Liquid discharge apparatus and control method for liquid discharge apparatus

Abstract

To solve a problem in an inkjet recording apparatus which receives print data at a timing when cleaning cannot be canceled, such as a timing immediately before shifting to a sleep mode or when a cleaning operation has just started, and the wait time of a user occurs in such cases.SOLUTION: A liquid discharge apparatus comprises: a liquid discharge unit including a plurality of nozzles that discharge liquid; and a control unit that controls the liquid discharge unit. The control unit is capable of executing an operation mode being a power supply mode used when performing a cleaning operation of the liquid discharge unit, and a sleep mode being a power supply mode consuming less power than the operation mode. Further, the control unit determines whether to execute a cleaning operation before shifting to a sleep mode in accordance with an execution condition of the cleaning operation before shifting to a sleep mode being a cleaning operation performed when shifting to the sleep mode.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In inkjet recording devices, it is known that nozzles can become clogged due to thickening of the ink in the nozzles or the internal space connected to the nozzles, the inclusion of air bubbles, or the adhesion of paper powder or dust to the nozzles, resulting in poor ink ejection. Patent Document 1 discloses an optical method for detecting defective ink ejection by detecting the number of ink droplets that block the optical path. Patent document 2 also discloses a technology that detects residual vibrations that occur in the ejection section after driving a drive element with a drive pulse, and detects ink ejection defects based on the results of comparing the amplitude of the detected residual vibrations with a threshold value.

[0003] When such ink ejection defects are detected, a cleaning operation is performed. The inkjet recording device described in Patent Document 3 performs cleaning before going into sleep mode if a predetermined time has passed since the previous cleaning, with the aim of reducing the waiting time before printing that occurs due to cleaning being performed at regular intervals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-309963 [Patent Document 2] Japanese Patent Publication No. 2020-44804 [Patent Document 3] Japanese Patent Publication No. 2023-074706 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there are cases where the inkjet recording apparatus receives print data at a time when cleaning cannot be canceled, such as immediately before transitioning to sleep mode or when the cleaning operation is started, and in such cases the user has to wait. [Means for solving the problem]

[0006] In order to solve the above problem, the liquid ejection device of the present invention comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode which is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode which is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit determines whether or not to perform the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0007] The liquid ejection device of the present invention also comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit determines the intensity of the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0008] The liquid ejection device of the present invention also comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit executes a nozzle check process that detects defective ejection nozzles among the plurality of nozzles, and executes the cleaning operation if the number of defective ejection nozzles is equal to or greater than a set value, and further characterized in that the control unit changes the set value depending on the execution conditions of a pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode.

[0009] Furthermore, in the control method for a liquid ejection device of the present invention, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and the control method is characterized in that it includes a step of determining whether or not to perform the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0010] Furthermore, in the control method for a liquid ejection device of the present invention, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and the control method is characterized in that it includes a step of determining the content of the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0011] Furthermore, in the control method for a liquid ejection device of the present invention, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and the liquid ejection device is further capable of executing a nozzle check process to detect defective ejection nozzles among the plurality of nozzles, and performing the cleaning operation if the number of defective ejection nozzles is equal to or greater than a set value, and the control method is characterized in that it includes a step of changing the set value depending on the execution conditions of a pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a diagram showing a medium transport path of the liquid ejection device. [Figure 2] FIG. 2 is a diagram showing a medium transport path of the liquid ejection device. [Figure 3] FIG. 2 is a block diagram showing a control system of the liquid ejection device. [Figure 4] FIG. [Figure 5] 10 is a flowchart showing a process for determining whether or not to perform a cleaning operation before transitioning to a sleep mode. [Figure 6] 10 is a table showing an example of the availability rate of a liquid ejection device. [Figure 7] FIG. 1 is a schematic diagram of a network including a liquid ejection device and an external terminal. [Figure 8] 10 is a flowchart showing a process for determining the execution content of a cleaning operation before transition to a sleep mode. [Figure 9] 10 is a flowchart showing a process for setting the execution conditions of a cleaning operation before transition to a sleep mode. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be briefly described below. The liquid ejection device of the first aspect comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit determines whether or not to perform the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0014] According to this aspect, the control unit determines whether or not to perform the pre-sleep mode cleaning operation depending on the conditions for executing the pre-sleep mode cleaning operation. This reduces the waiting time that the user has to wait due to the pre-sleep mode cleaning operation compared to when the pre-sleep mode cleaning operation is uniformly performed when transitioning to the sleep mode.

[0015] A second aspect is an aspect dependent on the first aspect, characterized in that the control unit is capable of acquiring information related to the operating rate of the device, the execution conditions include the operating rate, and the control unit executes the pre-sleep mode cleaning operation when the operating rate is a first operating rate, and does not execute the pre-sleep mode cleaning operation when the operating rate is a second operating rate that is higher than the first operating rate.

[0016] According to this aspect, the control unit performs the pre-sleep mode cleaning operation when the operation rate is a first operation rate, and does not perform the pre-sleep mode cleaning operation when the operation rate is a second operation rate that is higher than the first operation rate, thereby preferably preventing the user from having to wait due to the pre-sleep mode cleaning operation.

[0017] A third aspect is an aspect dependent on the first aspect, characterized in that the execution conditions include the number of external terminals connected to the liquid ejection device that are powered on, and the control unit executes the pre-sleep mode cleaning operation when the number of external terminals that are powered on is a first number of terminals, and does not execute the pre-sleep mode cleaning operation when the number of external terminals that are powered on is a second number of terminals that is greater than the first number of terminals.

[0018] According to this aspect, when the number of external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, the control unit does not perform the pre-sleep mode cleaning operation, thereby preferably preventing the user from having to wait due to the pre-sleep mode cleaning operation. It should be noted that this aspect is not limited to the first aspect, but may be subordinate to the second aspect.

[0019] A liquid ejection device according to a fourth aspect comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode, which is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode, which is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit determines the intensity of the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0020] According to this aspect, the control unit determines the intensity of the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode cleaning operation. Therefore, there are cases where the time required for the pre-sleep mode cleaning operation can be shortened compared to when the pre-sleep mode cleaning operation is performed uniformly at the same intensity, thereby reducing the user's waiting time.

[0021] A fifth aspect is an aspect dependent on the fourth aspect, characterized in that the control unit is capable of acquiring information related to the operating rate of the device, the execution conditions include the operating rate, and the control unit performs the pre-sleep mode transition cleaning operation at a first intensity when the operating rate is a first operating rate, and performs the pre-sleep mode transition cleaning operation at a second intensity weaker than the first intensity when the operating rate is a second operating rate higher than the first operating rate.

[0022] According to this aspect, the control unit performs the pre-sleep mode cleaning operation at a first intensity when the operation rate is a first operation rate, and performs the pre-sleep mode cleaning operation at a second intensity that is weaker than the first intensity when the operation rate is a second operation rate that is higher than the first operation rate, thereby preferably shortening the user's waiting time caused by the pre-sleep mode cleaning operation.

[0023] A sixth aspect is a dependent aspect of the fourth aspect, characterized in that the execution conditions include the number of external terminals connected to the liquid ejection device that are powered on, and the control unit executes the pre-sleep mode transition cleaning operation at a first intensity when the number of external terminals that are powered on is a first number of terminals, and executes the pre-sleep mode transition cleaning operation at a second intensity that is weaker than the first intensity when the number of external terminals that are powered on is a second number of terminals that is greater than the first number of terminals.

[0024] According to this aspect, the control unit performs the pre-sleep mode cleaning operation at a first intensity when the number of external terminals in the power-on state is a first number of terminals, and performs the pre-sleep mode cleaning operation at a second intensity that is weaker than the first intensity when the number of external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, thereby preferably shortening the user's waiting time caused by the pre-sleep mode cleaning operation. It should be noted that this aspect is not limited to the fourth aspect, but may be subordinate to the fifth aspect.

[0025] A liquid ejection device according to a seventh aspect comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and a control unit that controls the liquid ejection unit, wherein the control unit is capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and further characterized in that the control unit executes a nozzle check process that detects defective ejection nozzles among the plurality of nozzles, and executes the cleaning operation if the number of defective ejection nozzles is equal to or greater than a set value, and further characterized in that the control unit changes the set value depending on the execution conditions of a pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode.

[0026] According to this aspect, the control unit changes the setting value depending on the execution conditions of the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode. Therefore, compared to when the pre-sleep mode cleaning operation is performed according to the same setting value, it is possible to reduce the waiting time that the user experiences due to the pre-sleep mode cleaning operation.

[0027] An eighth aspect is a dependent aspect of the seventh aspect, characterized in that the control unit is capable of acquiring information related to the operating rate of the device, the execution conditions include the operating rate, and the control unit sets the setting value to a first value when the operating rate is a first operating rate, and sets the setting value to a second value higher than the first value when the operating rate is a second operating rate higher than the first operating rate.

[0028] According to this aspect, the control unit sets the setting value to a first value when the operation rate is a first operation rate, and sets the setting value to a second value higher than the first value when the operation rate is a second operation rate higher than the first operation rate, thereby preferably preventing the user from having to wait due to the pre-sleep mode cleaning operation.

[0029] A ninth aspect is a dependent aspect of the seventh aspect, and is characterized in that the execution conditions include the number of external terminals connected to the liquid ejection device that are powered on, and the control unit sets the setting value to a first value when the number of external terminals that are powered on is a first number of terminals, and sets the setting value to a second value that is higher than the first value when the number of external terminals that are powered on is a second number of terminals that is greater than the first number of terminals.

[0030] According to this aspect, the control unit performs the pre-sleep mode cleaning operation at a first intensity when the number of external terminals in the power-on state is a first number of terminals, and performs the pre-sleep mode cleaning operation at a second intensity that is weaker than the first intensity when the number of external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, thereby preferably preventing the pre-sleep mode cleaning operation from causing the user to wait. This aspect is not limited to the seventh aspect, but may be subordinate to the eighth aspect.

[0031] In a control method for a liquid ejection device according to a tenth aspect, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is further capable of executing an operation mode, which is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode, which is a power supply mode that consumes less power than the operation mode, and the control method is characterized in that it includes a step of determining whether or not to perform the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0032] According to this aspect, the control method for a liquid ejection device includes a step of determining whether or not to perform the pre-sleep mode cleaning operation depending on the conditions for executing the pre-sleep mode cleaning operation, and therefore, compared to a case where the pre-sleep mode cleaning operation is performed uniformly when transitioning to the sleep mode, it is possible to reduce the waiting time that the user experiences due to the pre-sleep mode cleaning operation.

[0033] In a control method for a liquid ejection device according to an eleventh aspect, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is further capable of executing an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode that is a power supply mode that consumes less power than the operation mode, and the control method is characterized in that it includes a step of determining the content of the pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on the execution conditions of the pre-sleep mode transition cleaning operation.

[0034] According to this aspect, the control method for a liquid ejection device includes a step of determining the content of the pre-sleep mode cleaning operation depending on the conditions for executing the pre-sleep mode cleaning operation, and therefore, there are cases in which the time required for the pre-sleep mode cleaning operation can be shortened compared to when the same pre-sleep mode cleaning operation is performed uniformly, thereby reducing the user's waiting time.

[0035] In a control method for a liquid ejection device according to a twelfth aspect, the liquid ejection device comprises a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium, and a cap that can switch between an opposing state in which it faces the nozzles and a separated state in which it is separated from the nozzles from the opposing state, and the liquid ejection device is capable of executing an operation mode, which is a power supply mode when performing a cleaning operation of the liquid ejection unit, and a sleep mode, which is a power supply mode that consumes less power than the operation mode, and the liquid ejection device is capable of executing a nozzle check process to detect defective ejection nozzles among the plurality of nozzles, and performing the cleaning operation if the number of defective ejection nozzles is equal to or greater than a set value, and the control method is characterized in that it includes a step of changing the set value depending on the execution conditions of a pre-sleep mode transition cleaning operation, which is the cleaning operation when transitioning to the sleep mode.

[0036] According to this aspect, the control unit includes a step of changing the setting value depending on the execution conditions of the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode. Therefore, compared to when the pre-sleep mode cleaning operation is performed according to the same setting value, it is possible to reduce the waiting time that the user experiences due to the pre-sleep mode cleaning operation.

[0037] The present invention will be specifically described below. The XYZ coordinate system shown in each figure is a Cartesian coordinate system, with the Y axis direction being the width direction intersecting the medium transport direction and the depth direction of the device. In this embodiment, of the side surfaces that make up the periphery of the device body 2, the side surface in the +Y direction is the back surface, and the side surface in the -Y direction is the front surface. The X-axis direction is the width direction of the device, with the +X direction being the left side and the -X direction being the right side as seen by an operator of the liquid ejection device 1. The -X direction is also the direction in which media is fed out from each media cassette, which will be described later. The Z-axis direction is the vertical direction, that is, the height direction of the device, with the +Z direction being the upward direction and the -Z direction being the downward direction. Hereinafter, the direction in which the medium is transported may be referred to as "downstream," and the opposite direction may be referred to as "upstream." In Figure 1, the medium transport path is indicated by a dashed line. In the liquid ejection device 1, the medium is transported through the medium transport path indicated by the dashed line.

[0038] The liquid ejection device 1 described below is configured as an inkjet printer that performs recording by ejecting ink, which is an example of a liquid, onto a medium such as recording paper. The liquid ejection device 1 is provided with a plurality of media cassettes arranged vertically below the device main body 2, which is equipped with a line head 12 (described later), specifically a first media cassette 3, a second media cassette 4, a third media cassette 5, and a fourth media cassette 6. The symbol P indicates the media stored in each media cassette. Each media cassette is provided with a pick roller that feeds the stored media in the -X direction. Reference numerals 21, 22, 23, and 24 denote pick rollers provided for each media cassette. Further, a pair of feed rollers is provided for each medium cassette to feed the medium sent out by the pick roller further downstream. Reference numerals 25, 26, 27, and 28 denote pairs of feed rollers provided for each medium cassette. Unless otherwise specified, the term "roller pair" hereinafter refers to a pair of rollers consisting of a drive roller driven by a power source such as a motor, and a driven roller that rotates in contact with the drive roller.

[0039] Symbol T1 indicates the transport path of the media sent out from each media cassette and reaching the transport roller pair 34. The media sent out from the first media cassette 3 receives a feeding force from the transport roller pair 29, 33 and is sent to the transport roller pair 34. The media sent out from the second media cassette 4 receives a feeding force from the transport roller pairs 30, 29, 33 and is sent to the transport roller pair 34. The media sent out from the third media cassette 5 receives a feeding force from the transport roller pairs 31, 30, 29, 33 and is sent to the transport roller pair 34. The media sent out from the fourth media cassette 6 receives a feeding force from the transport roller pairs 32, 31, 30, 29, 33 and is sent to the transport roller pair 34.

[0040] The medium receiving the feeding force from the transport roller pair 34 is sent to a recording position between the line head 12, which is an example of a liquid ejection unit, and the transport belt 53, that is, facing the line head 12. The transport roller pair 34 constitutes a transport unit that transports the medium between the line head 12 and the transport belt 53.

[0041] The line head 12 performs recording by ejecting ink, which is an example of liquid, onto the surface of the medium. The line head 12 is an ink ejection head in which a plurality of nozzles 13 that eject ink are arranged so as to 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. However, the ink ejection head is not limited to this, and may be of a type that is mounted on a carriage and ejects ink while moving in the width direction of the medium.

[0042] The line head 12 according to this embodiment employs a piezoelectric element, which is a piezoelectric element whose volume changes when a voltage is applied. By controlling the drive waveform of the piezoelectric element, the movement of the meniscus of the nozzle 13 can be controlled, thereby controlling the size and ejection speed of the ink droplets ejected. In this embodiment, the multiple nozzles 13 are composed of multiple nozzles 13 that eject yellow ink, multiple nozzles 13 that eject magenta ink, multiple nozzles 13 that eject cyan ink, and multiple nozzles 13 that eject magenta ink.

[0043] Next, the conveyor belt 53 is an endless belt that is wound around a first roller 54 and a second roller 55, and is rotated by driving the first roller 54 by a belt rotation motor 89 (see FIG. 3). The medium is attracted to the belt surface of the conveyor belt 53 and conveyed to a position facing the line head 12. The first roller 54, the second roller 55, and the conveyor belt 53 constitute a belt unit 52. The belt unit 52 has the first roller 54 as a rotation axis and is rotatable by the power of a belt movement motor 90 (see FIG. 3). As the belt unit 52 rotates, the conveyor belt 53 moves between a support position (see FIG. 1) facing the line head 12 and a retracted position (see FIG. 2) away from the support position. The belt unit 52 is an example of a support section that supports the medium. Note that the support section is not limited to a configuration including the conveyor belt 53, and may be, for example, a platen that does not perform a medium conveying function.

[0044] The medium on whose first side has been recorded by the line head 12 is sent by the transport roller pair 35 located downstream of the transport belt 53 toward either the transport roller pair 36 or the transport roller pair 40. A path switching flap (not shown) is provided downstream of the transport roller pair 35, and the medium receiving the feeding force from the transport roller pair 35 is sent by this path switching flap to either the transport roller pair 36 or the transport roller pair 40.

[0045] When recording is not performed on the second side of the medium, which is opposite to the first side, i.e., when double-sided recording is not performed, the medium is sent from transport roller pair 35 to transport roller pair 36, and is discharged through discharge path T4 to discharge tray 8. Discharge path T4 is provided with transport roller pair 38 and transport roller pair 39.

[0046] When recording is to be performed on both the first side and the opposite second side of the medium, i.e., when double-sided recording is to be performed, the medium is sent from transport roller pair 35 towards transport roller pair 40 and enters switchback path T2. The rotation direction of transport roller pair 40 is then switched, and the medium enters reversal path T3 and is sent to transport roller pair 34 by transport roller pairs 41, 42, and 43.

[0047] Reference numerals 10A and 10B denote ink storage units serving as liquid storage units that store ink before ejection. The ink to be ejected from the line head 12 is supplied from the ink storage units 10A and 10B to the line head 12 via tubes (not shown). The ink storage unit 10A stores black ink, for example. The ink storage unit 10B stores yellow, magenta, and cyan ink, for example.

[0048] Reference numeral 9 denotes a cap unit having a cap 9a that caps the line head 12. The cap 9a can be switched between an opposed state (see FIG. 2) in which the cap 9a faces the nozzles 13 and a separated state (see FIG. 1) in which the cap 9a faces the nozzles 13, using the power of a cap movement motor 91 (see FIG. 3). Normally, except when printing, the cap 9a is in the opposed state and in close contact with the head surface 12a to prevent the ink in the nozzles 13 from thickening and clogging.

[0049] Reference numeral 11 denotes a waste liquid storage section that stores ink as waste liquid that is ejected from the nozzles 13 of the line head 12 toward the cap 9a for cleaning. The ink as waste liquid that is discharged from the nozzles 13 of the line head 12 toward the cap 9a for cleaning is sent to the waste liquid storage section 11 from the cap 9a via a tube (not shown).

[0050] The above is an outline of the overall configuration of the liquid ejection device 1, and the control unit 80 will be described below with reference to FIG. The control unit 80 performs various controls including recording control in the liquid ejection device 1. Note that only components necessary for explanation in this specification are shown in Fig. 3, and other components are not shown. The control unit 80 is electrically connected to an output system including a feed motor 87, a conveying motor 88, a belt rotation motor 89, a belt movement motor 90, a cap movement motor 91, a wiper movement motor 92, a head movement motor 93, a pump motor 96, and a line head 12. A feed motor 87 is a power source for each of the pick rollers and each of the feed roller pairs described above, and a transport motor 88 is a power source for each of the transport roller pairs described above.

[0051] The head movement motor 93 is a power source for moving the line head 12 toward and away from the conveyor belt 53. That is, the line head 12 is provided so as to be displaceable in the Z-axis direction, i.e., the direction of moving toward and away from the conveyor belt 53, by a guide unit (not shown). The control unit 80 can adjust the position of the line head 12 in the Z-axis direction by controlling the head movement motor 93. By raising and lowering the line head 12, the head surface 12a can be moved toward and away from the opposing cap 9a. As a result, it is possible to switch between a state in which the head surface 12a is in close contact with the cap 9a and a state in which the head surface 12a is spaced apart from the cap 9a. The flushing process described below is performed when the head surface 12a is spaced apart from the cap 9a, but the flushing process may also be performed when the head surface 12a is spaced apart from the cap 9a.

[0052] Each of the motors is, for example, a DC motor. Each of the motors is provided with a rotary encoder (not shown), and the control unit 80 can detect the rotation direction, rotation amount, and rotation speed of each of the motors using this rotary encoder. In other words, the control unit 80 can detect the drive direction, drive amount, and drive speed of each drive object.

[0053] The control unit 80 controls the power supply unit 94. The power supply unit 94 supplies the necessary power to each component of the liquid ejection device 1 under the control of the control unit 80. The control unit 80 controls the operation panel 95 and also receives information transmitted from the operation panel 95. The operation panel 95 is a part that receives inputs such as powering on / off the liquid ejection device 1, various settings, and recording execution, and can be configured as, for example, a touch panel that realizes a user interface under the control of the control unit 80.

[0054] The control unit 80 includes a CPU 81 that executes a computer program, in other words, software, a volatile memory 82, and a nonvolatile memory 83. The CPU 81 performs various calculations required to execute a program 84 stored in the nonvolatile memory 83. The volatile memory 82 is used as a temporary data storage area. The nonvolatile memory 83 stores the program 84 and control parameters 85 required to execute the program 84. The program 84 includes programs that execute various processes described below, and the control parameters 85 include parameters for executing the program 84. The various processes described below are realized when the control unit 80 executes the program 84.

[0055] The control unit 80 also controls a pump motor 96. The pump motor 96 is a motor for driving a pump (not shown) for creating negative pressure inside the cap 9a (see FIGS. 1 and 2). When the pump motor 96 operates with the cap 9a in close contact with the head surface 12a of the line head 12, negative pressure is created inside the cap 9a, and ink is sucked from the nozzles 13.

[0056] The control unit 80 also controls a wiper movement motor 92. The wiper movement motor 92 is a drive source for the wiper carriage 45 (see FIG. 4). The wiper carriage 45 is movable along the Y-axis direction, and receives power from the wiper movement motor 92 to move along the Y-axis direction. The wiper carriage 45 is provided with a wiper 46. The wiper 46 is made of an elastic material such as rubber, and wipes the head surface 12a by the wiper carriage 45 moving in the Y-axis direction while in elastic contact with the head surface 12a. The wiper carriage 45 is normally on standby at the end in the +Y direction.

[0057] The cleaning operation of the line head 12 will be outlined below. The cleaning operation of the line head 12 includes a flushing process, a wiping process, and a suction process. The flushing process is a process in which the cap 9a is placed in an opposing position and a predetermined amount of ink is ejected from all the nozzles 13 onto the cap 9a, regardless of the printing operation. The wiping process is a process of wiping the head surface 12a of the line head 12 with the wiper 46 described above. The suction process is a process of sucking ink from the nozzles 13 by driving the pump motor 96 with the cap 9a in close contact with the head surface 12a of the line head 12.

[0058] The cleaning operation can be performed by any one of the above-mentioned flushing process, wiping process, and suction process, or by appropriately combining two or more of them. Furthermore, the cleaning strength of the cleaning operation can be changed. For example, the flushing process can be made stronger by increasing the amount of ink ejected at one time. Similarly, the suction process can be made stronger by increasing the suction time at one time. As an example, the cleaning operation can be set to five levels of cleaning strength: CL0, CL1, CL2, CL3, and CL4. Of these, CL0 is the weakest cleaning strength, and the cleaning strength increases from CL0 to CL4, with CL4 being the strongest cleaning strength. However, the cleaning strength is not limited to five levels, and may be set to two, three, four, or six or more levels. Furthermore, CL0 requires the shortest time for cleaning, and the time required for cleaning increases from CL0 to CL4, with CL4 requiring the longest time for cleaning.

[0059] For example, CL0 performs only flushing processing, while CL1, CL2, CL3, and CL4 perform all of flushing, wiping, and suction processing, but the suction processing time increases from CL1 to CL4. However, this is just one example, and the cleaning operation for determining the cleaning strength may be other appropriate contents.

[0060] Next, we will explain the nozzle check process, which checks the ink discharge status from the nozzles 13 and extracts nozzles 13 that are in a discharge failure state. The cleaning operation described above may be performed based on the results of the nozzle check process. For example, if the result of the nozzle check process shows that the number of nozzles in a discharge failure state is greater than a set number, a cleaning operation is performed.

[0061] The nozzle check process is performed by a nozzle inspection unit (not shown) that includes a vibration detection circuit (not shown) that detects the back electromotive force signal of a piezoelectric element (not shown) based on the pressure vibrations that occur in the ink in a pressure chamber (not shown) in the line head 12, in other words, the residual vibrations, and a judgment circuit (not shown) that judges whether the ink is being ejected poorly in the nozzle 13 from the back electromotive force signal. Here, in the case of a faulty nozzle, where ink is not ejected properly from the nozzle 13, the pressure vibrations generated in the ink inside the pressure chamber after the piezoelectric element is driven will be different from those in normal cases. That is, in the case of a faulty nozzle, the back electromotive force signal detected by the vibration detection circuit will be different from that in normal cases, making it possible to detect a faulty nozzle. Causes of nozzle ejection failure include the inclusion of air bubbles, increased ink viscosity, and the adhesion of paper dust, and when these occur, the pressure vibrations will be different from those in normal cases. The inspection results obtained by the nozzle inspection unit are sent to the control unit 80. The control unit 80 then counts the number of nozzles with ejection defects based on the inspection results sent to it.

[0062] Note that either the vibration detection circuit or the determination circuit, or both, may be included as part of the control unit 80. In this case, the control unit 80 functions as a nozzle inspection unit. The nozzle inspection unit is not limited to the above configuration, and various other configurations may be employed. For example, an electric field may be formed between the head surface 12a and a detection surface (not shown) facing the head surface 12a, and a change over time in the voltage value of the detection surface due to electrostatic induction when ink flies from the nozzles 13 toward the detection surface may be detected to detect a nozzle with a defective ejection function. Furthermore, a camera may be provided to capture images of ink being ejected from the nozzles 13, and a defective ejection nozzle may be detected based on the image of ink flying captured by the camera.

[0063] When the nozzle check process is performed, ink is ejected from all of the nozzles 13. Therefore, it can be said that the nozzle check process also serves as the cleaning operation at the cleaning strength CL0 described above.

[0064] Next, the power supply modes of the liquid ejection device 1 will be described. The liquid ejection device 1 can be switched between a normal mode and a sleep mode as a device state controlled by the control unit 80. The normal mode is a mode in which the power necessary for printing by the line head 12 and the above-mentioned cleaning operation is supplied. The sleep mode is a mode in which the power necessary for printing by the line head 12 is not supplied, and is a mode that consumes less power than the normal mode. The name of the sleep mode may also be referred to as the standby mode, the power saving mode, etc.

[0065] In normal mode, the necessary power is supplied to each part of the liquid ejection device 1, and all functions of the liquid ejection device 1 operate normally. In sleep mode, power is supplied to some sensors and the control unit 80, and power is not supplied to others. In sleep mode, power is not supplied to the light-emitting elements (not shown) of the operation panel 95, and the operation panel 95 is turned off, but touch operations can be detected. When the print standby state has elapsed for a predetermined time, the control unit 80 performs processing to transition from the normal mode to the sleep mode. The predetermined time can be set by the user via the operation panel 95.

[0066] Next, the user of the liquid ejection device 1 can set the timing for performing the cleaning operation of the line head 12 via the operation panel 95. Specifically, the user can set the cleaning operation to either "perform" or "not perform" at each of the following timings 1 to 5. Note that timing 3, "when power is turned on," also includes when returning from sleep mode. The setting to "perform" the cleaning operation can be set not only at one of the timings 1 to 5 below, but also at multiple timings. Timing 1. Before printing Timing 2: After printing Timing 3: After power-on Timing 4. User-defined time Timing 5. Before transition to sleep mode

[0067] However, cleaning operations are not necessarily performed at each of the above timings; rather, a nozzle check process is performed at each of the above timings, and cleaning operations are performed depending on the results. Specifically, if the result of the nozzle check process shows that the number of nozzles in a discharge failure state is greater than a set number, the liquid ejection device 1 performs a cleaning operation. The liquid ejection device 1 then accepts the user's setting of the number of nozzles via the operation panel 95. Furthermore, even if there is a nozzle with a discharge defect, it may be possible for other nozzles to compensate for it, but if there are many nozzles with a discharge defect, compensation will not be possible, and as a result, some dots will not be formed. Therefore, in a configuration where even if there is a nozzle with a discharge defect, it is possible for other nozzles to compensate for it, the "number of nozzles with a discharge defect" can also be rephrased as the "number of nozzles that cannot be compensated for by other nozzles."

[0068] If the result of the nozzle check process indicates that the number of nozzles with ejection defects is equal to or greater than the number of nozzles set by the user, the control unit 80 executes a cleaning operation. However, even if the number of nozzles with ejection problems is equal to or greater than the number of nozzles set by the user, there are cases in which the cleaning operation is not performed. This will be explained below.

[0069] Some users prioritize quick print completion over print quality, i.e., they dislike waiting time more than the degradation of print quality when printing, such as when printing text that does not contain images. Here, a setting that performs cleaning before printing, as in timing 1, or a setting that performs cleaning when the power is turned on, as in timing 3, will make the user wait, which goes against user needs. Also, a setting that performs cleaning after printing, as in timing 2, will make the user who sent the print job wait if another print job is received while printing is in progress, which goes against user needs.

[0070] Furthermore, in a setting such as timing 5 where cleaning is performed before transitioning to sleep mode, a print job may be entered at a time when the cleaning operation cannot be canceled, such as immediately before transitioning to sleep mode or when the cleaning operation begins. In this case, the user who sent the print job will be kept waiting, which goes against user needs. Furthermore, if the user sets the time for timing 5, for example, at a time during the night when the liquid ejection device 1 is hardly used, there is little chance that the user will have to wait. However, if timing 5 is selected as the only time to perform the cleaning operation, the frequency of cleaning will decrease, which may result in a drastic deterioration in print quality. The embodiments described below aim to reduce the waiting time for the user when a cleaning operation is performed before transitioning to the sleep mode.

[0071] <<First Example>> The process of determining whether or not to perform the cleaning operation before transitioning to the sleep mode will be described below. In FIG. 5, when the print standby state has elapsed for a set time (Yes in step S101), the control unit 80 performs a nozzle check process (step S102). As a result, if the number of ejection-failed nozzles is less than the set value (No in step S103), the control unit 80 performs a process for transitioning to sleep mode (step S106).

[0072] If the nozzle check process results in the number of nozzles with ejection failure being equal to or greater than the set value (Yes in step S103), the control unit 80 determines whether the execution conditions for the pre-sleep mode cleaning operation are met (step S104). These execution conditions will be described in detail later. If the execution conditions for the pre-sleep mode cleaning operation are met (Yes in step S104), the control unit 80 executes the pre-sleep mode cleaning operation (step S105), and then performs the sleep mode transition process (step S106).

[0073] In this way, the control unit 80 determines whether or not to perform the pre-sleep mode cleaning operation, which is a cleaning operation performed when transitioning to sleep mode, depending on the conditions for performing the pre-sleep mode cleaning operation. This reduces the waiting time that the user has to wait due to the pre-sleep mode cleaning operation, compared to when the pre-sleep mode cleaning operation is performed uniformly when transitioning to sleep mode.

[0074] The execution conditions for step S104 will be explained below. The above-mentioned execution conditions may include the availability of the liquid ejection device 1. FIG. 6 shows an example of the usage time and operation rate for each time period of the liquid ejection device 1. When the control unit 80 receives a print job, it stores the start time and end time of the print job in non-volatile memory 83 (see FIG. 3). Then, at a predetermined timing, such as when the date changes, the control unit 80 calculates the usage time and operation rate for each time period as shown in FIG. 6 and stores these in non-volatile memory 83 (see FIG. 3). The start time of the print job can be set as appropriate, and the time when the print data is received can be used as an example. The end time of the print job can also be set as appropriate, and the time when the trailing edge of the last medium in the print job passes the media detection sensor furthest downstream in the media transport path can be used as an example. The time period settings shown in FIG. 6 are merely an example, and the number of divisions into the time period may be increased or, conversely, decreased. The usage time may also include the time it takes for the user to replenish the medium when the paper runs out, or the time it takes for the user to replenish the ink when the ink runs out.

[0075] As shown in Figure 6, the operating rate of the liquid ejection device 1 varies depending on the time of day. In particular, the operating rate is high during the daytime and low during the late night hours and at noon. If an attempt is made to perform a cleaning operation before transitioning to sleep mode during a time when the operating rate is high, a print job may be received at a time when the cleaning operation cannot be canceled, such as immediately before transitioning to sleep mode or when the cleaning operation begins. In this case, the user who sent the print job will be kept waiting, which goes against the user's needs.

[0076] In light of this, in this embodiment, the execution conditions for step S104 include the operation rate. The control unit 80 according to this embodiment executes the pre-sleep mode cleaning operation when the operation rate is a first operation rate, and does not execute the pre-sleep mode cleaning operation when the operation rate is a second operation rate that is higher than the first operation rate. This effectively prevents the user from having to wait for the pre-sleep mode cleaning operation. It should be noted that the first and second operating rates are relative to each other. For example, if the operating rate of 1.9% in the 8:00 a.m. time slot in FIG. 6 is the first operating rate, then the operating rate of 22.5% in the 10:00 a.m. time slot is the second operating rate.

[0077] Alternatively, a threshold value may be set for the operation rate, and if the operation rate falls below the threshold value, the pre-sleep mode cleaning execution condition is deemed satisfied and the pre-sleep mode cleaning operation is executed. In this case, the threshold value may be set, for example, between the time periods with the highest operation rates and the time period just below them. For example, in the example of Figure 6, if the top three operation rates are between 9:00, 10:00, and 11:00, and the 12:00 hour is the fourth-highest operation rate, the threshold value may be set to 14.2, which is the midpoint between the operation rates between 9:00 and 13:00. Such threshold setting can be performed by the control unit 80. The threshold value may be set by the user via the operation panel 95. In this case, operation rate data such as that shown in FIG. 6 is preferably a moving average of the past few days. In this case, days when the operating rate is lower than a predetermined value throughout the day, such as holidays, may be excluded from the moving average.

[0078] <<Modification of the First Embodiment>> In the above embodiment, the execution conditions for step S104 include the availability rate of the liquid ejection device 1, but the execution conditions may also include the number of external terminals that are powered on. 7 shows, as an example, a state in which external terminals 201, 202, 203, 204, 205, and 206 are connected to a network NW to which the liquid ejection device 1 is connected. Of these, the external terminals 201, 202, 203, 204, and 205 are in a power-on state, and the external terminal 206 is in a power-off state. The control unit 80 of the liquid ejection device 1 can grasp the number of external terminals that are in a power-on state by searching the network.

[0079] The control unit 80 may perform a cleaning operation before transition to sleep mode when the number of powered-on external terminals is a first number of terminals, and may not perform the cleaning operation before transition to sleep mode when the number of powered-on external terminals is a second number of terminals that is greater than the first number of terminals. This makes it possible to preferably reduce waiting times for the user caused by the cleaning operation before transition to sleep mode. The first number of terminals and the second number of terminals are relative to each other. For example, if the first number of terminals is "1," the cleaning operation before transitioning to sleep mode is performed, and if the second number of terminals is "10," the cleaning operation before transitioning to sleep mode is not performed. Alternatively, a threshold value related to the number of external terminals in a powered-on state may be set, and when the number of external terminals in a powered-on state falls below the threshold value, it may be determined that the pre-sleep mode cleaning execution condition has been met and the pre-sleep mode cleaning operation may be executed. Furthermore, such a threshold value may be set by the user via the operation panel 95.

[0080] In the first embodiment, the cleaning strength when performing the cleaning operation before transition to the sleep mode may be any of the above-mentioned CL0, CL1, CL2, CL3, and CL4.

[0081] <<Second Example>> In the first embodiment described above, whether or not to perform the cleaning operation before transitioning to sleep mode is determined based on the execution conditions, but instead of or in addition to this, the execution content of the cleaning operation before transitioning to sleep mode may be determined based on the execution conditions. In the process shown in FIG. 8, steps S201, S202, S203, S205, and S206 are similar to steps S101, S102, S103, S105, and S106 described above, and therefore, redundant explanations will be avoided below. This embodiment is characterized in that the cleaning strength is determined based on the execution conditions (step S204). According to this embodiment, the time required for the cleaning operation before shifting to the sleep mode can be shortened in some cases compared to when the cleaning operation before shifting to the sleep mode is uniformly performed with the same intensity, thereby shortening the waiting time for the user.

[0082] As in the first embodiment, the operation rate of the liquid ejection device 1 can be used as the execution condition. When the operation rate is a first operation rate, the control unit 80 executes the pre-sleep mode cleaning operation at a first intensity, and when the operation rate is a second operation rate higher than the first operation rate, the control unit 80 executes the pre-sleep mode cleaning operation at a second intensity weaker than the first intensity. The cleaning operation at the second intensity takes less time than the cleaning operation at the first intensity. This effectively reduces the user's waiting time caused by the pre-sleep mode cleaning operation. The first and second operating rates have a relative relationship. For example, if the operating rate of 1.9% in the 8:00 am hour in Figure 6 is the first operating rate, then the operating rate of 22.5% in the 10:00 am hour is the second operating rate. The first intensity and second intensity also have a relative relationship.

[0083] The cleaning strength is one of the above-mentioned CL0, CL1, CL2, CL3, and CL4. In this case, it is preferable to divide the operation rate into regions and assign a cleaning strength to each region. For example, if the operation rate is 20% or more, the cleaning strength is CL1, and if the operation rate is 15% or more but less than 20%, the cleaning strength is CL2. Also, if the operation rate is 10% or more but less than 15%, the cleaning strength is CL3, and if the operation rate is less than 10%, the cleaning strength is CL4. However, this is just an example, and the region division of the operation rate and the corresponding cleaning strength can be set as appropriate. The cleaning strength corresponding to the operating rate range may be set by the user via the operation panel 95. In this case, operating rate data such as that shown in FIG.

[0084] <<Modification of the Second Embodiment>> In the above embodiment, the execution conditions for step S204 include the availability of the liquid ejection device 1, but the execution conditions may also include the number of external terminals that are powered on. The external terminals are the same as those described with reference to FIG.

[0085] The control unit 80 may perform the pre-sleep mode cleaning operation at a first intensity when the number of powered-on external terminals is a first terminal number, and may perform the pre-sleep mode cleaning operation at a second intensity that is weaker than the first intensity when the number of powered-on external terminals is a second terminal number that is greater than the first terminal number. This makes it possible to suitably shorten the user's waiting time caused by the pre-sleep mode cleaning operation. The first number of terminals and the second number of terminals have a relative relationship, and the first intensity and the second intensity also have a relative relationship.

[0086] Specifically, it is preferable to divide the number of powered-on external terminals into regions and assign a cleaning intensity to each region. For example, if the number of powered-on external terminals is 20 or more, the cleaning intensity is set to CL1, and if the number of powered-on external terminals is 15 or more but less than 20, the cleaning intensity is set to CL2. Also, if the number of powered-on external terminals is 10 or more but less than 15, the cleaning intensity is set to CL3, and if the number of powered-on external terminals is less than 10, the cleaning intensity is set to CL4. However, this is just an example, and the number of powered-on external terminals and the corresponding cleaning intensity can be set as appropriate. The cleaning strength according to the number of external terminals that are turned on may be set by the user via the operation panel 95. In this case, operation rate data such as that shown in FIG. 6 may be presented to the user.

[0087] <<Third Example>> The third embodiment will be described below with reference to Fig. 9. In the process shown in Fig. 9, steps S301, S302, S304, S305, and S306 are the same as steps S101, S102, S103, S105, and S106 described above, and therefore, redundant description will be avoided below. This embodiment is characterized in that the control unit 80 changes the set value for the number of ejection-failure nozzles in accordance with the execution conditions (step S303). According to this embodiment, compared to when the pre-sleep mode cleaning operation is performed uniformly according to the same set value, it is possible to reduce the waiting time that the user has to wait due to the pre-sleep mode cleaning operation.

[0088] As in the first embodiment, the operation rate of the liquid ejection device 1 can be used as the execution condition. The control unit 80 can set the setting value to a first value when the operation rate is a first operation rate, and can set the setting value to a second value higher than the first value when the operation rate is a second operation rate higher than the first operation rate. This can suitably prevent the user from having to wait due to the cleaning operation before transitioning to sleep mode. The first and second operating rates have a relative relationship. For example, if the operating rate of 1.9% in the 8:00 am hour in Figure 6 is the first operating rate, then the operating rate of 22.5% in the 10:00 am hour would be the second operating rate. The first and second values ​​also have a relative relationship.

[0089] Specifically, it is preferable to divide the operation rate into regions and assign a setting value to each region. For example, if the operation rate is 20% or higher, the setting value is "4," and if the operation rate is 15% or higher but less than 20%, the setting value is "3." If the operation rate is 10% or higher but less than 15%, the setting value is "2," and if the operation rate is less than 10%, the setting value is "1." However, this is just an example, and the region division of the operation rate and the corresponding setting values ​​can be set as appropriate. The set value corresponding to the operation rate region may be set by the user via the operation panel 95. In this case, operation rate data such as that shown in FIG. The setting value according to the availability range may also be set for each print quality. For example, it is preferable to set a higher setting value for "normal" print quality than for "high quality."

[0090] <<Modification of the Third Embodiment>> In the above embodiment, the execution conditions for step S303 include the availability of the liquid ejection device 1, but the execution conditions may also include the number of external terminals that are powered on. The external terminals are the same as those described with reference to FIG. The control unit 80 may set the setting value to a first value when the number of powered-on external terminals is a first number of terminals, and may set the setting value to a second value higher than the first value when the number of powered-on external terminals is a second number of terminals that is greater than the first number of terminals. This makes it possible to suitably prevent the user from having to wait for a while due to the cleaning operation before transitioning to sleep mode. The first number of terminals and the second number of terminals have a relative relationship, and the first value and the second value also have a relative relationship.

[0091] Specifically, it is preferable to divide the number of powered-on external terminals into ranges and assign a setting value to each range. For example, if the number of powered-on external terminals is 20 or more, the setting value is "4," and if the number of powered-on external terminals is 15 or more but less than 20, the setting value is "3." Also, if the number of powered-on external terminals is 10 or more but less than 15, the setting value is "2," and if the number of powered-on external terminals is less than 10, the setting value is "1." However, this is just an example, and the number of powered-on external terminals and the corresponding setting value can be set as appropriate. The set value according to the number of external terminals in a power-on state may be set by the user via the operation panel 95. In this case, operation rate data such as that shown in FIG. 6 may be presented to the user. The setting value according to the number of external terminals in the power-on state may also be set for each print quality. For example, it is preferable to set a higher setting value for "normal" print quality than for "high quality."

[0092] In the first and second embodiments, the pre-sleep mode cleaning operation is performed based on the results of the nozzle check process (steps S102, S103, S202, and S203), but the pre-sleep mode cleaning operation may also be performed based only on the execution conditions for the pre-sleep mode cleaning. In other words, steps S102 and S103 in Fig. 5 and steps S202 and S203 in Fig. 8 may be omitted.

[0093] Furthermore, while the above-described embodiments are directed to control of the cleaning operation before transition to sleep mode, control of the cleaning operation after printing, for example, may also be performed in a similar manner. In other words, the above-described term "cleaning operation before transition to sleep mode" may all be rephrased as "cleaning operation after printing."

[0094] The present invention is not limited to the embodiments and modifications 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 within the scope of the present invention. [Explanation of symbols]

[0095] 1...liquid ejection device, 2...device main body, 3...first medium cassette, 4...second medium cassette, 5...third medium cassette, 6...fourth medium cassette, 8...discharge tray, 9...cap unit, 9a...cap, 10A, 10B...ink storage section, 11...waste liquid storage section, 12...line head, 13...nozzle, 19...feed roller pair, 21, 22, 23, 24...pick roller, 25, 26, 27, 28...feed roller pair, 29-42...transport roller pair, 45...wiper carriage, 46...wiper, 52...Belt unit, 53...Conveyor belt, 54...First roller, 55...Second roller, 80...Control unit, 81...CPU, 82...Volatile memory, 83...Non-volatile memory, 84...Program, 85...Control parameters, 87...Feed motor, 88...Conveyor motor, 89...Belt rotation motor, 90...Belt movement motor, 91...Cap movement motor, 92...Wiper movement motor, 93...Head movement motor, 94...Power supply unit, 95...Operation panel, 96...Pump motor

Claims

1. a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; a control unit that controls the liquid ejection unit; Equipped with The control unit an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, Furthermore, the control unit determines whether or not to execute the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode, depending on an execution condition of the pre-sleep mode cleaning operation. A liquid ejection device characterized by:

2. The liquid ejection device according to claim 1 , the control unit is capable of acquiring information relating to the availability rate of the device, the execution conditions include the availability rate; The control unit If the operation rate is a first operation rate, the pre-sleep mode cleaning operation is performed; When the operation rate is a second operation rate that is higher than the first operation rate, the pre-sleep mode cleaning operation is not executed. A liquid ejection device characterized by:

3. The liquid ejection device according to claim 1 , the execution conditions include the number of external terminals that are connected to the liquid ejection device and are in a power-on state; The control unit If the number of the external terminals in the power-on state is a first number of terminals, the cleaning operation before transitioning to the sleep mode is performed; When the number of the external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, the pre-sleep mode cleaning operation is not executed. A liquid ejection device characterized by:

4. a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; a control unit that controls the liquid ejection unit; Equipped with The control unit an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, Furthermore, the control unit determines the intensity of the pre-sleep mode cleaning operation in accordance with an execution condition of the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode. A liquid ejection device characterized by:

5. 5. The liquid ejection device according to claim 4, the control unit is capable of acquiring information relating to the availability rate of the device, the execution conditions include the availability rate; The control unit If the operation rate is a first operation rate, the pre-sleep mode cleaning operation is performed at a first intensity; When the operation rate is a second operation rate that is higher than the first operation rate, the pre-sleep mode cleaning operation is performed at a second intensity that is weaker than the first intensity. A liquid ejection device characterized by:

6. 5. The liquid ejection device according to claim 4, the execution conditions include the number of external terminals that are connected to the liquid ejection device and are in a power-on state; The control unit When the number of the external terminals in the power-on state is a first number of terminals, the pre-sleep mode cleaning operation is performed at a first intensity; When the number of the external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, the pre-sleep mode cleaning operation is performed at a second intensity that is weaker than the first intensity. A liquid ejection device characterized by:

7. a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; a control unit that controls the liquid ejection unit; Equipped with The control unit an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, Furthermore, the control unit executes a nozzle check process to detect defective nozzles among the plurality of nozzles, and executes the cleaning operation when the number of defective nozzles is equal to or greater than a set value. Furthermore, the control unit changes the set value in accordance with an execution condition of a pre-sleep mode cleaning operation, which is the cleaning operation when the printer is switched to the sleep mode. A liquid ejection device characterized by:

8. 8. The liquid ejection device according to claim 7, the control unit is capable of acquiring information relating to the availability rate of the device, the execution conditions include the availability rate; The control unit When the operation rate is a first operation rate, the set value is set to a first value; When the operation rate is a second operation rate that is higher than the first operation rate, the set value is set to a second value that is higher than the first value. A liquid ejection device characterized by:

9. 8. The liquid ejection device according to claim 7, the execution conditions include the number of external terminals that are connected to the liquid ejection device and are in a power-on state; The control unit When the number of the external terminals in the power-on state is a first number of terminals, the setting value is set to a first value; When the number of the external terminals in the power-on state is a second number of terminals that is greater than the first number of terminals, the setting value is set to a second value that is higher than the first value. A liquid ejection device characterized by:

10. A method for controlling a liquid ejection device, comprising: The liquid ejection device a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; Equipped with Furthermore, the liquid ejection device an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, The control method includes a step of determining whether or not to execute a pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode, according to an execution condition of the pre-sleep mode cleaning operation. A method for controlling a liquid ejection device.

11. A method for controlling a liquid ejection device, comprising: The liquid ejection device a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; Equipped with Furthermore, the liquid ejection device an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, The control method includes a step of determining content of a pre-sleep mode cleaning operation in accordance with an execution condition of the pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode. A method for controlling a liquid ejection device.

12. A method for controlling a liquid ejection device, comprising: The liquid ejection device a liquid ejection unit having a plurality of nozzles that eject liquid onto a medium; a cap that is switchable between an opposed state in which it faces the nozzle and a separated state in which it is separated from the nozzle; Equipped with Furthermore, the liquid ejection device an operation mode that is a power supply mode when performing a cleaning operation of the liquid ejection unit; a sleep mode, which is a power supply mode in which power consumption is lower than that in the operation mode; is executable, Furthermore, the liquid ejection device is capable of executing a nozzle check process to detect ejection-failed nozzles among the plurality of nozzles, and executing the cleaning operation when the number of the ejection-failed nozzles is equal to or greater than a set value; The control method includes a step of changing the set value in accordance with an execution condition of a pre-sleep mode cleaning operation, which is the cleaning operation when transitioning to the sleep mode. A liquid ejection device characterized by:

Images