Liquid ejection device, control method for liquid ejection device, and recording medium

Abstract

The present application relates to a liquid ejection device, a control method for a liquid ejection device, and a storage medium. The technical problem to be solved is that the poor slidability between the conveyor belt and the squeegee may cause damage to the squeegee in contact with the conveyor belt, and it may be impossible to maintain the function of the squeegee. A liquid ejection device includes: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state in which it contacts the conveyor belt and a separation state in which it is separated from the conveyor belt; and a control unit that controls the liquid ejection operation performed by the liquid ejection unit, the rotation operation of the conveyor belt, and the state switching of the cleaning member. When performing a cleaning operation of cleaning the conveyor belt by the cleaning member, the control unit performs pre-ejection of ejecting liquid from the liquid ejection unit onto the conveyor belt according to preset cleaning control information.

Description

Technical Field

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

[0002] In a liquid ejection device typified by a printer, a configuration is known in which a conveyor belt is used to convey a medium typified by a recording sheet. Further, in such a configuration, a configuration is sometimes adopted in which an ink adhering to the conveyor belt is cleaned by a blade.

[0003] The blade described in Patent Document 1 is formed by coating a urethane rubber with a fluororesin and is provided so as to be able to contact and separate from the conveyor belt.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-179953

[0005] For example, when ink is ejected in a state where there is no medium on the conveyor belt due to a blockage of the medium, that is, when ink is erroneously ejected, there may be a landing portion and a non-landing portion of the ink on the conveyor belt. Further, even in the landing portion of the ink, the amount of the landed ink may be small. Since the landing portion is a wet region, the slidability between the conveyor belt and the blade is good. On the other hand, when it is the non-landing portion, or even in the landing portion but the amount of ink is small, the slidability between the conveyor belt and the blade deteriorates. Poor slidability between the conveyor belt and the blade causes damage to the blade in contact with the conveyor belt, and it may not be possible to maintain the function of the blade. Summary of the Invention

[0006] The liquid ejection device of the present invention is for solving the above problems, and is characterized by including: a liquid ejection unit that ejects a liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state of contacting the conveyor belt and a separation state of separating from the conveyor belt; and a control unit that controls a liquid ejection operation performed by the liquid ejection unit, a rotation operation of the conveyor belt, and a state change of the cleaning member. When performing a cleaning operation of cleaning the conveyor belt by the cleaning member, the control unit performs a pre-ejection of pre-ejecting a liquid from the liquid ejection unit onto the conveyor belt according to pre-set cleaning control information.

[0007] In addition, in the control method of the liquid ejection device of the present invention, the liquid ejection device includes: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; and a cleaning member that cleans the conveyor belt by contacting the conveyor belt. The cleaning member can be switched between a contact state in which it contacts the conveyor belt and a separation state in which it is separated from the conveyor belt. The control method of the liquid ejection device is characterized in that when the conveyor belt is cleaned by the cleaning member, pre-ejection of liquid from the liquid ejection unit onto the conveyor belt is performed.

[0008] In addition, the program of the present invention is a program executed by a control unit of a liquid ejection device. The liquid ejection device includes: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; and a cleaning member that cleans the conveyor belt by contacting the conveyor belt. The cleaning member can be switched between a contact state in which it contacts the conveyor belt and a separation state in which it is separated from the conveyor belt. The program is characterized by including the following steps: when the conveyor belt is cleaned by the cleaning member, pre-ejection of liquid from the liquid ejection unit onto the conveyor belt is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram showing a medium conveyance path of a printer.

[0010] Figure 2 It is a block diagram showing the configuration and control system of a belt unit.

[0011] Figure 3 It is a side view of a conveyor belt, a first cleaning unit, and a second cleaning unit.

[0012] Figure 4 It is a side view of a conveyor belt, a first cleaning unit, and a second cleaning unit.

[0013] Figure 5 It is a flowchart showing a belt cleaning process using a squeegee.

[0014] Figure 6 It is a diagram showing an example of an ink ejection area when ink is erroneously ejected onto a conveyor belt.

[0015] Figure 7 It is a table showing an example of cleaning control information.

[0016] Figure 8 It is a table showing an example of cleaning control information.

[0017] Figure 9 It is a table showing an example of ejection amount adjustment information.

[0018] Figure 10 This is a diagram showing an example of an ink ejection area when ink is erroneously ejected onto a conveyor belt.

[0019] Explanation of reference numerals:

[0020] 1: Inkjet printer; 2: Device main body; 3: First media cassette; 4: Second media cassette; 5: Ink storage section; 9, 10: Sheet feeding rollers; 11, 12: Feed roller pair; 13, 14, 15, 16, 18, 19, 20, 21, 22: Conveyor roller pair; 17: Conveyor roller pair; 23, 24: Baffles; 25: Print head unit; 26: Line printer head; 27: Discharge tray; 29: Charging roller; 30: Belt unit; 31: Driving pulley; 32: Driven pulley; 33: Conveyor belt; 33a: Outer peripheral surface; 34: Support roller; 35: First cleaning section; 36: Scraper; 37: Fixing member; 38: Rotating shaft; 40: Second cleaning section; 41: Cleaning sheet; 42: Driving pulley; 43, 44: Driven pulleys; 45: Tensioner; 50: Control section; 51: CPU; 52: Non-volatile memory; 53: Interface; 54: Operation panel; 57: Belt driving motor; 58: Belt charging section; 59: Scraper driving section; 60: Unit driving section; 61: Sheet driving motor; 65: Upstream sensor; 66: Downstream sensor; 67: Temperature and humidity sensor; 90: External computer; P: Media. Detailed implementation

[0021] Next, the present invention will be described schematically.

[0022] The liquid ejection device according to the first aspect is characterized by including: a liquid ejection section that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection section and is used to convey the medium; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state of contacting the conveyor belt and a separation state of separating from the conveyor belt; and a control section that controls the liquid ejection operation performed by the liquid ejection section, the rotation operation of the conveyor belt, and the state switching of the cleaning member. When performing a cleaning operation of cleaning the conveyor belt by the cleaning member, the control section performs a pre-ejection of pre-ejecting liquid from the liquid ejection section onto the conveyor belt according to preset cleaning control information.

[0023] According to this aspect, since when performing a cleaning operation of cleaning the conveyor belt by the cleaning member, the control section performs a pre-ejection of pre-ejecting liquid from the liquid ejection section onto the conveyor belt according to preset cleaning control information, the slidability between the conveyor belt and the cleaning member is improved through the pre-ejection, and thus the function of the cleaning member can be maintained.

[0024] Based on the first aspect, the second aspect is characterized in that the cleaning control information is set to include one or more of the injection duty ratio, humidity, temperature, and elapsed time after the liquid is mis-injected from the liquid injection unit as the execution conditions for the pre-injection. At least one of the first event that the injection duty ratio is lower than the first injection duty ratio, the second event that the humidity is lower than the first humidity, the third event that the temperature is higher than the first temperature, and the fourth event that the elapsed time is longer than the first elapsed time acts on the execution of the pre-injection.

[0025] According to this aspect, the cleaning control information is set such that at least one of the first event that the injection duty ratio is lower than the first injection duty ratio, the second event that the humidity is lower than the first humidity, the third event that the temperature is higher than the first temperature, and the fourth event that the elapsed time is longer than the first elapsed time acts on the execution of the pre-injection. Therefore, the pre-injection is appropriately performed according to the state during the cleaning operation, and the function of the cleaning component can be maintained.

[0026] In addition, when the pre-injection is not required, the pre-injection is not performed, so that waste of liquid can be suppressed.

[0027] It should be noted that each of the first event, the second event, the third event, and the fourth event acting on the execution of the pre-injection does not mean that the pre-injection must be performed when each event occurs, but rather that the occurrence of each event is conducive to the execution of the pre-injection.

[0028] Based on the second aspect, the third aspect is characterized in that the cleaning control information is set such that the injection duty ratio and the humidity are used as the execution conditions for the pre-injection. When the first event and the second event occur simultaneously, the control unit is made to execute the pre-injection. When the first event and the second event do not occur simultaneously, the control unit is made not to execute the pre-injection.

[0029] Even if the first event occurs, if the second event does not occur, it is easy to ensure the slidability of the conveyor belt and the cleaning component. Conversely, even if the second event occurs, if the first event does not occur, it is easy to ensure the slidability of the conveyor belt and the cleaning component. According to this aspect, the pre-injection is not performed in this case, so that waste of liquid can be suppressed.

[0030] Based on any one of the first to third aspects, the fourth aspect is characterized in that the control unit adjusts the liquid injection amount during the pre-injection according to the preset injection amount adjustment information.

[0031] According to this aspect, the control unit adjusts the liquid injection amount during the pre-injection according to the preset injection amount adjustment information. Therefore, the liquid injection amount during the pre-injection is set to an appropriate amount, so that the slipperiness between the conveyor belt and the cleaning member is improved, and in addition, waste of liquid can be suppressed.

[0032] Based on the fourth aspect, the fifth aspect is characterized in that the injection amount adjustment information is set to include one or more of the injection duty ratio, the humidity, the temperature, and the elapsed time as adjustment conditions for the liquid injection amount, and at least one of a decrease in the injection duty ratio, a decrease in the humidity, an increase in the temperature, and an increase in the elapsed time acts on an increase in the liquid injection amount during the pre-injection.

[0033] According to this aspect, it is set to include one or more of the injection duty ratio, the humidity, the temperature, and the elapsed time as adjustment conditions for the liquid injection amount, and at least one of a decrease in the injection duty ratio, a decrease in the humidity, an increase in the temperature, and an increase in the elapsed time acts on an increase in the liquid injection amount during the pre-injection. Therefore, when the slipperiness between the conveyor belt and the cleaning member is low, the liquid injection amount increases, and the slipperiness between the conveyor belt and the cleaning member can be appropriately improved.

[0034] Based on the fifth aspect, the sixth aspect is characterized in that the injection amount adjustment information includes the injection duty ratio as a determination condition for the liquid injection amount, and the control unit calculates the injection duty ratio for each region divided along the width direction, which is the direction crossing the traveling direction of the conveyor belt, and adjusts the liquid injection amount for each region.

[0035] According to this aspect, the control unit calculates the injection duty ratio for each region divided along the width direction, which is the direction crossing the traveling direction of the conveyor belt, and adjusts the liquid injection amount for each region. Therefore, the liquid injection amount can be adjusted in a finer range, the slipperiness between the conveyor belt and the cleaning member is improved, and in addition, waste of liquid can be suppressed.

[0036] Based on any one of the second to sixth aspects, the seventh aspect is characterized in that the control unit performs the pre-injection on the conveyor belt in such a manner that the region of the pre-injection contacts the cleaning member prior to the region where liquid has landed due to mis-injection.

[0037] According to this aspect, the control unit performs the pre-injection on the conveyor belt in such a manner that the area of the pre-injection comes into contact with the cleaning member prior to the area where the liquid has landed due to the mis-injection. Therefore, the cleaning member can clean the area of the mis-injection in a pre-wetted state, and the function of the cleaning member can be maintained more reliably.

[0038] Based on any one of the second to seventh aspects, the eighth aspect is characterized in that the control unit performs the pre-injection on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-injection.

[0039] According to this aspect, the control unit performs the pre-injection on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-injection. Therefore, the pre-injection is performed while avoiding the already wetted portion, thereby suppressing waste of the liquid.

[0040] Based on any one of the second to seventh aspects, the ninth aspect is characterized in that when performing the pre-injection, the control unit selects a first injection mode and a second injection mode according to pre-set injection area setting information. The first injection mode injects the liquid on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-injection, and the second injection mode injects the liquid on the conveyor belt toward the portion where the liquid has landed due to the mis-injection and the portion where the liquid has not landed.

[0041] According to this aspect, when performing the pre-injection, the control unit selects a first injection mode and a second injection mode according to pre-set injection area setting information. The first injection mode injects the liquid on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-injection, and the second injection mode injects the liquid on the conveyor belt toward the portion where the liquid has landed due to the mis-injection and the portion where the liquid has not landed. Therefore, the liquid consumption can be suppressed in the first injection mode. In addition, in the second injection mode, the portion where the liquid has landed due to the mis-injection on the conveyor belt is also injected with the liquid, so that the portion where the liquid has landed due to the mis-injection can be softened, and the cleaning effect can be improved.

[0042] Based on the ninth aspect, the tenth aspect is characterized in that it is set that when the humidity exceeds the standard humidity, the control unit is made to select the first injection mode, and when the humidity is below the standard humidity, the control unit is made to select the second injection mode.

[0043] According to this aspect, when the portion of the conveyor belt where liquid has landed due to the mis-jetting has not dried yet, selecting the first jetting mode can suppress the consumption of the liquid. In addition, when the drying of the portion of the conveyor belt where liquid has landed due to the mis-jetting intensifies, selecting the second jetting mode can soften the portion of the conveyor belt where liquid has landed due to the mis-jetting, and can improve the cleaning effect.

[0044] Based on any one of the first to tenth aspects, the eleventh aspect is characterized in that the control unit rotates the conveyor belt while maintaining the cleaning member in the separated state until the cleaning member faces the area on the conveyor belt where liquid has landed, and when the cleaning member faces the area on the conveyor belt where liquid has landed, the cleaning member is switched from the separated state to the contact state.

[0045] According to this aspect, the control unit keeps the cleaning member in the separated state and rotates the conveyor belt until the cleaning member faces the area on the conveyor belt where liquid has landed, and when the cleaning member faces the area on the conveyor belt where liquid has landed, the cleaning member is switched from the separated state to the contact state. Therefore, the contact time between the cleaning member and the area on the conveyor belt where no liquid has landed can be suppressed, and thus the function of the cleaning member can be more reliably maintained.

[0046] The control method according to the twelfth aspect is a control method of a liquid jetting device, the liquid jetting device including: a liquid jetting unit that jets liquid onto a medium; a conveyor belt that is opposed to the liquid jetting unit and is used to convey the medium; and a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state of contacting the conveyor belt and a separated state of being separated from the conveyor belt. The control method of the liquid jetting device is characterized in that when the conveyor belt is cleaned by the cleaning member, pre-jetting of jetting liquid from the liquid jetting unit onto the conveyor belt is performed.

[0047] According to this aspect, when performing the cleaning operation of cleaning the conveyor belt by the cleaning member, pre-jetting of jetting liquid from the liquid jetting unit onto the conveyor belt is performed. Therefore, through the pre-jetting, the slidability between the conveyor belt and the cleaning member is improved, and thus the function of the cleaning member can be maintained.

[0048] The program according to the thirteenth aspect is a program executed by a control unit of a liquid ejection device, the liquid ejection device including: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; and a cleaning member that cleans the conveyor belt by contacting the conveyor belt, the cleaning member being capable of switching between a contact state of contacting the conveyor belt and a separation state of separating from the conveyor belt. The program is characterized by including a step of pre-ejecting liquid from the liquid ejection unit onto the conveyor belt when the conveyor belt is cleaned by the cleaning member.

[0049] According to this aspect, when performing a cleaning operation of cleaning the conveyor belt by the cleaning member, pre-ejecting liquid from the liquid ejection unit onto the conveyor belt, so that through the pre-ejection, the slidability between the conveyor belt and the cleaning member is improved, thereby enabling the function of the cleaning member to be maintained.

[0050] Next, the present invention will be specifically described.

[0051] Hereinafter, an inkjet printer 1 will be described as an example of a liquid ejection device. The inkjet printer 1 performs recording by ejecting liquid such as ink onto a medium represented by a recording paper.

[0052] The X-Y-Z coordinate system shown in each figure is an orthogonal coordinate system. The Y-axis direction is the width direction intersecting the conveying direction of the medium and is also the device depth direction. It should be noted that the +Y direction in the Y-axis direction is set as the direction from the front of the device toward the back of the device, and the -Y direction is set as the direction from the back of the device toward the front of the device.

[0053] In addition, the X-axis direction is the device width direction. When observed from the operator of the inkjet printer 1, the direction of the arrow, i.e., the +X direction, is the left side, and the opposite -X direction is the right side. The Z-axis direction is the vertical direction, i.e., the device height direction. The direction of the arrow, i.e., the +Z direction, is upward, and the opposite -Z direction is downward.

[0054] In addition, the G-axis direction is the normal direction with respect to the ink ejection surface 26a of a line head 26 described later. Further, the F-axis direction is a direction parallel to the ink ejection surface 26a and is the medium conveying direction at a position facing the ink ejection surface 26a. The direction of the arrow, i.e., the +F direction, is the downstream of the conveying direction, and the opposite -F direction is the upstream of the conveying direction. It should be noted that hereinafter, the direction of medium conveyance is sometimes referred to as "downstream", and the opposite direction is referred to as "upstream".

[0055] In addition, in some figures, the F-G-Y coordinate system is used instead of the X-Y-Z coordinate system.

[0056] InFigure 1 The dashed line indicates the medium conveyance path. In the inkjet printer 1, the medium is conveyed through the medium conveyance path indicated by the dashed line.

[0057] The apparatus main body 2 of the inkjet printer 1 includes a first medium cassette 3 and a second medium cassette 4 that accommodate the medium before feeding. The reference numeral P represents the medium accommodated in each medium cassette. The first medium cassette 3 and the second medium cassette 4 are configured to be detachable from the front side of the apparatus main body 2.

[0058] A paper feed roller 9 for feeding out the accommodated medium is provided for the first medium cassette 3, and a paper feed roller 10 for feeding out the accommodated medium is provided for the second medium cassette 4.

[0059] In addition, for the first medium cassette 3, a pair of feed rollers 11 for feeding the fed-out medium obliquely upward is provided. Further, for the second medium cassette 4, a pair of feed rollers 12 for feeding the fed-out medium obliquely upward and a pair of conveying rollers 13 for conveying the medium upward are provided.

[0060] It should be noted that, unless otherwise specified, the following "pair of rollers" refers to a pair of rollers composed of a driving roller driven by a motor (not shown) and a driven roller that rotates following contact with the driving roller.

[0061] The medium fed out from each medium cassette is sent to the pair of conveying rollers 16 through the pair of conveying rollers 14 and the pair of conveying rollers 15. The medium receiving the conveying force from the pair of conveying rollers 16 is sent between the line head 26 and the conveyor belt 33, that is, to the position opposed to the line head 26.

[0062] The print head unit 25 includes a line head 26 that ejects ink, which is an example of a liquid, onto the surface of the medium to perform recording. The line head 26 is an ink ejection head configured to cover the entire area in the width direction of the medium with nozzles (not shown) for ejecting ink, and is configured as an ink ejection head capable of performing recording over the entire area of the medium width without moving in the width direction of the medium. The line head 26 is an example of a liquid ejection unit that ejects a liquid.

[0063] Among them, the ink ejection head may also be of a type that performs recording while moving in the width direction of the medium.

[0064] The reference numeral 5 is an ink storage unit that stores ink. The ink ejected from the line head 26 is supplied from the ink storage unit 5 to the line head 26 via a tube (not shown). The ink storage unit 5 is composed of a plurality of ink cartridges arranged along the X-axis direction.

[0065] 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 wound around the drive pulley and the driven pulley 32. The conveyor belt 33 is driven to rotate by the belt drive motor 57 (see Figure 2 reference).

[0066] The medium is adsorbed on the conveyor belt 33 and is conveyed while being opposed to the line head 26. Regarding the adsorption of the medium on the conveyor belt 33, it will be described again later.

[0067] Among them, the medium conveyance path at the position opposed to the line head 26 intersects both the horizontal direction and the vertical direction and conveys the medium obliquely upward. The conveyance direction obliquely upward is Figure 1 a direction including a -X direction component and a +Z direction component. With this configuration, the horizontal dimension of the inkjet printer 1 can be suppressed.

[0068] It should be noted that, in the present embodiment, the medium conveyance path at the position opposed to the line head 26 is set to an inclination angle in the range of 50° to 70° with respect to the horizontal direction, and more specifically, it is set to an inclination angle of 60°.

[0069] The medium that has been recorded on the first surface by the line head 26 is further conveyed obliquely upward by the conveying roller pair 17 located downstream of the conveyor belt 33.

[0070] A baffle 23 is provided downstream of the conveying roller pair 17, and the conveyance direction of the medium is switched by the baffle 23. When directly discharging the medium, the conveyance path of the medium is switched by the baffle 23 to the upward conveying roller pair 20. A baffle 24 is also provided downstream of the conveying roller pair 20, and the conveyance path is switched by the baffle 24 to either discharging from the discharge position A1 or further conveying to the conveying roller pair 21 located vertically above. When the medium is conveyed toward the conveying roller pair 21, it is discharged from the discharge position A2.

[0071] The medium discharged from the discharge position A1 is received by the discharge tray 27 inclined obliquely upward including a +X direction component and a +Z direction component. The medium discharged from the discharge position A2 is received by an optional tray (not shown).

[0072] When recording is to be performed on the second surface in addition to the first surface of the medium, the medium is conveyed obliquely upward including a -X direction component and a +Z direction component by the baffle 23, passes through the branch position K1, and is conveyed from the branch position K1 to the upper return path. A conveying roller pair 22 is provided on the return path, and the medium that enters the return path is conveyed upward by the conveying roller pair 22. Then, after passing through the branch position K1 at the upstream end of the medium, the rotation direction of the conveying roller pair 22 is switched, and thus the medium is conveyed downward.

[0073] The medium conveyed downward by the conveying roller pair 22 receives conveying forces from the conveying roller pairs 18, 19, and 15, reaches the conveying roller pair 16, and is conveyed again by the conveying roller pair 16 to the conveyor belt 33.

[0074] The medium conveyed again to the position facing the line head 26 has its second side, which is the opposite side of the first side on which recording has been performed, facing the line head 26. Thus, the line head 26 can be used to record on the second side of the medium. The medium on which recording has been performed on the second side is discharged from the above-described discharge position A1 or discharge position A2.

[0075] Next, with reference to Figure 3 、 Figure 4 the belt unit 30, the first cleaning unit 35, and the second cleaning unit 40 will be described.

[0076] The conveyor belt 33 constituting the belt unit 30 is an endless belt containing a conductive material as needed in a base material made of urethane, rubber, or the like in order to adjust the resistance value, and is wound around the drive pulley 31 on the upstream side and the driven pulley 32 on the downstream side. A prescribed tension is imparted to the conveyor belt 33 by a tensioner (not shown).

[0077] The drive pulley 31 is driven to rotate by a belt drive motor 57 (refer to Figure 2 ) controlled by the control unit 50 (refer to Figure 2 ). When the drive pulley 31 is driven to rotate in the direction of arrow a, the conveyor belt 33 rotates in the Figure 3 、 Figure 4 clockwise direction. Hereinafter, the rotation of the conveyor belt 33 may sometimes be referred to as "forward rotation".

[0078] When the drive pulley 31 is driven to rotate in the direction of arrow b, the conveyor belt 33 rotates in the Figure 3 、 Figure 4 counterclockwise direction. Hereinafter, the rotation of the conveyor belt 33 may sometimes be referred to as "reverse rotation".

[0079] A charging roller 29 is provided at a position facing the drive pulley 31 with the conveyor belt 33 interposed therebetween.

[0080] The charging roller 29 is in contact with the outer surface of the conveyor belt 33 and rotates idly in accordance with the rotation of the conveyor belt 33. A DC voltage is applied to the charging roller 29 by a belt charging unit 58 (refer to Figure 2 ), whereby the charging roller 29 supplies charges to the portion in contact with the conveyor belt 33. The belt charging unit 58 (refer to Figure 2 ) is controlled by the control unit 50 to switch the on / off of the voltage applied to the charging roller 29 or to switch the voltage applied to the charging roller 29.

[0081] It should be noted that, in this embodiment, the charged roller 29 supplies positive charges to the conveyor belt 33, making the outer peripheral surface 33a of the conveyor belt 33 charged positively. Thus, the outer peripheral surface 33a of the conveyor belt 33 becomes the adsorption surface for the adsorption medium.

[0082] A support roller 34 in contact with the medium is provided on the upstream side of the line printer head 26. The support roller 34 presses the medium against the portion of the conveyor belt 33 wound around the driving pulley 31. It should be noted that the support roller 34 is grounded to remove the charges on the recording surface side of the medium.

[0083] Next, a first cleaning unit 35 is provided near the driven pulley 32. The first cleaning unit 35 includes a squeegee 36. The squeegee 36 is an example of a cleaning member for cleaning the outer peripheral surface 33a of the conveyor belt 33. The squeegee 36 is fixed to a fixing member 37, and the fixing member 37 is arranged to be rotatable about a rotating shaft 38.

[0084] Exemplarily, the squeegee 36 is a plate-shaped elastic member having a prescribed thickness, formed of urethane or rubber, etc., and capable of elastically deforming in a state of being in contact with the conveyor belt 33. The front end portion of the squeegee 36 contacts the portion of the conveyor belt 33 wound around the driven pulley 32 to clean the outer peripheral surface 33a of the conveyor belt 33.

[0085] The rotating shaft 38 is rotated by a squeegee driving unit 59 (refer to Figure 2 ). The rotating shaft 38 rotates such that the squeegee 36 switches between a contact state (refer to Figure 3 ) of contacting the conveyor belt 33 and a separation state (refer to Figure 4 ) of separating from the conveyor belt 33. When the conveyor belt 33 rotates forward in the contact state of the squeegee 36, the attachments such as ink and paper powder attached to the outer peripheral surface 33a of the conveyor belt 33 are removed.

[0086] It should be noted that the squeegee driving unit 59 (refer to Figure 2 ) can be constituted by an actuator such as a motor. In addition, the control unit 50 can adjust the pressing force when the squeegee 36 presses against the conveyor belt 33 by adjusting the rotation amount of the rotating shaft 38.

[0087] A second cleaning unit 40 is provided below the first cleaning unit 35. The second cleaning unit 40 includes a cleaning sheet 41. The cleaning sheet 41 is wound around a driving pulley 42 and driven pulleys 43, 44, and is given tension by a tensioner 45.

[0088] In this embodiment, the cleaning sheet 41 is an annular cloth, and can press against the outer peripheral surface 33a of the conveyor belt 33 through the driven pulley 43. The driving pulley 42 is driven to rotate by a sheet driving motor 61 (refer to Figure 2 ). The driving pulley 42 rotates towardsFigure 3 is driven to rotate in the clockwise direction, whereby the cleaning sheet 41 moves towards Figure 3 and moves around in the clockwise direction.

[0089] The second cleaning unit 40 is arranged to be able to move in a direction advancing and retreating relative to the conveyor belt 33, specifically in the direction along the G axis, and is driven by the unit drive unit 60 (see Figure 2 ) to advance and retreat relative to the conveyor belt 33. The unit drive unit 60 can be constituted by an actuator such as a motor.

[0090] 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. In this state, the conveyor belt 33 rotates forward, and the cleaning sheet 41 moves around, so that the outer peripheral surface 33a of the conveyor belt 33 is wiped. It should be noted that Figure 3 , Figure 4 represents the state where the second cleaning unit 40 retreats relative to the conveyor belt 33, and the state where the second cleaning unit 40 advances relative to the conveyor belt 33 is not shown.

[0091] The above-mentioned belt drive motor 57, belt electrifying unit 58, blade drive unit 59, unit drive unit 60, sheet drive motor 61, etc. are controlled by the control unit 50 as shown in Figure 2 .

[0092] The control unit 50 is a control unit that controls the entire inkjet printer 1. In addition to the above configuration, it also controls the line head 26, a medium conveying motor (not shown), etc.

[0093] The control unit 50 includes a CPU 51 and a non-volatile memory 52. In the non-volatile memory 52, programs PR for performing various controls of the inkjet printer 1, various parameters, etc. are stored. The program PR includes programs for implementing various controls described below. In addition, various parameters required for executing the program PR are stored in the non-volatile memory 52.

[0094] It should be noted that the reference numeral N1 is data related to cleaning control information described later, the reference numeral N2 is data related to ejection amount adjustment information described later, and the reference numeral N3 is data related to ejection area setting information described later.

[0095] Signals from the operation panel 54 are input to the control unit 50, and signals for information display are output from the control unit 50 to the display unit (not shown) of the operation panel 54. Various setting information input through the operation panel 54 is stored in the non-volatile memory 52. The control unit 50 performs various controls based on the above various setting information.

[0096] The control unit 50 is provided with an interface 53 for communicating with an external computer 90. The control unit 50 acquires data for recording, i.e., recording data, generated by a printer driver running in the external computer 90 or a printer driver provided in the control unit 50. Then, based on the recording data, it controls each mechanism part led by the line head 26. The recording data also includes the size information of the medium.

[0097] In addition, detection signals of various sensors are input to the control unit 50, and the control unit 50 performs required control based on the detection signals. Figure 2 A part of various sensors is shown, i.e., an upstream sensor 65, a downstream sensor 66, and a temperature and humidity sensor 67.

[0098] As Figure 3 、 Figure 4 shown, the upstream sensor 65 is arranged at a position facing the conveyor belt 33 and upstream of the line head 26. In addition, the downstream sensor 66 is arranged at a position facing the conveyor belt 33 and downstream of the line head 26. The upstream sensor 65 and the downstream sensor 66 are optical sensors, each having a light emitting part that emits light toward the conveyor belt 33 and a light receiving part that receives reflected light from the conveyor belt 33 or the medium. Based on the detection signal of the upstream sensor 65, the control unit 50 can detect the position where the front end or the rear end of the medium passes through the upstream sensor 65, and can also detect the position where the front end or the rear end of the medium passes through the downstream sensor 66.

[0099] In particular, when the control unit 50 detects that the front end of the medium has passed through the position of the upstream sensor 65 and still cannot detect that the front end of the medium has passed through the position of the downstream sensor 66 even after a predetermined time, 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. The stop of this recording operation includes stopping the ejection of ink from the line head 26, or stopping the drive of the conveyor belt 33 or other conveying roller pairs.

[0100] The temperature and humidity sensor 67 is arranged inside the device, and the control unit 50 can grasp the temperature and humidity inside the device based on the information received from the temperature and humidity sensor 67.

[0101] It should be noted that in the present embodiment, it is more preferable that the temperature and humidity sensor 67 is arranged near the conveyor belt 33. In the present embodiment, the temperature or humidity obtained by the temperature and humidity sensor 67 is used to judge the ease or difficulty of drying the ink adhering to the conveyor belt 33, and the details will be described later.

[0102] In the present embodiment, the control unit 50 cleans the outer peripheral surface 33a of the conveyor belt 33 using at least one of the first cleaning unit 35 and the second cleaning unit 40. The control unit 50 can select a first cleaning mode that uses only the first cleaning unit 35, a second cleaning mode that uses both the first cleaning unit 35 and the second cleaning unit 40, and a third cleaning mode that uses only the second cleaning unit 40.

[0103] As a case where the control unit 50 selects the first cleaning mode, for example, a regular cleaning operation can be cited. The control unit 50 includes a unit that counts the elapsed time after the regular cleaning operation is performed. After the elapsed time since the last regular cleaning operation reaches a predetermined time, the regular cleaning operation is performed. In addition, the first cleaning mode is also performed after the recording task ends and the inkjet printer 1 transitions to the standby state.

[0104] As a case where the control unit 50 selects the second cleaning mode, for example, it can be cited when a media jam occurs and the recording operation stops, and the user removes the media and presses the OK button on the operation panel 54. When such a media jam occurs, since ink may adhere to the conveyor belt 33 due to mis-jetting of ink, the control unit 50 performs a cleaning operation in the second cleaning mode. It should be noted that pre-jetting, which will be described below, is applied to the second cleaning mode, but is not limited thereto.

[0105] As a case where the control unit 50 selects the third cleaning mode, it can be cited when the number of times of double-sided recording reaches a predetermined value, or when condensation may occur on the conveyor belt 33. The control unit 50 includes a unit that counts the number of times of double-sided recording. After the number of times of double-sided recording reaches a predetermined value, the control unit 50 performs a cleaning operation in the third cleaning mode. This is because when double-sided recording is performed, the first side on which recording was initially performed comes into contact with the conveyor belt 33 when recording the opposite second side, and ink may adhere to the conveyor belt 33. In addition, when condensation occurs on the conveyor belt 33, since the media may be wetted, the control unit 50 performs a cleaning operation in the third cleaning mode. It should be noted that as a case where condensation may occur on the conveyor belt 33, for example, a case where the state suddenly changes to a high humidity state, or a case where the temperature suddenly rises from a low temperature storage state can be cited.

[0106] Next, the pre-jetting when cleaning the conveyor belt 33 using the first cleaning unit 35 will be described. The pre-jetting when cleaning the conveyor belt 33 means that, before cleaning the conveyor belt 33 with the squeegee 36, ink is intentionally jetted onto the conveyor belt 33 to improve the slidability between the conveyor belt 33 and the squeegee 36, which will be described in detail below.

[0107] Figure 5It shows the control process when using the first cleaning unit 35 to clean the conveyor belt 33. When the control unit 50 executes the belt cleaning operation using the first cleaning unit 35, i.e., the squeegee 36 (Yes in step S101), it performs a pre-injection determination (step S102).

[0108] The pre-injection determination in step S102 includes determining whether to perform pre-injection, and when performing pre-injection, determining the ink injection position and ink injection amount on the conveyor belt 33 and the cleaning start position of the squeegee 36. The details will be described again later.

[0109] When the control unit 50 determines that pre-injection is required (Yes in step S103), it performs an injection start position adjustment (step S104). This injection start position adjustment is an operation to rotate the conveyor belt 33 so that the position where pre-injection starts on the conveyor belt 33 faces the line printer head 26. In this embodiment, at the moment when it is determined that a media jam has occurred and the drive of the conveyor belt 33 has stopped, since the position where pre-injection starts exceeds the contact position of the squeegee 36 in the forward rotation direction, the injection start position adjustment is mainly based on the reverse rotation of the conveyor belt 33.

[0110] Then, the control unit 50 performs pre-injection (step S105).

[0111] Next, the control unit 50 adjusts the cleaning start position of the squeegee 36 (step S106). When performing pre-injection (step S105), this cleaning start position adjustment is mainly based on the forward rotation of the conveyor belt 33.

[0112] When pre-injection is not performed (step S105), the cleaning start position adjustment in step S106 is mainly based on the reverse rotation of the conveyor belt 33. This is because, at the moment when it is determined that a media jam has occurred and the drive of the conveyor belt 33 has stopped as described above, the position where pre-injection starts exceeds the contact position of the squeegee 36 in the forward rotation direction.

[0113] [[ID=1,8]]Through the cleaning start position adjustment in step S106, the squeegee 36 faces the cleaning start position.

[0114] Next, the control unit 50 switches the squeegee 36 from the separated state to the contact state (step S107), and then rotates the conveyor belt 33 forward by a specified amount in this state to clean the conveyor belt 33 with the squeegee 36 (step S108). After the cleaning of the conveyor belt 33 by the squeegee 36 is completed, the squeegee 36 is switched from the contact state to the separated state (step S109).

[0115] Next, a detailed description of the pre-injection determination process in step S102 will be given.

[0116] Figure 6An example is shown when ink is erroneously ejected onto the conveyor belt 33 due to a media clogging. Area B2 represents the area where the ink is erroneously ejected. Area B2 is a part of the entire recording area of the media. Figure 6 The area B2 shown in the example of Figure 6 includes the landing part and the non-landing part of the ink. In particular, the range in the width direction of the media indicated by the reference numeral Na is the range where there is no landing part of the ink along the traveling direction of the conveyor belt 33. It should be noted that in Figure 6 Figure 6 , the traveling direction of the conveyor belt 33 is upward in the figure (+F direction).

[0117] Since the landing part is a wet area, the slidability between the conveyor belt 33 and the squeegee 36 is improved. In contrast, when it is the non-landing part, or even when it is the landing part but the ink amount is small, the slidability between the conveyor belt 33 and the squeegee 36 deteriorates. In particular, in the range Na, since it is the range where there is no landing part of the ink along the traveling direction of the conveyor belt 33, the slidability between the conveyor belt 33 and the squeegee 36 is the worst.

[0118] Poor slidability between the conveyor belt 33 and the squeegee 36 can cause damage such as curling, chipping, and wear of the edge part of the squeegee 36 in contact with the conveyor belt 33, and it may not be possible to maintain the function of the squeegee 36.

[0119] Therefore, the control unit 50 performs pre-injection of ink from the line head 26 onto the conveyor belt 33 according to the pre-set cleaning control information.

[0120] In this way, when performing the cleaning operation of cleaning the conveyor belt 33 with the squeegee 36, the control unit 50 performs pre-injection of ink from the line head 26 onto the conveyor belt 33 according to the pre-set cleaning control information. Therefore, through this pre-injection, the slidability between the conveyor belt 33 and the squeegee 36 is improved, and thus the function of the squeegee 36 can be maintained.

[0121] Next, an example of the cleaning control information will be described. It should be noted that the cleaning control information described below is pre-stored in the non-volatile memory 52 (refer to Figure 2 ) provided in the control unit 50.

[0122] Figure 7 The tables shown in (a), (b), (c), and (d) are an example of the cleaning control information. It should be noted that hereinafter, the temperature and humidity refer to the temperature and humidity obtained by the temperature and humidity sensor 67 (refer to Figure 2 ). In addition, hereinafter, exemplarily, the temperature and humidity are the temperature and humidity when performing the cleaning operation of cleaning the conveyor belt 33 with the squeegee 36.

[0123] In addition, hereinafter, the ejection duty ratio refers to the ejection duty ratio when ink is erroneously ejected from the line head 26. Here, the ejection duty ratio is the ratio of the area where recording is performed within a specified area of the medium. The lower the ejection duty ratio, the less ink is ejected, and the higher the ejection duty ratio, the more ink is ejected.

[0124] It should be noted that the ejection duty ratio can be the ejection duty ratio in the area where ink has actually been ejected onto the conveyor belt 33 (exemplarily, Figure 6 area B2). Hereinafter, this will be referred to as the "actual ejection duty ratio". Exemplarily, the control unit 50 can obtain the actual ejection duty ratio based on the ink ejection amount ejected until the front end of the medium is detected by the upstream sensor 65 and the drive of the conveyor belt 33 is stopped and the corresponding recording area (exemplarily, Figure 6 area B2). Since the actual ejection duty ratio is based on the ink ejection amount actually ejected onto the conveyor belt 33, it can be said that it more accurately reflects the condition of the conveyor belt 33.

[0125] In addition, Figure 6 area B2 is a part of the entire recording area, but the ejection duty ratio in the entire recording area can also be used. Hereinafter, this will be referred to as the "overall ejection duty ratio". The control unit 50 can obtain the overall ejection duty ratio based on the recording data. The overall ejection duty ratio does not require measurement of the ink ejection amount actually ejected onto the conveyor belt 33 and can be calculated more simply than the actual ejection duty ratio.

[0126] The control unit 50 adopts either the actual ejection duty ratio or the overall ejection duty ratio according to the specification of the program PR (refer to Figure 2 ).

[0127] Thus, in this specification, the ejection duty ratio when ink is erroneously ejected does not only refer to the ejection duty ratio in the area where ink has actually been ejected onto the conveyor belt 33.

[0128] Figure 7 (a), (b), (c), (d) show examples where the cleaning control information is set with humidity and ejection duty ratio as the execution conditions for pre-ejection. In Figure 7 , regarding the ejection duty ratio, when it is the first event where the ejection duty ratio is lower than the first ejection duty ratio, it is "suitable", and otherwise it is "unsuitable". Hereinafter, "suitable" means suitable for pre-ejection, and "unsuitable" means unsuitable for pre-ejection.

[0129] "Suitable" for the injection duty ratio means that the above-described first event occurs. In the present embodiment, the first injection duty ratio may also be referred to as the threshold value of the injection duty ratio. When the first event in which the injection duty ratio is lower than the first injection duty ratio occurs, the slipperiness between the conveyor belt 33 and the squeegee 36 is poor compared to when the first event does not occur, and thus it is advantageous for the execution of the pre-injection.

[0130] In addition, regarding the humidity, it is "suitable" when the second event in which the humidity is lower than the first humidity occurs, and "unsuitable" otherwise. "Suitable" for the humidity means that the above-described second event occurs. In the present embodiment, the first humidity may also be referred to as the threshold value of the humidity. When the second event in which the humidity is lower than the first humidity occurs, the ink dries easily and the slipperiness between the conveyor belt 33 and the squeegee 36 is poor compared to when the second event does not occur, and thus it is advantageous for the execution of the pre-injection.

[0131] Next, in Figure 7 , "ON" indicates that pre-injection is performed, and "OFF" indicates that pre-injection is not performed.

[0132] Moreover, in Figure 7 In each of the examples (a), (b), (c), and (d), it is set that when the above-described first event and the above-described second event occur simultaneously, it is "ON", that is, the control unit 50 is made to execute pre-injection, and when the above-described first event and the above-described second event do not occur simultaneously, it is "OFF", that is, the control unit 50 is made not to execute pre-injection.

[0133] Even if the above-described first event occurs, if the above-described second event does not occur, it is easy to ensure the slipperiness between the conveyor belt 33 and the squeegee 36. Conversely, even if the above-described second event occurs, if the above-described first event does not occur, it is easy to ensure the slipperiness between the conveyor belt 33 and the squeegee 36. According to Figure 7 the example, since pre-injection is not performed in this case, waste of ink can be suppressed.

[0134] It should be noted that in Figure 7 the example of (a), the injection duty ratio is divided into "low" and "high" ranges, and the first injection duty ratio as the threshold value defines the boundary between "low" and "high", but it may also be as in Figure 7 (b) or Figure 7 (d), where the injection duty ratio is divided into "low", "medium", and "high" ranges, and the first injection duty ratio as the threshold value defines the boundary between "medium" and "high".

[0135] Similarly, in Figure 7 the example of (a), the humidity is divided into "low" and "high" ranges, and the first humidity as the threshold value defines the boundary between "low" and "high", but it may also be as in Figure 7 (c) or Figure 7As shown in (d), the humidity is divided into ranges of "low", "medium", and "high", and the first humidity as a threshold defines the boundary between "low" and "medium".

[0136] It should be noted that in Figure 7 (b), the humidity "medium" is set as "unsuitable", but it can also be set as "suitable" as shown in Figure 8 (a).

[0137] In addition, although in each of the examples of Figure 7 (a), (b), (c), and (d), it is set that when the above first event and the above second event occur simultaneously, it is "ON", that is, the control unit 50 is made to perform pre-injection, and when the above first event and the above second event do not occur simultaneously, it is "OFF", that is, the control unit 50 is made not to perform pre-injection, but a part of them can also be changed.

[0138] For example, in the example of Figure 7 (d), the humidity "medium" and "low" are set as the occurrence of the second event and are "suitable". Moreover, when the humidity is "medium" and the injection duty ratio is "medium", it is "ON" in the above example, but even if the humidity is "medium", if the injection duty ratio is "medium", the slidability of the conveyor belt 33 and the squeegee 36 is ensured, so it can also be "OFF". Such an example is as shown in Figure 8 (b).

[0139] In addition, the cleaning control information is not limited to humidity and injection duty ratio, and can also include at least any one of temperature and the elapsed time after mis-injecting ink as the execution condition of pre-injection. That is, the cleaning control information can also use one or more of the injection duty ratio, humidity, temperature, and the elapsed time after mis-injecting ink when ink is mis-injected from the line head 26 as the execution condition of pre-injection. In this case, it is preferably set that at least one of the first event where the injection duty ratio is lower than the first injection duty ratio, the second event where the humidity is lower than the first humidity, the third event where the temperature is higher than the first temperature, and the fourth event where the above elapsed time is longer than the first elapsed time acts on the execution of pre-injection.

[0140] Thus, the pre-injection is appropriately performed according to the state during the cleaning operation, and the function of the squeegee 36 can be maintained.

[0141] In addition, since pre-injection is not performed when it is not required, waste of ink can be suppressed.

[0142] It should be noted that as described above, the above various events acting on the execution of pre-injection does not mean that pre-injection must be performed when each event occurs, but means that the occurrence of each event is beneficial to the execution of pre-injection.

[0143] In addition, the control unit 50 does not need to store in the non-volatile memory 52 information related to events other than the events required to determine pre-injection in each of the above events.

[0144] In addition, the start time of the elapsed time after ink mis-injection can be set to the first ink injection time for the entire recording surface, or the last ink injection time for the entire recording surface, or a time in between the first ink injection time and the last ink injection time for the entire recording surface. Alternatively, the start time of the elapsed time can be set to the first ink injection time for the area (e.g., Figure 6 area B2) where ink is actually injected onto the conveyor belt 33, or the last ink injection time for the area where ink is actually injected onto the conveyor belt 33, or a time in between the first ink injection time and the last ink injection time for the area where ink is actually injected onto the conveyor belt 33.

[0145] In addition, the end time of the elapsed time can be set to the time when the user removes the medium and presses the OK button on the operation panel 54 after the recording operation is stopped due to media clogging.

[0146] It should be noted that hereinafter, when only referred to as the "elapsed time", it means the elapsed time after ink injection grasped by the control unit 50 as described above.

[0147] Next, the case of using temperature and elapsed time will be described.

[0148] Regarding temperature, the case of the third event where the temperature is higher than the first temperature is "suitable", and otherwise it is "unsuitable". "Suitable" for temperature means that the above third event occurs. In this embodiment, the first temperature can also be referred to as the temperature threshold. When the third event where the temperature is higher than the first temperature occurs, compared with when the third event does not occur, the ink is more likely to dry, and the slidability between the conveyor belt 33 and the squeegee 36 is poor, so it is beneficial for the execution of pre-injection.

[0149] In addition, regarding the elapsed time, the case of the fourth event where the elapsed time is longer than the first elapsed time is "suitable", and otherwise it is "unsuitable". "Suitable" for the elapsed time means that the above fourth event occurs. In this embodiment, the first elapsed time can also be referred to as the elapsed time threshold. When the fourth event where the elapsed time is longer than the first elapsed time occurs, compared with when the fourth event does not occur, the drying of the ink is aggravated, and the slidability between the conveyor belt 33 and the squeegee 36 is poor, so it is beneficial for the execution of pre-injection.

[0150] By replacing these third events or fourth events with Figure 7One or both of the first event and the second event in each of the examples (a), (b), (c), and (d) can be the temperature or the elapsed time. Of course, any one of the third event and the fourth event can be used as the execution condition for the pre-injection.

[0151] When one or both of the temperature and the elapsed time are further applied to Figure 7 each of the examples (a), (b), (c), and (d), Figure 7 when it is "ON" in each of the examples (a), (b), (c), and (d), and further, when the temperature is "suitable" or the elapsed time is "suitable", it is finally set to "ON" to perform the pre-injection. If the temperature is "not suitable" or the elapsed time is "not suitable", then even if Figure 7 it is "ON" in each of the examples (a), (b), (c), and (d), the pre-injection is not performed.

[0152] As described above, in Figure 7 each of the examples (a), (b), (c), and (d), the humidity and the injection duty ratio are used as the execution conditions for the pre-injection, but any one of the humidity, the injection duty ratio, the temperature, and the elapsed time can also be used as the execution condition for the pre-injection.

[0153] Specifically, when only the injection duty ratio is used as the execution condition for the pre-injection, the pre-injection is performed when a first event occurs in which the injection duty ratio is lower than the first injection duty ratio.

[0154] Or, when only the humidity is used as the execution condition for the pre-injection, the pre-injection is performed when a second event occurs in which the humidity is lower than the first humidity.

[0155] Or, when only the temperature is used as the execution condition for the pre-injection, the pre-injection is performed when a third event occurs in which the temperature is higher than the first temperature.

[0156] Or, when only the elapsed time is used as the execution condition for the pre-injection, the pre-injection is performed when a fourth event occurs in which the elapsed time is longer than the first elapsed time.

[0157] Next, the control unit 50 can also be configured to be able to adjust the ink injection amount during the pre-injection according to the preset injection amount adjustment information. The ink injection amount during the pre-injection is set to an appropriate amount so as to improve the slidability between the conveyor belt 33 and the squeegee 36, and also to suppress the waste of ink.

[0158] In addition, preferably, the above ink ejection amount adjustment information is set to include one or more of the ejection duty ratio, humidity, temperature, and elapsed time as the adjustment conditions for the ink ejection amount, and at least one of a decrease in the ejection duty ratio, a decrease in humidity, an increase in temperature, and an increase in the elapsed time acts on an increase in the ink ejection amount during pre-ejection. Thus, when the slipperiness between the conveyor belt 33 and the squeegee 36 is poor, the ink ejection amount increases, and the slipperiness between the conveyor belt 33 and the squeegee 36 can be appropriately improved.

[0159] It should be noted that the control unit 50 does not need to have information in the non-volatile memory 52 related to other conditions other than the conditions required for adjusting the ink ejection amount among the ejection duty ratio, humidity, temperature, and elapsed time.

[0160] Next, with reference to Figure 9 specific examples of the ink ejection amount adjustment information will be described. Figure 9 The coefficients shown are coefficients multiplied by the standard ink ejection amount Sh during pre-ejection. Therefore, the smaller the multiplied coefficient, the smaller the ink ejection amount during pre-ejection. On the contrary, the larger the coefficient, the larger the ink ejection amount during pre-ejection.

[0161] Figure 9 (a) shows the coefficient set for the ejection duty ratio Q. The ejection duty ratio Q increases in the order of Q1, Q2, Q3, and the larger the ejection duty ratio Q, the smaller the coefficient. This is because the better the slipperiness between the conveyor belt 33 and the squeegee 36 as the ejection duty ratio Q increases. In other words, the smaller the ejection duty ratio Q, the smaller the coefficient.

[0162] Figure 9 (b) shows the coefficient set for the humidity H. The humidity H increases in the order of H1, H2, H3, H4, and the higher the humidity H, the smaller the coefficient. This is because the more difficult it is for the ink to dry as the humidity H increases, and the slipperiness between the conveyor belt 33 and the squeegee 36 is maintained. In other words, the lower the humidity H, the larger the coefficient.

[0163] Figure 9 (c) shows the coefficient set for the temperature S. The temperature S increases in the order of S1, S2, S3, S4, and the higher the temperature S, the larger the coefficient. This is because the drying of the ink is accelerated as the temperature S increases, and the slipperiness between the conveyor belt 33 and the squeegee 36 becomes worse. In other words, the lower the temperature S, the smaller the coefficient.

[0164] Figure 9 (d) shows the coefficient set for the elapsed time T. The elapsed time T increases in the order of T1, T2, T3, and the longer the elapsed time T, the larger the coefficient. This is because the drying of the ink is accelerated as the elapsed time T increases, and the slipperiness between the conveyor belt 33 and the squeegee 36 becomes worse. In other words, the shorter the elapsed time T, the smaller the coefficient.

[0165] As described above, a decrease in the ejection duty ratio Q, a decrease in the humidity H, an increase in the temperature S, and an increase in the elapsed time T act on an increase in the ink ejection amount in the pre-ejection.

[0166] The coefficient multiplied by the standard ink ejection amount Sh can be, for example, any one of the coefficient of the ejection duty ratio Q, the coefficient of the elapsed time T, and the coefficient of the humidity H used alone.

[0167] Alternatively, both the coefficient of the elapsed time T and the coefficient of the ejection duty ratio Q can be multiplied by the standard ink ejection amount Sh.

[0168] Alternatively, both the coefficient of the ejection duty ratio Q and the coefficient of the humidity H can be multiplied by the standard ink ejection amount Sh.

[0169] Alternatively, all of the coefficient of the elapsed time T, the coefficient of the ejection duty ratio Q, and the coefficient of the humidity H can be multiplied by the standard ink ejection amount Sh.

[0170] Alternatively, all of the coefficient of the ejection duty ratio Q, the coefficient of the humidity H, the coefficient of the temperature S, and the coefficient of the elapsed time T can be multiplied by the standard ink ejection amount Sh.

[0171] That is, the ejection amount adjustment information only needs to include one or more of the ejection duty ratio Q, the humidity H, the temperature S, and the elapsed time T as the adjustment conditions for the ink ejection amount during pre-ejection.

[0172] In addition, the ejection amount adjustment information includes the ejection duty ratio as the determination condition for the ink ejection amount during pre-ejection. The control unit 50 can calculate the ejection duty ratio Q for each region divided along the direction (Y-axis direction) crossing the traveling direction (+F direction) of the conveyor belt 33, and adjust the ink ejection amount for each region.

[0173] Figure 10 To represent such an example, reference numerals Y1, Y2, Y3, Y4, Y5, and Y6 denote a plurality of regions divided along the width direction (Y-axis direction). Each region constitutes the region B2.

[0174] Region Y3 is a region where no ink is ejected and the slidability between the conveyor belt 33 and the squeegee 36 is poor. Therefore, ink of the standard ink ejection amount Sh is ejected onto such a region (pre-ejection region Db2). In contrast, for example, a smaller amount of ink than the standard ink ejection amount Sh is ejected onto regions Y1 and Y2 (pre-ejection region Db1), and an even smaller amount of ink than that is ejected onto regions Y4, Y5, and Y6 where the most ink is ejected (pre-ejection region Db3). Exemplarily, the ink ejection amount in each region is adjusted by multiplying the coefficient shown in Figure 9 (a) by the standard ink ejection amount Sh.

[0175] In this way, the ejection duty ratio Q is calculated for each region divided along the width direction by the control unit 50, and the ink ejection amount is adjusted for each of the above regions, so that the ink ejection amount during pre-ejection can be adjusted within a finer range, the slidability between the conveyor belt 33 and the squeegee 36 is improved, and in addition, waste of ink can be suppressed.

[0176] It should be noted that in the above example, the ejection duty ratio Q is calculated for each region divided along the width direction, and the ink ejection amount is adjusted for each of the above regions. However, in this case, one or more of the coefficients of humidity H, coefficient of temperature S, and coefficient of elapsed time T described with reference to Figure 9 (b), (c), and (d) can be further applied.

[0177] Next, the ink ejection position during pre-ejection will be described.

[0178] In Figure 10 the example, the control unit 50 performs pre-ejection on the conveyor belt 33 in such a manner that the pre-ejection regions Db1, Db2, and Db3 contact the squeegee 36 prior to the region B2 where ink has landed due to mis-ejection. In Figure 9 the pre-ejection regions Db1, Db2, and Db3 are set to be closer to the +F direction than the region B2.

[0179] By setting the position of the pre-ejection in this way, the squeegee 36 cleans the region B2 where mis-ejection has occurred in a pre-wetted state, and the function of the squeegee 36 can be maintained more reliably.

[0180] It should be noted that in Figure 10 the example, the pre-ejection regions Db1, Db2, and Db3 do not overlap with the region B2, but a part of the pre-ejection regions Db1, Db2, and Db3 may also overlap with the region B2.

[0181] In addition, when it is not necessary for the pre-ejection regions Db1, Db2, and Db3 to contact the squeegee 36 prior to the region B2, the pre-ejection regions Db1, Db2, and Db3 may all overlap with the region B2.

[0182] In addition, the control unit 50 may also perform pre-ejection on the conveyor belt 33 in such a manner as to avoid the portion where ink has landed due to mis-ejection. Here, performing pre-ejection in such a manner as to avoid the portion where ink has landed due to mis-ejection means, for example, Figure 6 inside the region B2, ink is ejected onto the portion where no ink has landed. Thus, by performing pre-ejection while avoiding the wetted portion, waste of ink can be suppressed.

[0183] It should be noted that in this case, reference can also be made toFigure 9 The described injection amount adjustment.

[0184] In addition, the control unit 50 may also be configured to select the first injection mode and the second injection mode according to the preset injection area setting information when performing pre-injection. The first injection mode injects ink on the conveyor belt 33 in a manner that avoids the portion where ink has landed due to mis-injection, and the second injection mode injects ink on the conveyor belt 33 toward the portion where ink has landed due to mis-injection and the portion where ink has not landed. The injection area setting information is stored in the non-volatile memory 52 (refer to Figure 2 ) provided in the control unit 50.

[0185] In Figure 6 's example, when the first injection mode is selected, ink is injected into the portion where ink has not landed inside area B2. In addition, when the second injection mode is selected, ink is injected into both the portion where ink has landed and the portion where ink has not landed inside area B2.

[0186] Accordingly, the consumption of ink can be suppressed in the first injection mode. In addition, in the second injection mode, the portion where ink has landed due to mis-injection on the conveyor belt 33 is also injected with ink, so that the portion where ink has landed due to mis-injection can be softened, and the cleaning effect can be improved.

[0187] The above injection area setting information may also be set such that when the humidity exceeds the standard humidity, the control unit 50 is made to select the first injection mode, and when the humidity is below the standard humidity, the control unit 50 is made to select the second injection mode. Accordingly, when the portion where ink has landed due to mis-injection on the conveyor belt 33 has not dried, the first injection mode is selected, and the consumption of ink can be suppressed. In addition, when the portion where ink has landed due to mis-injection on the conveyor belt 33 is drying more severely, the second injection mode is selected, and the portion where ink has landed due to mis-injection on the conveyor belt 33 can be softened, and the cleaning effect can be improved.

[0188] In each of the above embodiments, the control unit 50 may also rotate the conveyor belt 33 while maintaining the blade 36 in the separated state until the blade 36 faces the area where ink has landed on the conveyor belt 33, and when the blade 36 faces the area where ink has landed on the conveyor belt 33, switch the blade 36 from the separated state to the contact state.

[0189] Accordingly, in Figure 6 's example, cleaning by the blade 36 is performed from the end of area B2 in the +F direction, i.e., position F1 or a position slightly closer to the +F direction than F1, toward the -F direction. Through such control, the time when the blade 36 contacts the area where ink has not landed on the conveyor belt can be suppressed, and the function of the blade 36 can be more reliably maintained.

[0190] It should be noted that the pre-injection described above is applied to the cleaning of the conveyor belt 33 after mis-injecting ink, but is not limited thereto, and can also be applied to the above-mentioned regular cleaning operation or other cleaning operations.

[0191] In addition, although in this embodiment, the line-type print head 26 is provided with nozzle rows for each ink color of cyan, magenta, yellow, and black, the nozzle row used for pre-injection can be the nozzle row of any ink color, or all nozzle rows can be used for pre-injection. Additionally, when the slidability between the conveyor belt 33 and the squeegee 36 varies according to the ink color, ink of the ink color with the best slidability among multiple ink colors can also be used for pre-injection.

[0192] Furthermore, although the temperature and humidity sensor 67 is configured to be provided inside the device, it is not limited thereto and can also be provided outside the device. Additionally, the temperature sensor and the humidity sensor can be provided separately, and in this case, at least one of them can be provided outside the device.

[0193] Moreover, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and of course, these modifications are also included within the scope of the present invention.

Claims

1. A liquid ejection device, characterized in that, Comprising: A liquid ejection unit that ejects liquid onto a medium; A conveyor belt that faces the liquid ejection unit and is used to convey the medium; A cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state of contacting the conveyor belt and a separation state of separating from the conveyor belt; And A control unit that controls the liquid ejection operation performed by the liquid ejection unit, the rotation operation of the conveyor belt, and the state switching of the cleaning member. During the cleaning operation of the conveyor belt by the cleaning member, the control unit performs pre-ejection of pre-spraying liquid from the liquid ejection unit to the conveyor belt according to preset cleaning control information. The cleaning control information includes one or more of the ejection duty ratio, humidity, temperature, and elapsed time since the mis-ejection as the execution conditions for the pre-ejection.

2. The liquid ejection device according to claim 1, wherein The cleaning control information is set as: At least one of a first event where the ejection duty ratio is lower than a first ejection duty ratio, a second event where the humidity is lower than a first humidity, a third event where the temperature is higher than a first temperature, and a fourth event where the elapsed time is longer than a first elapsed time acts on the execution of the pre-ejection.

3. The liquid ejection device according to claim 2, wherein The cleaning control information is set as: Taking the ejection duty ratio and the humidity as the execution conditions for the pre-ejection, When the first event and the second event occur simultaneously, the control unit executes the pre-ejection, and when the first event and the second event do not occur simultaneously, the control unit does not execute the pre-ejection.

4. The liquid ejection device according to claim 2 or 3, wherein The control unit adjusts the liquid ejection amount during the pre-ejection according to preset ejection amount adjustment information.

5. The liquid ejection device according to claim 4, wherein The ejection amount adjustment information is set as: Including one or more of the ejection duty ratio, humidity, temperature, and elapsed time as the adjustment conditions for the liquid ejection amount, and At least one of a decrease in the ejection duty ratio, a decrease in humidity, an increase in temperature, and an increase in the elapsed time acts on an increase in the liquid ejection amount during the pre-ejection.

6. The liquid ejection device according to claim 5, wherein The ejection amount adjustment information includes the ejection duty ratio as the determination condition for the liquid ejection amount. The control unit calculates the ejection duty ratio for each region divided along the width direction that intersects the traveling direction of the conveyor belt, and adjusts the liquid ejection amount for each region.

7. The liquid ejection device according to claim 2, wherein The control unit performs the pre-ejection on the conveyor belt in such a way that the region of the pre-ejection contacts the cleaning member prior to the region where liquid has landed due to the mis-ejection.

8. The liquid ejection device according to claim 2, wherein: the control unit performs the pre-ejection on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-ejection.

9. The liquid ejection device according to claim 2, wherein: when performing the pre-ejection, the control unit selects a first ejection mode and a second ejection mode according to preset ejection area setting information, the first ejection mode ejects liquid on the conveyor belt in such a manner as to avoid the portion where the liquid has landed due to the mis-ejection, the second ejection mode ejects liquid on the conveyor belt toward the portion where the liquid has landed due to the mis-ejection and the portion where the liquid has not landed due to the mis-ejection.

10. The liquid ejection device according to claim 9, wherein: the ejection area setting information is set such that when the humidity exceeds the standard humidity, the control unit selects the first ejection mode, and when the humidity is below the standard humidity, the control unit selects the second ejection mode.

11. The liquid ejection device according to claim 1, wherein: the control unit keeps the cleaning member in the separated state and rotates the conveyor belt until the cleaning member faces the area on the conveyor belt where the liquid has landed, and when the cleaning member faces the area on the conveyor belt where the liquid has landed, the control unit switches the cleaning member from the separated state to the contact state.

12. A control method for a liquid ejection device, characterized in that, The liquid ejection device includes: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state in which it contacts the conveyor belt and a separated state in which it is separated from the conveyor belt; in the control method of the liquid ejection device, when the conveyor belt is cleaned by the cleaning member, a pre-ejection of ejecting liquid from the liquid ejection unit onto the conveyor belt in advance is performed, one or more of the ejection duty ratio, humidity, temperature when liquid is mis-ejected from the liquid ejection unit, and the elapsed time since the mis-ejection are used as the execution conditions for the pre-ejection.

13. A storage medium, characterized in that, A program is stored, and the program is executed by a control unit of the liquid ejection device. The liquid ejection device includes: a liquid ejection unit that ejects liquid onto a medium; a conveyor belt that faces the liquid ejection unit and is used to convey the medium; a cleaning member that cleans the conveyor belt by contacting the conveyor belt, and the cleaning member can be switched between a contact state in which it contacts the conveyor belt and a separated state in which it is separated from the conveyor belt; the program includes a step of performing a pre-ejection of ejecting liquid from the liquid ejection unit onto the conveyor belt in advance when the conveyor belt is cleaned by the cleaning member, and one or more of the ejection duty ratio, humidity, temperature when liquid is mis-ejected from the liquid ejection unit, and the elapsed time since the mis-ejection are included as the execution conditions for the pre-ejection.

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