Cleaning device, liquid dispensing device, cleaning method, and program

Abstract

To efficiently clean the discharge surface. [Solution] A cleaning device for cleaning the discharge surface of a liquid discharge head, which has a plurality of discharge ports for discharging liquid, comprising: a suction wiper that sucks liquid from the discharge ports and wipes the discharge surface; an execution means that performs cleaning of the discharge surface by scanning the suction wiper along the scanning direction of the discharge surface; a determination means that determines whether at least one discharge port located in each section along the scanning direction has discharged liquid since the last time cleaning was performed in that section; and an adjustment means that makes the speed at which the suction wiper scans the section in which the determination means has determined that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections.

Description

Technical Field

[0001] The present disclosure relates to a cleaning device and a cleaning method for cleaning a discharge surface of a liquid discharge device, a liquid discharge device including the cleaning device, and a program.

Background Art

[0002] There is known a liquid discharge device that forms an image on a recording medium by discharging a liquid such as ink from a discharge port provided in a liquid discharge head. Generally, such a liquid discharge device is provided with a mechanism for cleaning foreign substances such as deposits derived from the liquid attached to the discharge surface in order to keep the discharge state of the liquid from the discharge port of the liquid discharge head good. And the discharge surface is regularly cleaned using such a mechanism.

[0003] Patent Document 1 discloses a cleaning method in which a suction nozzle that moves along a discharge port row facing the discharge surface of a liquid discharge head sucks liquid from a discharge port at a position facing the suction nozzle when the suction nozzle moves.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the cleaning method of Patent Document 1, every time the suction nozzle cleans the discharge surface, the entire area of the discharge port row in the traveling direction of the suction nozzle is cleaned. In this case, the discharge ports that have not discharged ink since the previous cleaning step are also included. Therefore, the cleaning method of Patent Document 1 has problems of consuming more time for cleaning the discharge surface and consuming more ink drawn out from the discharge ports than necessary.

[0006] This disclosure has been made in view of the above points and aims to efficiently clean the discharge surface. [Means for solving the problem]

[0007] One embodiment of the present disclosure is a cleaning device for cleaning a discharge surface of a liquid discharge head, which has a plurality of discharge ports for discharging liquid, comprising: a suction wiper for sucking liquid from the discharge ports and wiping the discharge surface; an execution means for performing cleaning of the discharge surface by scanning the suction wiper along the scanning direction of the discharge surface; a determination means for determining whether at least one discharge port located in each section along the scanning direction has discharged liquid since the last time the cleaning was performed in that section; and an adjustment means for making the speed at which the suction wiper scans the section in which the determination means has determined that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections. [Effects of the Invention]

[0008] According to this disclosure, the discharge surface can be cleaned efficiently. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of the general configuration of a liquid dispensing device. [Figure 2] This block diagram shows an overview of the overall control system for a liquid dispensing device. [Figure 3] This is a block diagram showing the printer control unit in detail. [Figure 4] This is a schematic diagram of the recording unit showing the state when the liquid discharge head is in the standby position. [Figure 5] This diagram illustrates the discharge surfaces of the first and second liquid discharge heads. [Figure 6] These are side and top views showing the liquid dispensing head and suction wiper, etc. [Figure 7]It is a side view and a plan view showing a diagram of the arrangement of a liquid ejection head and a suction wiper during cleaning. [Figure 8] It is a perspective view and a plan view showing an outline of a cleaning mechanism according to an embodiment. [Figure 9] It is a diagram for explaining a cleaning method according to an embodiment. [Figure 10] It is a diagram for explaining a cleaning method according to an embodiment. [Figure 11] It is a diagram for explaining a cleaning method according to a conventional example. [Figure 12] It is a table showing an example of a moving speed when the third and fourth cleaning methods are combined. [Figure 13] It is a flowchart showing a reset method included in the first and second cleaning methods. [Figure 14] It is a flowchart showing a history recording method included in the first and second cleaning methods. [Figure 15] It is a flowchart showing a moving speed determination method included in the first cleaning method. [Figure 16] It is a flowchart showing a speed control method included in the first to fourth cleaning methods. [Figure 17] It is a flowchart showing a moving speed determination method included in the second cleaning method. [Figure 18] It is a flowchart showing a reset method included in the third cleaning method. [Figure 19] It is a flowchart showing a history recording method included in the third cleaning method. [Figure 20] It is a flowchart showing a moving speed determination method included in the third cleaning method. [Figure 21] It is a flowchart showing a reset method included in the fourth cleaning method. [Figure 22] It is a flowchart showing a history recording method included in the fourth cleaning method. [Figure 23] It is a flowchart showing a moving speed determination method included in the fourth cleaning method.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be specifically described with reference to the drawings. Note that the components described in the following embodiments are merely examples, and the configuration of the apparatus to which the present disclosure is applied and various conditions can be appropriately modified or changed without departing from the gist of the present disclosure, and the present disclosure is not limited to the following embodiments. For example, dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments can be appropriately changed according to the configuration of the apparatus to which the present disclosure is applied and various conditions, and the present disclosure is not limited to the following embodiments unless otherwise specified.

[0011] This embodiment relates to a liquid ejection device.

[0012] <Configuration of Liquid Ejection Device> FIG. 1 is a schematic diagram showing an example of the schematic configuration of a liquid ejection device 100. The liquid ejection device 100 is a sheet-fed liquid ejection device that manufactures a recorded object in which an ink image is formed on a recording medium 101 using two types of liquids, a processing liquid and ink. In the present embodiment, the X direction, the Y direction, and the Z direction respectively correspond to the width direction (overall length direction), the depth direction, and the height direction (gravity direction) of the liquid ejection device 100. In the present embodiment, in order to describe an example in which the recording medium 101 is conveyed in the X direction, the X direction also corresponds to the conveyance direction of the recording medium. Further, the Y direction also corresponds to the width direction of the paper (recording medium 101).

[0013] As shown in Figure 1, the liquid ejection device 100 includes a transport unit 107 for transporting the recording medium 101 and a paper feeding unit 106 for feeding the recording medium 101 to the transport unit 107. The liquid ejection device 100 also includes a paper discharge unit 108 for collecting the printed recording medium 101 from the transport unit 107. The liquid ejection device 100 also includes a line-type first liquid ejection head 102 for ejecting a processing liquid that reacts with ink onto the recording medium 101, and a line-type second liquid ejection head 103 for ejecting ink onto the recording medium 101 from which the processing liquid has been ejected, forming an ink image. In this embodiment, there is one line-type first liquid ejection head 102 and four line-type second liquid ejection heads 103. The line-type first liquid ejection head 102 and the line-type second liquid ejection heads 103 are collectively referred to simply as line-type liquid ejection heads 103 or liquid ejection heads 103. The transport unit 107 may have additional units (not shown) with functions such as drying or cooling, which may be added at any position depending on the system.

[0014] <Control System> Figure 2 is a block diagram illustrating the overall control system of the liquid dispensing device 100. The liquid dispensing device 100 includes a recording data generation unit 201, an operation control unit 202, a printer control unit 203, a recording medium transport control unit 204, and a liquid dispensing device 205. The recording data generation unit 201 generates recording data and sends the generated recording data to the printer control unit 203. The recording data generation unit 201 may be configured by an external print server or the like, or it may be provided within the liquid dispensing device 100. The operation control unit 202 is an operation panel or the like that receives operation instructions from the user. The printer control unit 203 is a printer control unit that performs the recording process. The recording medium transport control unit 204 is a recording medium transport control unit for transporting the recording medium. The liquid dispensing device 205 is a liquid dispensing device used for recording and includes a first liquid dispensing head 102 and a second liquid dispensing head 103.

[0015] Figure 3 is a block diagram showing the printer control unit 203 in detail. Figure 3 also includes other components shown in Figure 2. The printer control unit 203 includes a processor 301 such as a CPU, ROM 302, RAM 303, ASIC 304, and a head control unit 305. These are interconnected via a bus 306. The processor 301 controls the entire liquid ejection device 100. The ROM 302 stores the control program for the processor 301. The RAM 303 is used to temporarily store data and when executing programs. The ASIC 304 is an application-specific integrated circuit that incorporates a network controller, serial IF controller, head data generation controller, motor controller, etc. The head control unit 305 generates ejection data used by the liquid ejection device 205 and generates drive voltages, etc.

[0016] The processor 301 is connected to a first motor interface (IF) 307, a second motor IF 308, and a third motor IF 309 via a bus 306. The first to third motor IFs 307 to 309 are each connected to the first to third motors 310 to 312. Based on ejection data acquired from the head control unit 305, the processor 301 can control the first to third motors 310 to 312 via the first to third motor IFs 307 to 309. The first to third motors 310 to 312 will be described later. Note that the first to third motor IFs 307 to 309 may be included in the ASIC 304.

[0017] <Conveyor Unit> Returning to Figure 1, we will now explain the transport unit 107 in the recording unit 110. In the recording unit 110, the first liquid discharge head 102 and the second liquid discharge head 103 discharge liquid onto the transported recording medium 101 from above in the direction of gravity. This discharge operation performs the recording process and forms an image on the recording medium 101. The transport unit 107 in the recording unit 110 is equipped with a transport belt 107a horizontally to stabilize the transport behavior of the recording medium 101 directly below the first liquid discharge head 102 and the second liquid discharge head 103. The transport belt 107a transports the recording medium 101 sent from the paper feed unit 106 while being sucked in the -Z direction.

[0018] The type of recording medium 101 is not particularly limited, and any known recording medium 101 can be used. In addition to sheet-fed recording medium cut to predetermined dimensions, long rolls of recording medium 101 can also be used. The material of the recording medium 101 can be paper, plastic film, wooden board, corrugated cardboard, or metal film.

[0019] The recording medium 101 is transported in the transport direction (X direction) by the transport unit 107. The transport belt 107a is a belt that rotates around a rotation axis that extends in the depth direction (Y direction) intersecting the transport direction, and its material may be resin or metal. The transport belt 107a is a suction transport belt configured to attract and fix the recording medium 101 through numerous holes in the belt using a suction pump or suction fan installed on the inside of the belt. However, this embodiment is not limited to fixing the recording medium 101 by suction. It may also be attracted by electrostatics, and the method of fixing and transporting the recording medium 101 can be appropriately selected according to the system.

[0020] In Figure 1, the arrows on the inside of the transport unit 107 indicate the rotation direction of the transport belt 107a, and the arrows on the outside of the transport unit 107 indicate the transport path of the recording medium 101. The recording medium 101 is transported from the paper feeding unit 106 to the transport unit 107. An ink image is formed on the recording medium 101 on the transport unit 107 by the first liquid discharge head 102, which discharges processing liquid, and the second liquid discharge head 103, which discharges ink. The recording medium 101 with the formed ink image is transported from the transport unit 107 to the paper discharge unit 108, where the recording medium 101 is loaded into the paper discharge unit 108.

[0021] <Liquid dispensing head> Figure 1 will be used to explain the liquid dispensing head.

[0022] The first liquid ejection head 102 and the second liquid ejection head 103 are full-line heads extending in the paper width direction (Y direction). The first liquid ejection head 102 and the second liquid ejection head 103 each have ejection ports 404 (see Figure 5, described later) arranged in an area that covers the width of the image recording area of ​​the largest usable recording medium 101. The downward surface of the first liquid ejection head 102 and the second liquid ejection head 103 in the direction of gravity (towards the recording medium 101) is provided with an ejection surface through which the ejection ports are opened. The ejection surfaces of the first liquid ejection head 102 and the second liquid ejection head 103 are fixed facing the recording medium 101 (transport unit 107) while maintaining a small gap (about a few millimeters) between them and the surface of the transported recording medium 101. The position of the liquid ejection head at this time is called the recording position.

[0023] As shown in Figure 1, multiple liquid discharge heads are arranged along the transport direction (X direction) as liquid discharge heads. In this example, a first liquid discharge head 102 that discharges the processing liquid is located upstream in the transport direction. Downstream from the first liquid discharge head 102 in the transport direction, four second liquid discharge heads 103 are arranged in order. The four second liquid discharge heads 103 correspond to line-type liquid discharge heads for four colors: Bk (black), Y (yellow), M (magenta), and C (cyan). Note that the types of colors, the order of colors, and the number of colors are not limited to this example. The liquid used in each liquid discharge head is supplied to the first liquid discharge head 102 and the second liquid discharge head 103, respectively, from an ink tank (not shown) via ink tubes.

[0024] Figure 4 is a schematic diagram of the recording unit 110 showing the state when the liquid discharge head is in the standby position. The standby position corresponds to the standby position of the liquid discharge head when no recording operation is being performed. In the standby position, the first liquid discharge head 102 and the second liquid discharge head 103 are in standby positions retracted upward in the direction of gravity relative to the recording position.

[0025] The first liquid dispensing head 102 and the second liquid dispensing head 103 can be moved to a maintenance position, which is neither the standby position nor the recording position. The maintenance unit 109 is configured to move downward in the direction of gravity from the first liquid dispensing head 102 and the second liquid dispensing head 103 in the standby position. The maintenance position is the position in which the first liquid dispensing head 102 and the second liquid dispensing head 103 have moved downward in the direction of gravity from the standby position so that they are in contact with the moved maintenance unit 109. For example, when the dispensing surfaces of the first liquid dispensing head 102 and the second liquid dispensing head 103 are capped after recording is complete, the first liquid dispensing head 102 and the second liquid dispensing head 103 move to the maintenance position. Alternatively, if debris or other substances adhere to the dispensing surface of the first liquid dispensing head 102, causing poor liquid dispensing, the first liquid dispensing head 102 will also move to the maintenance position in order to perform maintenance. Similarly, if debris or other contaminants adhere to the discharge surface of the second liquid discharge head 103, causing poor liquid discharge, the second liquid discharge head 103 will move to the maintenance position in order to perform maintenance.

[0026] When the first liquid discharge head 102 and the second liquid discharge head 103 move to the standby position, a space is created between the first and second liquid discharge heads 102 and 103 and the transport unit 107. This allows the maintenance unit 109, which is movable in the transport direction (X direction), to move to a position facing the liquid discharge heads. In the maintenance position, maintenance (also called a recovery operation) of the discharge surface is performed.

[0027] The maintenance unit 109 includes multiple cap sections (not shown) and a suction wiper 601 (see Figure 6) corresponding to the first liquid discharge head 102 and the second liquid discharge head 103. The cap sections prevent the discharge ports from drying out by sealing (capping) the discharge surfaces of the first liquid discharge head 102 and the second liquid discharge head 103. By periodically wiping away any dirt or droplets adhering to the discharge surface with the suction wiper 601, the discharge surface can be kept in a normal state.

[0028] Furthermore, the maintenance unit 109 equipped with the suction wiper 601 and the maintenance unit 109 equipped with the cap portion may be provided separately. These may be arranged, for example, at mutually different positions in the Z direction.

[0029] <Discharge surface> Figure 5 illustrates the discharge surfaces of the first liquid discharge head 102 and the second liquid discharge head 103. Figure 5(a) is a plan view showing the discharge surfaces of the first liquid discharge head 102 and the second liquid discharge head 103. Figure 5(a) is a view of the first liquid discharge head 102 and the second liquid discharge head 103 from the -Z direction. In this embodiment, an example is described in which the discharge surfaces of the first liquid discharge head 102 and the second liquid discharge head 103 have the same configuration, but the discharge surfaces of the first liquid discharge head 102 and the second liquid discharge head 103 may be different from each other. Hereafter, the discharge surface shown in Figure 5 will be described as the discharge surface of the first liquid discharge head 102. As shown in Figure 5(a), the first liquid discharge head 102 has multiple recording element substrates 401 having multiple discharge ports 404 (see Figure 5(b)) for discharging liquid onto a base substrate 407, which are arranged in a line in the paper width direction (Y direction). Furthermore, positioning members 403 for the first liquid discharge head 102 are provided at both ends of the row of recording element substrates 401. The positioning members 403 are configured to be able to contact a liquid discharge head positioning member (not shown) provided on the opposite transport unit 107 side. By the contact between the positioning members 403 and the liquid discharge head positioning member (not shown), the distance between the discharge surface of the first liquid discharge head 102 and the transport belt 107a can be defined. In addition, by adjusting the height of the liquid discharge head positioning member (not shown), the distance between the discharge surface of the first liquid discharge head 102 and the transport belt 107a can be adjusted to a desired distance.

[0030] Figure 5(b) is a schematic diagram of the recording element substrate 401 viewed from the -Z direction. Here, the surface on which the ejection ports 404 are provided is described as the top surface. Figure 5(c) is an enlarged view of a part of Figure 5(b). The surface (ejection surface) of the recording element substrate 401 is made of resin. The recording element substrate 401 is provided with a plurality of ejection ports 404 for ejecting liquid, arranged in rows. The plurality of ejection ports 404 are arranged along a direction (Y direction) perpendicular to the transport direction (X direction) of the recording medium 101. A configuration in which a plurality of ejection ports 404 are arranged in the Y direction is called an ejection port row. As shown in Figure 5(b), the recording element substrate 401 has multiple ejection port rows arranged in the X direction. Specifically, there are four rows of ejection port rows in the X direction, each having 512 ejection ports arranged at 600 dpi (dots / inch). In addition, two rows of ejection port rows that are adjacent to each other in the X direction are offset by 1200 dpi in the Y direction. As shown in Figure 5(c), a pressure chamber 23 is provided for each of the four discharge ports 404 beneath the resin section where the rows of discharge ports are formed. By controlling the pressure in the pressure chamber 23, ink can be discharged from any of the four discharge ports 404.

[0031] The recording element substrate 401 is constructed by laminating a Si substrate made of Si and an ejection port forming member made of a photosensitive resin. As shown in Figure 5(c), a recording element 15 is formed on one side of the Si substrate, and grooves constituting a liquid supply passage 18 and a liquid recovery passage 19 extending along the row of ejection ports are formed on the back side thereof. A differential pressure is generated between the liquid supply passage 18 and the liquid recovery passage 19 by a circulation mechanism (not shown). When recording is performed by ejecting liquid from multiple ejection ports 404, liquid flow is generated by this differential pressure even in ejection ports 404 that are not performing ejection operations. That is, the liquid in the liquid supply passage 18 provided in the Si substrate flows to the liquid recovery passage 19 via the supply port 17a, pressure chamber 23, and recovery port 17b. This flow makes it possible to suppress the viscosity increase of the liquid even in ejection ports 404 and pressure chamber 23 where liquid ejection is suspended. Furthermore, this flow allows the thickened ink generated by evaporation from the discharge port 404, as well as foam and foreign matter, to be recovered into the liquid recovery path 19. In this way, the liquid discharge head of this embodiment can suppress the thickening of the liquid in the pressure chamber 23 and near the discharge port 404, thereby suppressing discharge irregularities and non-discharge, and as a result, high-quality recording can be achieved.

[0032] The recording element board 401 is electrically connected to the liquid ejection device body via terminal 405. Communication between the recording element board 401 and the liquid ejection device body is conducted using signals from the liquid ejection head. Terminal 405 is protected by a sealing material 402 to prevent contact with the liquid.

[0033] Any liquid dispensing method can be adopted, such as a method using a heating element, a method using a piezoelectric element, a method using an electrostatic element, or a method using a MEMS element.

[0034] Figure 6 shows the liquid discharge head and suction wiper, etc. Figure 6(a) is a side view (XZ plane), and Figure 6(b) is a top view (XY plane).

[0035] Referring to Figure 6, the recording unit 110 includes a liquid ejection head 103 having an ejection surface 406 facing the recording medium 101, and a maintenance unit 109 including a suction wiper 601. Reference numeral 603 indicates a tube for supplying ink from an ink tank (not shown) to the liquid ejection head 103. As mentioned above, there are multiple liquid ejection heads 103, and there is also a single liquid ejection head 102, but it is omitted in Figure 6. However, there may be only one liquid ejection head 103, which corresponds to multiple colors. Also, there may be a configuration in which there is no liquid ejection head 102.

[0036] The liquid ejection head 103 may be an ink-circulating type head that can circulate ink between the ink tank and the liquid ejection head 103. Generally, ink-circulating type heads can suppress the thickening of ink due to evaporation from the ejection port 404 (see Figure 5) and can also discharge any bubbles that have been mixed in, thus providing high ejection reliability over long periods.

[0037] Figure 7 shows the arrangement of the liquid discharge head 103 and the suction wiper 601 during cleaning. Figure 7(a) is a side view, and Figure 7(b) is a top view. Note that the maintenance unit 109 is not shown.

[0038] As shown in Figure 7(a), in preparation for cleaning, the liquid discharge head 103 is lifted upward by the first motor 310, as indicated by arrow 701. Then, the suction wiper 601 is moved by the second motor 311 into the space created between the conveyor belt 107a and the liquid discharge head 103, as indicated by arrow 702.

[0039] Furthermore, when cleaning is performed, as shown in Figure 7(b), the suction wiper 601 moves in the Y direction, as indicated by the arrow 703, by the third motor 312. Details of this will be described later.

[0040] Figure 8(a) is a perspective view of a suction wiper 601 according to an embodiment of the present disclosure. The suction wiper 601 comprises a suction nozzle 801 and a suction holder 802 that supports and holds the nozzle. A tube 803 is connected to the suction holder 802. The suction nozzle 801 has four side walls, which form a space 804 enclosed by them. This space has an opening on the side opposite to the side to which the suction holder 802 is connected (the Z-direction side). Furthermore, as shown in Figure 8(b), the angles between the four side walls of the suction nozzle 801 are adjusted so that the Z-direction ends of the four side walls of the suction nozzle 801 contact the discharge surface 406 at the position indicated by the dashed parallelogram 805. In other words, the angles between the four side walls of the suction nozzle 801 are adjusted so that their cross-section is a parallelogram.

[0041] Since the suction nozzle 801 is made of rubber, the end of the side wall on the opening side conforms well to the irregularities of the discharge surface 406, allowing the suction nozzle 801 to contact the discharge surface 406 with uniform pressure. In particular, the elastic modulus of the material of the suction nozzle 801 is preferably in the range of 5 MPa to 0.5 MPa. If the elastic modulus is higher than this, the conformability may be poor, and if it is lower, the strength may be insufficient, and the suction nozzle 801 may break while sliding against the discharge surface 406.

[0042] Furthermore, from the viewpoint of the suction nozzle 801's ability to follow the discharge surface 406, it is desirable that the thickness W1 of the side wall of the suction nozzle 801 (see Figure 8(a)) be 2.0 mm or less. A depressurization means such as a suction pump is connected to the tube 803. When the depressurization means is activated, the open space 804 of the suction nozzle 801 is depressurized.

[0043] During cleaning, the suction nozzle 801 is pressed against the discharge surface 406 and slides along it. Ink is then sucked in from the discharge ports 404 located in the opening of the space 804 surrounded by the side walls of the suction nozzle 801 (i.e., one or more discharge ports 404 in the area enclosed by the dashed line 805 at each point in time). The ink drawn out from the discharge ports 404 and flowing is sucked into the suction nozzle 801, dissolving and peeling off any solidified material originating from the ink on the discharge surface 406. The ink and solidified material that have flowed into the suction nozzle 801 are then discharged to the outside via the tube 803 and the pump. This removes the solidified material present on the discharge surface 406.

[0044] The slower the relative speed of the suction wiper 601 with respect to the discharge surface 406, the more ink is drawn in from the discharge port 404, resulting in a better cleaning of the discharge surface 406.

[0045] Figure 9 is a schematic diagram illustrating the cleaning process according to this disclosure. Figure 9(a) shows the state in which the liquid ejection head 103 ejects ink from the ejection surface 406 onto the recording medium 101 to form an image.

[0046] Upon receiving a cleaning instruction, the liquid discharge head 103 moves upward (in the Z direction) as shown in Figure 9(b) by means of the first motor IF307, the first motor 310, and a mechanism not shown, in accordance with instructions from the processor 301. This creates space between the conveyor belt 107a and the discharge surface 406 of the liquid discharge head 103 for the suction wiper 601 to enter.

[0047] Next, in accordance with instructions from the processor 301, the suction wiper 601 moves in the transport direction (X direction) by the second motor IF308, the second motor 311, and a mechanism not shown.

[0048] Next, in accordance with instructions from the processor 301, the suction wiper 601 moves to the cleaning start position along the scanning direction (Y direction) as shown in Figure 9(c), by means of the third motor IF309, the third motor 312, and a mechanism not shown.

[0049] Next, in accordance with instructions from the processor 301, the liquid discharge head 103 is lowered by the first motor IF307, the first motor 310, and a mechanism (not shown) until the discharge surface 406 contacts the suction wiper 601, as shown in Figure 9(d). Alternatively, the suction wiper 601 may be raised instead of lowering the liquid discharge head 103.

[0050] Next, in accordance with instructions from the processor 301, the suction wiper 601 moves in the scanning direction (Y direction) as shown in Figures 9(d) and 9(e) by the third motor IF309, the third motor 312, and a mechanism not shown. During the period when the suction wiper 601 moves in the scanning direction (Y direction) at a speed V, the end of the side wall of the suction nozzle 801 of the suction wiper 601 slides against the discharge surface 406. Also during this period, the inside of the suction wiper 601 is reduced in pressure. As a result, the discharge surface 406 is cleaned.

[0051] This allows for a single cleaning pass using a one-way scan. Multiple cleaning passes may be performed if necessary. Alternatively, a reciprocal scan may be performed instead of a one-way scan.

[0052] Furthermore, since ink adheres to the ejection surface 406 due to ink ejection during printing, it should be cleaned periodically. The cleaning interval may be determined by the cumulative time spent performing printing operations, or by the cumulative amount of ink ejected from the ejection port 404.

[0053] In this embodiment, the relative movement speed V of the suction wiper 601 as it moves across the discharge surface 406 is varied based on the discharge history at each discharge port 404.

[0054] Figures 10(a) to 10(d) are diagrams illustrating the first to fourth cleaning methods according to this embodiment. The top of each figure shows a bottom view (viewed from below) of the liquid discharge head 102 or 103. The bottom of each figure shows the movement speed of the suction wiper 601 according to its position along the Y direction. As described above, multiple recording element substrates 401 are arranged along the Y direction on the bottom surface of the liquid discharge head 102 or 103. Although not shown in Figure 10(a), multiple discharge ports 404 are arranged on the discharge surface 406 of each recording element substrate 401, as shown in Figure 5(a) or Figure 5(b). As shown in the figures, the movement speed V is not constant but varies depending on the position along the Y direction. In contrast, in conventional examples, as shown in Figure 11, the movement speed V is constant.

[0055] As shown in Figure 11, in the conventional example, the speed V at which the suction wiper 601 scans the discharge surface 406 in the scanning direction (Y direction) is V0 throughout the entire Y-direction A0, except during the initial acceleration and final deceleration. Speed ​​V0 is a speed that matches the maximum estimated amount of ink fixed to the discharge surface 406.

[0056] In contrast, as shown in Figure 10(a), according to the first cleaning method of this embodiment, the speed V at which the suction wiper 601 scans the discharge surface 406 in the scanning direction (Y direction) is V1 in sections A1-1 and A-2, and V2 in section A2. Here, sections A1-1 and A1-2 are sections that do not include the discharge port 404 from which liquid has been discharged since the last cleaning was performed. Section A2, on the other hand, is a section that includes the discharge port 404 from which liquid has been discharged since the last cleaning was performed.

[0057] As an example, a basic unit of interval is established for each recording element board 401. Then, for each recording element board 401, it is checked whether or not the discharge port 404 that discharged liquid during the period from the last cleaning to the present is included. Interval A1-1 is constructed by connecting the recording element boards 401 that do not contain the discharge port 404 that discharged liquid during the period from the last cleaning to the present. Similarly, interval A1-2 is constructed by connecting the recording element boards 401 that do not contain the discharge port 404 that discharged liquid during the period from the last cleaning to the present. Interval A2 is constructed by connecting the recording element boards 401 that do contain the discharge port 404 that discharged liquid during the period from the last cleaning to the present. In the example in Figure 10(a), interval A1-1 is constructed by connecting recording element board 401#1 to recording element board 401#4. Interval A1-2 is constructed by recording element board 401#n. Furthermore, section A2 is formed by connecting recording element board 401#5 to recording element board 401#(n-1).

[0058] Establishing a basic unit of interval for each recording element board 401 is merely one example. A basic unit of interval may be established for multiple recording element boards 401, or for each part of the recording element board 401. Furthermore, a basic unit of interval may be established at regular intervals along the Y direction. If a basic unit of interval is established at regular intervals along the Y direction, the discharge port 404 that discharged the liquid will not be examined for each recording element board, but rather for each position of the discharge port 404 along the Y direction. In other words, for example, the discharge / non-discharge status of liquid will be examined for all discharge ports 404 in the interval from distance Y1 to Y2.

[0059] In all of the above cases, the lengths of the basic units in the interval are made equal, but this is not limited to this, and the lengths of the basic units in the interval may be made unequal. For example, a basic unit with a predetermined length as the standard may be mixed with basic units that have a longer length or a shorter length.

[0060] According to the first cleaning method, for each section along the scanning direction (Y direction), it is determined whether at least one discharge port 404 located in the section has discharged liquid since the last cleaning was performed. The speed at which the suction wiper 601 scans the section in which it is determined that at least one discharge port 404 has discharged liquid is set lower than the speed at which the suction wiper 601 scans the other sections. Therefore, according to the first cleaning method, it is possible to shorten the overall cleaning time while reliably removing any remaining solidified material from the section in which it is determined that at least one discharge port 404 has discharged liquid.

[0061] In the example shown in Figure 10(A), speed V2 is smaller than speed V1. Furthermore, speed V2 can be made equal to speed V0 in the conventional example. In this case, speed V1 is larger than speed V0. Therefore, compared to the conventional example, the time required for the suction wiper 601 to scan the discharge surface 406 from one end to the other can be shortened.

[0062] Furthermore, since cleaning is performed by suctioning liquid, the amount of liquid consumed for cleaning is proportional to the cleaning time. Therefore, according to the first cleaning method, the amount of ink consumed for cleaning can be reduced compared to conventional methods.

[0063] The cleaning interval may be set to, for example, one hour, but is not limited to this. As mentioned above, cleaning may be performed when the accumulated printing time or accumulated ink ejection amount reaches a predetermined value.

[0064] Furthermore, while speed V1 may be, for example, 100 mm / second and speed V2 may be, for example, 10 mm / second, it is not limited to these. For example, if the combined length of section A-1 and section A-2 is equal to the length of section A2, and speed V2 is equal to speed V0, the cleaning time can be reduced by 55% compared to the conventional example.

[0065] Since the ejection surface 406 of the recording element substrate 401 is a parallelogram, sections overlap between adjacent recording element substrates 401. When sections with different speeds overlap, it is preferable to prioritize the smaller speed, as shown in Figure 10(a). Furthermore, in order to avoid scanning a section where a smaller speed should be applied at a higher speed near the boundary of the sections, it is preferable to know the speed for each section in advance and adjust the speed accordingly.

[0066] Figure 10(b) is a diagram illustrating the second cleaning method of this embodiment. The second cleaning method is a modification of the first cleaning direction. The second cleaning method will be explained while comparing Figure 10(a) and Figure 10(b). Section B1 shown in Figure 10(b) is a basic unit immediately before section A2, and section B2 shown in the same figure is a basic unit immediately after section A2. In the second cleaning method, the speed V2 applied to section A2 is applied to sections B1 and B2. Therefore, the second cleaning method expands the section to which speed V2 is applied. Here, solidified material originating from the liquid discharged from the discharge port 404 may exist on the discharge surface 406 with a certain degree of spread. Therefore, for example, solidified material originating from the ink discharged from the discharge port 404 in section A2 may remain in section B1 or section B2. By using the second cleaning method, the solidified material remaining in sections B1 and B2 can be cleaned. In other words, even if liquid discharged from a discharge port 404 in a certain section spreads to a discharge surface 406 in an adjacent section and solidifies, it can still be cleaned.

[0067] The section expanded by the second cleaning method may have a different length from the basic unit used in the first cleaning method. For example, suppose that in the first cleaning method, one recording element substrate 401 is used as the basic unit, and the length of the basic unit is equal to the length of the recording element substrate 401. In this case, the length of the section expanded by the second cleaning method may be shorter than that. For example, the length of the section expanded by the second cleaning method may be a few percent to more than ten percent of the length of the recording element substrate, or even several tens of percent.

[0068] Figure 10(c) is a diagram illustrating a third cleaning method of this embodiment. The third cleaning method takes into account the amount of liquid discharged from the discharge port 404. The more liquid discharged from the discharge port 404 that is present on the discharge surface 406, the more liquid-derived deposits remain. Therefore, in the third cleaning method, the suction wiper 601 is scanned at a slower speed in the sections of the discharge surface 406 where the amount of liquid discharged from the discharge port 404 has been greater since the last cleaning was performed. In other words, in the third cleaning method, the suction wiper 601 is scanned at a slower speed in sections where the amount of liquid discharged from the discharge port 404 has been greater since the last cleaning was performed. Conversely, the suction wiper 601 is scanned at a higher speed in sections where the amount of liquid is smaller. This allows for the removal of deposits from the discharge surface 406 over a period of time corresponding to the amount of remaining deposits, while simultaneously shortening the time required for cleaning.

[0069] Sections A3-1 and A3-2 shown in Figure 10(c) are sections where no discharge port 404 discharges liquid. Section A4 is a section where the average liquid discharge volume per discharge port 404 is small. Section A5 is a section where the average liquid discharge volume per discharge port 404 is large. Speed ​​V3 is applied to sections A3-1 and A3-2. Speed ​​V4, which is smaller than speed V3, is applied to section A4. Speed ​​V5, which is smaller than speed V4, is applied to section A5.

[0070] Although different from the example in Figure 10(c), as an example, a moving speed V of 100 mm / second is applied to the section where the average liquid discharge volume per outlet 404 is zero. A moving speed V of 20 mm / second is applied to the section where the average liquid discharge volume per outlet 404 is greater than zero but 5 mmg or less. A moving speed V of 10 mm / second is applied to the section where the average liquid discharge volume per outlet 404 is greater than 5 mmg but 50 mmg or less. A moving speed V of 5 mm / second is applied to the section where the average liquid discharge volume per outlet 404 is greater than 50 mmg.

[0071] The average liquid discharge volume per outlet 404 can be determined as follows: For each outlet 404, the discharge volume is calculated by multiplying the liquid discharge volume per discharge by the number of times liquid has been discharged since the last cleaning was performed. Then, the average discharge volume per outlet 404 is calculated for the outlets 404 belonging to the interval. It is assumed that the surface density of the outlets 404 is constant, but if there is a distribution in the surface density, this may be taken into consideration. In addition, if there are factors that affect the degree to which liquid-derived deposits adhere to and remain on the discharge surface 404, such as the physical properties of the liquid or the structure of the liquid discharge head, these may also be taken into consideration.

[0072] Figure 10(d) is a diagram illustrating the fourth cleaning method of this embodiment. The fourth cleaning method takes into account the length of time elapsed since the liquid was discharged from the discharge port 404. The longer the time elapsed since the liquid was discharged from the discharge port 404, the more likely it is to solidify on the discharge surface 406. In other words, the longer the time elapsed since the liquid was discharged from the discharge port 404, the more it dries and the more difficult it becomes to remove by cleaning. After the discharge surface 406 has been cleaned for the last time, the longer the time elapsed since the liquid was first discharged from the discharge port 404 on that discharge surface 406 (also called the "elapsed period"), the more difficult it becomes to remove solidified material derived from the liquid. This tendency does not change even if there are subsequent discharges of liquid during the elapsed period. Therefore, in the fourth cleaning method, the suction wiper 601 is scanned at a slower speed in the section of the discharge surface 406 where the elapsed period is longer. In other words, in the fourth cleaning method, the suction wiper 601 is scanned at a low speed over sections with a long elapsed time, and at a higher speed over sections with a short elapsed time. This allows for the removal of remaining solidified material from the discharge surface 406 over a period of time corresponding to the difficulty of removing the remaining solidified material, while simultaneously shortening the time required for cleaning.

[0073] Sections A6-1 and A6-2 shown in Figure 10(d) are sections where there is no discharge port 404 from which liquid is discharged. Section A7 is a section with a short elapsed time. Section A8 is a section with a long elapsed time. Speed ​​V6 is applied to sections A6-1 and A6-2. Speed ​​V7, which is smaller than speed V6, is applied to section A7. Speed ​​V8, which is smaller than speed V7, is applied to section A8.

[0074] Although different from the example in Figure 10(d), as an example, a travel speed V of 100 mm / second is applied to sections where there is no discharge port 404 from which liquid has been discharged since the last cleaning. A travel speed V of 20 mm / second is applied to sections where the elapsed time is 30 minutes or less. A travel speed V of 10 mm / second is applied to sections where the elapsed time is more than 30 minutes but 1 hour or less. A travel speed V of 5 mm / second is applied to sections where the elapsed time is more than 1 hour.

[0075] In any of the above cleaning methods, it is desirable that the absolute values ​​of acceleration and deceleration when changing the speed of the suction wiper 601 be 30 mm / sec^2 or less. Here, "sec^2" means seconds squared. If the absolute value of acceleration or deceleration is greater than this, the posture of the suction wiper 601 may change to such an extent that it cannot maintain contact between the suction nozzle 801 and the discharge surface 406. As a result, the amount of liquid sucked from the discharge port 404 may decrease, and the cleaning ability of the discharge surface 406 may be reduced.

[0076] The third method may be combined with the second method. Using the example in Figure 10(c), the section to which speed V5 is applied may be extended to near the end of section A3-1 and near the beginning of section A4, and the section to which speed V4 is applied may be extended to near the beginning of section A3-2. Similarly, the fourth method may be combined with the second method.

[0077] The third cleaning method and the fourth cleaning method may be combined. For example, as shown in Figure 12(a), the smaller of the speed determined by the third cleaning method and the speed determined by the fourth cleaning method may be applied. As shown in Figure 12(b), the average value of the speed determined by the third cleaning method and the speed determined by the fourth cleaning method may be applied. As shown in Figure 12(c), a weighted average value of the speed determined by the third cleaning method and the speed determined by the fourth cleaning method may be applied. The maximum speed that can maintain a sufficient cleaning effect for each combination of average liquid discharge volume and elapsed time may be measured in advance, and a speed based on that may be applied. Here, the measurement may be carried out in conjunction with product design or manufacturing.

[0078] The first cleaning method includes a reset method shown in Figure 13, a history recording method shown in Figure 14, a movement speed determination method shown in Figure 15, and a speed control method shown in Figure 16. These will be explained in order.

[0079] Referring to Figure 13, in the reset method included in the first cleaning method, the processor 301 resets the flag F(k) for all basic units (also simply called "basic units") k in all sections. That is, the step S1302 of resetting the flag F(k) is repeated for all basic units k (k=1 to n) (S1301, S1303). The flag (k) indicates whether or not liquid has been discharged from at least one discharge port in section k after the previous cleaning process.

[0080] Referring to Figure 14, in the history recording method included in the first cleaning method, the processor 301 performs the following processing.

[0081] Processor 301 waits until printing begins (NO in S1401).

[0082] When printing starts (YES in S1401), in S1402, the processor 301 acquires binary output data.

[0083] Then, if ink is ejected from at least one ejection port 404 in the k-th basic unit (S1404), the processor 301 repeats the process of setting the flag F(k) (S1405) for all basic units k (S1403, S1406).

[0084] While printing continues (NO in S1407), processor 301 repeats the processes from S1402 to S1406.

[0085] If printing is complete (YES in S1407), processor 301 returns to S1401 and waits until the next print job begins.

[0086] Referring to Figure 15, in the method for determining the movement speed included in the first cleaning method, the processor 301 performs the following processing.

[0087] Processor 301 repeats the following process for all basic units k (S1501, S1505): In each iteration, the processor 301 first determines in S1502 whether ink has been ejected from at least one ejection port 404 in the kth basic unit since the last cleaning operation. In other words, the processor 301 determines whether flag F(k) is set.

[0088] If it is determined that ink has been ejected from at least one ejection port 404 in the kth base unit since the last cleaning was performed (YES in S1502), the processor 301 sets V2 as the movement speed V(k) to be applied to the kth base unit.

[0089] If it is determined that no ink was ejected from any of the ejection ports 404 in the kth basic unit since the last cleaning (NO in S1502), the processor 301 sets V1 as the movement speed V(k) to be applied to the kth basic unit. Here, movement speed V1 is greater than movement speed V2.

[0090] Referring to Figure 16, in the movement speed control method included in the first cleaning method, the processor 301 performs the following processing.

[0091] In S1601, the processor 301 starts moving the suction wiper 601 and sucking up the liquid.

[0092] In S1602, processor 301 initializes the base unit number k to 1.

[0093] In S1603, the processor 301 adjusts the speed of the suction wiper 601 to the speed of the first basic unit V(1).

[0094] If the process proceeds from S1603 to S1604, in S1604, the processor 301 performs control to scan the suction wiper 601 at a speed V(1) over the portion of the first basic unit of the discharge surface 406.

[0095] If the process proceeds from S1608 to S1604, in S1604, the processor 301 adjusts the speed so that the suction wiper 601 scans the k-th (k=2 to n) basic unit portion of the discharge surface 406 at a speed V(k).

[0096] In S1605, the processor 301 determines whether the suction wiper 601 has reached the end position of the last basic unit.

[0097] If the suction wiper 601 has not reached the end position of the last basic unit (NO in S1605), the processor 301 proceeds to S1606. If the suction wiper 601 has reached the end position of the last basic unit (YES in S1605), the process proceeds to S1609.

[0098] In S1606, the processor 301 determines whether the suction wiper 601 has reached the end position of the kth basic unit.

[0099] If the suction wiper 601 has not reached the end position of the kth basic unit (NO in S1606), the processor 301 returns to processing S1604; otherwise, it proceeds to processing S1607 (YES in S1606).

[0100] If the processor 301 returns processing to S1604, the suction wiper 601 continues to be controlled to scan the current basic unit portion of the discharge surface 406 at speed V(k).

[0101] In S1607, processor 301 increments the number k of the base unit by 1.

[0102] In S1608, the processor 301 adjusts the speed at which the suction wiper 601 scans the discharge surface 406 to a new speed V(k) for a given k. Then, the processor 301 returns to processing in S1604. As a result, the suction wiper 601 scans the next basic unit portion of the discharge surface 406.

[0103] In S1609, the processor 301 terminates the movement of the suction wiper 601 and the suction of liquid.

[0104] In S1610, the processor 301 performs a reset operation. This reset operation corresponds to the reset method described with reference to Figure 13.

[0105] The second cleaning method includes the reset method shown in Figure 13, the history recording method shown in Figure 14, the movement speed determination method shown in Figure 17, and the speed control method shown in Figure 16. The second cleaning method differs from the first cleaning method only in the movement speed determination method, so only this will be explained.

[0106] Referring to Figure 17, in the method for determining the movement speed included in the second cleaning method, the processor 301 performs the following processing.

[0107] Processor 301 repeats the following process for all basic units k (S1701, S1707).

[0108] In each iteration, the processor 301 first determines in S1702 whether ink has been ejected from at least one ejection port 404 in the kth basic unit since the last cleaning operation. In other words, the processor 301 determines whether flag F(k) is set.

[0109] If it is determined that ink has been ejected from at least one nozzle 404 in the kth basic unit since the last cleaning (YES in S1702), the processor 301 proceeds to S1706. In S1706, the processor 301 sets V2 as the movement speed V(k) to be applied to the kth basic unit.

[0110] If it is determined that no ink was ejected from any of the ejection ports 404 in the k-th basic unit since the last cleaning (NO in S1702), the processor 301 proceeds to S1703. In S1703, the processor 301 determines whether or not ink was ejected from at least one ejection port 404 in the (k-1)-th basic unit since the last cleaning. In other words, the processor 301 determines whether or not flag F(k-1) is set.

[0111] If it is determined that ink has been ejected from at least one nozzle 404 in the (k-1)th basic unit since the last cleaning (YES in S1703), the processor 301 proceeds to S1706. In S1706, the processor 301 sets V2 as the movement speed V(k) to be applied to the kth basic unit.

[0112] If it is determined that no ink was ejected from any of the ejection ports 404 in the (k-1)th basic unit since the last cleaning (NO in S1703), the processor 301 proceeds to S1704. In S1704, the processor 301 determines whether or not ink was ejected from at least one ejection port 404 in the (k+1)th basic unit since the last cleaning. In other words, the processor 301 determines whether or not flag F(k+1) is set.

[0113] If it is determined that ink has been ejected from at least one nozzle 404 in the (k+1)th base unit since the last cleaning (YES in S1704), the processor 301 proceeds to S1706. In S1706, the processor 301 sets V2 as the movement speed V(k) to be applied to the kth base unit.

[0114] If it is determined that no ink was ejected from any of the ejection ports 404 in the (k+1)th basic unit since the last cleaning (NO in S1704), the processor 301 proceeds to S1705. In S1705, the processor 301 sets V1 as the movement speed V(k) to be applied to the kth basic unit. Here, movement speed V1 is greater than movement speed V2.

[0115] The third cleaning method includes the reset method shown in Figure 18, the history recording method shown in Figure 19, the movement speed determination method shown in Figure 20, and the speed control method shown in Figure 16. Since the speed control method shown in Figure 16 has already been explained, a redundant explanation will be omitted, and the other methods will be explained.

[0116] Referring to Figure 18, in the reset method included in the third cleaning method, the processor 301 resets the discharge count CNT(k,j) to zero for all nozzles NZL(k,j) included in the basic unit k of all sections. That is, step S1803, which resets the flag CNT(k,j) to zero, is repeated for all basic units k (k=1 to n) and all nozzles (S1801, S1805; S1802, S1804). The count CNT(k,j) indicates the number of times liquid has been discharged from each discharge port NZL(k,j) in section k since the previous cleaning process.

[0117] Referring to Figure 19, in the history recording method included in the third cleaning method, the processor 301 performs the following processing.

[0118] Processor 301 waits until printing begins (NO in S1901).

[0119] When printing starts (YES in S1901), in S1902, the processor 301 acquires binary ejection data. The binary ejection data indicates whether or not liquid is ejected from each nozzle.

[0120] Processor 301 repeats the following process for all nozzles NZL(k,j) included in all basic units k (S1903, S1908; S1904, S1907). That is, if liquid is discharged from nozzle NZL(k,j) (YES in S1905), processor 301 repeats the process of incrementing the count CNT(k,j) by 1 (S1906).

[0121] While printing continues (NO in S1909), processor 301 repeats the processes from S1902 to S1908.

[0122] If printing is complete (YES in S1909), processor 301 returns to S1901 and waits until the next print job begins.

[0123] Referring to Figure 20, in the method for determining the movement speed included in the third cleaning method, the processor 301 performs the following processing.

[0124] Processor 301 repeats the following process for all basic units k (S2001, S2010).

[0125] In each iteration, the processor 301 first calculates the average liquid discharge rate (also called the "average discharge rate") Q(k) per nozzle of the kth basic unit from the last cleaning to the present using the following formula in S2002.

[0126]

number

[0127] Here, CNT(k,j) is the number of times nozzle NZL(k,j) is dispensed. qq(k,j) is the weight of the droplet at nozzle NZL(k,j). N(k) represents the number of nozzles included in the base unit k.

[0128] Next, if the average discharge volume Q(k) is zero (YES in S2003), the processor 301 sets the moving speed V(k) to be applied to the kth base unit to V1 (S2004).

[0129] If the average discharge volume Q(k) is greater than zero and less than or equal to 5 mg (YES in S2005), the processor 301 sets the movement speed V(k) applied to the kth base unit to V2 (S2006).

[0130] If the average discharge volume Q(k) exceeds 5 mg and is 50 mg or less (YES in S2007), the processor 301 sets the movement speed V(k) applied to the k-th base unit to V3 (S2008).

[0131] If the average discharge volume Q(k) exceeds 50 mg (NO in S2007), the processor 301 sets the movement speed V(k) applied to the kth base unit to V4 (S2009).

[0132] Here, velocity V1 > velocity V2 > velocity V3 > velocity V4.

[0133] The fourth cleaning method includes the reset method shown in Figure 21, the history recording method shown in Figure 22, the movement speed determination method shown in Figure 23, and the speed control method shown in Figure 16. The speed control method shown in Figure 16 has already been explained, so a redundant explanation will be omitted, and the other methods will be explained.

[0134] Referring to Figure 21, in the reset method included in the fourth cleaning method, the processor 301 invalidates the print time TS(k) for all basic units k in all intervals (NULL). That is, the step S2102 of invalidating the print time TS(k) is repeated for all basic units k (k=1 to n) (S2101, S2103). The print time TS(k) indicates the time when ink was first ejected from any of the ejection ports 404 included in the basic unit k after the previous cleaning process.

[0135] Referring to Figure 22, in the history recording method included in the fourth cleaning method, the processor 301 performs the following processing.

[0136] Processor 301 waits until printing begins (NO in S2201).

[0137] When printing starts (YES in S2201), in S2202, the processor 301 acquires binary output data.

[0138] Then, processor 301 repeats the following for all base units k (S2203, S2207):

[0139] In other words, the processor 301 determines in each iteration for the kth basic unit whether or not ink was ejected from at least one ejection port 404 in the kth basic unit (S2204).

[0140] If the processor 301 determines that ink has been ejected from at least one ejection port 404 in the kth basic unit (YES in S2204), it determines whether a valid value is stored in the print time TS(k) (S2205).

[0141] If an invalid value is stored in the print time TS(k) (NO in S2205), the processor 301 assigns the current time to the print time TS(k) (S2206).

[0142] If processor 301 determines that no ink was ejected from any of the ejection ports 404 in the k-th basic unit (NO in S2204), it omits the execution of S2206. Also, if processor 301 determines that a valid value is stored in the print time TS(k) (YES in SS2204, YES in S2205), it omits the execution of S2206.

[0143] While printing continues (NO in S2208), processor 301 repeats the processes from S2202 to S2207.

[0144] If printing is complete (YES in S2208), processor 301 returns processing to S2201 and waits until the next print job begins.

[0145] Referring to Figure 23, in the method for determining the movement speed included in the fourth cleaning method, the processor 301 performs the following processing.

[0146] Processor 301 repeats the following process for all basic units k (S2301, S2310).

[0147] In each iteration, if the print time TS(k) is an invalid value (YES in S2302), the processor 301 sets the movement speed V(k) to be applied to the kth base unit to V1 (S2303).

[0148] If the print time TS(k) is a valid value (NO in S2302), the processor 301 proceeds to S2304.

[0149] In S2304, the processor 301 calculates the elapsed time ΔT(k) using the following formula.

[0150] Elapsed time ΔT(k) = Current time - TS(k) If the elapsed time ΔT(k) is 30 minutes or less (YES in S2305), the processor 301 sets the movement speed V(k) to be applied to the kth base unit to V2 (S2306).

[0151] If the elapsed time ΔT(k) exceeds 30 minutes but is less than 1 hour (YES in S2307), the processor 301 sets the movement speed V(k) to be applied to the kth base unit to V3 (S2308).

[0152] If the elapsed time ΔT(k) exceeds 1 hour (NO in S2307), the processor 301 sets the movement speed V(k) applied to the kth base unit to V4 (S2309).

[0153] Here, velocity V1 > velocity V2 > velocity V3 > velocity V4.

[0154] The above cleaning method may be combined with other methods commonly used for cleaning the discharge surface 406 of the liquid discharge head 103. For example, cleaning fluid may be applied to the discharge surface 406 before performing suction wiping to enhance the cleaning effect, or a combination of wiping with a wiping blade, cloth, or brush may be used.

[0155] The above cleaning method may be performed by a computer mounted as part of the liquid dispensing device, or by a host computer connected to the liquid dispensing device.

[0156] Embodiments of the present disclosure may also be implemented by a computer in a system or device that includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing one or more functions of the embodiments described above, which are recorded on a storage medium (which may be more entirely referred to as a “non-temporary computer-readable storage medium”), and / or for performing one or more functions of the embodiments described above, and or by being implemented by a computer in a system or device that includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing one or more functions of the embodiments described above, which are recorded on a storage medium. The computer may comprise one or more processors (e.g., a central processing unit (CPU), a microprocessing unit (MPU)), and may include separate computers or a network of separate processors for reading and executing computer-executable instructions. Computer-executable instructions may be provided to the computer from, for example, a network or a storage medium. The storage medium may include, for example, one or more of the following: hard disks, random access memory (RAM), read-only memory (ROM), storage for distributed computing systems, optical discs (Compact Discs (CDs), Digital Multipurpose Discs (DVDs), or Blu-ray Discs (BDs) (registered trademarks)), flash memory devices, and memory cards.

[0157] <Technical Features of This Disclosure> This disclosure includes the following configurations, methods, and programs.

[0158] [Configuration 1] A cleaning device for cleaning the discharge surface of a liquid discharge head, which has multiple discharge ports for discharging liquid, A suction wiper that sucks liquid from the discharge port and wipes the discharge surface, An execution means for performing cleaning of the discharge surface by scanning the suction wiper along the scanning direction of the discharge surface, For each section along the scanning direction, a determination means for determining whether at least one discharge port located in that section has discharged liquid since the last time the cleaning was performed, An adjustment means for making the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A cleaning device equipped with the following features.

[0159] [Configuration 2] The adjustment means makes the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid, and the section adjacent to said section, less than the speed at which the suction wiper scans the other sections. The cleaning device described in Configuration 1.

[0160] [Configuration 3] Each of the aforementioned sections further includes means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The adjusting means makes the speed at which the suction wiper scans the section in which the average liquid discharge amount is a first discharge amount less than the speed at which the suction wiper scans the section in which the average liquid discharge amount is a second discharge amount less than the first discharge amount. A cleaning device as described in configuration 1 or 2.

[0161] [Structure 4] The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The adjusting means makes the speed at which the suction wiper scans the interval where the time is the first time less than the speed at which the suction wiper scans the interval where the time is later than the first time, which is the second time. A cleaning device as described in configuration 1 or 2.

[0162] [Composition 5] For each of the aforementioned sections, means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The aforementioned adjustment means is The speed at which the suction wiper scans the section where the average liquid discharge amount is the first discharge amount is made smaller than the speed at which the suction wiper scans the section where the average liquid discharge amount is the second discharge amount, which is less than the first discharge amount. The speed at which the suction wiper scans the interval where the aforementioned time is the first time is made smaller than the speed at which the suction wiper scans the interval where the aforementioned time is later than the first time, which is the second time. A cleaning device as described in configuration 1 or 2.

[0163] [Composition 6] Each of the aforementioned sections further includes means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease in sections where the average liquid discharge volume is high. A cleaning device as described in configuration 1 or 2.

[0164] [Composition 7] The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease as the time interval becomes earlier. A cleaning device as described in configuration 1 or 2.

[0165] [Structure 8] For each of the aforementioned sections, means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, For each of the aforementioned sections, means for obtaining the time when liquid was first discharged from any of the discharge ports belonging to the section since the previous cleaning was performed, Furthermore, The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease as the average liquid discharge volume increases, and the speed at which the suction wiper scans the discharge surface tends to decrease as the time is earlier. A cleaning device as described in configuration 1 or 2.

[0166] [Composition 9] The aforementioned suction wiper is A suction nozzle having side walls that surround the non-open portion of a space that is partially open, A suction holder that holds the suction nozzle, It has, During the cleaning process, the end of the side wall on the opening side slides against the discharge surface, and the space is depressurized. A cleaning device according to any one of configurations 1 to 8.

[0167] [Configuration 10] The elastic modulus of the material of the side wall is in the range of 5 MPa to 0.5 MPa. The thickness of the aforementioned side wall is 2.0 mm or less. The absolute value of the acceleration or deceleration when changing the speed at which the suction wiper scans the discharge surface of the liquid discharge head is 30 mm / sec² or less. The cleaning device described in configuration 9.

[0168] [Composition 11] A cleaning device described in any one of items 1 to 10, Means for forming an image on a recording medium using the liquid ejection head, A liquid dispensing device equipped with the following features.

[0169] [method] A cleaning method for cleaning the discharge surface of a liquid discharge head, which has multiple discharge ports for discharging liquid, An execution step in which a suction wiper that sucks liquid from the discharge and wipes the discharge surface is scanned along the scanning direction of the discharge surface to perform cleaning of the discharge surface, A determination step for each section along the scanning direction, which determines whether at least one discharge port located in the section has discharged liquid since the last time the cleaning was performed, An adjustment step to make the speed at which the suction wiper scans the section in which it is determined by the determination step that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A cleaning method having the following characteristics.

[0170] [program] A program for causing a liquid dispensing device to function as a cleaning device for cleaning the dispensing surface of a liquid dispensing head, which has multiple dispensing ports for dispensing liquid, The aforementioned liquid dispensing device, An execution means for performing cleaning of the discharge surface by scanning a suction wiper, which sucks liquid from the discharge port and wipes the discharge surface, along the scanning direction of the discharge surface, For each section along the scanning direction, a determination means for determining whether at least one discharge port located in that section has discharged liquid since the last time the cleaning was performed, An adjustment means for making the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A program designed to function as such.

Claims

1. A cleaning device for cleaning the discharge surface of a liquid discharge head, which has multiple discharge ports for discharging liquid, A suction wiper that sucks liquid from the discharge port and wipes the discharge surface, An execution means for performing cleaning of the discharge surface by scanning the suction wiper along the scanning direction of the discharge surface, For each section along the scanning direction, a determination means for determining whether at least one discharge port located in that section has discharged liquid since the last time the cleaning was performed, An adjustment means that makes the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A cleaning device equipped with the following features.

2. The adjustment means makes the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid, and the section adjacent to said section, less than the speed at which the suction wiper scans the other sections. The cleaning device according to claim 1.

3. Each of the aforementioned sections further includes means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The adjusting means makes the speed at which the suction wiper scans the section in which the average liquid discharge amount is a first discharge amount smaller than the speed at which the suction wiper scans the section in which the average liquid discharge amount is a second discharge amount that is less than the first discharge amount. The cleaning device according to claim 1.

4. The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The adjusting means makes the speed at which the suction wiper scans the interval where the time is the first time less than the speed at which the suction wiper scans the interval where the time is the second time, which is later than the first time. The cleaning device according to claim 1.

5. For each of the aforementioned sections, means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The aforementioned adjustment means is The speed at which the suction wiper scans the section where the average liquid discharge amount is the first discharge amount is made smaller than the speed at which the suction wiper scans the section where the average liquid discharge amount is the second discharge amount, which is less than the first discharge amount. The speed at which the suction wiper scans the interval where the aforementioned time is the first time is made smaller than the speed at which the suction wiper scans the interval where the aforementioned time is the second time, which is later than the first time. The cleaning device according to claim 1.

6. Each of the aforementioned sections further includes means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease in sections where the average liquid discharge volume is high. The cleaning device according to claim 1.

7. The system further includes means for obtaining the time when liquid was first discharged from any outlet belonging to the section since the previous cleaning was performed in each section. The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease as the time interval becomes earlier. The cleaning device according to claim 1.

8. For each of the aforementioned sections, means for obtaining the average liquid discharge volume per outlet since the last time the cleaning was performed, For each of the aforementioned sections, means for obtaining the time when liquid was first discharged from any of the discharge ports belonging to the section since the previous cleaning was performed, Furthermore, The adjustment means controls the speed at which the suction wiper scans the discharge surface such that the speed at which the suction wiper scans the discharge surface tends to decrease as the average liquid discharge volume increases, and the speed at which the suction wiper scans the discharge surface tends to decrease as the time is earlier. The cleaning device according to claim 1.

9. The aforementioned suction wiper is A suction nozzle having side walls that surround the non-open portion of a space that is partially open, A suction holder that holds the suction nozzle, It has, During the cleaning process, the end of the side wall on the opening side slides against the discharge surface, and the space is depressurized. The cleaning device according to claim 1.

10. The elastic modulus of the material of the side wall is in the range of 5 MPa to 0.5 MPa. The thickness of the aforementioned side wall is 2.0 mm or less. The absolute value of the acceleration or deceleration when changing the speed at which the suction wiper scans the discharge surface of the liquid discharge head is 30 mm / s² or less. The cleaning device according to claim 9.

11. A cleaning device according to any one of claims 1 to 10, Means for forming an image on a recording medium using the liquid ejection head, A liquid dispensing device equipped with the following features.

12. A cleaning method for cleaning the discharge surface of a liquid discharge head, which has multiple discharge ports for discharging liquid, An execution step in which a suction wiper that sucks liquid from the discharge and wipes the discharge surface is scanned along the scanning direction of the discharge surface to perform cleaning of the discharge surface, A determination step for each section along the scanning direction, which determines whether at least one discharge port located in the section has discharged liquid since the last time the cleaning was performed, An adjustment step to make the speed at which the suction wiper scans the section in which it is determined by the determination step that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A cleaning method having the following characteristics.

13. A program for causing a liquid dispensing device to function as a cleaning device for cleaning the dispensing surface of a liquid dispensing head, which has multiple dispensing ports for dispensing liquid, The aforementioned liquid dispensing device, An execution means for performing cleaning of the discharge surface by scanning a suction wiper, which sucks liquid from the discharge port and wipes the discharge surface, along the scanning direction of the discharge surface, For each section along the scanning direction, a determination means for determining whether at least one discharge port located in that section has discharged liquid since the last time the cleaning was performed, An adjustment means that makes the speed at which the suction wiper scans the section in which the determination means determines that at least one discharge port has discharged liquid smaller than the speed at which the suction wiper scans the other sections, A program designed to function as such.

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