JP2014104665A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both reduction of a waste liquid amount and damage prevention of a discharge surface when wiping the discharge surface.SOLUTION: An inkjet printer 1 includes: heads 10a and 10b each of which has a discharge surface 10x; a wiper 36a for wiping the discharge surface 10x; and a liquid reception part 42 having a facing surface 42a that faces the discharge surface 10x. The printer 1 performs preliminary discharge of liquid to the facing surface 42a and then starts recording operation. After that, the printer 1 stops the recording operation, and then, with the wiper 36a, wipes the facing surface before wiping the discharge surface.

Description

  The present invention relates to a liquid ejection apparatus that ejects a liquid such as ink.

  In a liquid ejection apparatus, after purging to discharge liquid from the ejection port by applying pressure to the liquid in the liquid ejection head in order to remove foreign matter (paper dust etc.) adhering to the ejection surface of the liquid ejection head A technique for wiping (wiping cleaning) the ejection surface with a wiper is known (see Patent Document 1).

JP 2012-91410 A (paragraph 0093)

  According to the above technique, by performing purging in advance before wiping the ejection surface, it is possible to perform wiping on the ejection surface while a part of the liquid discharged by the purge is held on the ejection surface. Therefore, at the time of wiping the discharge surface, the frictional resistance between the wiper and the discharge surface can be suppressed, and damage to the discharge surface can be prevented. However, since a relatively large amount of liquid is discharged in the purge, the amount of waste liquid increases, which is uneconomical.

  An object of the present invention is to provide a liquid ejection apparatus capable of realizing both reduction of the amount of waste liquid and prevention of damage to the ejection surface during wiping the ejection surface.

  In order to achieve the above object, according to an aspect of the present invention, a liquid discharge head having a discharge surface with a plurality of discharge ports from which liquid is discharged, a wiper for wiping the discharge surface, and the discharge surface are opposed to each other. A liquid receiving portion having a facing surface and receiving the liquid discharged from the discharge port on the facing surface; and a control means for controlling the liquid discharge head and the wiper, wherein the control means is a recording medium. A preliminary ejection step of controlling the liquid ejection head based on preliminary ejection data different from the image data recorded in the image, ejecting liquid from the ejection port, and receiving the liquid by the facing surface; The wiper is controlled after the preliminary ejection step so that the wiper wipes the opposing surface, and the wiper is controlled after the opposing surface wiping step, and the wiper The wipes opposing surface the ejection surface by wiping portion to be characterized by performing the discharge surface wiping step, the liquid discharge apparatus is provided.

  According to the above aspect, the preliminary ejection and the wiping of the opposing surface are performed in this order, and then the ejection surface is wiped, whereby the ejection surface can be wiped in a state where the liquid related to the preliminary ejection adheres to the wiper. . Therefore, at the time of wiping the discharge surface, the frictional resistance between the wiper and the discharge surface can be suppressed, and damage to the discharge surface can be prevented. Further, the preliminary discharge has a smaller amount of waste liquid than the purge, and can reduce the amount of waste liquid. Therefore, according to the said viewpoint, both reduction of the amount of waste liquids and prevention of damage to the discharge surface at the time of wiping the discharge surface can be realized.

  The liquid discharge apparatus of the present invention may further include a pressure applying unit that performs a purge for discharging the liquid from the discharge port by applying a pressure to the liquid in the liquid discharge head. In this case, the control means performs the purge by controlling the pressure applying unit in a period other than a period in which a series of steps of the preliminary ejection step, the facing surface wiping step, and the ejection surface wiping step is performed. It is preferable. Thus, by performing the purge that increases the amount of waste liquid during the above period, it is possible to reliably reduce the amount of waste liquid when wiping the discharge surface.

  The control means performs the preliminary ejection step after receiving the recording command and before controlling the liquid ejection head based on image data recorded on a recording medium to eject liquid from the ejection port. Is preferred. As described above, by performing preliminary discharge after recording is received and before recording is performed, a liquid meniscus is satisfactorily formed at the discharge port, and the recording quality can be improved. In addition, since the discharge surface can be prevented from being damaged when the discharge surface is wiped by using the liquid related to the preliminary discharge performed for improving the recording quality, the amount of waste liquid can be more reliably reduced. .

  The liquid ejection device according to the present invention includes the plurality of ejection ports together with the liquid receiving unit when the liquid receiving unit and the facing surface of the liquid receiving unit face the ejection surface with a gap therebetween. A cap mechanism that includes a partition portion that partitions the gap from an external space, wherein the partition portion can take a partition state in which the gap is partitioned from the external space and an open state in which the partition portion opens the gap to the external space. You may have more. In this case, after the recording command is received, the control means controls the liquid discharge head based on image data recorded on the recording medium and before discharging the liquid from the discharge port, It is preferable that an uncapping step for controlling and taking the open state is performed, and the preliminary ejection step is performed after the uncapping step. Accordingly, since the liquid receiving portion is an element constituting the cap mechanism, it is not necessary to provide the liquid receiving portion separately from the cap mechanism, and the configuration can be simplified. Moreover, the structure which makes an opposing surface and an ejection surface oppose at the time of the preliminary discharge after uncapping can be implement | achieved by simple operation | movement.

  The control means performs a determination step of determining whether or not a predetermined time has elapsed after the preliminary discharge step is performed after the preliminary discharge step and before the opposing surface wiping step. When it is determined that the predetermined time has elapsed, before the opposing surface wiping step, the liquid discharge head is controlled based on the preliminary discharge data to discharge liquid from the discharge port, and the liquid is It is preferable to further perform a re-pre-discharge step received by the opposite surface. When a predetermined time elapses after the preliminary ejection, the liquid received on the ejection surface dries, and it is considered that the liquid is difficult to adhere to the wiper when the opposing surface is wiped. Therefore, as described above, when a predetermined time has elapsed since the preliminary ejection, the preliminary ejection is performed again before the opposing surface wiping, so that the liquid adheres to the wiper during the opposing surface wiping, and the ejection surface wiping is performed. It is possible to reliably prevent the discharge surface from being damaged.

  The liquid ejection device according to the present invention reverses the wiper in the vicinity of the opposing surface and an end portion of the ejection surface in the first direction along the wiping direction by the wiper so as to contact the opposing surface of the wiper. A wiper reversing mechanism may be further provided for changing the contact surface from a state facing the first direction to a second direction opposite to the first direction. In this case, the control means controls the wiper in the facing surface wiping step, moves the wiper in the first direction in a state where the contact surface is in contact with the facing surface, and wipes the facing surface. After the step, before the discharge surface wiping step, the wiper is reversed by the wiper reversing mechanism, and the wiper is controlled in the discharge surface wiping step so that the wiper is brought into contact with the discharge surface. It is preferable to move in the second direction in contact. Accordingly, a series of steps of wiping the opposing surface and wiping the discharge surface can be performed smoothly by moving (reciprocating) the wiper in the first direction and the second direction.

  The liquid discharge head may be a line type head, and the discharge surface may be long in the first direction and the second direction. As a result, even in the case of a long head such as a line type head, it is possible to effectively remove foreign matters on the ejection surface while wiping the ejection surface while suppressing the width of the wiper.

  According to the present invention, the preliminary ejection and the wiping of the opposing surface are performed in this order, and then the ejection surface is wiped, so that the ejection surface can be wiped in a state where the liquid related to the preliminary ejection adheres to the wiper. Therefore, at the time of wiping the discharge surface, the frictional resistance between the wiper and the discharge surface can be suppressed, and damage to the discharge surface can be prevented. Further, the preliminary discharge has a smaller amount of waste liquid than the purge, and can reduce the amount of waste liquid. Therefore, according to the said viewpoint, both reduction of the amount of waste liquids and prevention of damage to the discharge surface at the time of wiping the discharge surface can be realized.

1 is a schematic side view showing an internal structure of an ink jet printer according to an embodiment of the present invention. It is a top view which shows the flow path unit contained in each head of 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 a side view for demonstrating operation | movement of a cap mechanism and a platen. It is a side view of the wiper drive mechanism which functions as a wiper inversion mechanism, and three wiper units fixed to the wiper drive mechanism. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. (A) is preliminary discharge, (b) is wiping opposite surface, (c) is a partial side view of the vicinity of the head for explaining discharge surface wiping. It is a flowchart which shows the control which a controller performs.

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

  First, an overall configuration of an ink jet printer 1 according to an embodiment 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. In the internal space of the housing 1a, two heads 10a and 10b, two platens 5, two cap mechanisms 40, a paper sensor 32, a controller 1p, a transport mechanism 20, a paper feed unit 1c, and the like are accommodated. In the internal space of the housing 1a, a transport path for transporting the paper P is formed from the paper feed unit 1c toward the paper discharge unit 31 along the thick arrow shown in FIG. Although not shown in FIG. 1, two wiper driving mechanisms 50 (see FIG. 6) are arranged in the internal space of the housing 1a. As will be described later, three wiper units 36 are fixed to each wiper drive mechanism 50.

  The heads 10a and 10b are line heads having the same structure and having a substantially rectangular parallelepiped shape elongated in the main scanning direction (direction perpendicular to the paper surface of FIG. 1). A plurality of discharge ports 14a are opened on the lower surfaces (discharge surfaces 10x) of the heads 10a and 10b (see FIGS. 3 and 4). Pretreatment liquid and black ink (hereinafter, these may be collectively referred to as “liquid”) are discharged from the discharge ports 14a of the heads 10a and 10b, respectively. The pretreatment liquid is a liquid having a function of preventing bleeding and back-through of the ink by aggregating pigment pigments in the ink and a function of improving the color development property and quick drying property of the ink. The pretreatment liquid may contain a cationic polymer or a polyvalent metal salt such as a magnesium salt.

  The heads 10 a and 10 b are arranged apart from each other in the sub-scanning direction (a direction perpendicular to the main scanning direction and the vertical direction), and are supported by the housing 1 a via the holder 3. The holder 3 supports the heads 10 a and 10 b so that a predetermined gap suitable for recording (image formation) is formed between the ejection surface 10 x and the support surface 5 a of the platen 5. The holder 3 further supports a partition 41 provided in each head 10a, 10b. The partition 41 is an annular member that surrounds the outer periphery of the discharge surface 10 x and constitutes a part of the cap mechanism 40.

  The platen 5 is provided for each of the heads 10a and 10b, and is disposed below the corresponding heads 10a and 10b. Each platen 5 is composed of two plates 6a and 6b. The plates 6a and 6b are rotatable about axes 7a and 7b extending in the main scanning direction, respectively. Each platen 5 is rotated by driving a platen rotation motor 5M (see FIG. 7) under the control of the controller 1p. At this time, the platen 5 can take a support surface forming position (FIG. 1) and an open position (FIG. 5B). At the support surface forming position, the tips of the plates 6a and 6b are abutted with each other, and a support surface 5a for supporting the paper P is formed. The support surface 5a is opposed to the ejection surface 10x with a predetermined gap, and has a planar shape as a whole. In the open position, the plates 6a and 6b hang downward. The platen 5 is disposed at a support surface forming position during recording, and at an open position when capping, wiping, preliminary ejection, purging, etc. described later are performed.

  The cap mechanism 40 is provided for each of the heads 10a and 10b. Each cap mechanism 40 includes a liquid receiving portion 42 and a partition portion 41. The liquid receiving portion 42 is a rectangular plate that is slightly larger than the partition portion 41 and has substantially the same size as the platen 5, and is disposed below the corresponding heads 10a and 10b. The liquid receiving part 42 is made of a material that does not absorb or hardly absorbs moisture (for example, glass, metal, etc.). The partition 41 is made of an elastic material such as rubber. A more specific configuration and operation of the cap mechanism 40 will be described in detail later.

  The transport mechanism 20 includes roller pairs 22, 23, 24, 25, 26, 27, guides 29 a, 29 b, 29 c, 29 d, 29 e, and an intermediate roller 21. The roller pairs 22 to 27 are arranged in this order from the upstream side in the transport direction so as to form a transport path. One roller of each of the roller pairs 23 to 27 is a drive roller, and is connected to the transport motor 20M (see FIG. 7). The drive roller is rotated by driving the carry motor 20M under the control of the controller 1p. The other roller of each of the roller pairs 23 to 27 is a driven roller and rotates with the rotation of the driving roller. The guides 29a to 29e are arranged in this order from the upstream side in the transport direction so as to form a transport path. Each of the guides 29a to 29e includes a pair of plates that are spaced apart from each other in the surface direction. The intermediate roller 21 is disposed at a position above the transport path between the head 10a and the roller pair 24. The intermediate roller 21 is, for example, a spur roller, and guides the paper P, on which the pretreatment liquid has landed, to the roller pair 24 so that the surface does not come into contact with other portions.

  The paper feed unit 1c has a paper feed tray 1c1 and a paper feed roller 1c2. Among these, the paper feed tray 1c1 is detachable from the housing 1a. The paper feed tray 1c1 is a box whose upper surface is open and can accommodate a plurality of papers P. The paper feed roller 1c2 is rotated by driving a paper feed motor 1cM (see FIG. 7) under the control of the controller 1p, and feeds the uppermost paper P in the paper feed tray 1c1.

  In addition to a CPU (Central Processing Unit) which is an arithmetic processing unit, the controller 1p includes a ROM (Read Only Memory), a RAM (Random Access Memory: including a nonvolatile RAM), an ASIC (Application Specific Integrated Circuit), an I / F ( Interface), I / O (Input / Output Port), built-in timer for measuring time, and the like. The ROM stores programs executed by the CPU, various fixed data, and the like. The RAM temporarily stores data (image data and the like) necessary for executing the program. In the ASIC, image data is rewritten and rearranged (for example, signal processing and image processing). The I / F performs data transmission / reception with an external device (such as a PC connected to the printer 1). I / O inputs / outputs detection signals of various sensors. Note that the controller 1p does not include an ASIC, and image data rewriting and rearrangement may be processed by a program executed by the CPU.

  Based on a recording command supplied from an external device, the controller 1p is a liquid synchronized with a preparation operation related to recording, supply / conveyance / discharge operation of the paper P, and conveyance of the paper P so that an image is formed on the paper P. Controls the discharge operation and the like. The paper P is sent out from the paper supply unit 1c and is transported in the transport direction by the roller pairs 22 to 27 and the guides 29a to 29e. When the sheet P passes directly below the heads 10a and 10b (on the support surface 5a), liquid is sequentially discharged from the discharge port 14a (see FIG. 4) under the control of the controller 1p, so that an image is formed on the surface. It is formed. The liquid discharge operation from the discharge port 14 a is performed based on a paper leading edge detection signal from the paper sensor 32. The paper P on which the image is formed is discharged to the paper discharge unit 31 through the opening 30 formed in the upper part of the housing 1a.

  Next, the configuration of the heads 10a and 10b will be described in detail with reference to FIGS. In FIG. 3, the pressure chamber 16 and the aperture 15 which are located below the actuator unit 17 and should be indicated by dotted lines are indicated by solid lines.

  Each head 10a, 10b includes a flow path unit 12, eight actuator units 17, eight FPCs (flat flexible substrates) 19, a reservoir unit, a circuit board, and the like.

  The channel unit 12 is a laminated body in which nine rectangular metal plates 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, and 12i having substantially the same size are stacked, and a channel is formed therein. ing. The flow path includes a manifold flow path 13, a sub-manifold flow path 13 a, and an individual flow path 14. An opening 12 y is formed on the upper surface 12 x of the flow path unit 12. The manifold channel 13 has an opening 12y at one end and branches into a plurality of sub-manifold channels 13a at the other end. The individual flow path 14 is provided for each discharge port 14a, and reaches from the outlet of the sub-manifold flow path 13a to the discharge port 14a via the aperture 15 and the pressure chamber 16 that are flow-path resistance restrictors. It is a flow path. The lower surface of the flow path unit 12 opposite to the upper surface 12x is the discharge surface 10x.

  One pressure chamber 16 is connected to one discharge port 14a. The opening of the pressure chamber 16 has a substantially rhombus shape. The pressure chambers 16 are arranged in a matrix on the upper surface 12x and constitute a pressure chamber group. The area occupied by the pressure chamber group corresponds to the fixed area of the actuator unit 17. The opening of each pressure chamber 16 is sealed with an actuator unit 17. The discharge ports 14a are arranged in a matrix in the region facing the fixed region of the actuator unit 17 on the discharge surface 10x.

  As shown in FIG. 2, the eight actuator units 17 are arranged in a zigzag pattern in two rows along the main scanning direction, and are fixed to the upper surface 12x. Each actuator unit 17 is a laminate of two piezoelectric layers each having a trapezoidal outer shape. Of the two piezoelectric layers, the piezoelectric layer far from the pressure chamber 16 is sandwiched between the common electrode and the individual electrodes. The common electrode is formed on a surface near the pressure chamber 16 in the piezoelectric layer, and the individual electrode is formed on a surface far from the pressure chamber 16 in the piezoelectric layer. The individual electrode is provided for each pressure chamber 16 and is disposed to face the pressure chamber 16. A portion sandwiched between each individual electrode and each pressure chamber 16 in the actuator unit 17 functions as an individual unimorph actuator for each pressure chamber 16. Each actuator can be deformed independently, and when a drive voltage is applied via the FPC 19, the actuator is unimorph-deformed to change the volume of the corresponding pressure chamber 16. At this time, energy is applied to the liquid in the pressure chamber 16, and the liquid is discharged from the discharge port 14a.

  The eight FPCs 19 are connected to each of the eight actuator units 17. In FIG. 4, the FPC 19 is depicted as being in contact with the actuator unit 17, but in reality, a slight gap is provided between the two. Each FPC 19 has one end fixed to the actuator unit 17 and the other end fixed to the circuit board, and a driver IC is mounted in the middle thereof. The circuit board adjusts the signal input from the controller 1p, and outputs the adjusted signal to the driver IC via the wiring of the FPC 19. The driver IC converts this signal into a drive signal and transmits the drive signal to each electrode of the actuator unit 17.

  A flow path including a reservoir is formed inside the reservoir unit. One end of the flow path is connected to the cartridge via a tube or the like, and the other end is connected to the flow path of the flow path unit 12. The reservoir temporarily stores liquid supplied from a cartridge (not shown). Irregularities are provided on the lower surface of the reservoir unit. As for the convex part, the front end surface is being fixed to the upper surface 12x so that the actuator unit 17 may be avoided. A flow path connected to the reservoir opens at the front end surface of the convex portion and is connected to the opening 12y. The recess faces the upper surface 12x, the surface of the actuator unit 17, and the surface of the FPC 19 with a slight gap therebetween.

  Next, the configuration of the cap mechanism 40, the configuration of the wiper drive mechanism 50, the configuration of the wiper unit 36, and the capping, wiping, preliminary discharge, and purge operations will be described with reference to FIGS. .

  Of the cap mechanism 40, the partition portion 41 includes a portion fixed over the entire circumference of the side surface of the corresponding head 10a, 10b, and a portion movable along the side surface. The partition portion 41 includes all the discharge ports 14a formed on the discharge surface 10x together with the liquid reception portion 42 when the liquid reception portion 42 is in the first position described below, and is separated from the external space V2 by a gap (discharge surface). A discharge space V1) facing 10x is defined (capping). The partition unit 41 is connected to a plurality of gears (not shown), and moves up and down under the control of the controller 1p by driving the partition unit lifting motor 41M (see FIG. 7).

  Of the cap mechanism 40, the liquid receiving portion 42 has a facing surface 42a that faces the ejection surface. The liquid receiving unit 42 is moved up and down by driving a liquid receiving unit lifting motor 42M (see FIG. 7) under the control of the controller 1p. The liquid receiving portion 42 is disposed at any one of the first position, the second position, the third position, and the fourth position (see FIG. 5). The first position is at the uppermost position, the second position is at the second highest position, the third position is at the third highest position, and the fourth position is at the lowest position.

  The liquid receiving portion 42 is disposed at the first position when capping or preliminary ejection is performed, is disposed at the second position when wiping the opposing surface 42a is performed, and third when wiping or purging the ejection surface 10x is performed. It is arranged at the position, and is arranged at the fourth position at the time of recording. The separation distance between the facing surface 42a and the ejection surface 10x when the liquid receiving portion 42 is disposed at the first position is equal to the separation distance between the support surface 5a and the ejection surface 10x during recording.

  The cap mechanism 40 has a partition state in which the partition portion 41 partitions the discharge space V1 from the external space V2 (see FIG. 5B), and an open state in which the partition portion 41 opens the discharge space V1 to the external space V2 (FIG. 5). (See (a)). Capping refers to bringing the cap mechanism 40 into a partitioned state. Uncapping means that the cap mechanism 40 is opened. When the controller 1p places the cap mechanism 40 in the partitioned state, as shown in FIG. 5 (b), the controller 1p moves the partition portion 41 with the platen 5 in the open position and the liquid receiving portion 42 in the first position. Lower. Thereby, the discharge space V1 is formed between the opposed surface 42a and the ejection surface 10x by the tip 41a of the partition part 41 coming into contact with the opposed surface 42a. By capping, drying of the discharge space V1 is prevented, and the increase in the viscosity of the liquid in the discharge port 14a is suppressed.

  Preliminary ejection refers to an operation of driving the actuator unit 17 and ejecting liquid from the ejection port 14a based on preliminary ejection data different from recording data (image data). In the present embodiment, the purge means that the liquid is sent to the heads 10a and 10b by driving the pumps 2Pa and 2Pb (see FIG. 7) disposed between the liquid tank (not shown) and the heads 10a and 10b. It refers to an operation of discharging liquid from the discharge port 14a by applying pressure to the liquid in 10a and 10b. Preliminary ejection or purging discharges the thickened liquid in the ejection port 14a or liquid mixed with foreign matter (dust, bubbles, etc.) and restores the ejection performance.

  When the controller 1p performs preliminary discharge, the platen 5 is disposed in the open position and the liquid receiving portion 42 is disposed in the first position, and the tip 41a of the partition 41 is at the same height as the discharge surface 10x or above the discharge surface 10x. In this state, the actuator units 17 of the heads 10a and 10b are driven. When purging, the controller 1p has the platen 5 in the open position and the liquid receiving portion 42 in the third position, and the tip 41a of the partition portion 41 is at the same height as the discharge surface 10x or above the discharge surface 10x. In a certain state, the pumps 2Pa and 2Pb are driven. The liquid discharged by the preliminary discharge or purge is received by the facing surface 42a.

  The purging is performed during a period other than a period during which a series of steps S3 (preliminary ejection step), S10 (opposing surface wiping step), and S11 (ejection surface wiping step) described later is performed. For example, the purge may be performed when a recording command is not received for a predetermined period or longer.

  Wiping refers to an operation of removing foreign matter on the object by moving the wiper 36a (see FIG. 6) relative to the object while abutting the wiper 36a (see FIG. 6). Wiping includes wiping the discharge surface 10x and wiping the opposing surface 42a. The wiper 36 a is included in the wiper unit 36.

  Here, the configuration of the wiper unit 36 and the wiper drive mechanism 50 will be described. The wiper drive mechanism 50 is provided slightly below the ejection surface 10x for each of the two heads 10a and 10b. As shown in FIG. 6, the wiper drive mechanism 50 includes a pair of rollers 51 a and 51 b having rotation axes that are separated from each other in the main scanning direction and extend in the sub-scanning direction. The pair of rollers 51a and 51b are disposed in the vicinity of the ends of the facing surface 42a and the ejection surface 10x along the main scanning direction. Two flexible narrow belts 52a and 52b that are spaced apart from each other in the sub-scanning direction are wound around the outer peripheral surfaces of the pair of rollers 51a and 51b (in FIG. 6, two belts are used). 52a and 52b overlap and appear as one). These two belts 52a and 52b are disposed slightly outside the head 10a (or the head 10b) along the sub-scanning direction.

  A gear 54 is coaxially fixed to the rotation shaft of the roller 51a. The gear 54 meshes with a gear 55 connected to the wiper drive motor 36M (see FIG. 7). Accordingly, by rotating the wiper drive motor 36M, the two belts 52a and 52b travel around the pair of rollers 51a and 51b. That is, the roller 51a is a driving roller, and the roller 51b is a driven roller.

  Three wiper units 36 are attached to the wiper drive mechanism 50. The wiper unit 36 includes a wiper 36a and a base portion 36c that is a member that supports the wiper 36a. The wiper 36a is a plate-like member made of an elastic body (such as rubber) and is slightly longer than the lengths of the ejection surface 10x and the opposing surface 42a in the sub-scanning direction. The tip of the wiper 36a is cut obliquely, and the surface formed by the cut is a contact surface 36ax that contacts the facing surface 42a and the discharge surface 10x.

  The base portion 36c has substantially the same length as the wiper 36a in the sub-scanning direction. Through holes extending in the main scanning direction are formed at positions corresponding to the two belts 52a and 52b in the vicinity of both ends of the base portion 36c. The two belts 52a and 52b are fitted into these through holes, so that the base portion 36c is fixed at a predetermined position of the two belts 52a and 52b. Accordingly, the wiper unit 36 moves as the two belts 52a and 52b travel.

  The three wiper units 36 are arranged at equal intervals in the circumferential direction of the two belts 52a and 52b. In the state shown in FIG. 6, the wipers 36a of the two wiper units 36 are located in the lower horizontal portion of the two belts 52a and 52b. These wipers 36a protrude downward from the two belts 52a and 52b, and their contact surfaces 36ax face the right direction (first direction) in FIG. 6 along the main scanning direction. When these wiper units 36 pass the roller 51a as the two belts 52a and 52b travel counterclockwise, the wiper 36a moves to the upper horizontal portion of the two belts 52a and 52b and moves upward. The abutting surface 36ax protrudes to the left in FIG. 6 (second direction) along the main scanning direction.

  In the state shown in FIG. 6, the wiper 36a of the remaining one wiper unit 36 is positioned on the upper horizontal portion of the two belts 52a and 52b. The wiper 36a protrudes upward from the two belts 52a and 52b, and the contact surface 36ax faces the left direction (second direction) in FIG. 6 along the main scanning direction. When the wiper unit 36 passes the roller 51b as the two belts 52a and 52b travel counterclockwise, the wiper 36a moves to the lower horizontal portion of the two belts 52a and 52b and moves downward. The abutting surface 36ax protrudes in the right direction (first direction) in FIG. 6 along the main scanning direction. Thus, the wiper drive mechanism 50 functions as a wiper reversing mechanism. As the two belts 52a and 52b travel counterclockwise, the three wipers 36a have a first contact surface 36ax whose orientation is the first. A reciprocating motion is performed so as to alternate between the direction and the second direction.

  Next, the control executed by the controller 1p will be described with reference to FIGS.

  The controller 1p first determines whether or not a recording command has been received (S1). When receiving the recording command (S1: YES), the controller 1p performs uncapping when the cap mechanism 40 is in the partitioned state (S2). Specifically, the controller 1p raises the partition part 41 with the platen 5 in the open position and the liquid receiving part 42 in the first position. If it is determined in S1 that the recording command has been received, the controller 1p skips S2 and advances the process to S3.

  After S2, the controller 1p controls each unit so that preliminary discharge is performed (S3: preliminary discharge step). Specifically, the controller 1p includes the platen 5 in the open position and the liquid receiving portion 42 in the first position, and the tip 41a of the partition portion 41 is at the same height as the discharge surface 10x or above the discharge surface 10x. In a certain state, the actuator unit 17 is driven to perform preliminary discharge. At this time, the controller 1p controls the wiper drive motor 36M to change one of the three wipers 36a to the lower horizontal portion of the two belts 52a and 52b in the head 10a ( Alternatively, it is positioned near the upstream end of the head 10b). (See FIG. 8 (a)).

  After S3, the controller 1p controls each unit so that the recording operation is started (S4). Specifically, the controller 1p moves the platen 5 from the open position to the support surface forming position after moving the liquid receiving portion 42 from the first position to the fourth position. Thereafter, the controller 1p controls the transport mechanism 20 so that the paper P is transported along the transport path, and at the same time the head 10a, so that the liquid is ejected from the ejection port 14a based on the image data included in the recording command. 10b is controlled.

  After S4, the controller 1p determines whether or not the number of sheets P to be recorded (scheduled number of recordings) exceeds X (a predetermined natural number, such as 100, 500, etc.) based on the recording command (S5). . When the scheduled recording number is X or less (S5: NO), the controller 1p advances the process to S14.

  When the scheduled number of recordings exceeds X (S5: YES), the controller 1p determines whether or not recording of nX (n = arbitrary natural number) sheets P has been completed (S6). When the recording of nX sheets P is completed (S6: YES), the controller 1p controls each unit so that the recording operation is stopped (S7). After S7, the controller 1p determines whether or not a predetermined time has elapsed since the preliminary ejection was performed in S3 (S8). When the predetermined time has not elapsed (S8: NO), the controller 1p skips S9 and proceeds to S10.

  When the predetermined time has elapsed (S8: YES), the controller 1p controls each unit so that re-preliminary discharge is performed (S9). Specifically, the controller 1p moves the platen 5 from the support surface forming position to the open position, and then moves the liquid receiving unit 42 from the fourth position to the first position. Thereafter, similarly to the case of S3, the controller 1p drives the actuator unit 17 to perform preliminary discharge.

  After S9, the controller 1p controls each part so that the facing surface 42a is wiped (S10: facing surface wiping step). Specifically, the controller 1p moves the liquid receiving portion 42 from the first position to the second position, and raises the heads 10a and 10b together with the holder 3 by driving the head lifting motor 10M (see FIG. 7). Thereafter, the controller 1p controls the wiper drive motor 36M to run the two belts 52a and 52b counterclockwise. As a result, the wiper 36a waiting in the vicinity of the upstream end of the head 10a (or head 10b) in the first direction moves in the first direction to the vicinity of the downstream end of the head 10a (or head 10b) (FIG. 8). (See (b)). At this time, the wiper 36a bends in the vicinity of the tip due to contact with the opposing surface 42a, and moves relative to the opposing surface 42a while the contact surface 36ax contacts the opposing surface 42a. Thereby, the foreign material on the opposing surface 42a is removed. In the present embodiment, the counter surface wiping is performed only once (one movement of the one wiper 36a in the first direction). However, by continuously rotating the belts 52a and 52b, 3 The opposing surface wiping may be continuously performed a plurality of times using two wipers 36a.

  Further, the controller 1p controls the wiper drive motor 36M to cause the two belts 52a and 52b to travel further counterclockwise even after the wiper 36a has passed through the facing surface 42a. As a result, the wiper unit 36 passes the roller 51a, and the wiper 36a is reversed. When the wiper 36a is positioned in the vicinity of the upstream end of the head 10a (or the head 10b) in the second direction, the traveling of the two belts 52a and 52b is stopped. Thereafter, the process proceeds to S11.

  In S11, the controller 1p controls each unit so that the ejection surface 10x is wiped (S11: ejection surface wiping step). Specifically, the controller 1p moves the liquid receiving portion 42 from the second position to the third position, and lowers the heads 10a and 10b together with the holder 3 by driving the head lifting motor 10M (see FIG. 7). Thereafter, the controller 1p controls the wiper drive motor 36M to run the two belts 52a and 52b counterclockwise. As a result, the wiper 36a waiting in the vicinity of the upstream end of the head 10a (or head 10b) in the second direction moves in the second direction to the vicinity of the downstream end of the head 10a (or head 10b) (FIG. 8). (See (c)). At this time, the wiper 36a is bent near the tip due to contact with the discharge surface 10x, and the contact surface 36ax (the portion in contact with the opposing surface 42a in S10) is in contact with the discharge surface 10x while being in contact with the discharge surface 10x. Move relatively. Thereby, the foreign material on the ejection surface 10x is removed. The controller 1p stops the wiper 36a in the second direction in the vicinity of the downstream end of the head 10a (or the head 10b). In the present embodiment, the ejection surface wiping is performed only once (one movement of one wiper 36a in the second direction). However, by continuously rotating the belts 52a and 52b, 3 The discharge surface wiping may be continuously performed a plurality of times using two wipers 36a.

  After S11, the controller 1p controls each unit so that the recording operation is resumed (S12). Specifically, the controller 1p moves the platen 5 from the open position to the support surface forming position after moving the liquid receiving portion 42 from the third position to the fourth position. Thereafter, the controller 1p controls the transport mechanism 20 so that the paper P is transported along the transport path, and at the same time the head 10a, so that the liquid is ejected from the ejection port 14a based on the image data included in the recording command. 10b is controlled.

  After S12, the controller 1p determines whether or not the number of remaining sheets P to be recorded (remaining scheduled recording number) exceeds X (for example, 100, 500, etc.) based on the recording command (S13). . When the remaining scheduled number of recordings is X or less (S13: NO), the controller 1p advances the process to S14. When the remaining scheduled number of recordings exceeds X (S13: YES), the controller 1p returns the process to S6.

  In S14, the controller 1p determines whether or not the recording of the paper P based on the recording command is completed. When the recording is completed (S14: YES), the controller 1p ends the routine.

  As described above, according to the present embodiment, the preliminary discharge and the wiping of the facing surface 42a are performed in this order, and then the discharge surface 10x is wiped, whereby the liquid related to the preliminary discharge adheres to the wiper 36a. The discharge surface 10x can be wiped in a state. Therefore, when wiping the discharge surface 10x, it is possible to suppress the frictional resistance between the wiper 36a and the discharge surface 10x and prevent the discharge surface 10x from being damaged. Further, the preliminary discharge has a smaller amount of waste liquid than the purge, and can reduce the amount of waste liquid. Therefore, according to the present embodiment, it is possible to reduce both the amount of waste liquid and prevent damage to the ejection surface 10x when wiping the ejection surface 10x.

  In this embodiment, since the purge is performed in a period other than the period in which the series of steps of the preliminary ejection step, the facing surface wiping step, and the ejection surface wiping step is performed, the amount of waste liquid during the wiping of the ejection surface 10x is reduced. Can be realized reliably.

  Further, by performing preliminary discharge after recording command reception and before recording on the paper P, a liquid meniscus is satisfactorily formed at the discharge port 14a, and the recording quality can be improved. In addition, it is possible to prevent damage to the ejection surface 14a during wiping of the ejection surface by using a liquid related to preliminary ejection performed for improving the recording quality, so that the amount of waste liquid can be more reliably reduced. it can.

  Further, in the ink jet printer 1 according to the present embodiment, since the liquid receiving portion 42 is an element constituting the cap mechanism 40, it is not necessary to provide the liquid receiving portion 42 separately from the cap mechanism 40, and the configuration can be simplified. Can be realized. In addition, a configuration in which the facing surface 42a and the ejection surface 10x are opposed to each other at the time of preliminary ejection after uncapping can be realized with a simple operation.

  Further, in the present embodiment, when a predetermined time has elapsed since the preliminary discharge is performed, the preliminary discharge is performed again before the counter surface wiping, so that the liquid adheres to the wiper 36a during the counter surface wiping. Accordingly, it is possible to reliably prevent the discharge surface 10x from being damaged when the discharge surface is wiped.

  In this embodiment, the series of steps of wiping the opposing surface and wiping the discharge surface can be performed smoothly by moving the wiper 36a in the first direction and the second direction (reciprocating).

  Further, even when the long line type heads 10a and 10b are provided as in the ink jet printer 1 according to the present embodiment, the width of the wiper 36a is suppressed and the discharge surface 10x is removed when the discharge surface is wiped. The foreign matter can be effectively removed.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims.

The wiper may move relatively in the width direction of the ejection surface and / or the opposing surface.
The wiper reversing mechanism is not limited to the form integrated with the wiper driving mechanism 50 described above, and can be arbitrarily changed.
Only one wiper may be attached to the wiper drive mechanism 50.
-A cap mechanism is not limited to the form mentioned above. For example, when the transport mechanism is a belt transport type, the cap mechanism may be configured by the partition portion 41 and the transport belt. In this case, the discharge space V1 is defined between the surface and the discharge surface by the tip 41a coming into contact with the surface of the transport belt. In addition, the cap mechanism is not limited to being composed of a plurality of members (the partition portion 41 and the liquid receiving portion 42 according to the above-described embodiment, the partition portion 41 and the transport belt, etc.), for example, the discharge surface on the upper surface It may consist of one recess material having recesses of approximately the same size. For example, the concave member has a configuration in which the partition portion and the liquid receiving portion are integrated so that the partition portion is erected along the periphery of the liquid receiving portion, and is not fixed to the liquid discharge head. In this case, the cap mechanism is in the partitioned state by the tip of the partitioning portion coming into contact with the ejection surface 10x. In this case, the purge pump may be provided on the waste liquid side rather than between the liquid tank and the heads 10a and 10b. Further, the cap mechanism may be omitted.
-A control means does not need to judge whether predetermined time passed since the preliminary discharge step was performed before the opposing surface wiping step.
The preliminary ejection step is not limited to being performed after the recording command is received and before the start of the recording operation, and may be performed at an arbitrary timing. For example, the preliminary ejection step may be performed every time recording on a predetermined number of recording media is completed.
The purge may not be performed. The number of liquid discharge heads provided in the liquid discharge apparatus may be an arbitrary number of 1 or more.
The liquid discharge head may discharge any liquid other than ink and pretreatment liquid.
The liquid discharge head is not limited to the line type, and may be a serial type.
The liquid ejection device is not limited to a printer, and may be a facsimile, a copier, or the like.
The recording medium is not limited to paper and may be any recordable medium.

1 Inkjet printer (liquid ejection device)
1p controller (control means)
2Pa, 2Pb pump (pressure applying part)
10a, 10b Inkjet head (liquid ejection head)
10x discharge surface 14a discharge port 36a wiper 36ax contact surface 42 liquid receiving portion 42a facing surface 50 wiper drive mechanism 51a, 51b roller 52a, 52b belt

Claims (7)

A liquid ejection head having an ejection surface with a plurality of ejection openings from which liquid is ejected;
A wiper for wiping the discharge surface;
A liquid receiving portion that has a facing surface facing the discharge surface, and that receives the liquid discharged from the discharge port on the facing surface;
Control means for controlling the liquid discharge head and the wiper,
The control means includes
A preliminary ejection step of controlling the liquid ejection head based on preliminary ejection data different from image data recorded on a recording medium, ejecting the liquid from the ejection port, and receiving the liquid by the facing surface; ,
An opposing surface wiping step of controlling the wiper after the preliminary ejection step so that the wiper wipes the opposing surface;
An ejection surface wiping step of controlling the wiper after the facing surface wiping step to wipe the ejection surface at a portion where the facing surface of the wiper is wiped. A pressure applying unit that performs purging to discharge the liquid from the discharge port by applying pressure to the liquid in the liquid discharge head;
The control means performs the purge by controlling the pressure applying unit in a period other than a period in which a series of steps of the preliminary ejection step, the facing surface wiping step, and the ejection surface wiping step is performed. The liquid ejection apparatus according to claim 1.   The control means performs the preliminary ejection step after receiving the recording command and before controlling the liquid ejection head based on image data recorded on a recording medium to eject liquid from the ejection port. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. When the liquid receiving portion and the facing surface of the liquid receiving portion are opposed to the discharge surface with a gap therebetween, the liquid receiving portion and the plurality of discharge ports are included to partition the gap from an external space. A partition mechanism, further comprising a cap mechanism that can take a partition state in which the partition portion partitions the gap from an external space and an open state in which the partition portion opens the gap to the external space;
The control means includes
After receiving the recording command, the cap mechanism is controlled to take the open state before the liquid discharge head is controlled based on the image data recorded on the recording medium and the liquid is discharged from the discharge port. Perform the uncapping step,
The liquid ejection apparatus according to claim 3, wherein the preliminary ejection step is performed after the uncapping step. The control means includes
After the preliminary ejection step, before the opposing surface wiping step, perform a determination step of determining whether a predetermined time has elapsed since the preliminary ejection step was performed,
If it is determined in the determination step that the predetermined time has elapsed, before the facing surface wiping step, the liquid discharge head is controlled based on the preliminary discharge data to discharge liquid from the discharge port, 5. The liquid ejection apparatus according to claim 1, further comprising a re-preliminary ejection step in which the liquid is received by the facing surface. 6. In the vicinity of the end of the opposing surface and the discharge surface in the first direction along the wiping direction by the wiper, the wiper is reversed, and the contact surface of the wiper that contacts the opposing surface is changed in the first direction. Further comprising a wiper reversing mechanism for changing from a facing state to a second direction opposite to the first direction,
The control means controls the wiper in the facing surface wiping step, moves the wiper in the first direction with the abutting surface in contact with the facing surface, and after the facing surface wiping step. Before the discharge surface wiping step, the wiper is reversed by the wiper reversing mechanism, and the wiper is controlled in the discharge surface wiping step so that the contact surface of the wiper is in contact with the discharge surface. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus moves in the second direction.   The liquid ejection apparatus according to claim 6, wherein the liquid ejection head is a line-type head, and the ejection surface is elongated in the first direction and the second direction.

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