the ejection surface 10a is flat. The platen 7 has a rotation shaft 7x extending in the main scanning direction at the downstream end portion in the conveyance direction, and is rotatable about the rotation shaft 7x. Under the control of the control device 1p, the platen 7 has a facing position (a position indicated by a solid line in FIG. 7A) where the facing surface 7a faces the ejection surface 10a in parallel, and the facing surface 7a intersects the ejection surface 10a. A non-opposing position (a position indicated by a two-dot chain line in FIG. 7A) is selectively taken. The platen 7 takes a non-opposing position at the time of wiping, and takes an opposing position at other times.

  The moving mechanism 80 is a mechanism for reciprocating the wiper unit 70 in the main scanning direction, and is arranged for each head 10. The moving mechanism 80 includes a guide pair 81 that supports the wiper unit 70, a drive motor 82 (see FIG. 8), and a transmission mechanism (not shown) that transmits the power of the drive motor 82. The guide pair 81 includes two parallel guides (round bars) 81a and 81b, and sandwiches the ejection space S1 from both sides in the sub-scanning direction as shown in FIG. A male screw is formed on the outer peripheral surface of the guide 81 a, and a rotational force is transmitted from the drive motor 82.

  The wiper unit 70 includes a vertical movement mechanism for the wiper case 78 and the wiper 71. As shown in FIG. 7C, the wiper case 78 is a rectangular parallelepiped box. An opening 78x through which the wiper 71 enters and exits is formed in the upper wall 78t.

  Two cylindrical members 79 and one solenoid 75 are attached to the outer surface of the wiper case 78. The cylindrical member 79 is fixed to the outer surface facing the sub-scanning direction, and guides 81 a and 81 b are inserted through the cylindrical member 79 and supported by the guide pair 81. In particular, the cylindrical member 79 for the guide 81a is formed with a female screw on the inner peripheral surface. The other cylindrical member 79 is slidable on the outer peripheral surface of the guide 81b. Accordingly, when the guide 81a rotates forward or backward under the control of the control device 1p, the wiper unit 70 moves together with the case 78. Note that the wiper unit 70 remains at the standby position (the position of the space S3 shown in FIG. 7B) except during the cleaning operation. In addition, the solenoid 75 is fixed to the outer surface facing the main scanning direction.

  Inside the wiper case 78, as shown in FIG. 7C, a wiper 71, a holder 71h, a sponge 70S and the like are accommodated. The wiper 71 is a plate-like elastic member such as rubber and is long in the sub-scanning direction. The length of the wiper 71 is substantially the same as the length (width) of the ejection surface. The wiper 71 is fixed to the holder 71h. A pair of plates 77 are erected from the bottom surface of the case 78, and holders 71h are sandwiched from both sides in the main scanning direction. The holder 71 h can move up and down between the plates 77. Further, a spring 71S is disposed on the bottom surface between the two plates 77, and biases the holder 71h upward. The sponge 70 </ b> S is disposed on the entire bottom portion except between the pair of plates 77.

  As shown in FIG. 7C, slits 77s and 78s are formed in the side wall of one plate 77 and the case 78 facing the plate 77, respectively. The connecting rod 71p accommodated in the case 78 penetrates both the slits 77s and 78s, and connects the holder 71h and the drive shaft of the solenoid 75. Therefore, when the drive shaft of the solenoid 75 expands and contracts, the holder 71 h moves up and down between the plates 77. The holder 71h is moved upward and the wiper 71 takes the exposed position (see FIG. 7C), and is moved downward and the wiper 71 takes the storage position (see FIG. 7B). The exposure position is a position where the wiper 71 can come into contact with the ejection surface 10 a, and the tip of the wiper 71 is exposed from the case 78. The storage position is an arrangement position at the standby position, and the entire wiper 71 is stored in the case 78. The pair of plates 77, the connecting rod 71p, the solenoid 75, etc. constitute a vertical movement mechanism of the wiper 71.

  In the cleaning operation, the wiper unit 70 is moved from the standby position to the second facing position (see FIG. 9A) under the control of the control device 1p. The second facing position is a position where the wiper 71 and the suction port 51b face each other. At this position, the wiper 71 is moved to the exposed position, and humidified air is blown toward the tip of the wiper 71. Thereafter, the wiper 71 is moved together with the wiper unit 70 toward the standby position. During this time, the discharge surface 10 a is wiped by the wiper 71. When the wiper 71 reaches the first facing position, humidified air is blown toward the tip of the wiper 71 again. The first facing position is a position where the wiper 71 and the discharge port 51a face each other. At this position, the wiper 71 is then returned to the storage position, and the wiper unit 70 is further moved back to the standby position.

  Next, the electrical configuration of the printer 1 will be described with reference to FIG.

  As shown in FIG. 8, in addition to a CPU (Central Processing Unit) 101 that is an arithmetic processing unit, the control device 1p includes a ROM (Read Only Memory) 102, a RAM (Random Access Memory: including a nonvolatile RAM) 103, An ASIC (Application Specific Integrated Circuit) 104, an I / F (Interface) 105, an I / O (Input / Output Port) 106, and the like are included. The ROM 102 stores programs executed by the CPU 101, various fixed data, and the like. The RAM 103 temporarily stores data necessary for program execution. In the ASIC 104, rewriting and rearranging of image data (for example, signal processing and image processing) are performed. The I / F 105 performs data transmission / reception with an external device. The I / O 106 inputs / outputs detection signals of various sensors.

  The control device 1p is connected to the motors 125 and 127, the paper sensor 32, the control board of the head 10, the water temperature sensor 46, the heater 58, and the like. The control device 1p further drives a platen rotation motor 7M that rotates the platen 7, a lift motor 44 that drives the gear 43 (see FIG. 6), and a moving mechanism 80 that moves the wiper unit 70 together with the case 78 in the main scanning direction. The motor 82 and the solenoid 75 that moves the wiper 71 in the vertical direction are connected. Although the motor 7M, the drive motor 82, and the solenoid 75 are provided for each head 10, only those corresponding to one head 10 are shown and simplified in FIG.

  Next, the control content of the wiping operation performed by the control device 1p will be described with reference to FIGS.

  As shown in FIG. 10, the control device 1p first determines whether or not a wiping command has been received (F1). The wiping command is received, for example, after preliminary ejection (for example, after preliminary ejection is performed immediately after the printer 1 is turned on). Before receiving the wiping command, the platen 7 is in the facing position, the cap 40 is in the separated position, the wiper unit 70 is in the standby position, and the wiper 71 is in the storage position.

  When receiving the wiping command (F1: YES), the control device 1p drives the platen rotation motor 7M to retract the platen 7 (moves from the facing position to the non-facing position) (F2). At this time, the platen 7 hangs down, and a space in which the wiping unit 70 can be moved is secured at a position facing the discharge surface 10a.

  After step 2, the control device 1p drives the drive motor 82 to move the wiper unit 70 together with the case 78 from the standby position to the second facing position as shown in FIG. 9A (step 3: F3). . In the standby position, the wiper unit 70 is below the tip 41a1 of the cap 40. Therefore, when the wiper unit 70 crosses below the cap 40 in step 3, the wiper unit 70 does not collide with the cap 40.

  After step 3, the control device 1p drives the solenoid 75 to move the wiper 71 from the storage position to the exposure position (F4). At this time, the tip of the wiper 71 exists between the suction port 51b and the ejection surface 10a in the vertical direction as shown in FIG. 9A. That is, when the wiper unit 70 moves toward the standby position, the wiper 71 can wipe the ejection surface 10a.

  After step 4, the control device 1p drives the pump 56 to discharge the humidified air in the tank 54 from the suction port 51b for a predetermined time (step 5: F5). At this time, the humidified air is discharged vertically downward (in the direction of the arrow indicated by the solid line) from the suction port 51b. Thereby, humidified air is blown to the tip of the wiper 71, and when the thickened ink is attached to the tip of the wiper 71, water is replenished to the thickened ink and the viscosity is lowered. For this reason, the thickened ink at the tip tends to flow downward from the tip together with the wiped residual ink. At this time, dust or the like adhering to the thickened ink also flows down. When humidified air is being discharged from the suction port 51b, air is sucked from the discharge port 51a.

  After step 5, the control device 1p drives the drive motor 82 to move the wiper unit 70 together with the case 78 toward the standby position (in the wiping direction) as shown in FIG. (Step 6: F6). At this time, the vicinity of the upper end of the wiper 71 moves relative to the ejection surface 10a while being in contact with the ejection surface 10a. Thereby, the foreign material adhering to the discharge surface 10a is wiped off. Then, as shown in FIG. 9C, the control device 1p stops driving the drive motor 82 when the wiper 71 reaches the first facing position (step 7: F7).

  After step 7 and when the wiper 71 is in the first facing position, the control device 1p drives the pump 53 to discharge the humid air in the tank 54 from the discharge port 51a for a predetermined time (step 8: F8). At this time, the humidified air is discharged vertically downward (in the direction of the arrow indicated by the solid line) from the discharge port 51a. As a result, the humidified air is blown to the tip of the wiper 71, and the ink adhering to the tip of the wiper 71 effectively flows downward from the tip of the wiper 71. At this time, even if the ink has a quick drying property, since the humidified air is blown to the tip of the wiper 71, the viscosity does not remain at the tip of the wiper 71 and remains. At this time, dust or the like adhering to the ink (thickened ink) also flows down below the wiper 71 together with the ink having a reduced viscosity. When humidified air is being discharged from the discharge port 51a, air is sucked from the suction port 51b.

  After step 8, the control device 1p drives the solenoid 75 to move the wiper 71 from the exposure position to the storage position (step 9: F9). Thereafter, the control device 1p drives the drive motor 82 to move the wiper unit 70 together with the case 78 to the standby position (step 10: F10).

  After step 10, the control device 1p drives the platen rotation motor 7M to return the platen 7 (move from the non-facing position to the facing position) (step 11: F11). Thereby, the wiping operation ends.

  Next, the control content of capping and humidification maintenance executed by the control device 1p will be described with reference to FIG.

  As shown in FIG. 11, the control device 1p first determines whether or not a capping command has been received (G1). Before receiving the capping command, the platen 7 is in the facing position and the cap 40 is in the separated position.

  When receiving the capping command (G1: YES), the control device 1p drives the elevating motor 44 to bring the tip 41a1 of the cap 40 into contact with the opposing surface 7a (moving from the separation position to the contact position) (Step 2: G2). As a result, the discharge space S1 formed between the discharge surface 10a and the opposing surface 7a of the platen 7 is sealed from the external space S2 (see FIG. 5).

  After step 2, the control device 1p drives the pump 53 to discharge the humidified air in the tank 54 from the discharge port 51a for a predetermined time (step 3: G3). Thereby, the humidified air discharged | emitted from the discharge port 51a is supplied in discharge space S1. At this time, air in the discharge space S1 is sucked from the suction port 51b. That is, humidified air circulates from the tank 54 to the discharge space S1 and from the discharge space S1 to the tank 54, and the humidity of the air in the discharge space S1 is adjusted to a desired humidity. Thereby, it is possible to suppress the viscosity increase of the ink in the ejection port 14a. Further, since the humidified air blown to the tip of the wiper 71 and the humidified air to be circulated to the sealed discharge space S1 are supplied by the same humidified air supply mechanism 50, the configuration of the apparatus can be simplified and miniaturized.

  Thus, the capping and humidification maintenance is completed. Thereafter, when a signal such as a recording command is received from the external device, the control device 1p drives the elevating motor 44 to move the tip 41a1 of the cap 40 away from the facing surface 7a (moves from the contact position to the separated position). . As a result, the discharge space S1 formed between the discharge surface 10a and the opposing surface 7a of the platen 7 is in an unsealed state opened to the external space S2 (see FIG. 1). As described above, the recording operation is performed under the control of the control device 1p.

  As described above, according to the printer 1 according to the present embodiment, since humidified air can be blown to the tip of the wiper 71, foreign matter (such as thickened ink or dust) adhered to the tip of the wiper 71 in a non-contact manner. ) Can be removed. In addition, since the humidified air is blown to the wiper 71, for example, even if quick-drying ink adheres to the tip of the wiper 71, the ink is not contacted from the tip of the wiper 71 while preventing the ink from thickening. Can be removed. Therefore, it is possible to wipe the ejection surface 10a in a state where no foreign matter is attached to the tip of the wiper 71, and the ink ejection performance from the ejection port 14a can be maintained. In addition, since the foreign matter is removed from the tip of the wiper 71 in a non-contact manner, it is possible to suppress wear at the tip of the wiper 71 than to remove the foreign matter from the wiper by directly contacting the wiper 71 with an absorbent such as a sponge. It becomes possible.

  Further, immediately after the wiping is performed, the humidified air is blown to the tip of the wiper 71, so that the foreign matter adhering to the tip of the wiper 71 by wiping can be effectively removed from the wiper 71. That is, even if the ink to be used is quick-drying, the humidified air is blown to the wiper 71 immediately after wiping. Therefore, it is possible to remove the ink from the tip of the wiper 71 while preventing the ink from thickening.

  In addition, since the humidified air is blown to the tip of the wiper 71 immediately before wiping is performed, it is possible to wipe the discharge surface 10a in a state in which no foreign matter is attached to the tip of the wiper 71. That is, even if foreign matter such as dust adheres to the wiper 71 before the wiper 71 moves from the standby position and wipes the ejection surface 10a, it can be removed. Furthermore, even if thickened ink remains at the tip of the wiper 71, it can be removed from the tip of the wiper 71 by blowing humidified air.

  Further, since the humidified air supply mechanism 50 has the pump 56 (switching mechanism), the humidified air can be discharged from the suction port 51b upstream of the wiping direction during wiping in addition to the discharge port 51a. It becomes. When only humidification maintenance is performed in the discharge space S1 in the sealed state, it is not necessary to switch the path (flow direction) of the humidified air that connects the discharge port 51a and the suction port 51b, but the suction port can be switched by switching the flow direction. By allowing humid air to be discharged also from 51b, it becomes possible to blow humid air from the suction port 51b to the wiper 71 immediately before wiping, and to blow humid air from the discharge port 51a to the wiper 71 immediately after wiping. . Thereby, it is possible to shorten the time and the moving distance from the time when the humidified air is blown to the wiper 71 until the wiper 71 wipes the ejection surface 10a. And it becomes possible to spray humidified air on the wiper 71 immediately after wiping by discharging humidified air from the discharge port 51a downstream in the wiping direction. By having the pump 56 as the switching mechanism in this way, it is possible to easily blow humidified air onto the wiper 71 immediately before and after wiping.

  Further, the discharge port 51a and the suction port 51b are arranged at positions sandwiching the head 10, and discharge the humid air in the same direction as the ink discharge direction. Thus, the wiper 71 can be easily opposed to the suction port 51b, the discharge surface 10a, and the discharge port 51a in this order only by moving the wiper 71 in one direction (main scanning direction) by the moving mechanism 80.

  As a modification, the humidified air may be discharged from the discharge port 51a and the suction port 51b in a direction crossing the ink discharge direction. That is, as indicated by the dashed arrows in FIG. 9, the humidified air discharged from the discharge port 51a and the suction port 51b is oblique to the lower side in the vertical direction (more preferably, obliquely outward from the discharge surface 10a). The joint 51 may be provided so as to be. Even in this case, the humidified air is discharged in the direction from the top to the bottom, which is oblique, so that the same effect as described above can be obtained. In this modification, the humidified air is blown onto the wiper 71 with the wiper 71 and the discharge port 51a (or the suction port 51b) facing each other with respect to the discharge direction of the humidified air.

  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 capping unit may not be provided in the printer 1. Further, as cap means that can take the discharge space S1 in a sealed state and an unsealed state, a cap having a bottom portion facing the discharge surface 10a and an annular portion standing on the periphery of the bottom portion, and a tip of the annular portion May be configured to include a moving mechanism that moves the cap to a position in contact with the discharge surface 10a and a position separated from the discharge surface 10a. In addition, a discharge port and a suction port may be provided at a position sandwiching all the discharge ports on the discharge surface 10a. In this case, the wiper 71 may be moved by a moving mechanism to a position facing the discharge port. Further, in the moving mechanism 80 of the above-described embodiment, the wiper 71 (wiper unit 70) is moved in the main scanning direction. However, the moving mechanism moves the discharge port 51a (suction port 51b) of the humidified air supply mechanism 50. You may move to the position facing the wiper 71, and you may move both so that it may mutually oppose. Further, the wiping by the wiper 71 may be performed by moving the head 10 or by moving both the head 10 and the wiper 71 relative to each other.

  Further, the humidified air supply mechanism 50 may not have the switching mechanism (pump 56). Moreover, the humidified air supply mechanism should just have the production | generation part (tank) which produces | generates humidified air, and the discharge port which discharges the produced | generated humidified air. Further, the outlet for discharging the humid air may be arranged at a position away from the head 10 (a position not included by the cap 40). For example, a discharge port may be provided at a position facing the wiper 71 disposed at the standby position. In this case, humidified air can be blown to the wiper 71 at the standby position before (immediately before) wiping. Further, it is possible to blow humidified air onto the wiper 71 at the standby position after (just after) wiping. In the above-described embodiment, the humidified air is blown to the tip of the wiper 71 immediately before and after wiping. However, the wiper 71 has a timing other than this (for example, when the power of the printer 1 is turned on). Humidified air may be blown to the tip. In this case as well, foreign matters such as thickened ink can be removed without contact from the tip of the wiper 71 while preventing thickening.

  It is preferable that the width of the discharge port 51a and the suction port 51b in the sub-scanning direction is smaller than the width of the ejection surface 10a. More preferably, the width may be equal to or greater than the width of the region where the discharge port 14a is formed on the discharge surface 10a in the sub-scanning direction.

  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.

1 Inkjet printer (liquid ejection device)
1p control device (control means)
7 Opposing member 7a Opposing surface 10 head (liquid ejection head)
10a Discharge surface 14a Discharge port 40 Cap (annular member)
50 Humidified air supply mechanism 51a Discharge port 51b Suction port 56 Pump (switching mechanism)
71 Wiper 80 Moving mechanism S1 Discharge space S2 External space

Claims (7)

A liquid ejection head having an ejection surface in which an ejection port for ejecting liquid is formed;
A wiper that performs wiping to wipe the discharge surface by moving relative to the discharge surface while contacting the discharge surface;
A humidified air supply mechanism for generating humidified air and exhausting the humidified air from the outlet;
A moving mechanism that moves at least one of the wiper and the humidified air supply mechanism so as to be able to take a first facing position where the wiper faces the discharge port;
Control means for controlling the moving mechanism so that the wiper faces the discharge port, and for controlling the humidified air supply mechanism so as to blow the humidified air on the tip of the wiper at the first facing position; ,
Includes a sealing state in which the discharge space facing the ejection surface and isolated from the outside space together with the ejection face and a cap unit that can take the unsealed state of opening the discharge space to the external space ,
The humidified air supply mechanism has the discharge port for discharging the humidified air into the discharge space in the sealed state, and the suction port for sucking air in the discharge space,
Said control means, said discharge space after controlling the capping means so as to the sealing state, that you control the humidified air supply mechanism such that the humidified air is circulated through the discharge space A liquid ejecting apparatus.   The liquid ejecting apparatus according to claim 1, wherein the control unit controls the moving mechanism so that the wiper faces the discharge port after the wiping is performed.   The liquid ejecting apparatus according to claim 1, wherein the control unit controls the moving mechanism so that the wiper faces the discharge port before the wiping is performed. The moving mechanism moves at least one of the wiper and the humidified air supply mechanism so as to be able to take the first facing position and the second facing position where the wiper faces the suction port. ,
The humidified air supply mechanism is a switching mechanism that switches a path of the humidified air connected to the suction port and the discharge port so that the humidified air can be discharged from the suction port and air can be sucked from the discharge port. In addition,
With respect to the wiping direction in which the discharge surface is wiped with the wiper, the discharge port is disposed downstream of all the discharge ports formed on the discharge surface, and the suction ports are formed on all the discharge ports formed on the discharge surface. It is located upstream from the exit,
The control means blows the humidified air onto the tip of the wiper at the second facing position immediately before the wiping is performed, and immediately after the wiping is performed, the control means to blow the humidified air to the tip, the moving mechanism, a liquid ejecting apparatus according to any one of claims 1 to 3, wherein the controller controls the switching mechanism and the humidified air supply mechanism. Claim 4 and the suction port and the discharge port, while being arranged at a position sandwiching the liquid discharge head, the humidified air in the same direction as the liquid discharge direction from said discharge port, characterized in that it is discharged The liquid discharge apparatus according to 1. The humidified air is discharged in a direction intersecting a liquid discharge direction from the discharge port while the suction port and the discharge port are arranged at positions sandwiching the liquid discharge head. 5. The liquid ejection device according to 4 . The cap means includes a facing member having a facing surface facing the discharge surface, and the discharge port and the suction port, and the tip is in contact with the facing surface to isolate the discharge space from the external space. apparatus according to any one of claims 1 to 6, characterized in that it comprises an annular member.

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