Liquid ejection device, liquid ejection device control method, and program

Abstract

To solve the problem that moisture of ink adhering to a blade evaporates with time, so that the ink adheres to the blade, which may prevent a cleaning effect from being obtained properly, even when a conveying belt is cleaned using the blade to which the ink adheres.SOLUTION: A control part of a liquid discharge device can execute cleaning operation of cleaning a conveying belt using a cleaning member, and recovery operation of recovering a cleaning ability of the cleaning member, by rotating the conveying belt with the cleaning member contacting the conveying belt.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device that ejects liquid onto a medium, and also to a control method and program for the liquid ejection device. [Background technology]

[0002] In liquid ejection devices such as inkjet printers, a configuration is known in which a conveyor belt is used to convey a medium such as recording paper, and in such configurations, a configuration is sometimes adopted in which a blade is used to clean the conveyor belt that has ink adhering to it. The blade described in Patent Document 1 is made of urethane rubber coated with fluororesin, and is provided so as to be able to come into contact with and separate from the conveyor belt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-179953 Summary of the Invention [Problem to be solved by the invention]

[0004] The ink adhering to the blade evaporates over time, causing the ink to adhere to the blade. If an attempt is made to clean the conveyor belt using a blade with ink adhering to it, there is a risk that the cleaning effect will not be adequate. [Means for solving the problem]

[0005] In order to solve the above problem, the liquid ejection device of the present invention comprises a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and rotates to transport the medium, a cleaning member that cleans the conveying belt by contacting the conveying belt, the cleaning member being capable of switching between a contact state in which it is in contact with the conveying belt and a separation state in which it is separated from the conveying belt, and a control unit that controls the liquid ejection operation by the liquid ejection unit, the rotation operation of the conveying belt, and the state switching of the cleaning member, and is characterized in that the control unit is capable of performing a cleaning operation in which the cleaning member cleans the conveying belt, and a recovery operation in which the cleaning member rotates the conveying belt while in contact with the conveying belt, thereby recovering the cleaning ability of the cleaning member.

[0006] Furthermore, the control method for a liquid ejection device of the present invention is a control method for a liquid ejection device that includes a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and conveys the medium by rotating, and a cleaning member that cleans the conveying belt by contacting the conveying belt, the cleaning member being switchable between a contact state in which it is in contact with the conveying belt and a separated state in which it is separated from the conveying belt, and is characterized by including the steps of: performing a cleaning operation to clean the conveying belt with the cleaning member; and, when the elapsed time since performing the cleaning operation reaches a set time, performing a recovery operation to restore the cleaning ability of the cleaning member by rotating the conveying belt with the cleaning member in contact with the conveying belt.

[0007] The program of the present invention is a program executed by a control unit of a liquid ejection device having a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and rotates to convey the medium, and a cleaning member that cleans the conveying belt by contacting the conveying belt, the cleaning member being switchable between a contact state in which it is in contact with the conveying belt and a separated state in which it is separated from the conveying belt, and is characterized by including the steps of: causing the cleaning member to perform a cleaning operation to clean the conveying belt; and, when the elapsed time since the cleaning operation was performed reaches a set time, causing the cleaning member to rotate the conveying belt with the cleaning member in contact with the conveying belt, thereby performing a recovery operation to restore the cleaning ability of the cleaning member. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing a media transport path of the printer. [Figure 2] FIG. 2 is a block diagram showing the control system of the printer. [Figure 3] FIG. 4 is a side view of the conveyor belt, the first cleaning unit, and the second cleaning unit. [Figure 4] FIG. 4 is a side view of the conveyor belt, the first cleaning unit, and the second cleaning unit. [Figure 5] 10 is a graph showing the relationship between the amount of water in ink remaining on the blade and the elapsed time. [Figure 6] 10 is a flowchart showing a control flow for performing a blade recovery operation. [Figure 7] 10 is a flowchart showing the flow of a process for adjusting the timing of performing a blade recovery operation. [Figure 8] 10 is a graph showing the relationship between the evaporation rate of water contained in ink and humidity. [Figure 9] Graphs (a), (b), and (c) show the moving speed of the conveyor belt when the blade is performing a recovery operation. [Figure 10] 10 is a flowchart showing a control flow when a cleaning operation of the conveyor belt is performed. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be briefly described below. A liquid ejection device according to a first aspect includes a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and rotates to transport the medium, a cleaning member that contacts the conveying belt to clean the conveying belt, the cleaning member being switchable between a contact state in which it contacts the conveying belt and a separation state in which it is separated from the conveying belt, and a control unit that controls the liquid ejection operation by the liquid ejection unit, the rotation operation of the conveying belt, and the state switching of the cleaning member, and is characterized in that the control unit is capable of performing a cleaning operation in which the cleaning member cleans the conveying belt, and a recovery operation in which the cleaning member rotates the conveying belt while in contact with the conveying belt to restore the cleaning ability of the cleaning member.

[0010] According to this aspect, the control unit can execute a cleaning operation in which the cleaning member cleans the conveyor belt, and a recovery operation in which the cleaning member rotates the conveyor belt while in contact with the conveyor belt, thereby recovering the cleaning ability of the cleaning member. Therefore, if liquid remains on the cleaning member, the recovery operation can remove at least a portion of the remaining liquid. This restores the cleaning ability of the cleaning member and allows the conveyor belt to be properly cleaned. The liquid removed from the cleaning member by the recovery operation includes liquid that has adhered to the cleaning member with little or no water evaporation, liquid that has adhered to the cleaning member with increased viscosity due to progress in water evaporation, and liquid that has adhered to the cleaning member with almost all water evaporated and solidified, and at least one of these is removed from the cleaning member by the recovery operation.

[0011] The second aspect is characterized in that, in the first aspect, the control unit performs the recovery operation after performing the cleaning operation and after the amount of water in the liquid in the cleaning member reaches a predetermined amount of water. After the cleaning operation is performed, the amount of water in the liquid on the cleaning element decreases due to evaporation. According to this aspect, the control unit performs the recovery operation after the amount of water in the liquid on the cleaning element reaches a predetermined amount after the cleaning operation is performed, thereby preventing unnecessary recovery operations from being performed and reducing a reduction in the lifespan of the cleaning element.

[0012] A third aspect is the second aspect, characterized in that the control unit determines the timing based on the time that has elapsed since the cleaning operation was performed. According to this aspect, the control unit determines the timing based on the elapsed time since the cleaning operation was performed, which makes it easy to manage the timing.

[0013] A fourth aspect is characterized in that, in the second or third aspect, a detection unit is provided that can acquire at least one of humidity and temperature, and the control unit, when acquiring the humidity and the humidity is a first humidity, sets the time until the timing is reached to be shorter than when a second humidity higher than the first humidity, and when acquiring the temperature and the temperature is a first temperature, sets the time until the timing is reached to be shorter than when a second temperature lower than the first temperature.

[0014] The amount of water remaining in the liquid on the cleaning member is affected by at least one of humidity and temperature. For example, the evaporation of water from the liquid becomes more pronounced as humidity decreases or temperatures increase. According to this aspect, the control unit adjusts the timing based on at least one of humidity and temperature, thereby making it possible to more appropriately time the recovery operation.

[0015] A fifth aspect is characterized in that, in any of the second to fourth aspects, the control unit performs the cleaning operation when liquid is erroneously ejected from the liquid ejection unit onto the conveying belt, and when the ejection duty at the time of the erroneous ejection is a first ejection duty, the control unit sets the time until the timing is reached to be shorter than when a second ejection duty that is higher than the first ejection duty is used.

[0016] The amount of water remaining in the cleaning member is affected by the discharge duty when the liquid discharge unit erroneously discharges liquid onto the conveyor belt. According to this aspect, the control unit adjusts the timing based on the discharge duty, so that the timing of executing the recovery operation can be more appropriate.

[0017] A sixth aspect is the second aspect, characterized in that the control unit determines the timing by calculating the amount of water in the liquid. According to this aspect, the control unit determines the timing by calculating the water content of the liquid, so that the timing of performing the recovery operation can be more appropriate. Furthermore, unnecessary execution of the recovery operation can be prevented, and shortening of the lifespan of the cleaning member can be prevented.

[0018] A seventh aspect is characterized in that, in any of the first to sixth aspects, the recovery operation includes a first mode in which the conveying belt is moved relative to the cleaning member at a first speed, and a second mode in which the conveying belt is moved relative to the cleaning member at a second speed that is faster than the first speed.

[0019] According to this aspect, the recovery operation includes a first mode in which the conveying belt is moved relative to the cleaning member at a first speed, and a second mode in which the conveying belt is moved relative to the cleaning member at a second speed that is faster than the first speed.Therefore, the second mode ensures the effect of the recovery operation, while the first mode suppresses wear on the cleaning member.

[0020] An eighth aspect is characterized in that, in any of the first to seventh aspects, the recovery operation includes a speed change mode in which the movement speed of the conveying belt relative to the cleaning member is periodically changed. According to this aspect, the recovery operation includes a speed change mode that periodically changes the moving speed of the conveying belt relative to the cleaning member, which imparts a bending behavior to the cleaning member, thereby enhancing the effectiveness of removing liquid remaining on the cleaning member. Incidentally, the cyclic change in the moving speed of the conveyor belt means that the moving speed is repeatedly increased and decreased so as to change, for example, in a rectangular wave shape.

[0021] A ninth aspect is characterized in that, in any of the first to eighth aspects, the control unit is capable of executing a first cleaning operation and a second cleaning operation that has a higher cleaning effect than the first cleaning operation as the cleaning operation, and when the cleaning operation is performed between performing the cleaning operation and performing the recovery operation, the control unit selects the first cleaning operation until a predetermined operation switching timing is reached, and selects the second cleaning operation after the operation switching timing.

[0022] If the cleaning operation is performed between the cleaning operation and the recovery operation, the longer the time that has elapsed since the cleaning operation, the higher the viscosity of the liquid remaining on the cleaning member, which may result in a decrease in the cleaning ability when cleaning the conveying belt. According to this aspect, when the control unit performs the cleaning operation between performing the cleaning operation and performing the recovery operation, after the specified operation switching timing, it selects the second cleaning operation, which has a higher cleaning effect than the first cleaning operation, thereby compensating for the decrease in cleaning ability of the cleaning member and properly cleaning the conveying belt.

[0023] The tenth aspect is characterized in that, in the ninth aspect, the control unit increases at least one of the cleaning time, the contact pressure of the cleaning member against the conveying belt, and the movement speed of the conveying belt relative to the cleaning member in the second cleaning operation compared to the first cleaning operation.

[0024] According to this aspect, the control unit increases at least one of the cleaning time, the contact pressure of the cleaning member against the conveying belt, and the movement speed of the conveying belt relative to the cleaning member in the second cleaning operation compared to the first cleaning operation, thereby easily achieving the second cleaning operation with a higher cleaning effect than the first cleaning operation.

[0025] The 11th aspect is characterized in that, in any of the 1st to 10th aspects, the cleaning member is a first cleaning member, and a second cleaning member is provided downstream of the cleaning member in the movement direction of the conveying belt, which cleans the conveying belt by contacting the conveying belt. According to this aspect, the cleaning member is a first cleaning member, and a second cleaning member is provided in addition to the first cleaning member, so that the conveyor belt can be cleaned more reliably.

[0026] A control method for a liquid ejection device according to a twelfth aspect is a control method for a liquid ejection device that includes a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and rotates to convey the medium, and a cleaning member that cleans the conveying belt by contacting the conveying belt, the cleaning member being switchable between a contact state in which it is in contact with the conveying belt and a separated state in which it is separated from the conveying belt, and is characterized by including the steps of: performing a cleaning operation to clean the conveying belt with the cleaning member; and performing a recovery operation to restore the cleaning ability of the cleaning member by rotating the conveying belt with the cleaning member in contact with the conveying belt after the elapsed time since the cleaning operation was performed reaches a set time.

[0027] According to this aspect, if liquid remains on the cleaning member, it is expected that at least a portion of the remaining liquid will be removed by the recovery operation, thereby restoring the cleaning ability of the cleaning member and enabling the conveyor belt to be properly cleaned.

[0028] The program according to the thirteenth aspect is a program executed by a control unit of a liquid ejection device having a liquid ejection unit that ejects liquid onto a medium, a conveying belt that faces the liquid ejection unit and rotates to convey the medium, and a cleaning member that cleans the conveying belt by contacting the conveying belt, the cleaning member being switchable between a contact state in which it is in contact with the conveying belt and a separated state in which it is separated from the conveying belt, and is characterized by including the steps of causing the cleaning member to perform a cleaning operation to clean the conveying belt, and, after the elapsed time since the cleaning operation has been performed reaches a set time, causing the cleaning member to rotate the conveying belt with the cleaning member in contact with the conveying belt, thereby performing a recovery operation to restore the cleaning ability of the cleaning member.

[0029] According to this aspect, if liquid remains on the cleaning member, it is expected that at least a portion of the remaining liquid will be removed by the recovery operation, thereby restoring the cleaning ability of the cleaning member and enabling the conveyor belt to be properly cleaned.

[0030] The present invention will be specifically described below. In the following, an inkjet printer 1 that performs recording by ejecting a liquid, such as ink, onto a medium, such as recording paper, will be described as an example of a liquid ejection device. In the following, the inkjet printer 1 will be abbreviated as printer 1.

[0031] The XYZ coordinate system shown in each figure is a Cartesian coordinate system, with the Y axis direction being the width direction that intersects with the media transport direction and the depth direction of the device. Note that the +Y direction of the Y axis direction is the direction from the front of the device to the back of the device, and the -Y direction is the direction from the back of the device to the front of the device. The X axis direction is the width direction of the device, and the +X direction, in which the arrow points, is the left side as seen by the operator of the printer 1, and the opposite, -X direction, is the right side. The Z axis direction is the vertical direction, that is, the height direction of the device, and the +Z direction, in which the arrow points, is the upward direction, and the opposite, -Z direction, is the downward direction.

[0032] The G-axis direction is the normal direction to the ink ejection surface 26a of the line head 26, which will be described later. The F-axis direction is parallel to the ink ejection surface 26a and is the medium transport direction at a position facing the ink ejection surface 26a, with the +F direction, in which the arrow points, being the downstream transport direction and the opposite -F direction being the upstream transport direction. Note that, hereinafter, the direction in which the medium is transported may be referred to as "downstream" and the opposite direction as "upstream." In addition, some diagrams use the FGY coordinate system instead of the XYZ coordinate system.

[0033] The medium transport path is indicated by a dashed line in Figure 1. In the printer 1, the medium is transported through the medium transport path indicated by the dashed line. The device main body 2 of the printer 1 is equipped with a first media cassette 3 and a second media cassette 4 that store media before feeding. The symbol P indicates the media stored in each media cassette. The first media cassette 3 and second media cassette 4 are detachably mounted on the device main body 2 from the front side of the device. A pick roller 9 is provided for the first medium cassette 3 to feed out the stored medium, and a pick roller 10 is provided for the second medium cassette 4 to feed out the stored medium.

[0034] A pair of feed rollers 11 that feeds the fed medium diagonally upward is provided for the first medium cassette 3. A pair of feed rollers 12 that feeds the fed medium diagonally upward and a pair of transport rollers 13 that transports the medium upward are provided for the second medium cassette 4. Unless otherwise specified, hereinafter, a "roller pair" is defined as consisting of a drive roller driven by a motor (not shown) and a driven roller that rotates in contact with the drive roller.

[0035] The medium fed from each medium cassette is sent to a transport roller pair 16 by a transport roller pair 14 and a transport roller pair 15. The medium receiving a transport force from the transport roller pair 16 is sent to a position between the line head 26 and the transport belt 33, that is, a position facing the line head 26.

[0036] The head unit 25 is equipped with a line head 26, which performs recording by ejecting ink, an example of liquid, onto the surface of the medium. The line head 26 is an ink ejection head configured so that nozzles (not shown) that eject ink cover the entire area in the width direction of the medium, and is configured as an ink ejection head that can record across the entire width of the medium without moving in the width direction of the medium. The line head 26 is an example of a liquid ejection unit that ejects liquid. However, the ink ejection head may be of a type that performs recording by moving in the width direction of the medium.

[0037] Reference numeral 5 denotes an ink storage section that stores ink. Ink ejected from the line head 26 is supplied from the ink storage section 5 to the line head 26 via a tube (not shown). The ink storage section 5 is composed of multiple ink tanks arranged along the X-axis direction.

[0038] The conveyor belt 33, the drive pulley 31, and the driven pulley 32 constitute the belt unit 30. The conveyor belt 33 is an endless belt that is wound around the drive pulley and the driven pulley 32. The conveyor belt 33 rotates when the drive pulley 31 is driven by a belt drive motor 57 (see FIG. 2). The medium is transported to a position facing the line head 26 while being attracted to the transport belt 33. The attraction of the medium to the transport belt 33 will be described later.

[0039] The medium transport path that passes through the position facing the line head 26 intersects both the horizontal and vertical directions and transports the medium diagonally upward. This diagonally upward transport direction includes a -X direction component and a +Z direction component in Figure 1, and this configuration makes it possible to reduce the horizontal dimension of the printer 1. In this embodiment, the medium transport path passing through a position facing the line head 26 is set at an inclination angle in the range of 50° to 70° with respect to the horizontal direction, and more specifically, at an inclination angle of 60°.

[0040] The medium on whose first side recording has been performed by the line head 26 is further sent obliquely upward by the pair of transport rollers 17 located downstream of the transport belt 33. A flap 23 is provided downstream of the transport roller pair 17, and this flap 23 switches the transport direction of the medium. When the medium is to be discharged as is, the flap 23 switches the transport path of the medium toward the upper transport roller pair 20. A further flap 24 is provided downstream of the transport roller pair 20, and this flap 24 switches the transport path to either discharge from discharge position A1 or transport to the transport roller pair 21 located further vertically above. When the medium is sent toward the transport roller pair 21, it is discharged from discharge position A2. The medium discharged from discharge position A1 is received by discharge tray 27, which is inclined diagonally upward including a +X direction component and a +Z direction component. The medium discharged from discharge position A2 is received by an optional tray (not shown).

[0041] When recording is to be performed on the second side of the medium in addition to the first side, the medium is sent by the flap 23 in an obliquely upward direction including a -X direction component and a +Z direction component, passes through the branching position K1, and is sent from the branching position K1 to an upward switchback path. A transport roller pair 22 is provided on this switchback path, and the medium that enters the switchback path is transported upward by the transport roller pair 22. When the upstream end of the medium passes the branching position K1, the rotation direction of the transport roller pair 22 is switched, causing the medium to be transported downward.

[0042] The medium transported downward by the transport roller pair 22 receives a feed force from the transport roller pair 18, the transport roller pair 19, and the transport roller pair 15, reaches the transport roller pair 16, and is sent again to the transport belt 33 by the transport roller pair 16. The medium is sent again to a position facing the line head 26, with the second side, opposite to the first side on which recording has already been performed, facing the line head 26. This makes it possible to record on the second side of the medium by the line head 26. The medium with recording on the second side is discharged from the above-mentioned discharge position A1 or discharge position A2.

[0043] Next, the belt unit 30, the first cleaning unit 35, and the second cleaning unit 40 will be described with reference to FIGS. The conveyor belt 33 constituting the belt unit 30 is an endless belt made of a base material such as urethane or rubber, with conductive material added as needed to adjust the resistance, and is wound around a drive pulley 31 on the upstream side and a driven pulley 32 on the downstream side. A predetermined tension is applied to the conveyor belt 33 by a tensioner (not shown).

[0044] The drive pulley 31 is driven to rotate by a belt drive motor 57 (see FIG. 2) controlled by a control unit 50 (see FIG. 2). When the drive pulley 31 is driven to rotate in the direction of arrow a, the conveyor belt 33 rotates in the clockwise direction in FIGS. 3 and 4. Hereinafter, this rotation of the conveyor belt 33 may be referred to as "forward rotation." When the drive pulley 31 is driven to rotate in the direction of arrow b, the conveyor belt 33 rotates counterclockwise in Figures 3 and 4. Hereinafter, this rotation of the conveyor belt 33 may be referred to as "reverse rotation."

[0045] A charging roller 29 is provided at a position opposite to the drive pulley 31 across the conveyor belt 33. The charging roller 29 is in contact with the outer surface of the conveyor belt 33 and is rotated in accordance with the rotation of the conveyor belt 33. A direct current voltage is applied to the charging roller 29 by a belt charging unit 58 (see FIG. 2), which causes the charging roller 29 to supply an electric charge to the portion of the charging roller 29 that is in contact with the conveyor belt 33. The belt charging unit 58 (see FIG. 2) is controlled by a control unit 50, which switches on / off the application of voltage to the charging roller 29 and switches the voltage applied to the charging roller 29.

[0046] In this embodiment, the charging roller 29 supplies a positive charge to the conveyor belt 33, charging the outer peripheral surface 33a of the conveyor belt 33 with a positive polarity, thereby making the outer peripheral surface 33a of the conveyor belt 33 an attraction surface that attracts the medium.

[0047] A support roller 34 that comes into contact with the medium is provided upstream of the line head 26. The support roller 34 presses the medium against the portion of the conveyor belt 33 that is wound around the drive pulley 31. The support roller 34 is grounded, which removes charge from the recording surface of the medium.

[0048] Next, a first cleaning unit 35 is provided near the driven pulley 32. The first cleaning unit 35 includes a blade 36, which is an example of a cleaning member that cleans the outer peripheral surface 33a of the conveyor belt 33. The blade 36 is fixed to a fixed member 37, and the fixed member 37 is provided rotatably about a rotation shaft 38.

[0049] The blade 36 is, for example, a plate-shaped elastic member having a predetermined thickness, and is made of urethane, rubber, or the like, and can elastically deform when in contact with the conveyor belt 33. The tip of the blade 36 comes into contact with the portion of the conveyor belt 33 that is wound around the driven pulley 32, thereby cleaning the outer peripheral surface 33a of the conveyor belt 33.

[0050] The rotating shaft 38 is rotated by a blade driving unit 59 (see FIG. 2), and the rotation of the rotating shaft 38 switches the blade 36 between a contact state (see FIG. 3) in which it is in contact with the conveyor belt 33 and a separation state (see FIG. 4) in which the blade 36 is separated from the conveyor belt 33. When the blade 36 is in the contact state, the conveyor belt 33 rotates forward, thereby removing ink, paper dust, and other deposits that have adhered to the outer peripheral surface 33a of the conveyor belt 33. The blade driving unit 59 (see FIG. 2) can be configured with an actuator such as a motor. The control unit 50 can also adjust the amount of rotation of the rotation shaft 38 to adjust the pressure with which the blade 36 presses against the conveyor belt 33.

[0051] A second cleaning unit 40 is provided below the first cleaning unit 35. The second cleaning unit 40 is located downstream of the first cleaning unit 35 in the direction of movement of the conveyor belt 33. A cleaning sheet 41 is looped around a drive pulley 42 and driven pulleys 43 and 44, and tension is applied to the cleaning sheet 41 by a tensioner 45. If the blade 36 is considered to be the first cleaning member, then the cleaning sheet 41 is considered to be the second cleaning member.

[0052] In this embodiment, the cleaning sheet 41 is an endless fabric, and can be pressed against the outer circumferential surface 33a of the conveyor belt 33 by a driven pulley 43. The drive pulley 42 is driven to rotate by a sheet drive motor 61 (see FIG. 2). The drive pulley 42 is driven to rotate in the clockwise direction in FIG. 3, which causes the cleaning sheet 41 to move around in the clockwise direction in FIG. 3.

[0053] The second cleaning unit 40 is provided so as to be movable in a direction to move back and forth relative to the conveyor belt 33, specifically along the G-axis direction, and receives power from a unit drive unit 60 (see FIG. 2) to move back and forth relative to the conveyor belt 33. The unit drive unit 60 can be configured with an actuator such as a motor. When the second cleaning unit 40 advances relative to the conveyor belt 33, the cleaning sheet 41 is pressed against the conveyor belt 33 by the driven pulley 43, and in this state the conveyor belt 33 rotates forward and the cleaning sheet 41 moves in a circular motion, thereby wiping the outer peripheral surface 33a of the conveyor belt 33. Note that Figures 3 and 4 show a state in which the second cleaning unit 40 is retracted relative to the conveyor belt 33, and a state in which the second cleaning unit 40 advances relative to the conveyor belt 33 is not shown.

[0054] The above-mentioned belt drive motor 57, belt charging section 58, blade drive section 59, unit drive section 60, and sheet drive motor 61 are controlled by a control section 50 as control means, as shown in FIG. The control unit 50 is a control unit that controls the entire printer 1, and in addition to the components described above, it controls the line head 26, a medium transport motor (not shown), and the like.

[0055] The control unit 50 has a CPU 51 and nonvolatile memory 52, and the nonvolatile memory 52 stores a program PR and various parameters for performing various controls on the printer 1. The program PR includes programs for implementing the various controls described below, and the nonvolatile memory 52 stores various parameters required to execute the program PR. Note that the symbol N1 is data required for the recovery operation of the conveyor belt 33, which will be described later.

[0056] Signals are input to the control unit 50 from the operation panel 54, and signals for displaying information are output from the control unit 50 to a display unit (not shown) of the operation panel 54. Various setting information input via the operation panel 54 is stored in the non-volatile memory 52. ​​The control unit 50 performs various controls based on the various setting information.

[0057] The control unit 50 has an interface 53 for communicating with an external computer 90. The control unit 50 acquires recording data, which is data for recording and is generated by a printer driver running on the external computer 90 or a printer driver provided in the control unit 50. Then, based on the recording data, it controls each mechanical part, including the line head 26. The recording data also includes medium size information.

[0058] In addition, detection signals from the various sensors are input to the control unit 50, and the control unit 50 performs necessary control based on these detection signals. Figure 2 shows an upstream sensor 65, a downstream sensor 66, and a temperature and humidity sensor 67, which are some of the various sensors. 3 and 4, the upstream sensor 65 is located opposite the conveyor belt 33 and is provided upstream of the line head 26. The downstream sensor 66 is located opposite the conveyor belt 33 and is provided downstream of the line head 26. The upstream sensor 65 and the downstream sensor 66 are optical sensors that include a light-emitting portion that emits light toward the conveyor belt 33 and a light-receiving portion that receives light reflected from the conveyor belt 33 or the medium. Based on the detection signal from the upstream sensor 65, the control unit 50 can detect the passage of the leading edge or trailing edge of the medium at the position of the upstream sensor 65, and can also detect the passage of the leading edge or trailing edge of the medium at the position of the downstream sensor 66.

[0059] In particular, if the control unit 50 cannot detect the passage of the leading edge of the medium at the downstream sensor 66 even after a predetermined time has elapsed after detecting the passage of the leading edge of the medium at the upstream sensor 65, it determines that a medium jam has occurred. When the control unit 50 determines that a medium jam has occurred, it stops the recording operation. This stopping of the recording operation includes stopping the ejection of ink from the line head 26 and stopping the driving of the conveyor belt 33 and other conveyor roller pairs.

[0060] A temperature and humidity sensor 67 is provided inside the device, and the control unit 50 can grasp the temperature and humidity inside the device based on information received from the temperature and humidity sensor 67. In this embodiment, it is more preferable to place the temperature and humidity sensor 67 near the conveyor belt 33. As will be described in detail later, the temperature or humidity acquired by the temperature and humidity sensor 67 in this embodiment is used to determine how easily or difficultly the ink adhering to the conveyor belt 33 dries. However, the temperature and humidity sensor 67 may be provided outside the device. Also, the temperature sensor and humidity sensor may be provided separately, in which case at least one of them may be provided outside the device.

[0061] In this embodiment, the control unit 50 uses at least one of the first cleaning unit 35 and the second cleaning unit 40 to clean the outer peripheral surface 33a of the conveyor belt 33. The control unit 50 can select a cleaning operation that uses only the first cleaning unit 35, a cleaning operation that uses both the first cleaning unit 35 and the second cleaning unit 40, or a cleaning operation that uses only the second cleaning unit 40.

[0062] An example of a case in which the control unit 50 selects a cleaning operation that uses only the first cleaning unit 35 is during a regular cleaning operation. The control unit 50 has a means for counting the time that has elapsed since the regular cleaning operation was performed, and performs the regular cleaning operation when a predetermined time has elapsed since the previous regular cleaning operation. A cleaning operation that uses only the first cleaning unit 35 is also performed when the printer 1 transitions to standby mode after a recording job has finished.

[0063] An example of a case in which the control unit 50 selects a cleaning operation that uses both the first cleaning unit 35 and the second cleaning unit 40 is when, after a medium jam occurs and the recording operation is stopped, the user removes the medium and presses the OK button on the operation panel 54. When a medium jam occurs in this way, there is a risk that ink may have been accidentally ejected onto the conveyor belt 33, resulting in ink adhering to the conveyor belt 33. Therefore, the control unit 50 executes the cleaning operation using both the first cleaning unit 35 and the second cleaning unit 40. Other examples of when the control unit 50 selects a cleaning operation that uses both the first cleaning unit 35 and the second cleaning unit 40 include when performing borderless recording, in which ink is ejected both onto the edge of the medium and onto areas outside the edge of the medium to record without any margins along the edge of the medium, or when ink is ejected from the line head 26 onto the conveyor belt 33 as part of maintenance of the line head 26. The recovery operation of the blade 36 described below is triggered by the execution of a cleaning operation that uses both the first cleaning unit 35 and the second cleaning unit 40, but is not limited to this.

[0064] The control unit 50 selects the cleaning operation using only the second cleaning unit 40 when the number of double-sided recordings reaches a predetermined value or when there is a risk of condensation on the conveyor belt 33. The control unit 50 is equipped with a means for counting the number of double-sided recordings, and when the number of double-sided recordings reaches a predetermined value, the control unit 50 executes the cleaning operation using only the second cleaning unit 40. This is because, when double-sided recording is performed, the first side, on which recording is performed first, comes into contact with the conveyor belt 33 when recording is performed on the opposite side, the second side, and ink may adhere to the conveyor belt 33. Furthermore, if condensation occurs on the conveyor belt 33, the medium may become wet, so the control unit 50 executes the cleaning operation using only the second cleaning unit 40. Examples of situations where there is a risk of condensation on the conveyor belt 33 include a sudden change to a high humidity state or a sudden increase in temperature from a low-temperature storage state.

[0065] Next, the recovery operation of the blade 36 will be described. In particular, after cleaning the conveyor belt 33 that is soiled due to the above-mentioned erroneous ejection, there is a high possibility that ink will remain on the blade 36. Then, over time, the moisture in the ink remaining on the blade 36 evaporates and the ink will adhere to the blade 36. Even if an attempt is made to clean the conveyor belt 33 using a blade 36 with ink adhered thereto, there is a risk that an appropriate cleaning effect will not be obtained. Therefore, the control unit 50 is configured to be able to execute the recovery operation of the blade 36.

[0066] 5 shows the relationship between the amount of moisture H contained in the ink remaining on the blade 36 and the elapsed time T. The starting point of the elapsed time T can be set to any appropriate point in time, such as when the cleaning operation of the conveyor belt 33 starts, when it is completed, or during the cleaning operation. The moisture amount H1 is the amount of moisture at the starting point of the elapsed time T. The amount of moisture H of the ink remaining on the blade 36 decreases over time as the cleaning operation of the conveyor belt 33 proceeds. If the amount of moisture H decreases to, for example, H3, and this adversely affects the cleaning of the conveyor belt 33, the blade 36 performs a recovery operation after the elapsed time T reaches time T2.

[0067] In this embodiment, the recovery operation of the blade 36 is performed by rotating the conveyor belt 33 while the blade 36 is in contact with the conveyor belt 33. This causes at least a portion of the ink remaining on the blade 36 to fall and be removed by friction with the conveyor belt 33. In this case, the amount of rotation of the conveyor belt 33 can be set as appropriate, but it is preferable to rotate the conveyor belt 33 at least one full rotation.

[0068] 6 shows a process executed by the control unit 50 at a predetermined timing, which determines whether or not to perform recovery operation for the blade 36, and executes the recovery operation depending on the conditions. Examples of the predetermined timing include when the printer 1 is turned on, when a print job ends, when the printer 1 transitions to power saving mode, and when the printer 1 returns from power saving mode. Of course, the process of FIG. 6 may be executed at other times as well. Furthermore, the process of FIG. 6 may be executed at all of the above-mentioned multiple timings, or may be executed at some of the timings.

[0069] The control unit 50 determines whether the cleaning flag is ON or OFF (step S101). The cleaning flag is data stored in the non-volatile memory 52 (see FIG. 2) and takes on either an ON or OFF value. The cases when the cleaning flag is set to ON and when it is set to OFF will be explained later, but when the cleaning flag is ON, it means that there is a high possibility that ink remains on the blade 36, for example, after a cleaning operation of the conveyor belt 33 has been performed. On the other hand, when the cleaning flag is OFF, it means that there is a high possibility that no ink remains on the blade 36, for example, after a recovery operation of the blade 36 has been performed. Of course, in the process of determining whether or not to perform the recovery operation of the blade 36, it is not always necessary to use the cleaning flag as described above.

[0070] If the cleaning flag is OFF, the control unit 50 ends the process. If the cleaning flag is ON, it determines whether the elapsed time T is equal to or greater than time T2 (step S102). Time T2 is information stored in the nonvolatile memory 52 (FIG. 2), and the control unit 50 reads time T2 from the nonvolatile memory 52. If the elapsed time T is less than the time T2 (No in step S102), the cleaning flag is set to ON again (step S106), and the process ends. If the elapsed time T is equal to or greater than the time T2 (Yes in step S102), a recovery operation of the blade 36 is performed (step S103), the elapsed time T is reset to zero (step S104), and the cleaning flag is set to OFF (step S105).

[0071] The elapsed time T is constantly counted when the printer 1 is turned on or in power saving mode. When the printer 1 is turned off, the elapsed time T up to that point and the date and time when the printer is turned off are saved in the non-volatile memory 52 (see FIG. 2). When the printer 1 is turned on, the elapsed time T up to that point is calculated based on the information saved in the non-volatile memory 52 and the date and time when the printer was turned on, and counting resumes.

[0072] As described above, the control unit 50 can perform a cleaning operation to clean the conveying belt 33 with the blade 36, and a recovery operation to restore the cleaning ability of the blade 36 by rotating the conveying belt 33 while the blade 36 is in contact with the conveying belt 33. In addition, the program executed by the control unit 50 and the control method realized by the control unit 50 executing the program include a step of performing a cleaning operation to clean the conveying belt 33 with the blade 36 (steps S302 and S306 in Figure 10 described later), and a step (step S103) of performing a recovery operation to restore the cleaning ability of the blade 36 by rotating the conveying belt 33 with the blade 36 in contact with the conveying belt 33 after the elapsed time T since the cleaning operation was performed reaches a set time T2. As a result, if ink remains on the blade 36, at least a portion of the remaining ink can be removed by the recovery operation, the cleaning ability of the blade 36 can be restored, and the conveyor belt 33 can be properly cleaned. Furthermore, compared to the case where ink adhering to the blade 36 is dissolved using water, a solvent, or the like, or where a means for mechanically removing the ink is employed, an increase in cost and an increase in the size of the apparatus can be avoided.

[0073] Furthermore, after the controller 50 has performed the cleaning operation on the conveyor belt 33, it performs the above-described recovery operation after the moisture content of the ink on the blade 36 reaches a predetermined moisture content. In the above example, the predetermined moisture content is moisture content H3 in Figure 5. This makes it possible to prevent unnecessary recovery operations from being performed. In addition, in this embodiment, the control unit 50 determines the timing based on the elapsed time T, which makes it easy to manage the timing.

[0074] The time T2 read from the nonvolatile memory 52 (see FIG. 2) can also be adjusted based on at least one of humidity and temperature. In this embodiment, humidity and temperature can be obtained by the temperature and humidity sensor 67 (see FIG. 2). For example, when the control unit 50 acquires the humidity and the humidity is a first humidity, it sets the time T2 to be shorter than when the humidity is a second humidity that is higher than the first humidity. This is because when the humidity is relatively low, evaporation of water from the ink becomes significant. Alternatively, when the control unit 50 acquires the temperature, if the temperature is a first temperature, it sets the time T2 to be shorter than if the temperature is a second temperature that is lower than the first temperature. This is because when the temperature is relatively high, evaporation of water from the ink becomes significant. The control unit 50 can also adjust the time T2, that is, the timing, based on both the temperature and humidity. As a result, the timing for executing the recovery operation of the blade 36 can be made more appropriate.

[0075] FIG. 7 shows the process for adjusting the time T2. When the elapsed time T reaches a predetermined cycle (Yes in step S201), the control unit 50 acquires the humidity and temperature (step S202). The predetermined cycle can be set to an appropriate time interval, such as 24 hours, 48 ​​hours, or 72 hours. The process shown in FIG. 7 may also be performed at a predetermined timing instead of the predetermined cycle of the elapsed time T. Examples of this predetermined timing include when the printer 1 is turned on, when a print job ends, when the printer 1 transitions to power saving mode, and when the printer 1 returns from power saving mode. Of course, the process shown in FIG. 7 may also be performed at other times. The process shown in FIG. 7 may also be performed at all of the above-mentioned multiple timings, or at some of the timings. Then, the control unit 50 adjusts the time T2 based on the acquired temperature and humidity (step S203).

[0076] Furthermore, when the ejection duty when ink is erroneously ejected onto the conveyor belt 33 is the first ejection duty, the control unit 50 may set the time T2 to be shorter than when the ejection duty is the second ejection duty, which is higher than the first ejection duty. This is because when the ejection duty is the first ejection duty, the time until the amount of water in the ink on the blade 36 reaches a predetermined amount is relatively shorter than when the ejection duty is the second ejection duty. This allows the timing of executing the recovery operation of the blade 36 to be more appropriate.

[0077] Here, the ejection duty is the ratio of the area to be printed within a predetermined area of ​​the medium or the conveyor belt 33, and the lower the ejection duty, the smaller the amount of ink ejected, and the higher the ejection duty, the greater the amount of ink ejected. The ejection duty can be the ejection duty in the area where ink is actually ejected onto the conveyor belt 33. Hereinafter, this will be referred to as the "actual ejection duty." As an example, the control unit 50 can obtain the actual ejection duty based on the amount of ink ejected from the time the upstream sensor 65 detects the leading edge of the medium until the drive of the conveyor belt 33 is stopped, and the corresponding recording area. Because the actual ejection duty is based on the amount of ink actually ejected onto the conveyor belt 33, it can be said to more accurately reflect the status of the conveyor belt 33.

[0078] The ejection duty may also be the ejection duty for the entire printing area. Hereinafter, this will be referred to as the "total ejection duty." The control unit 50 can obtain the total ejection duty based on the printing data. The total ejection duty does not require measuring the amount of ink actually ejected onto the conveyor belt 33, and can be calculated more easily than the actual ejection duty. The ejection duty when ink is ejected erroneously in this manner does not only mean the ejection duty in the area where ink is actually ejected onto the conveyor belt 33 . The control unit 50 may acquire only one of the actual ejection duty and the total ejection duty, or may acquire both and then adopt either one of them.

[0079] Furthermore, since the amount of ink remaining on the blade 36 when the cleaning operation is performed varies depending on the area of ​​the blade 36, the deformation state and angle of the blade 36 when it is in contact with the conveyor belt 33, etc., it is also possible to define the maximum possible initial moisture content of the ink on the blade 36 (moisture content H1 in Figure 5) as the moisture content H1 from the above perspective, rather than the amount of moisture actually contained in the ink remaining on the blade 36, and set the time T2 based on that moisture content.

[0080] In the example described above, the timing at which the moisture content of the ink reaches a predetermined moisture content is determined by the elapsed time T, but the timing may also be determined by calculating the moisture content of the ink on the blade 36. The amount of moisture in the ink on the blade 36 can be calculated each time the elapsed time T reaches a predetermined cycle after the cleaning operation of the conveyor belt 33 is performed. The predetermined cycle can be set to an appropriate time interval, such as 24 hours, 48 ​​hours, or 72 hours. The calculation can also be performed at a predetermined timing instead of or in addition to the predetermined cycle of the elapsed time T. Examples of predetermined timing include when the printer 1 is turned on, when a print job ends, when the printer 1 transitions to power saving mode, and when the printer returns from power saving mode. Of course, the calculation can also be performed at other times. The calculation can also be performed at all of the above-mentioned multiple timings, or at some of the timings.

[0081] The above calculation can be performed based on dryness information obtained in advance. Figure 8 shows the relationship between the time required for evaporation of a unit amount of moisture, i.e., the moisture evaporation rate Fh, and the temperature M, with graph C1 showing an example for a humidity of 20%, graph C2 showing an example for a humidity of 50%, and graph C3 showing an example for a humidity of 80%. As shown in the figures, the higher the temperature and lower the humidity, the faster the moisture evaporation rate Fh. Such dryness information is stored in advance in nonvolatile memory 52 (see Figure 2), and control unit 50 calculates (estimates) the current moisture content H (see Figure 5) based on this dryness information and the acquired temperature and humidity. Of course, the initial moisture content (moisture content H1 in FIG. 5) that is the basis for calculating the moisture content H may be found based on the above-mentioned actual ejection duty or total ejection duty.

[0082] In the embodiment described above, the recovery operation of the blade 36 is performed at a predetermined timing. However, for example, after the cleaning operation of the conveyor belt 33, the recovery operation of the blade 36 may be performed periodically and repeatedly. Furthermore, when performing the recovery operation of the blade 36, the second cleaning unit 40 may be retracted from the conveyor belt 33 or may be advanced onto the conveyor belt 33. By advancing the second cleaning unit 40 onto the conveyor belt 33 when performing the recovery operation of the blade 36, when residual ink transfers from the blade 36 to the conveyor belt 33, the ink can be captured by the second cleaning unit 40.

[0083] Next, a further description will be given of the recovery operation of the blade 36. As described above, the recovery operation of the blade 36 is performed by rotating the conveyor belt 33 with the blade 36 in contact with the conveyor belt 33. The moving speed Vb of the conveyor belt 33 relative to the blade 36 can be set to a constant speed Vb1 as shown in Fig. 9(a) or to a constant speed Vb2 (Vb2>Vb1) as shown in Fig. 9(b). The speed Vb1 is an example of a first speed, and the speed Vb2 is an example of a second speed. The control unit 50 may also configure the recovery operation to include a first mode in which the conveyor belt 33 is moved at a speed Vb1 and a second mode in which the conveyor belt 33 is moved at a speed Vb2. For example, the first mode and the second mode may be performed alternately for a fixed time, or the second mode may be performed for a predetermined time, and then the first mode may be performed for a predetermined time, and the recovery operation may be terminated. In this way, the effect of the recovery operation can be reliably obtained in the second mode, while wear on the blade 36 can be suppressed in the first mode.

[0084] The control unit 50 may also include in the recovery operation a speed change mode in which the movement speed Vb of the conveyor belt 33 relative to the blade 36 is periodically changed, as shown in FIG. 9(c). FIG. 9(c) shows an example in which the movement speed Vb is repeatedly increased from zero to speed Vb1 and decreased from speed Vb1 to zero. This causes the blade 36 to bend, thereby improving the effectiveness of removing ink remaining on the blade 36. Note that in the example of FIG. 9(c), the minimum value of the speed Vb in the speed change mode is zero, but this is not limiting, and the minimum value of the speed Vb may be greater than zero. It is possible to employ only the speed change mode in the recovery operation, or to include the first mode and second mode in addition to the speed change mode in the recovery operation.

[0085] Next, a control for performing the cleaning operation of the conveyor belt 33 between the cleaning operation of the conveyor belt 33 and the recovery operation will be described. 5, when the elapsed time T exceeds time T2, the above-described recovery operation is performed, but there are cases where a cleaning operation of the conveyor belt 33 is performed before the elapsed time T reaches time T2. In this case, the closer the elapsed time T is to time T2, the higher the viscosity of the ink on the blade 36 becomes, and the lower the cleaning ability of the blade 36 becomes. Therefore, it is preferable to increase the cleaning effect of the conveyor belt 33 as the elapsed time T approaches time T2.

[0086] That is, it is preferable that the control unit 50 be able to execute a first cleaning operation and a second cleaning operation that is more effective than the first cleaning operation as cleaning operations for cleaning the conveyor belt 33. When performing cleaning operations between a cleaning operation and a recovery operation, the control unit 50 selects the first cleaning operation until a predetermined operation switching timing is reached, and selects the second cleaning operation after the operation switching timing. This makes it possible to compensate for the decrease in cleaning ability of the blade 36 and properly clean the conveyor belt 33. The operation switching timing can be set, for example, to time T1 shown in Fig. 5. Time T1 is the timing when the moisture content H becomes H2.

[0087] 10 shows the flow of processing when performing the cleaning operation of the conveyor belt 33. The control unit 50 checks the cleaning flag (step S301), and if the cleaning flag is OFF, cleans the conveyor belt 33 by the first cleaning operation (step S302). Next, the elapsed time T is reset to zero (step S303), and the cleaning flag is set ON (step S304). By setting the cleaning flag ON, a recovery operation of the blade 36 may be performed thereafter, if necessary.

[0088] If the cleaning flag is ON in step S301, the elapsed time T is determined (step S305). If the elapsed time T is less than T1, the process proceeds to step S302. If the elapsed time T is equal to or greater than T1 and less than T2, the conveyor belt 33 is cleaned by a second cleaning operation (step S306). Then, steps S303 and onward are executed. By such control, the deterioration of the cleaning ability of the blade 36 can be compensated for, and the conveyor belt 33 can be properly cleaned.

[0089] In the second cleaning operation, the control unit 50 increases at least one of the cleaning time, the contact pressure of the blade 36 against the conveyor belt 33, and the movement speed of the conveyor belt 33 against the blade 36, compared to the first cleaning operation. This can be achieved by increasing one, two, or all of the cleaning time, contact pressure, and movement speed. This makes it easy to achieve the second cleaning operation with a higher cleaning effect than the first cleaning operation.

[0090] The above-mentioned operation switching timing (time T1 in FIG. 5) can be adjusted according to the temperature, humidity, and discharge duty, similar to the above-mentioned timing (time T2 in FIG. 5) related to the recovery operation of the blade 36. Specifically, the higher the temperature, the lower the humidity, or the lower the discharge duty, the earlier the operation switching timing should be shifted. Furthermore, the timing of the above-mentioned operation switching may be determined by appropriately calculating the amount of residual moisture in the ink on the blade 36, similar to the timing related to the above-mentioned recovery operation of the blade 36, and may be determined as the timing when the residual moisture reaches a predetermined moisture amount, for example, the moisture amount H2 in Fig. 5. The calculation method in this case is the same as the calculation method related to the above-mentioned recovery operation of the blade 36, and is calculated using dryness information.

[0091] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these modifications are also included in the scope of the present invention. [Explanation of symbols]

[0092] 1...inkjet printer, 2...device main body, 3...first media cassette, 4...second media cassette, 5...ink storage section, 9, 10...pick roller, 11, 12...feed roller pair, 13, 14, 15, 16, 18, 19, 20, 21, 22...transport roller pair, 17...transport roller pair, 23, 24...flap, 25...head unit, 26...line head, 27...ejection tray, 29...charging roller, 30...belt unit, 31...drive pulley, 32...driven pulley, 33...transport belt, 33a...outer periphery, 34...support roller , 35...first cleaning unit, 36...blade, 37...fixed member, 38...rotating shaft, 40...second cleaning unit, 41...cleaning sheet, 42...driving pulley, 43, 44...driven pulley, 45...tensioner, 50...control unit, 51...CPU, 52...non-volatile memory, 53...interface, 54...operation panel, 57...belt drive motor, 58...belt charging unit, 59...blade drive unit, 60...unit drive unit, 61...sheet drive motor, 65...upstream sensor, 66...downstream sensor, 67...temperature and humidity sensor, 90...external computer, P...medium

Claims

1. a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and conveys a medium by rotating; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, the cleaning member being switchable between a contact state in which it contacts the conveyor belt and a spaced state in which it is spaced from the conveyor belt; a control unit that controls the liquid ejection operation of the liquid ejection unit, the rotation operation of the conveyor belt, and the state switching of the cleaning member; a detection unit capable of acquiring at least one of humidity and temperature; Equipped with the control unit performs a cleaning operation to clean the conveyor belt with the cleaning member; a recovery operation of recovering the cleaning ability of the cleaning member by rotating the conveyor belt while the cleaning member is in contact with the conveyor belt; is executable, the control unit executes the recovery operation after a timing when the amount of water in the liquid on the cleaning member reaches a predetermined amount of water after the cleaning operation has been executed, Furthermore, when the humidity is acquired and the humidity is a first humidity, the control unit sets the time until the timing is reached to be shorter than when a second humidity higher than the first humidity is acquired, When the temperature is acquired and the temperature is a first temperature, the time until the timing is reached is set shorter than when the temperature is a second temperature lower than the first temperature. A liquid ejection device characterized by:

2. a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and conveys a medium by rotating; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, the cleaning member being switchable between a contact state in which it contacts the conveyor belt and a spaced state in which it is spaced from the conveyor belt; a control unit that controls the liquid ejection operation by the liquid ejection unit, the rotation operation of the conveyor belt, and the state switching of the cleaning member, the control unit performs a cleaning operation to clean the conveyor belt with the cleaning member; a recovery operation of recovering the cleaning ability of the cleaning member by rotating the conveyor belt while the cleaning member is in contact with the conveyor belt; is executable, the control unit executes the recovery operation after a timing when the amount of water in the liquid on the cleaning member reaches a predetermined amount of water after the cleaning operation has been executed, Furthermore, the control unit executes the cleaning operation when the liquid is erroneously ejected from the liquid ejection unit onto the conveyor belt, Furthermore, when the ejection duty at the time of the erroneous ejection is a first ejection duty, the control unit sets the time until the timing is reached to be shorter than when the ejection duty is a second ejection duty that is higher than the first ejection duty. A liquid ejection device characterized by:

3. In the liquid ejection device according to claim 1 or claim 2, the control unit determines the timing based on the elapsed time since the cleaning operation was performed. A liquid ejection device characterized by:

4. In the liquid ejection device according to claim 1 or claim 2, the control unit determines the timing by calculating the water content of the liquid. A liquid ejection device characterized by:

5. 5. The liquid ejection device according to claim 1, wherein the recovery operation includes a first mode in which the conveying belt is moved at a first speed relative to the cleaning member; a second mode in which the conveyor belt is moved relative to the cleaning member at a second speed that is faster than the first speed, A liquid ejection device characterized by:

6. 6. The liquid ejection device according to claim 1, wherein the recovery operation includes a speed change mode in which a moving speed of the conveyor belt relative to the cleaning member is periodically changed. A liquid ejection device characterized by:

7. 7. The liquid ejection device according to claim 1, wherein the control unit is capable of executing, as the cleaning operation, a first cleaning operation and a second cleaning operation that has a higher cleaning effect than the first cleaning operation; When the cleaning operation is performed between the cleaning operation and the recovery operation, the first cleaning operation is selected until a predetermined operation switching timing is reached, and the second cleaning operation is selected after the operation switching timing. A liquid ejection device characterized by:

8. a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and conveys a medium by rotating; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, the cleaning member being switchable between a contact state in which it contacts the conveyor belt and a spaced state in which it is spaced from the conveyor belt; a control unit that controls the liquid ejection operation by the liquid ejection unit, the rotation operation of the conveyor belt, and the state switching of the cleaning member, the control unit performs a cleaning operation to clean the conveyor belt with the cleaning member; a recovery operation of recovering the cleaning ability of the cleaning member by rotating the conveyor belt while the cleaning member is in contact with the conveyor belt; is executable, Furthermore, the control unit is capable of executing, as the cleaning operation, a first cleaning operation and a second cleaning operation having a higher cleaning effect than the first cleaning operation, When the cleaning operation is performed between the cleaning operation and the recovery operation, the first cleaning operation is selected until a predetermined operation switching timing is reached, and the second cleaning operation is selected after the operation switching timing. A liquid ejection device characterized by:

9. In the liquid ejection device according to claim 7 or claim 8, the control unit increases at least one of the cleaning time, the contact pressure of the cleaning member against the conveying belt, and the movement speed of the conveying belt against the cleaning member in the second cleaning operation compared to the first cleaning operation. A liquid ejection device characterized by:

10. 10. The liquid ejection device according to claim 1, wherein the cleaning member is a first cleaning member, and a second cleaning member is provided downstream of the cleaning member in the moving direction of the conveyor belt, the second cleaning member contacting the conveyor belt to clean the conveyor belt. A liquid ejection device characterized by:

11. a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and conveys a medium by rotating; A method for controlling a liquid ejection device including a cleaning member that cleans a conveying belt by contacting the conveying belt, the cleaning member being switchable between a contact state in which it contacts the conveying belt and a spaced state in which it is spaced from the conveying belt, performing a cleaning operation to clean the conveyor belt with the cleaning member; and after a set time has elapsed since the cleaning operation was performed, performing a recovery operation to recover the cleaning ability of the cleaning member by rotating the conveyor belt with the cleaning member in contact with the conveyor belt, The cleaning operation includes a first cleaning operation and a second cleaning operation having a higher cleaning effect than the first cleaning operation, When the cleaning operation is performed between the cleaning operation and the recovery operation, the first cleaning operation is selected until a predetermined operation switching timing is reached, and the second cleaning operation is selected after the operation switching timing. A method for controlling a liquid ejection device.

12. a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and conveys a medium by rotating; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, the cleaning member being switchable between a contact state in which the cleaning member contacts the conveyor belt and a spaced state in which the cleaning member is spaced from the conveyor belt, the program being executed by a control unit of a liquid ejection device; a step of causing the cleaning member to perform a cleaning operation to clean the conveyor belt; and after a set time has elapsed since the cleaning operation was performed, performing a recovery operation to recover the cleaning ability of the cleaning member by rotating the conveyor belt with the cleaning member in contact with the conveyor belt, The cleaning operation includes a first cleaning operation and a second cleaning operation having a higher cleaning effect than the first cleaning operation, When the cleaning operation is performed between the cleaning operation and the recovery operation, the first cleaning operation is selected until a predetermined operation switching timing is reached, and the second cleaning operation is selected after the operation switching timing. A program characterized by:

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