Liquid discharge device

Abstract

To improve sealability onto a discharge surface.SOLUTION: A liquid discharge device includes: holding means holding a discharge head that discharges liquid; a cap mechanism capping the discharge surface of the discharge head; positioning means that positions the discharge head at a capping position for the cap mechanism to cap the discharge surface; and a retreating member that separates the cap mechanism from the discharge surface of the discharge head positioned at the capping position, when the member is in a first attitude, and contacts the cap mechanism with the discharge surface of the discharge head positioned at the capping position, when the member is in a second attitude. In a state where the discharge head is positioned at the capping position by the positioning means, the holding means is displaced relatively with respect to the discharge head, so that the retreating member changes in attitude between the first attitude and the second attitude.SELECTED DRAWING: Figure 25

Description

[Technical field]

[0001] The present disclosure relates to a liquid ejection device. [Background technology]

[0002] Conventionally, liquid ejection devices that eject ink droplets onto a recording medium such as a recording paper or a resin sheet to record characters or images are known. There are the following types of liquid ejection devices. The first type of liquid ejection device is a serial type liquid ejection device in which a liquid ejection head moves back and forth in a direction intersecting the transport direction of the recording medium to eject ink droplets to perform recording. The second type of liquid ejection device is a line head type liquid ejection device in which the liquid ejection head does not move relative to the main body, and ejects ink droplets from the liquid ejection head in accordance with the transport of the recording medium while keeping a fixed posture to perform recording. In such a liquid ejection device, if air continues to come into contact with the nozzle of the liquid ejection head, the ink in the nozzle may dry out and become thickened or solidified. In addition, if paper powder or dust gets mixed into the ink in the nozzle, the nozzle may become clogged, which may cause poor ink ejection, resulting in a decrease in recording quality and a malfunction of the liquid ejection head. Patent Document 1 discloses a liquid ejection device that solves this problem. This liquid ejection device has a liquid ejection head that can be raised and lowered, a capping means that can cap the ejection port surface of the liquid head, and a support means that can support the capping means. When the liquid discharge head is lowered and the first surface of the capping means caps the discharge port surface, the supporting means supports the second surface of the capping means that faces the first surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-43116 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the liquid ejection device disclosed in Patent Document 1, the liquid ejection surface of the liquid ejection head is brought into contact with the capping means while the liquid ejection head is moved by a cap positioning member. Therefore, the liquid ejection head is positioned in a state where the liquid ejection surface of the liquid ejection head and the capping means are in contact with each other. As a result, the liquid ejection head moves after the liquid ejection surface of the liquid ejection head and the capping means come into contact with each other, and this may cause the liquid ejection surface of the liquid ejection head to become misaligned with respect to the capping means, which may impair sealing properties.

[0005] The present disclosure has been made in consideration of the above problems, and has an object to improve the sealing performance for the ejection surface. [Means for solving the problem]

[0006] One embodiment of the present disclosure is a liquid ejection device comprising a holding means for holding an ejection head that ejects liquid, a capping mechanism for capping the ejection surface of the ejection head, a positioning means for positioning the ejection head at a capping position for capping the ejection surface with the capping mechanism, and a retracting member for separating the capping mechanism from the ejection surface of the ejection head positioned at the capping position when in a first position, and abutting the capping mechanism against the ejection surface of the ejection head positioned at the capping position when in a second position, wherein when the ejection head is positioned at the capping position by the positioning means, the holding means displaces relative to the ejection head, causing the retracting member to change its position between the first position and the second position. Effect of the Invention

[0007] According to the present disclosure, it is possible to improve the sealing performance for the ejection surface. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic front view showing an internal configuration of a liquid ejection device; [Diagram 2] FIG. 13 is a perspective view of a housing of a sheet conveying unit of a recording unit; [Diagram 3] FIG. 2 is a perspective view showing the front and left side of the liquid ejection head lifting mechanism; [Figure 4] FIG. 1 is a right side view of the liquid ejection head in the maintenance position. [Diagram 5] FIG. 1 is a diagram showing the left side of the liquid ejection head in the maintenance position. [Figure 6] FIG. 4 is a partial perspective view showing the front and left side of the liquid ejection head in the maintenance position; [Figure 7] FIG. 1 is a diagram showing a liquid ejection head and a biasing member positioned in a recording section. [Figure 8] FIG. 13 is a diagram illustrating a state in which the liquid ejection head is separated from the cap unit. [Figure 9] FIG. 13 is a diagram illustrating a state in which the positioning operation of the liquid ejection head relative to the cap unit is completed. [Figure 10] FIG. 1 is a block diagram showing a control configuration of a liquid ejection device. [Figure 11] A perspective view of a liquid ejection head [Figure 12] FIG. 13 is a diagram showing a state in which a plurality of liquid ejection heads are positioned at their respective recording positions. [Figure 13] FIG. 1 is a perspective view showing the arrangement of a liquid ejection head, a cap tray, and a cleaning tray during printing. [Figure 14] A front view showing the arrangement of the liquid ejection head, the cap tray, and the cleaning tray during printing. [Figure 15] FIG. 1 is a perspective view showing the arrangement of a liquid ejection head, a cap tray, and a cleaning tray during capping. [Figure 16] FIG. 2 is a plan view showing the arrangement of the liquid ejection head, the cap tray, and the cleaning tray during capping. [Figure 17] FIG. 2 is a perspective view showing the arrangement of the liquid ejection head, the cap tray, and the cleaning tray during cleaning. [Figure 18] FIG. 2 is a plan view showing the arrangement of the liquid ejection head, the cap tray, and the cleaning tray during cleaning. [Figure 19] A diagram showing the configuration of a cleaning mechanism. [Figure 20] FIG. 11 is a conceptual front view for explaining a change in arrangement of a liquid ejection head, a cap tray, and a cleaning tray; [Figure 21] FIG. 11 is a conceptual front view for explaining a change in arrangement of a liquid ejection head, a cap tray, and a cleaning tray; [Figure 22] Flowchart of liquid ejection head positioning operation during printing [Figure 23] Flowchart of liquid ejection head positioning operation during cleaning [Figure 24] FIG. 11 is an explanatory diagram showing the state immediately after the positioning member of the liquid ejection head comes into contact with the liquid ejection head positioning member of the cap unit; [Diagram 25] FIG. 1 is an explanatory diagram showing a state in which a liquid ejection head is capped; [Figure 26] FIG. 11 is an explanatory view showing an embodiment of the present invention immediately after a positioning member of a liquid ejection head comes into contact with a positioning member of a cap unit; [Figure 27] FIG. 11 is an explanatory diagram showing a state in which a liquid ejection head is capped in another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. The up-down direction (Z direction) on the paper surface of Fig. 1 is called the device up-down direction, the left-right direction (X direction) on the paper surface is called the device width direction, and the direction perpendicular to the paper surface (Y direction) is called the device depth direction. The front side of the paper surface (+Y side) is the device front side, and the back side of the paper surface (-Y side) is the device back side.

[0010] (Liquid discharge device) The liquid ejection device 1 of this embodiment shown in FIG. 1 is a high-speed line printer that uses a continuous sheet wound in a roll shape. The liquid ejection device 1 includes an unwinding roll section 2, a first dancer section 3, a first main conveyance section 4, a meandering correction section 5, a conveyance detection section 6, a mark sensor section 7, a recording section 8, and a first scanner section 9. The liquid ejection device of this embodiment also includes a first drying section 10, a second drying section 11, a cooling section 12, a second scanner section 13, a second main conveyance section 14, a second dancer section 15, a take-up roll section 16, and a maintenance section 17. The sheet S is conveyed along a sheet conveyance path shown by a solid line in the figure, and is processed in each unit. As shown in FIG. 1, the conveyance direction of the sheet S (hereinafter simply referred to as the "conveyance direction") changes inside the liquid ejection device 1, but the width direction of the sheet S (hereinafter referred to as the "sheet width direction") is basically constant and coincides with the device depth direction. One side in the sheet width direction (+Y side) is the front side of the device, and the other side (-Y side) is the rear side of the device.

[0011] The unwinding roll unit 2 is a unit for holding and supplying a continuous sheet wound in a roll shape. The unwinding roll unit 2 is configured to store an unwinding roll and pull out and supply the sheet S. The number of rolls that can be stored is not limited to one, and the unwinding roll unit 2 may store two or three or more rolls and selectively pull out and supply the sheet S.

[0012] The first dancer section 3 is a unit for applying a constant sheet tension between the unwinding roll section 2 and the first main conveyor section 4. In the first dancer section 3, tension is applied to the sheet by a tension applying means (not shown).

[0013] The first main conveyor 4 is a unit for feeding the sheet S to each unit between the meandering correction unit 5 and the second scanner unit 13 along the sheet conveying path, and for applying sheet tension between the first main conveyor 4 and the second main conveyor 14. Here, the units between the meandering correction unit 5 and the second scanner unit 13 include the meandering correction unit 5, the conveying detection unit 6, the mark sensor unit 7, the recording unit 8, the first scanner unit 9, the first drying unit 10, the second drying unit 11, the cooling unit 12, and the second scanner unit 13. The first main conveyor 4 rotates by driving a motor (not shown) and conveys the sheet S under tension.

[0014] The meandering correction unit 5 is a unit for correcting meandering in the sheet width direction when the sheet S is conveyed under tension. The meandering correction unit 5 is configured to include a meandering correction roller 5a and a meandering detection sensor (not shown) that detects meandering of the sheet S. The meandering correction roller 5a can change its inclination with respect to the sheet S by a motor (not shown), and corrects the meandering of the sheet S based on the measurement by the meandering detection sensor. At this time, the sheet S is wrapped around the meandering correction roller 5a, thereby improving the meandering correction function.

[0015] The transport detection unit 6 is a unit for detecting the tension of the sheet S when the sheet S is transported under tension between the first main transport unit 4 and the second main transport unit 14. The transport detection unit 6 is also a unit for detecting the transport speed of the sheet S in order to control the image formation timing of the recording unit 8.

[0016] The mark sensor section 7 is a unit for detecting a mark that is printed on the sheet S in advance in order to control the image formation timing of the recording section 8.

[0017] The recording unit 8 is a sheet processing unit that performs recording processing on the conveyed sheet S from above using the liquid ejection head 22 to form an image. The conveying path in the recording unit 8 is formed by guide rollers 23 arranged in an upwardly convex arc shape, and a certain tension is applied to the sheet S to ensure a clearance between the sheet S and the liquid ejection head 22. In the recording unit 8, a plurality of liquid ejection heads 22 are arranged along the conveying direction. In this example, in addition to the four colors of Bk (black), Y (yellow), M (magenta), and C (cyan), a total of eight line-type liquid ejection heads 22 corresponding to the reaction liquid and three special colors are arranged. Note that the number of colors and the number of liquid ejection heads 22 are not limited to eight. As the inkjet method (liquid ejection method), a method using a heat element, a method using a piezoelectric element, a method using an electrostatic element, a method using a MEMS element, etc. can be adopted. Ink of each color is supplied to the liquid ejection head 22 from an ink tank (not shown) via an ink tube (not shown).

[0018] FIG. 2 is a perspective view of the sheet conveying section housing 81. As shown in FIG. 2, the sheet conveying section housing 81 of the recording section 8 includes a plurality of liquid ejection head positioning members 811 (811a, 811b, 811c) for positioning the liquid ejection heads 22. In order to position each liquid ejection head 22 with respect to the sheet conveying section housing 81, it is necessary to arrange the three liquid ejection head positioning members 811 with respect to the sheet conveying section housing 81 at least so as not to be aligned in a straight line. Therefore, a first liquid ejection head positioning member 811a, a second liquid ejection head positioning member 811b, and a third liquid ejection head positioning member 811c are arranged for one liquid ejection head 22. The first liquid ejection head positioning member 811a is arranged on the front side (+Y side) of the sheet S, and the second liquid ejection head positioning member 811b and the third liquid ejection head positioning member 811c are arranged on the rear side (-Y side) of the sheet S. Therefore, the sheet S is sandwiched between the first liquid ejection head positioning member 811a and the second liquid ejection head positioning member 811b and the third liquid ejection head positioning member 811c located on the opposite side in the sheet width direction (Y direction). As will be described later, the liquid ejection head 22 changes position inside the liquid ejection device 1, and as shown in Fig. 2, the longitudinal direction of the liquid ejection head 22 (hereinafter referred to as the "head longitudinal direction") coincides with the device depth direction. One side of the head longitudinal direction (+Y side) is the front side of the device, and the other side (-Y side) is the rear side of the device.

[0019] 3 to 6, the liquid ejection head support shaft 27 (including the first pin 27a, the second pin 27b, and the third pin 27c) provided at both ends of the liquid ejection head 22 in the longitudinal direction is inserted into holes (including the first hole 261, the second hole 262, and the third hole 263) provided in the head holding part 26. The liquid ejection head support shaft 27 (including the first pin 27a, the second pin 27b, and the third pin 27c) is configured to be supported from below the lower edges of these holes (including the first hole 261, the second hole 262, and the third hole 263). Furthermore, as shown in FIG. 3, FIG. 7(a), and FIG. 7(b), the liquid ejection head 22 is urged to move downward relative to the head holding part 26 by a first urging member 51a, a second urging member 51b, and a third urging member 51c including compression springs provided in the head holding part 26.

[0020] 8(a) and 8(b), if no external force is applied to move the liquid ejection head 22 from below to above relative to the head holding part 26, the three pins are supported by the lower edges of the three holes in the head holding part 26. That is, the first pin 27a, the second pin 27b, and the third pin 27c are supported by the lower edges of the first hole 261, the second hole 262, and the third hole 263, respectively. The liquid ejection head 22 has a relative height with respect to the head holding part 26 that is determined by this support. That is, the relative position of the liquid ejection head 22 with respect to the head holding part 26 is limited by the relative height due to this support. This relative height is the relative height Hmin (see FIG. 24) of the lowest end of the liquid ejection head 22 with respect to the head holding part 26.

[0021] 9(a) and 9(b), if an external force is applied to move the liquid ejection head 22 from below to above relative to the head holding part 26, the liquid ejection head 22 is displaced above the position of the relative height of the lowest end with respect to the head holding part 26. As shown in FIGS. 8 and 9, the movement direction of the head holding part 26 is the vertical direction of the device (Z direction), and the displacement direction of the first pin 27a, the second pin 27b, and the third pin 27c in the holes (including the first hole 261, the second hole 262, and the third hole 263) provided in the head holding part 26 is also the vertical direction of the device (Z direction). Therefore, the movement direction of the head holding part 26 and the displacement direction of the first pin 27a, the second pin 27b, and the third pin 27c in the holes (including the first hole 261, the second hole 262, and the third hole 263) provided in the head holding part 26 are the same. In addition, the displacement direction of the first pin 27a, the second pin 27b, and the third pin 27c in the holes (including the first hole 261, the second hole 262, and the third hole 263) in the head holding portion 26 is common, and therefore, the relative displacement direction of the liquid ejection head 22 with respect to the head holding portion 26 is also the same as this common displacement direction.

[0022] As shown in FIG. 3, the head holding portion 26 can be raised and lowered along a lifting rail 29 provided in a frame 28 for lifting the liquid ejection head by a drive mechanism (not shown) provided inside.

[0023] The first scanner unit 9 is a unit that reads the image formed on the sheet S by the recording unit 8 during printing, detects misalignment and density of the image, and corrects the printing.

[0024] The first drying section 10 and the second drying section 11 are units that reduce the liquid content contained in the ink applied to the sheet S in the recording section 8, and increase the fixability of the sheet S and the ink. The second drying section 11 is disposed downstream of the first drying section 10 in the conveying direction. The first drying section 10 and the second drying section 11 heat the sheet S on which an image is recorded with ink, and dry the ink applied to the sheet S. Inside the first drying section 10 and the second drying section 11, hot air is applied to at least the ink-applied surface side of the sheet S passing through, to dry the ink-applied surface of the sheet S. The drying method is not limited to the method of applying hot air. For example, a method of irradiating the surface of the sheet S with electromagnetic waves (ultraviolet rays, infrared rays, etc.), a conductive heat transfer method by contact with a heating element, or a combination of two or more methods may be used.

[0025] The winding guide roller 31 is a roller that wraps the surface of the sheet S downstream of the recording unit 8 opposite the ink application surface at a certain winding angle because it is necessary to block the effect of the hot air from the first drying unit 10 on the recording unit 8. In this embodiment, two winding guide rollers 31 are arranged between the first scanner unit 9 and the first drying unit 10, and this causes the conveying direction to be turned back approximately 180 degrees from left to right. In the liquid ejection device 1, the first drying unit 10 is arranged below the recording unit 8, and the second drying unit 11 is arranged below the conveying detection unit 6 and the mark sensor unit 7 described above.

[0026] The cooling section 12 cools the sheet S on which the ink has been fixed in the first drying section 10 and the second drying section 11, thereby solidifying the softened ink and suppressing the amount of temperature change of the sheet S in downstream processes of the liquid ejection device 1. Inside the cooling section 12, air at a lower temperature than the sheet S is applied to at least the ink-applied surface side of the sheet S passing through, thereby cooling the ink-applied surface of the sheet S. The cooling method is not limited to the method of applying air. For example, a conductive heat transfer method using contact with a heat dissipating member or a combination of these may be used.

[0027] The second scanner unit 13 is a unit that reads a test image formed on the sheet S by the recording unit 8 before printing, detects image misalignment and density, and performs corrections for the actual printing.

[0028] The second main conveyor 14 is a unit that adjusts the tension of the sheet S by conveying the sheet S while applying tension to the sheet S in cooperation with the first main conveyor 4. The second main conveyor 14 rotates by being driven by a motor (not shown). The second main conveyor 14 is provided with a clutch for torque-controllable drive coupling. Therefore, the tension of the sheet S can be adjusted by controlling the torque by a tension control unit (not shown) according to the tension value detected by the conveyor detection unit 6. Note that, as an additional configuration for adjusting the tension of the sheet S, a configuration for controlling the speed of the second main conveyor 14 by the conveyor detection unit 6 may be added. In this case, two methods of tension control may be prepared: a torque control method for controlling the torque value transmitted by the clutch, and a speed control method for controlling the roller speed of the second main conveyor 14. Depending on the purpose, the tension control method may be switched between the torque control method and the speed control method, or both may be used simultaneously.

[0029] The second dancer section 15 is a unit for applying a constant sheet tension between the second main transport section 14 and the winding roll section 16. The second dancer section 15 applies tension to the sheet by a tension applying means (not shown).

[0030] The winding roll unit 16 is a unit for winding the sheet S after the recording process onto a core. The number of collectable rolls is not limited to one, and the roll may have two or three or more cores and may be configured to selectively switch between them to collect the sheet S. Depending on the content of the post-recording processing, the continuous sheet may be cut using a cutter and the cut sheets S may be stacked, instead of being wound onto a core.

[0031] The control unit 21 is a unit that controls each part included in the entire liquid ejection device 1 or controls performed by each part. The control unit 21 has a processor, a storage device, a controller equipped with various control units, an external interface, and an operation unit 24 where the user performs input and output. The operation of the liquid ejection device 1 is controlled based on commands from the controller or a host device 25 such as a host computer connected to the controller via an external interface.

[0032] 10 is a block diagram showing a control configuration in the liquid ejection device 1. The control configuration mainly includes a print engine unit 400 that controls the liquid ejection device 1, and a controller unit 300 that controls the entire liquid ejection device 1. A print controller 402 controls various mechanisms of the print engine unit 400 according to instructions from a main controller 301 of the controller unit 300. The control configuration will be described in detail below.

[0033] In the controller unit 300, a main controller 301 constituted by a processor controls the entire liquid ejection device 1 using a RAM 305 as a work area in accordance with programs and various parameters stored in a ROM 306. For example, when a print job is input from the host device 25 via a host I / F 302, an image processing unit 307 performs predetermined image processing on image data included in the input print job in accordance with instructions from the main controller 301. The main controller 301 then transmits the image data that has been subjected to the image processing to a print engine unit 400 via a print engine I / F 304.

[0034] The liquid ejection device 1 may acquire image data from the host device 25 via wireless communication or wired communication, or may acquire image data from an external storage device (such as a USB memory) connected to the liquid ejection device 1. There are no limitations on the communication method used for wireless communication or wired communication. For example, Wi-Fi (Wireless Fidelity) (registered trademark) and Bluetooth (registered trademark) can be used as communication methods used for wireless communication. Furthermore, USB (Universal Serial Bus) or the like can be used as a communication method used for wired communication.

[0035] The operation unit 24 is a mechanism for a user to perform input and output to the liquid ejection device 1. The user can set a print mode for the liquid ejection device 1 and recognize information related to the liquid ejection device 1 via the operation unit 24.

[0036] In the print engine unit 400, a print controller 402 configured by a processor controls various mechanisms of the liquid ejection device 1 according to programs and various parameters stored in a ROM 403, using a RAM 404 as a work area. When various commands and image data are received via a controller I / F 401, the print controller 402 temporarily stores them in the RAM 404. The print controller 402 causes an image processing controller 405 to convert the stored image data into recording data so that the liquid ejection head 22 can use the data for a recording operation. When the recording data is generated, the print controller 402 causes the liquid ejection head 22 to perform a recording operation based on the recording data via a head I / F 406. At this time, the print controller 402 drives each unit shown in FIG. 1 via a conveyance control unit 407 to convey the sheet S. Here, each unit includes an unwind roll unit 2, a first dancer unit 3, a first main conveyance unit 4, a meandering correction unit 5, a conveyance detection unit 6, a mark sensor unit 7, and a recording unit 8. The individual sections further include a first scanner section 9, a first drying section 10, a second drying section 11, a cooling section 12, a second scanner section 13, a second main transport section 14, a second dancer section 15, and a take-up roll section 16. According to an instruction from the print controller 402, a recording operation is performed by the liquid ejection head 22 in conjunction with the transport operation of the sheet S, and a printing process is performed.

[0037] A liquid ejection head moving means control unit 408 changes the position of the liquid ejection head 22 depending on the operating state of the liquid ejection device 1, such as the maintenance state or recording state. An ink supply control unit 409 controls an ink supply unit (not shown) so that the pressure of the ink supplied to the liquid ejection head 22 falls within an appropriate range. A maintenance control unit 410 controls the operation of the maintenance unit 17 (FIG. 1) when performing a maintenance operation on the liquid ejection head 22.

[0038] 1, the maintenance unit 17 is a unit including a cap tray 18 on which a cap mechanism 181 for protecting the liquid ejection surface of the liquid ejection head 22 is disposed, and a cleaning tray 19 on which a cleaning mechanism for recovering the ejection performance is disposed. The maintenance unit 17 will be described in detail later.

[0039] (Configuration of liquid ejection head and positioning at printing position) FIG. 11 is a perspective view of the liquid ejection head 22. As shown in FIG. 11, the liquid ejection head 22 has a nozzle plate 223 with a plurality of nozzles for ejecting ink aligned in the longitudinal direction of the liquid ejection head (i.e., the Y direction), and a pair of positioning members 221 are provided at both ends of the liquid ejection head 22. The positioning member 221 on the front side of the device in the longitudinal direction of the head is formed with a first contact portion 221a consisting of a recess with a conical slope. The positioning member 221 on the rear side of the device in the longitudinal direction of the head is formed with a second contact portion 221b having a groove portion with two V-shaped flat surfaces and a third contact portion 221c having a flat surface. Here, a guide shape 221d is provided near the third contact portion 221c. The guide shape 221d plays a role in solving the problem that when the third contact portion 221c and the third liquid ejection head positioning member 811c come into contact with each other, the liquid ejection head 22 slips and a position shift occurs, and a ball does not enter the positioning portion and positioning cannot be performed.

[0040] The liquid ejection head 22 is provided at one end in the longitudinal direction thereof with a first pin 27a extending in the longitudinal direction thereof, and at the other end thereof with a second pin 27b and a third pin 27c extending in the longitudinal direction thereof.

[0041] The first and second contact portions 221a and 221b of the liquid ejection head 22 are precisely positioned so that a straight line connecting the centers of the first and second contact portions 221a and 221b of the liquid ejection head 22 in the longitudinal direction of the liquid ejection head 22 is parallel to the arrangement of the multiple nozzle plates 223 of the liquid ejection head 22. The third contact portion 221c is positioned at a position spaced apart from the second contact portion 221b in a direction perpendicular to the longitudinal direction of the liquid ejection head.

[0042] Fig. 12 shows a state in which a plurality of liquid ejection heads 22 with different arrangement heights are positioned by contacting liquid ejection head positioning members 811 (811a, 811b, 811c) provided on a sheet transport unit housing 81. In this embodiment, as shown in Fig. 12, the plurality of liquid ejection heads 22 are positioned in a state in which they are inclined at different angles in the arc-shaped transport direction. However, it is not necessary to limit the inclination angle to the horizontal direction, and there may be liquid ejection heads 22 that have no inclination angle with respect to the horizontal direction.

[0043] 7 shows the head holding part 26 and the liquid ejection head 22 when the liquid ejection head 22 is positioned at the printing position in S2204 (see FIG. 22) described later. The head holding part 26 supporting the liquid ejection head 22 is provided with three urging members 51, namely, a first urging member 51a, a second urging member 51b, and a third urging member 51c. The first urging member 51a is disposed above the first contact portion 221a of the liquid ejection head 22. The second urging member 51b is disposed above the second contact portion 221b of the liquid ejection head 22. The third urging member 51c is disposed above the third contact portion 221c of the liquid ejection head 22.

[0044] The first biasing member 51a is composed of a first base portion 511a, a first sliding portion 512a, and a first spring (not shown), and the first sliding portion 512a is configured to be slidable relative to the first base portion 511a. Similarly, the second biasing member 51b is composed of a second base portion 511b, a second sliding portion 512b, and a second spring (not shown), and the second sliding portion 512b is configured to be slidable relative to the second base portion 511b. Moreover, the third biasing member 51c is composed of a third base portion 511c, a third sliding portion 512c, and a third spring (not shown), and the third sliding portion 512c is configured to be slidable relative to the third base portion 511c.

[0045] A plate 52 is provided at one end in the longitudinal direction of the liquid ejection head 22 so as to abut against the second sliding portion 512b and the third sliding portion 512c. Another plate 52 is provided at the other end in the longitudinal direction of the liquid ejection head 22 so as to abut against the first sliding portion 512a.

[0046] The sliding portions 512a, 512b, and 512c are configured as spheres at the portions that come into contact with the plate 52, and are configured to be slidable relative to the plate 52. As shown in Fig. 7, the biasing positions of the biasing members when the liquid ejection head 22 comes into contact are set in consideration of the moment M about the positioning member 811. In other words, the biasing positions are set so that a relationship is established in which a load is applied such that the abutment portions 221a, 221b, and 221c of the positioning member 221 always land on the positioning members 811a, 811b, and 811c.

[0047] (Maintenance Department Composition) Next, the configuration of the maintenance unit 17 of the liquid ejection device 1 according to an embodiment of the present disclosure will be described. Fig. 13 and Fig. 14 are a perspective view and a front view, respectively, showing the configuration of the main parts of the liquid ejection device 1, mainly the recording unit 8. Fig. 15 and Fig. 16 are a perspective view and a top view, respectively, showing a capped state in which the liquid ejection surface of the liquid ejection head 22 is protected by a capping mechanism 181, which will be described later. Fig. 17 and Fig. 18 are a perspective view and a top view, respectively, showing a state during a cleaning operation in which the ejection performance is restored by a cleaning mechanism, which will be described later.

[0048] As shown in Figs. 8 to 13, the maintenance unit 17 is divided into a cap tray 18 on which a cap mechanism 181 (see Fig. 18) is arranged, and a cleaning tray 19 on which a cleaning mechanism 191 (see Fig. 16) is arranged. The cap tray 18 and the cleaning tray 19 are configured to be movable in the longitudinal direction of the device (X direction) by a driving motor (not shown) and a rail 32 provided on the housing. Figs. 13 and 14 show a state during recording, in which the cap tray 18 and the cleaning tray 19 are located upstream in the transport direction with respect to the recording unit 8. At this time, the cap tray 18 is located directly above the cleaning tray 19. Figs. 15 and 16 show a capped state of the liquid ejection head 22, in which the cap tray 18 is located directly below the liquid ejection head 22 of the recording unit 8, and the cleaning tray 19 is located upstream in the transport direction with respect to the recording unit 8. 17 and 18 show the state during the cleaning operation of the liquid ejection head 22, in which the cleaning tray 19 is positioned directly below the liquid ejection head 22 of the recording unit 8, and the cap tray 18 is positioned upstream of the recording unit 8 in the transport direction.

[0049] As shown in FIG. 18, the cap tray 18 includes a plurality of spherical liquid ejection head positioning members 182 for positioning a plurality of liquid ejection heads 22. In order to position each liquid ejection head 22 with respect to each capping mechanism 181, it is necessary to arrange three liquid ejection head positioning members 182 for each capping mechanism 181 at least so as not to be aligned in a straight line. Therefore, in the example of FIG. 18, each capping mechanism 181 is provided with liquid ejection head positioning members 182a, 182b, and 182c. The liquid ejection head positioning members 182a, 182b, and 182c are arranged on both sides of the capping mechanism 181 in the sheet width direction. More specifically, a first liquid ejection head positioning member 182a is arranged on the front side (+Y side) of the capping mechanism 181. A second liquid ejection head positioning member 182b and a third liquid ejection head positioning member 182c are arranged on the rear side (-Y side) of the capping mechanism 181. The positioning of the liquid ejection head 22 with respect to the capping mechanism 181 is the same as the positioning of the liquid ejection head 22 with respect to the sheet transport unit housing 81. That is, the liquid ejection head 22 is positioned with respect to the capping mechanism 181 by the positioning members 221 provided on both ends of the liquid ejection head 22 abutting against a total of three liquid ejection head positioning members 182 with respect to the capping mechanism 181. More specifically, the positioning of each liquid ejection head 22 with respect to each capping mechanism 181 is performed by the abutment portions 221a, 221b, and 221c formed on the positioning members 221 abutting against the liquid ejection head positioning members 182a, 182b, and 182c, respectively.

[0050] As shown in FIG. 16, each cleaning mechanism 191 in the cleaning tray 19 is provided with a plurality of spherical liquid ejection head positioning members 192 for positioning a plurality of liquid ejection heads 22. In order to position each liquid ejection head 22 with respect to each cleaning mechanism 191, it is necessary to arrange three liquid ejection head positioning members 192 for each cleaning mechanism 191 at least so as not to be aligned in a straight line. Therefore, in the example of FIG. 16, each cleaning tray 19 is provided with liquid ejection head positioning members 192a, 192b, and 192c. The liquid ejection head positioning members 192a, 192b, and 192c are arranged on both sides of the cap mechanism 181 in the sheet width direction. More specifically, a first liquid ejection head positioning member 192a is arranged on the front side of the cleaning mechanism 191, and a second liquid ejection head positioning member 192b and a third liquid ejection head positioning member 192c are arranged on the rear side of the cleaning mechanism 191. The cleaning tray 19 is provided with a first beam member 193a extending in the transport direction on the front side of the cleaning mechanism 191, and a second beam member 193b extending in the transport direction on the rear side of the cleaning mechanism 191. The first liquid ejection head positioning member 192a is provided on the first beam member 193a, and the second liquid ejection head positioning member 192b and the third liquid ejection head positioning member 192c are provided on the second beam member 193b. The positioning of the liquid ejection head 22 with respect to the cleaning tray 19 is similar to the positioning of the liquid ejection head 22 with respect to the sheet transport unit housing 81. That is, the liquid ejection head 22 is positioned with respect to the cleaning mechanism 191 by the positioning members 221 provided on both ends of the liquid ejection head 22 coming into contact with a total of three liquid ejection head positioning members 192 of the cleaning mechanism 191. More specifically, contact portions 221a, 221b, and 221c formed on the positioning member 221 come into contact with the liquid ejection head positioning members 192a, 192b, and 192c, respectively. As a result, the liquid ejection heads 22 are positioned relative to the cleaning mechanisms 191.

[0051] Furthermore, the positioning configuration is not limited to a configuration using a spherical positioning member, and may be a configuration in which a part of the liquid ejection head 22 is butted against the cleaning tray 19, or a configuration in which positioning is performed using holes and pins provided in the cleaning tray 19 and the liquid ejection head 22.

[0052] FIG. 19 shows the configuration of a cleaning mechanism 191 arranged in the cleaning tray 19. The cleaning mechanism 191 has a cleaning liquid applying unit 50, a liquid removing unit 60, and a negative pressure applying unit 70. The cleaning liquid applying unit 50 applies cleaning liquid to the nozzle plate 223 of the liquid ejection head 22. The liquid removing unit 60 removes ink, paper dust, and cleaning liquid attached to the liquid ejection head 22. The liquid negative pressure applying unit 70 applies negative pressure to the nozzle plate 223 of the liquid ejection head 22 to remove ink stuck to the nozzle portion and bubbles in the ink flow path. In addition, as shown in FIG. 16, the cleaning tray 19 has a moving mechanism (not shown) that moves the cleaning mechanism 191 along a wiping direction D perpendicular to the transport direction. The cleaning mechanism 191 removes ink and dust from the nozzle surface of the liquid ejection head by a combination of the cleaning liquid applying unit 50, the liquid removing unit 60, and the negative pressure applying unit 70.

[0053] (Operation for positioning multiple liquid ejection heads, a cap tray, and a cleaning tray) Next, an operation for positioning the multiple liquid ejection heads 22, the cap tray 18, and the cleaning tray 19 included in the liquid ejection device 1 according to an embodiment of the present disclosure will be described. Fig. 20 is a schematic diagram showing the operation for positioning the multiple liquid ejection heads 22 with respect to the cap tray 18. Fig. 21 is a schematic diagram showing the operation for positioning the multiple liquid ejection heads 22 with respect to the cleaning tray 19.

[0054] With reference to Fig. 20, the operation including positioning to the capping position will be described. Fig. 20(a) shows a state in which the multiple liquid ejection heads 22, the cap tray 18, and the cleaning tray 19 are retracted to their respective retracted positions. Fig. 20(b) shows a state in which the multiple liquid ejection heads 22 are positioned at the recording position, while the cap tray 18 and the cleaning tray 19 are retracted to their respective retracted positions. Fig. 20(c) shows a state in which the cap tray 18 is positioned at the capping position, while the multiple liquid ejection heads 22 and the cleaning tray 19 are retracted to their retracted positions. Fig. 20(d) shows a state in which the multiple liquid ejection heads 22 and the cap tray 18 are positioned at the capping position, while the cleaning tray 19 is retracted to its retracted position.

[0055] 20(a), the liquid ejection heads 22 are retracted to retracted positions above the sheet transport unit housing 81. The cap tray 18 and the cleaning tray 19 are retracted approximately horizontally to their respective retracted positions upstream of the liquid ejection heads 22 in the transport direction.

[0056] 20(b), the multiple liquid ejection heads 22 are positioned at print positions for recording an image on the sheet S. In addition, in the state shown in Fig. 20(b), similar to the state shown in Fig. 20(a), the cap tray 18 and the cleaning tray 19 are substantially horizontally retracted to their respective retracted positions that are upstream of the multiple liquid ejection heads 22 in the transport direction.

[0057] A liquid ejection head lifting mechanism corresponding to each liquid ejection head 22 described with reference to Fig. 3 is used. This allows the liquid ejection heads 22 to be lowered from their respective retracted positions as shown in Fig. 20(a) to their respective recording positions as shown in Fig. 20(b). As shown in Fig. 20(b), at the recording positions, the positioning members 221 provided on each liquid ejection head 22 abut against the respective liquid ejection head positioning members 811 provided on the sheet transport unit housing 81.

[0058] 20(b), when the sheet transport section housing 81 is configured in an arc shape, first, the multiple liquid ejection heads 22 are lowered until they are detected by a position detection sensor (not shown) attached to the main body side of the liquid ejection device 1. Then, each liquid ejection head 22 is lowered by a lowering distance set for each liquid ejection head 22. In this way, the multiple liquid ejection heads 22 can be moved to different heights relative to the sheet transport section housing 81 configured in an arc shape.

[0059] When capping the liquid ejection head 22 after a printing operation, the liquid ejection head 22 is capped by the cap tray 18 .

[0060] When capping is performed after printing, first, the liquid ejection heads 22 in the recording position as shown in Fig. 20(b) are raised to the retracted position as shown in Fig. 20(a). Note that the cap tray 18 and cleaning tray 19 are left retracted to the retracted position.

[0061] Next, the cap tray 18, which is in the retracted position as shown in Fig. 20(a), is moved horizontally to the capping position as shown in Fig. 20(c). In other words, the cap tray 18 is moved (approximately horizontally) along the transport direction to the capping position below the liquid ejection heads 22.

[0062] Next, the liquid ejection heads 22 in the retracted position as shown in Fig. 20(c) are lowered to the capping position as shown in Fig. 20(d). As shown in Fig. 20(d), at the capping position, the positioning members 221 provided on each liquid ejection head 22 abut against the liquid ejection head positioning members 182 provided on the cap tray 18.

[0063] The operation including positioning to the cleaning position will be described with reference to Fig. 21. Fig. 21(a) shows a state in which the cleaning tray 19 is positioned at the cleaning position, while the multiple liquid ejection heads 22 and the cap tray 18 are retracted to the retracted position. Fig. 21(b) shows a state in which the multiple liquid ejection heads 22 and the cleaning tray 19 are positioned at the cleaning position, while the cap tray 18 is retracted to the retracted position.

[0064] In cases where the nozzles of the liquid ejection head 22 become clogged after a printing operation, causing ink ejection problems, a cleaning operation is performed on the liquid ejection head 22 by a cleaning mechanism 191 in the cleaning tray 19 .

[0065] When performing cleaning after printing, first, the liquid ejection heads 22 in the recording position as shown in Fig. 20(b) are raised to the retracted position as shown in Fig. 20(a). Note that the cap tray 18 and cleaning tray 19 are left retracted to the retracted position.

[0066] Next, the cleaning tray 19, which is in the retracted position as shown in Fig. 20(a), is moved horizontally to the cleaning position as shown in Fig. 21(a). In other words, the cleaning tray 19 is moved (approximately horizontally) along the transport direction to the cleaning position below the liquid ejection head 22.

[0067] Next, the liquid ejection heads 22 in the retracted position as shown in Fig. 21(a) are lowered to the cleaning position as shown in Fig. 21(b). As shown in Fig. 21(b), at the cleaning position, the positioning members 221 provided on each liquid ejection head 22 abut against the liquid ejection head positioning members 192 provided on the beam member 193 of the cleaning tray 19.

[0068] In this embodiment, since the cap tray 18 is configured in a straight line, it is not necessary to move the liquid ejection heads 22 to different heights. Therefore, the following method is performed to lower the liquid ejection heads 22 from the retracted position shown in FIG. 20(c) to the capping position shown in FIG. 20(d). First, the liquid ejection heads 22 are lowered until they are detected by a position detection sensor (not shown) attached to the main body side of the liquid ejection device 1. Then, the liquid ejection heads 22 are lowered by a common lowering distance set for them. The cleaning tray 19 is also configured in a straight line. Therefore, a similar method is performed to lower the liquid ejection heads 22 from the retracted position shown in FIG. 21(a) to the capping position shown in FIG. 21(b).

[0069] (Operation when printing) 22 is a flow chart for explaining the positioning operation of the liquid ejection heads 22 when printing. Basically, each liquid ejection head 22 positioned at the cap position is moved to the printing position and then printing is performed. Then, when printing is completed, each liquid ejection head 22 is returned to the cap position.

[0070] In S2201, as shown in FIG. 20(d), each liquid ejection head 22 is in the capping position and is capped by the capping mechanism 181 of the cap tray 18.

[0071] In S2202, the liquid ejection head moving means control unit 408 drives a drive motor (not shown) so that the head holding unit 26 rises, thereby moving the liquid ejection head 22 to the retracted position as shown in FIG. 20(c).

[0072] In S2203, the maintenance control unit 410 drives a drive motor (not shown) so that the cap tray 18 moves horizontally upstream along a rail provided on the housing, thereby moving the cap tray 18 to the retracted position as shown in Fig. 20(a). This allows the liquid ejection head 22 to move down to the printing position.

[0073] In S2204, an elevation motor (not shown) is driven so that each liquid ejection head 22 descends, thereby positioning each liquid ejection head 22 at the printing position as shown in FIG. 20(b).

[0074] In S2205, printing is executed.

[0075] When printing is completed, in S2206, an elevation motor (not shown) is driven to raise each liquid ejection head 22, thereby moving each liquid ejection head 22 to the retracted position as shown in FIG. 20(a).

[0076] In S2207, the maintenance control unit 410 drives a drive motor (not shown) so that the cap tray 18 moves horizontally downstream along a rail provided on the housing. This moves the cap tray 18 to the cap position as shown in Fig. 20(c). This allows each liquid ejection head 22 to move down to the cap position.

[0077] In S2208, an elevation motor (not shown) is driven so that each liquid ejection head 22 descends, thereby positioning each liquid ejection head 22 at the cap position as shown in FIG. 20(d).

[0078] (Operation when cleaning the liquid ejection head) 23 illustrates a flow chart of the positioning operation of the liquid ejection head 22 when cleaning the liquid ejection head 22. Basically, each liquid ejection head 22 positioned at the cap position is moved to the cleaning position and then cleaning is performed. Then, when cleaning is completed, each liquid ejection head 22 is returned to the cap position.

[0079] In S2301, as shown in FIG. 20(d), each liquid ejection head 22 is in the capping position and is capped by the capping mechanism 181 of the cap tray 18.

[0080] In S2302, the liquid ejection head moving means control unit 408 drives a drive motor (not shown) so that the head holding unit 26 rises, thereby moving the liquid ejection head 22 to the retracted position as shown in FIG. 20(c).

[0081] In S2303, the maintenance control unit 410 drives a drive motor (not shown) so that the cap tray 18 moves horizontally upstream along a rail provided on the housing, thereby moving the cap tray 18 to the retracted position as shown in Fig. 20(a). This allows the liquid ejection head 22 to move down to the cleaning position.

[0082] In S2304, the maintenance control unit 410 drives a drive motor (not shown) so that the cleaning tray 19 moves horizontally downstream along rails provided on the housing. This moves the cleaning tray 19 to the cleaning position as shown in Fig. 21(a). This allows each liquid ejection head 22 to move down to the cleaning position.

[0083] In S2305, an elevation motor (not shown) is driven so that each liquid ejection head 22 descends, thereby positioning each liquid ejection head 22 at the cleaning position as shown in FIG. 21(b).

[0084] In S2306, cleaning of each liquid ejection head 22 is performed.

[0085] When cleaning is completed, in S2307, an elevation motor (not shown) is driven to raise each liquid ejection head 22, thereby moving each liquid ejection head 22 to the retracted position as shown in FIG. 21(a).

[0086] In S2308, the maintenance control unit 410 drives a drive motor (not shown) so that the cleaning tray 19 moves horizontally upstream along a rail provided on the housing, thereby moving the cleaning tray 19 to the retracted position as shown in FIG.

[0087] In S2309, the maintenance control unit 410 drives a drive motor (not shown) so that the cap tray 18 moves horizontally downstream along a rail provided on the housing. This moves the cap tray 18 to the cap position as shown in Fig. 20(c). This allows each liquid ejection head 22 to move down to the cap position.

[0088] In S2310, an elevation motor (not shown) is driven so that each liquid ejection head 22 descends, thereby positioning each liquid ejection head 22 at the cap position as shown in FIG. 20(d). (Liquid ejection head support structure and positioning at capping position) When the liquid ejection head 22 held by the head holding portion 26 is in the retracted position as shown in FIG. 20( a ), the liquid ejection head 22 has a relative height Hmin of its lowermost end with respect to the head holding portion 26 .

[0089] In S2208 or S2320, when the liquid ejection head 22 held by the head holding part 26 is lowered from the retracted position as shown in FIG. 20(a), the positioning member 221 comes into contact with the liquid ejection head positioning member 182 as shown in FIG. 24. This contact prevents the liquid ejection head 22 from further lowering. The position where the positioning member 221 comes into contact with the liquid ejection head positioning member 182 is the capping position of the liquid ejection head 22. FIGS. 4, 5, and 6 show the head holding part 26 and the liquid ejection head 22 when they are lowered to a height where the positioning member 221 comes into contact with the liquid ejection head positioning member 182. FIG. 4 is a view from the rear side of the apparatus, FIG. 5 is a view from the front side of the apparatus, and FIG. 6 is a perspective view from the downstream side in the transport direction. As will be described later, at this time, as shown in FIG. 6, the cap mechanism 181 is separated from the liquid ejection head 22.

[0090] Here, as described above, the liquid ejection head 22 can be displaced upward from the relative height of the lowermost end with respect to the head holding part 26. In other words, the head holding part 26 can be displaced downward from the relative height of the uppermost end with respect to the liquid ejection head 22. Therefore, after this contact, the head holding part 26 can be further lowered while maintaining the height of the liquid ejection head 22. At this time, the liquid ejection head 22 has a relative height higher than the relative height Hmin of the lowermost end with respect to the head holding part 26. As will be described later, the head holding part 26 is lowered to a height at which the capping mechanism 181 can cap the liquid ejection head 22. If the relative height at which the head holding part 26 finishes lowering is Hmax, then after the contact, the head holding part 26 is further lowered while maintaining the height of the liquid ejection head 22 until the relative height changes from Hmin to Hmax.

[0091] (Liquid ejection head support structure and positioning at cleaning position) When the liquid ejection head 22 held by the head holding portion 26 is in the retracted position as shown in FIG. 20( a ), the liquid ejection head 22 has a relative height Hmin of its lowermost end with respect to the head holding portion 26 .

[0092] 20(a), the positioning member 221 comes into contact with the liquid ejection head positioning member 192. This contact prevents the liquid ejection head 22 from descending any further. The position where the positioning member 221 comes into contact with the liquid ejection head positioning member 192 is the cleaning position of the liquid ejection head 22.

[0093] (Cap unit operation) Fig. 24 is a diagram showing a state in which the liquid ejection head 22 is positioned at the capping position and the cap mechanism 181 included in the cap unit 180 is not abutted against the liquid ejection head 22. Fig. 25 is a diagram showing a state in which the liquid ejection head 22 is positioned at the capping position and the cap mechanism 181 included in the cap unit 180 is abutted against the liquid ejection head 22. When the head holding part 26 is lowered in S2208 or S2320, the head holding part 26, the liquid ejection head 22, and the cap mechanism 181 transition to the state shown in Fig. 25 via the state shown in Fig. 24.

[0094] As described above, the liquid ejection head 22 is held by the head holding portion 26 so as to be movable up and down. In the state shown in Fig. 24, the liquid ejection head 22 has a relative height Hmin of its lowermost end with respect to the head holding portion 26, and in the state shown in Fig. 25, the liquid ejection head 22 has a relative height Hmax of its lowermost end with respect to the head holding portion 26.

[0095] A pressing portion 186 is provided at the lower end of the head holding portion.

[0096] The cap unit 180 includes a cap mechanism 181 , a cap pressing spring 189 , a liquid ejection head positioning member 182 , a positioning holding member 183 , a cap retracting member 184 , a cap retracting spring 185 , and a pressed portion 187 .

[0097] The capping mechanism 181 is a mechanism for capping the liquid ejection head 22 .

[0098] The cap pressing spring 189 is provided between the housing 190 of the liquid ejection device 1 and the capping mechanism 181, and is an elastic member that urges the capping mechanism 181 upward.

[0099] The liquid ejection head positioning member 182 is a member for positioning the liquid ejection head 22 at the cap position. When the positioning member 221 provided on the liquid ejection head 22 abuts against the liquid ejection head positioning member 182, the liquid ejection head 22 is positioned at the cap position.

[0100] The positioning and holding member 183 is a member for holding the liquid ejection head positioning member 182 .

[0101] The cap retraction member 184 is a rod-shaped member, and one tip 184a is provided with a pressed portion 187, and the other tip 184b presses the upper surface 181b of the protruding portion 181a of the cap mechanism 181 from above. In addition, a rotation shaft 188 provided on the positioning and holding member 183 passes through a bearing (not shown) provided near the center along the longitudinal direction of the cap retraction member 184. Therefore, the cap retraction member 184 is rotatable about the rotation shaft 188, and converts the up and down movement of the pressed portion 187 and one tip 184a into up and down movement of the other tip 184b in the opposite direction.

[0102] Between the housing 190 of the liquid ejection device 1 and one end portion 184a of the cap retraction member 184, a cap retraction spring 185 is provided for urging the end portion 184a upward.

[0103] In S2208 or S2320, the head holding part 26 descends (moves in the direction indicated by the arrow 42 in FIG. 24). In the state shown in FIG. 24 where the head holding part 26 descends to a position where the positioning member 221 abuts against the liquid ejection head positioning member 182, the pressing part 186 is separated from the pressed part 187. Therefore, a moment M1 due to the biasing force of the cap retracting spring 185 and a moment M2 due to the biasing force of the cap pressing spring 189 act on the cap retracting member 184, but no moment due to the head holding part 26 attempting to descend acts on the cap retracting member 184. Here, the moment M1 has a direction that rotates the cap retracting member 184 in the direction of the arrow 40, and the moment M2 has a direction that rotates the cap retracting member 184 in the opposite direction to the direction of the arrow 40 in FIG. 24 (the direction of the arrow 41 in FIG. 25). The biasing force of the cap retracting spring 185, the biasing force of the cap pressing spring 189, the distance between the tip 184a and the bearing, and the distance between the tip 184b and the bearing are set so that moment M1 is greater than moment M2. Therefore, these composite moments MA (=M1+M2) have a direction that tends to rotate the cap retracting member 184 in the direction of arrow 40. Therefore, in the state shown in FIG. 24, the protruding portion 181a of the cap mechanism 181 is biased downward by the tip 184b of the cap retracting member 184, and the cap mechanism 181 maintains a position spaced downward from the liquid ejection head 22.

[0104] 24 where the positioning member 221 abuts against the liquid ejection head positioning member 182, the head holding part 26 continues to descend. When the head holding part 26 descends from the position shown in Fig. 24 to a position spaced downward by the distance between the pressing part 186 and the pressed part 187 in the state of Fig. 24, the pressing part 186 starts pressing the pressed part 187.

[0105] As the head holding portion 26 descends, the pressing portion 186 presses the pressed portion 187 downward against the biasing force of the cap retracting spring 185. In other words, the pressing portion 186 presses the tip portion 184a downward via the pressed portion 187 so as to cancel the force of the cap retracting spring 185 biasing the tip portion 184a of the cap retracting member 184 from below. This releases the downward biasing force that the protruding portion 181a of the cap mechanism 181 receives from the tip portion 184b of the cap retracting member 184. Therefore, the cap mechanism 181 moves upward (in the direction indicated by the arrow 43 in FIG. 25) due to the upward biasing force of the cap pressing spring 189, and the cap retracting member 184 rotates as indicated by the arrow 41 in FIG. 25. Therefore, while the head holding portion 26 is descending, the cap mechanism 181 moves upward (in the direction indicated by the arrow 43 in FIG. 25) due to the upward biasing force of the cap pressing spring 189.

[0106] Then, the head holding portion 26 stops descending when it reaches the position shown in Fig. 25. At this time, the upward biasing force of the cap pressing spring 189 on the cap mechanism 181 is maintained.

[0107] Through the above operations, first, the liquid ejection head 22 is positioned relative to the cap unit 180. After that, the cap mechanism 181 abuts against the liquid ejection head 22 while maintaining this positioning. Therefore, only a compressive force is applied to the seal member (not shown) and the like disposed at the portion of the cap mechanism 181 that abuts against the liquid ejection head 22, and no shear force is applied thereto. Therefore, a good abutment state (i.e., sealing performance) can be ensured.

[0108] Second embodiment Fig. 26 is a diagram showing a state in which the liquid ejection head 22 is positioned at the capping position and the cap mechanism 181 included in the cap unit 180 is not in contact with the liquid ejection head 22 in another embodiment. Fig. 27 is a diagram showing a state in which the liquid ejection head 22 is positioned at the capping position and the cap mechanism 181 included in the cap unit 180 is in contact with the liquid ejection head 22 in another embodiment.

[0109] In the embodiment described above, in the state shown in Fig. 24, the cap mechanism 181 is biased downward by the cap retracting member 184. In the state shown in Fig. 25, the biasing force of the cap retracting member 184 against the cap mechanism 181 is released, and the cap mechanism 181 moves in the direction of arrow 43 due to the upward biasing force of the cap pressing spring 189.

[0110] 26, in this embodiment, a tip portion 184b of the cap retraction member 184 and a protrusion portion 181a of the cap mechanism 181 are connected via a link member 90. In the state shown in FIG 26, the cap mechanism 181 is retracted from the liquid ejection head 22 due to its own weight.

[0111] In the state shown in FIG. 27, the head holding part 26 has moved downward as shown by the arrow 42 with respect to the state shown in FIG. 26. The pressing part 186 of the head holding part 26 presses the pressed part 187 via the pressing spring 91 arranged on the tip part 184a of the cap retracting member 184 via the pressed part 187. In this way, the tip part 184a of the cap retracting member 184 can be pressed downward with a constant force via the pressing spring 91. The pressing spring 91 may be arranged on the pressing part 186 side of the head holding part 26, or on the pressed part 187 side of the cap retracting member 184. This pressing causes the cap retracting member 184 to rotate in the direction shown by the arrow 41 around the rotation shaft 188. This rotation causes the cap mechanism 181 to move upward as shown by the arrow 43 via the link of the link member 90, and the cap mechanism 181 comes into contact with the liquid ejection head 22.

[0112] (Other embodiments) In the above embodiment, a droplet ejection head that ejects droplets of ink has been described as an example, but the present disclosure is not limited to this, and a droplet ejection head that ejects droplets of a liquid other than ink may also be used.

[0113] <Technical Features of the Present Disclosure> The present disclosure includes the following configurations. [Configuration 1] a holding means for holding a discharge head for discharging liquid; a capping mechanism for capping an ejection surface of the ejection head; a positioning unit that positions the ejection head at a capping position for capping the ejection surface by the capping mechanism; a retracting member that, when in a first position, separates the capping mechanism from the ejection surface of the ejection head positioned at the capping position, and, when in a second position, brings the capping mechanism into contact with the ejection surface of the ejection head positioned at the capping position; Equipped with and in a state in which the ejection head is positioned at the capping position by the positioning device, the holding device is displaced relative to the ejection head, thereby causing the retracting member to change its position between the first position and the second position. Liquid discharge device.

[0114] [Configuration 2] When the ejection head is at a position separated from the capping position, the retracting member is in the first position. 2. The liquid ejection device according to configuration 1.

[0115] [Configuration 3] the holding means moves while maintaining a relative position of the discharge head with respect to the holding means, thereby moving the discharge head between the capping position and a position spaced from the capping position. 3. The liquid ejection device according to configuration 1 or 2.

[0116] [Configuration 4] The ejection head is held by the holding means so that the holding means and the ejection head can be displaced relatively in the same direction as the displacement of the holding means. The liquid ejection device according to any one of configurations 1 to 3.

[0117] [Configuration 5] the ejection head is biased so as to be displaced relative to the holding means in the same direction as a direction in which the ejection head moves from a position spaced from the capping position toward the capping position, a relative displacement of the ejection head with respect to the holding means in a direction from a position away from the capping position toward the capping position is limited at a predetermined relative position. A liquid ejection device according to configuration 4.

[0118] [Configuration 6] a first biasing member that biases the cap mechanism in a direction from a position spaced apart from the ejection surface of the ejection head positioned at the capping position by the positioning device toward a position in contact with the ejection surface of the ejection head positioned at the capping position by the positioning device; a second biasing member that biases the retracting member in a direction in which the retracting member changes its posture from the second posture to the first posture; Further comprising: when the ejection head is at a position separated from the capping position, a biasing force of the second biasing member via the retracting member acts on the capping mechanism stronger than a biasing force of the first biasing member, so that the capping mechanism is separated from the ejection surface of the ejection head positioned at the capping position by the positioning means. The liquid ejection device according to any one of configurations 1 to 5.

[0119] [Configuration 7] when the ejection head is positioned at the capping position by the positioning device, the holding device, which is displaced relative to the ejection head, applies a force to the retracting member in a direction that offsets the biasing force of the second biasing member, thereby causing the cap mechanism to come into contact with the ejection surface of the ejection head positioned at the capping position by the positioning device. 7. A liquid ejection device according to configuration 6.

[0120] [Configuration 8] When the ejection head is at a position separated from the capping position, the cap mechanism is separated by its own weight from the ejection surface of the ejection head positioned at the capping position by the positioning device. The liquid ejection device according to any one of configurations 1 to 7.

[0121] [Configuration 9] the cap mechanism is connected to the retracting member by a link member, when the ejection head is positioned at the capping position by the positioning device, the holding device, which is displaced relatively to the ejection head, applies a force to the retracting member that is greater than or equal to the force due to the ejection head's own weight, so that the cap mechanism comes into contact with the ejection surface of the ejection head positioned at the capping position by the positioning device. A liquid ejection device according to configuration 8.

[0122] [Configuration 10] The positioning means includes a positioning member provided on the ejection head and a positioning member provided on a tray. The liquid ejection device according to any one of configurations 1 to 9.

[0123] [Configuration 11] The positioning member of the ejection head is formed with three contact portions, The tray has three positioning members, the three contact portions formed on the positioning member of the ejection head come into contact with the three positioning members of the tray, respectively, thereby positioning the ejection head at the capping position. A liquid ejection device according to configuration 10. [Explanation of symbols]

[0124] 1 Liquid discharge device 18 Cap Tray 22 Liquid ejection head 26 Head holder

Claims

1. a holding means for holding a discharge head for discharging liquid; a capping mechanism for capping an ejection surface of the ejection head; a positioning unit that positions the ejection head at a capping position for capping the ejection surface by the capping mechanism; a retracting member that, when in a first position, separates the capping mechanism from the ejection surface of the ejection head positioned at the capping position, and, when in a second position, brings the capping mechanism into contact with the ejection surface of the ejection head positioned at the capping position; Equipped with and when the ejection head is positioned at the capping position by the positioning device, the holding device is displaced relative to the ejection head, thereby causing the retracting member to change its position between the first position and the second position. Liquid discharge device.

2. When the ejection head is at a position separated from the capping position, the retracting member is in the first position. The liquid ejection device according to claim 1 .

3. the holding means moves while maintaining a relative position of the discharge head with respect to the holding means, thereby moving the discharge head between the capping position and a position spaced from the capping position. The liquid ejection device according to claim 1 .

4. The ejection head is held by the holding means so that the holding means and the ejection head can be displaced relatively in the same direction as the displacement of the holding means. The liquid ejection device according to claim 1 .

5. the ejection head is biased so as to be displaced relative to the holding means in the same direction as a direction in which the ejection head moves from a position spaced from the capping position toward the capping position, a relative displacement of the ejection head with respect to the holding means in a direction from a position away from the capping position toward the capping position is limited at a predetermined relative position. The liquid ejection device according to claim 4 .

6. a first biasing member that biases the cap mechanism in a direction from a position spaced apart from the ejection surface of the ejection head positioned at the capping position by the positioning device toward a position in contact with the ejection surface of the ejection head positioned at the capping position by the positioning device; a second biasing member that biases the retracting member in a direction in which the retracting member changes its posture from the second posture to the first posture; Further comprising: when the ejection head is at a position separated from the capping position, a biasing force of the second biasing member via the retracting member acts on the capping mechanism stronger than a biasing force of the first biasing member, so that the capping mechanism is separated from the ejection surface of the ejection head positioned at the capping position by the positioning means. The liquid ejection device according to claim 1 .

7. when the ejection head is positioned at the capping position by the positioning device, the holding device, which is displaced relative to the ejection head, applies a force to the retracting member in a direction that offsets the biasing force of the second biasing member, thereby causing the cap mechanism to come into contact with the ejection surface of the ejection head positioned at the capping position by the positioning device. The liquid ejection device according to claim 6 .

8. When the ejection head is at a position separated from the capping position, the cap mechanism is separated by its own weight from the ejection surface of the ejection head positioned at the capping position by the positioning device. The liquid ejection device according to claim 1 .

9. the cap mechanism is connected to the retracting member by a link member, when the ejection head is positioned at the capping position by the positioning device, the holding device, which is displaced relatively to the ejection head, applies a force to the retracting member that is greater than or equal to the force due to the ejection head's own weight, so that the cap mechanism comes into contact with the ejection surface of the ejection head positioned at the capping position by the positioning device. The liquid ejection device according to claim 8.

10. The positioning means includes a positioning member provided on the ejection head and a positioning member provided on a tray. The liquid ejection device according to claim 1 .

11. The positioning member of the ejection head is formed with three contact portions, The tray has three positioning members, the three contact portions formed on the positioning member of the ejection head come into contact with the three positioning members of the tray, respectively, thereby positioning the ejection head at the capping position. The liquid ejection device according to claim 10.

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