Liquid ejection device and method for controlling liquid ejection device

Abstract

To provide a liquid discharge device for efficiently reducing a liquid to be consumed and a control method of the liquid discharge device.SOLUTION: A liquid discharge device includes: a liquid discharge unit 21 for printing by discharging a liquid from a nozzle 20 to a medium 15; a maintenance unit 18 for performing maintenance of the liquid discharge unit 21; a determination unit for determining whether a printing mode is a rule mark mode which includes a vertical rule mark or a non-rule mark mode which does not include the vertical rule mark; a storage unit for storing a determination result by the determination unit; and a control unit. The control unit varies intensity of the maintenance depending on the frequency of the rule mark mode included in the determination result stored in the storage unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device such as a printer, and a method for controlling a liquid ejection device. [Background technology]

[0002] For example, Patent Document 1 discloses a printer, which is an example of a liquid ejection device, that ejects droplets from nozzle openings provided in a recording head, which is an example of a liquid ejection unit, to print on a medium. The liquid is exposed to air at the nozzle openings. As a result, the solvent components of the liquid near the nozzle openings are prone to evaporating. When the solvent components evaporate and the viscosity of the liquid increases, the landing position on the medium shifts. In particular, when printing ruled lines along the transport direction while moving the recording head in the main scanning direction, if the landing position of the droplets shifts, the ruled lines will be printed out of alignment.

[0003] The viscosity of the liquid can be maintained at an appropriate level by performing flushing, which forcibly ejects droplets of liquid. However, since this consumes a large amount of liquid, the printer in Patent Document 1 reduces the amount of liquid consumed by reducing the amount of liquid ejected from some nozzle openings depending on the recording mode. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-106394 Summary of the Invention [Problem to be solved by the invention]

[0005] The printer of Patent Document 1 only changes the ejection amount by flushing partially, so the reduction in liquid consumption is limited. [Means for solving the problem]

[0006] A liquid ejection device that solves the above problem comprises a liquid ejection unit that prints by ejecting liquid from nozzles onto a medium, a maintenance unit for performing maintenance on the liquid ejection unit, a discrimination unit that determines whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines, a memory unit that stores the discrimination results by the discrimination unit, and a control unit, wherein the control unit changes the intensity of the maintenance depending on the frequency of the ruled line mode included in the discrimination results stored in the memory unit.

[0007] A control method for a liquid ejection device that solves the above problem is a control method for a liquid ejection device that includes a liquid ejection unit that prints by ejecting liquid from nozzles onto a medium, a maintenance unit that performs maintenance on the liquid ejection unit, a discrimination unit that determines whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines, and a memory unit that stores the discrimination results made by the discrimination unit, and changes the intensity of the maintenance depending on the frequency of the ruled line mode included in the discrimination results stored in the memory unit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a first embodiment of a liquid ejection device. [Figure 2] FIG. 2 is a block diagram of a control unit included in the liquid ejection device. [Figure 3] 10 is a flowchart showing a determination routine. [Figure 4] 10 is a flowchart showing a setting routine. [Figure 5] 10 is a flowchart showing a setting routine according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] A first embodiment of a liquid ejection device and a method for controlling the liquid ejection device will be described below with reference to the drawings. The liquid ejection device is an inkjet printer that prints by ejecting ink, which is an example of a liquid, onto a medium such as paper, fabric, vinyl, plastic parts, or metal parts.

[0010] <Liquid discharge device> In the drawings, the liquid ejection device 11 is placed on a horizontal plane, with the direction of gravity indicated by the Z axis, and directions along the horizontal plane indicated by the X and Y axes. The X, Y, and Z axes are perpendicular to one another. In this embodiment, an increase in the viscosity of the liquid is also referred to as thickening.

[0011] 1, the liquid ejection device 11 may include a housing 12, a guide shaft 13, and a printing unit 14. The liquid ejection device 11 may also include a medium support unit 16 that supports a medium 15, a conveyance unit 17, and a maintenance unit 18.

[0012] The guide shaft 13 may be supported by the housing 12 . The printing unit 14 may be provided so as to be movable along the guide shaft 13. The printing unit 14 includes a liquid ejection unit 21 having a plurality of nozzles 20. The printing unit 14 may also include a carriage 22. The carriage 22 moves the liquid ejection unit 21 back and forth along the guide shaft 13. The liquid ejection unit 21 is movable in a first main scanning direction Dm1 and a second main scanning direction Dm2 opposite to the first main scanning direction Dm1. In this embodiment, the first main scanning direction Dm1 and the second main scanning direction Dm2 are parallel to the X-axis.

[0013] The carriage 22 may move with a liquid container 23 mounted thereon. The liquid container 23 supplies the stored liquid to the liquid ejection unit 21. The liquid ejection unit 21 performs printing by ejecting the liquid from the nozzles 20 onto the medium 15. The liquid ejection unit 21 performs printing by ejecting the liquid while moving in the first main scanning direction Dm1 or the second main scanning direction Dm2.

[0014] The medium support unit 16 is provided at a position facing the liquid ejection unit 21, which moves in the first main scanning direction Dm1 and the second main scanning direction Dm2. The medium support unit 16 supports the portion of the medium 15 that is to be printed by the liquid ejection unit 21.

[0015] The transport unit 17 transports the medium 15 along a transport path (not shown). The transport path may be curved. The transport unit 17 transports the portion of the medium 15 supported by the medium support unit 16 in the sub-scanning direction Ds. In this embodiment, the sub-scanning direction Ds is parallel to the Y axis. In other words, the sub-scanning direction Ds is a direction perpendicular to the first main scanning direction Dm1 and the second main scanning direction Dm2.

[0016] The transport unit 17 may include a drive source 25 and rollers 26. The drive source 25 is, for example, a motor that rotates the rollers 26. The rollers 26 transport the medium 15 by rotating. The rollers 26 may be provided at a position different from the medium support unit 16 in the sub-scanning direction Ds. Multiple rollers 26 may be provided on either side of the medium support unit 16 in the sub-scanning direction Ds.

[0017] The transport unit 17 transports the medium 15 at the timing when the reciprocating liquid discharge unit 21 turns around. The length of the medium 15 transported by the transport unit 17 at one time is equal to the length printed by the liquid discharge unit 21 in one movement. The liquid discharge device 11 is a serial type that prints on the medium 15 by alternately performing printing by the liquid discharge unit 21 and transport by the transport unit 17.

[0018] The maintenance unit 18 performs maintenance on the liquid discharge unit 21. The maintenance unit 18 may have a wiping unit 28 and a cleaning unit 29. The cleaning unit 29 may have a liquid receiving unit 30, a suction mechanism 31, and a waste liquid storage unit 32. The suction mechanism 31 may have a discharge path 33 and a discharge pump 34.

[0019] The wiping unit 28 is provided so as to be movable between a wiping position where it can wipe the liquid discharge unit 21 and a non-wiping position where it does not come into contact with the liquid discharge unit 21. The wiping unit 28 positioned at the wiping position comes into contact with the moving liquid discharge unit 21, thereby wiping the liquid discharge unit 21. Maintenance in which the wiping unit 28 wipes the liquid discharge unit 21 is also called wiping.

[0020] The discharge path 33 connects the liquid receiving portion 30 and the waste liquid storage portion 32. The upstream end of the discharge path 33 is connected to the liquid receiving portion 30, and the downstream end is connected to the waste liquid storage portion 32. The discharge path 33 may be formed of a tube that deforms in accordance with the movement of the liquid receiving portion 30.

[0021] The discharge pump 34 may be provided midway along the discharge path 33. The discharge pump 34 sends the liquid in the liquid receiving portion 30 to the waste liquid storage portion 32. The waste liquid storage section 32 stores the liquid sent from the liquid receiving section 30 as waste liquid.

[0022] The liquid receiving portion 30 receives the liquid discharged from the liquid ejection portion 21. The liquid receiving portion 30 is provided so as to be movable between a capping position shown in FIG. 1 and a spaced position (not shown). When positioned at the capping position, the liquid receiving portion 30 comes into contact with the liquid ejection portion 21. When positioned at the capping position, the liquid receiving portion 30 forms a closed space surrounding the nozzle 20 between itself and the liquid ejection portion 21.

[0023] The maintenance of forming a closed space between the liquid receiving portion 30 and the liquid discharge portion 21 is also called capping. The liquid receiving portion 30 located at the capping position caps the liquid discharge portion 21 located at the home position. The liquid receiving portion 30 opens the closed space by moving from the capping position to the separated position.

[0024] The suction mechanism 31 sucks the liquid from the nozzle 20 via the liquid receiving portion 30 that caps the liquid discharge portion 21. Specifically, the suction mechanism 31 drives the discharge pump 34 to reduce the pressure inside the closed space and forcibly discharge the liquid from the nozzle 20. The discharged liquid is stored as waste liquid in the waste liquid storage portion 32 via the discharge path 33. Maintenance in which the pressure inside the closed space is reduced to forcibly discharge the liquid from the nozzle 20 is also called suction cleaning. The cleaning portion 29 can perform suction cleaning, which is an example of cleaning in which the liquid is forcibly discharged from the nozzle 20 by using an external force, as maintenance.

[0025] The suction mechanism 31 may drive the discharge pump 34 while the liquid receiving portion 30 is in the separated position to discharge the liquid from the liquid receiving portion 30. Maintenance in which the liquid is forcibly discharged from the liquid receiving portion 30 while the closed space is open is also called empty suction.

[0026] Maintenance in which liquid is discharged from the nozzles 20 by ejection is also called flushing. Maintenance includes flushing in which liquid is ejected from the liquid ejection unit 21 to the liquid receiving unit 30. The liquid receiving unit 30 is capable of receiving the liquid ejected by the liquid ejection unit 21. In the present embodiment, flushing causes the liquid ejection unit 21, which is located at the home position, to eject liquid toward the liquid receiving unit 30, which is located at the separated position.

[0027] <Electrical configuration> 2, the liquid ejection device 11 includes a control unit 36. The control unit 36 ​​controls various components of the liquid ejection device 11, such as the liquid ejection unit 21, the transport unit 17, and the maintenance unit 18.

[0028] The control unit 36 ​​may be configured as a circuit including: α: one or more processors that execute various processes according to a computer program; β: one or more dedicated hardware circuits that execute at least some of the various processes; or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any readable medium that can be accessed by a general-purpose or dedicated computer.

[0029] The control unit 36 ​​has a storage unit 37. The storage unit 37 is, for example, a memory such as the RAM and ROM described above. The storage unit 37 stores various programs and various parameters. The control unit 36 ​​may function as a determination unit 38 by executing a program stored in the storage unit 37. Therefore, it can be said that the liquid ejection device 11 includes a determination unit 38.

[0030] The discrimination unit 38 discriminates whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include vertical ruled lines. The non-ruled line mode may include a document mode that prints document data and a photo mode that prints photo data. The discrimination unit 38 may discriminate whether the printing mode is a document mode or a photo mode. The document mode is printing that includes text, and the photo mode is printing that does not include text.

[0031] Vertical ruled lines are ruled lines that extend in the sub-scanning direction Ds. Vertical ruled lines are ruled lines that are not parallel to the first main scanning direction Dm1, and include ruled lines that are parallel to the sub-scanning direction Ds and ruled lines that are inclined with respect to both the first main scanning direction Dm1 and the sub-scanning direction Ds. The length of a vertical ruled line in the sub-scanning direction Ds is longer than the length that can be printed by the liquid ejection unit 21 in a single movement. The liquid ejection unit 21 prints vertical ruled lines by moving one or more times in each of the first main scanning direction Dm1 and the second main scanning direction Dm2. The transport unit 17 transports the medium 15 one or more times while the vertical ruled lines are being printed.

[0032] Characters include, for example, hiragana, katakana, kanji, symbols, Latin letters, Greek letters, Cyrillic letters, and Arabic letters. The discrimination unit 38 may determine that the print mode is document mode if the print data contains character codes, and may determine that the print mode is photo mode if the print data does not contain character codes. In other words, if the print data contains both characters and photos, the discrimination unit 38 may determine that the print mode is document mode.

[0033] Storage unit 37 stores the results of the determination by determination unit 38. Storage unit 37 may store, as the determination results, the number of media 15 printed in ruled line mode and the number of media 15 printed in non-ruled line mode. Storage unit 37 may store, as the determination results, the number of media 15 printed in non-ruled line mode and document mode, and the number of media 15 printed in non-ruled line mode and photo mode.

[0034] Next, a method for controlling the liquid ejection device 11 will be described with reference to the flowcharts shown in FIGS. The determination routine shown in FIG. 3 is executed when printing is performed.

[0035] In step S101, control unit 36 ​​causes discrimination unit 38 to determine whether the executed print includes vertical ruled lines. If vertical ruled lines are included, step S101 becomes YES, and control unit 36 ​​proceeds to step S102. In step S102, control unit 36 ​​adds the number of sheets printed this time to the number of sheets printed in ruled line mode stored in memory unit 37, and ends the process.

[0036] In step S101, if the currently executed printing does not include vertical ruled lines, step S101 becomes NO, and control unit 36 ​​proceeds to step S103. In step S103, control unit 36 ​​adds the number of sheets printed this time to the number of sheets printed in the non-ruled line mode stored in memory unit 37.

[0037] In step S104, control unit 36 ​​causes discrimination unit 38 to determine whether the executed printing is in document mode. If it is in document mode, step S104 becomes YES, and control unit 36 ​​proceeds to step S105. In step S105, control unit 36 ​​adds the number of sheets printed this time to the number of sheets printed in document mode stored in memory unit 37, and ends the process.

[0038] In step S104, if the executed printing is not in document mode, step S104 becomes NO, and control unit 36 ​​proceeds to step S106. In step S106, control unit 36 ​​adds the number of sheets printed this time to the number of sheets printed in photo mode stored in memory unit 37, and ends the process.

[0039] 4 is executed when the number of printed sheets stored in memory unit 37 exceeds a set threshold. That is, the setting routine is executed when the total number of sheets printed in ruled line mode and non-ruled line mode exceeds a set threshold. The set threshold is stored in advance in memory unit 37. The set threshold may be, for example, half the number of sheets that liquid ejection device 11 can print.

[0040] In step S201, the control unit 36 ​​determines whether one or more sheets of media 15 have been printed in ruled line mode. If at least one sheet has been printed in ruled line mode, step S201 becomes YES, and the control unit 36 ​​proceeds to step S202. In step S202, the control unit 36 ​​sets the maintenance intensity to the first intensity and ends the process.

[0041] If there is no medium 15 printed in the ruled line mode, step S201 becomes NO, and the control unit 36 ​​proceeds to step S203. In step S203, the control unit 36 ​​sets the maintenance intensity to the second intensity.

[0042] In step S204, the control unit 36 ​​compares the number of sheets of medium 15 printed in document mode with the number of sheets of medium 15 printed in photo mode. If the number of sheets of medium 15 printed in photo mode is greater than the number of sheets of medium 15 printed in document mode, step S204 becomes YES, and the control unit 36 ​​proceeds to step S205. In step S205, the control unit 36 ​​changes the maintenance intensity setting from the second intensity to the third intensity, and ends the process.

[0043] If the number of media 15 printed in document mode is equal to or greater than the number of media 15 printed in photo mode, step S204 becomes NO, and the control unit 36 ​​ends the process while maintaining the maintenance intensity at the second intensity.

[0044] <Operation of the First Embodiment> The operation of this embodiment will be described. The control unit 36 ​​changes the intensity of maintenance in accordance with the frequency of the ruled line mode included in the determination result stored in the storage unit 37.

[0045] If the determination result includes the ruled line mode, the control unit 36 ​​may perform maintenance at a first intensity. The first intensity may be the same as the intensity of maintenance before the control unit 36 ​​executes the setting routine.

[0046] When the determination result does not include the ruled line mode, the control unit 36 ​​may perform maintenance at a second intensity that is weaker than the first intensity. When the determination result includes a higher frequency of the photo mode than the frequency of the document mode, the control unit 36 ​​may change the intensity of the maintenance performed at the second intensity to a third intensity that is weaker than the second intensity.

[0047] The control unit 36 ​​may change the type of maintenance of the liquid ejection unit 21 depending on the timing of the maintenance. For example, the control unit 36 ​​may perform flushing as maintenance performed before printing. The control unit 36 ​​may perform suction cleaning as maintenance performed periodically.

[0048] The control unit 36 ​​may change the intensity of the maintenance by changing the amount of liquid ejected in one flushing. For example, for flushing at a first intensity, the control unit 36 ​​may set each nozzle 20 to eject a first number of droplets. For flushing at a second intensity, the control unit 36 ​​may set each nozzle 20 to eject a second number of droplets, which is less than the first number. For maintenance at a third intensity, the control unit 36 ​​may set each nozzle 20 to eject a third number of droplets, which is less than the second number.

[0049] The control unit 36 ​​may change the intensity of maintenance by changing the frequency of cleaning. For example, as maintenance of a first intensity, the control unit 36 ​​may perform suction cleaning when a first specified number of media 15 have been printed. As maintenance of a second intensity, the control unit 36 ​​may perform suction cleaning when a second specified number of media 15, which is greater than the first specified number, have been printed. As maintenance of a third intensity, the control unit 36 ​​may perform suction cleaning when a third specified number of media 15, which is greater than the second specified number, have been printed.

[0050] <Effects of the first embodiment> The effects of this embodiment will be described. (1) The control unit 36 ​​changes the intensity of maintenance depending on the frequency of the ruled line mode. The ruled line mode, which includes vertical ruled lines, requires higher dispensing accuracy than the non-ruled line mode, which does not include vertical ruled lines. Therefore, by performing maintenance as needed, it is possible to efficiently reduce the amount of liquid consumed.

[0051] (2) If the determination result does not include the ruled line mode, the control unit 36 ​​performs maintenance at a second intensity that is weaker than the first intensity, thereby reducing the amount of liquid that is wasted.

[0052] (3) If the frequency of photo mode is higher than the frequency of document mode among the non-ruled line modes included in the determination result, the control unit 36 ​​performs maintenance at a third intensity that is weaker than the second intensity. When printing a photo, a larger amount of liquid is used for printing than when printing a document, and the viscosity of the liquid in the liquid discharge unit 21 is less likely to increase. Therefore, by performing maintenance at the third intensity, it is possible to reduce the amount of liquid that is wasted.

[0053] (4) The liquid discharger 21 discharges the liquid with increased viscosity by flushing. The controller 36 changes the intensity of the maintenance by changing the amount of liquid discharged in one flushing. Therefore, the intensity of the maintenance can be easily changed.

[0054] (5) The cleaning unit 29 performs suction cleaning to remove liquid with increased viscosity and foreign matter such as air bubbles from the liquid discharge unit 21. The control unit 36 ​​changes the frequency of suction cleaning to change the intensity of maintenance. Therefore, the intensity of maintenance can be easily changed.

[0055] [Second embodiment] Next, a second embodiment of the liquid ejection device will be described with reference to the drawings. Note that the second embodiment differs from the first embodiment in the setting routine. Since the second embodiment is otherwise substantially the same as the first embodiment, the same components are designated by the same reference numerals and redundant description will be omitted.

[0056] The timing for executing the setting routine shown in FIG. 5 is the same as the timing for executing the setting routine shown in FIG. In step S301, the control unit 36 ​​determines whether the frequency of the ruled line mode is equal to or greater than a specified value. If the frequency of the ruled line mode is equal to or greater than the specified value, step S301 becomes YES, and the control unit 36 ​​proceeds to step S302. In step S302, the control unit 36 ​​sets the maintenance intensity to the first intensity and ends the process.

[0057] If the frequency of the ruled line mode is below the specified value, step S301 becomes NO, and the control unit 36 ​​moves the process to step S303. In step S303, the control unit 36 ​​sets the maintenance intensity to the second intensity.

[0058] In step S304, the control unit 36 ​​compares the number of sheets of medium 15 printed in document mode with the number of sheets of medium 15 printed in photo mode. If the number of sheets of medium 15 printed in photo mode is greater than the number of sheets of medium 15 printed in document mode, step S304 becomes YES, and the control unit 36 ​​proceeds to step S305. In step S305, the control unit 36 ​​changes the maintenance intensity setting from the second intensity to the third intensity, and ends the process.

[0059] If the number of media 15 printed in document mode is equal to or greater than the number of media 15 printed in photo mode, step S304 becomes NO, and the control unit 36 ​​ends the process while maintaining the maintenance intensity at the second intensity.

[0060] <Operation of the Second Embodiment> The operation of this embodiment will be described. The control unit 36 ​​may perform maintenance at the first intensity when the frequency of the ruled line mode included in the determination result is equal to or greater than a specified value. The specified value may be a value stored in the storage unit 37 in advance, or may be set by the user. The specified value may be, for example, 30%.

[0061] When the frequency of the ruled line mode included in the discrimination result is lower than a specified value, the control unit 36 ​​may perform maintenance at a second intensity that is weaker than the first intensity. When the frequency of the photo mode included in the discrimination result is higher than the frequency of the document mode, the control unit 36 ​​may change the intensity of the maintenance performed at the second intensity to a third intensity that is weaker than the second intensity.

[0062] The control unit 36 ​​may set the intensity of maintenance based on the frequency of the ruled line mode from the start of use of the liquid ejection device 11 to the present. The control unit 36 ​​may set the intensity of maintenance based on the frequency of the ruled line mode from the present to a specified number of sheets ago. The control unit 36 ​​may set the intensity of maintenance based on the frequency of the ruled line mode in printing performed before a specified period. The specified period may be, for example, the same period one year ago, the same month one year ago, or the same season one year ago. The specified period may be, for example, the same period from one year ago to several years ago, the same month from one year ago to several years ago, or the same season from one year ago to several years ago.

[0063] <Effects of the second embodiment> The effects of this embodiment will be described. (6) If the frequency of the ruled line mode included in the discrimination result is below a specified value, the control unit 36 ​​performs maintenance at a second intensity that is weaker than the first intensity, thereby reducing the amount of liquid that is wasted.

[0064] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0065] The set threshold may be a threshold related to time. The control unit 36 ​​may execute the set routine when the time from when the liquid ejection device 11 started to be used until the present time exceeds the set threshold.

[0066] The discrimination unit 38 may determine that the mode is text mode if the print duty is less than a density threshold. The discrimination unit 38 may determine that the mode is photo mode if the print duty is equal to or greater than a density threshold. The density threshold may be stored in advance in the storage unit 37 or may be set by the user. The print duty is the ratio of the number of dots of liquid actually deposited to the maximum number of dots of liquid that can be deposited on the medium 15.

[0067] The discrimination unit 38 may determine that the mode is document mode if the amount of liquid discharged onto the medium 15 and consumed is less than the consumption threshold. The discrimination unit 38 may determine that the mode is photo mode if the amount of liquid discharged onto the medium 15 and consumed is equal to or greater than the consumption threshold. The consumption threshold may be stored in advance in the storage unit 37 or may be set by the user.

[0068] The discrimination unit 38 may determine that the mode is document mode if the printing speed is faster than a speed threshold. The discrimination unit 38 may determine that the mode is photo mode if the printing speed is the same as or slower than the speed threshold. The speed threshold may be stored in the storage unit 37 in advance or may be set by the user.

[0069] The determination unit 38 may determine whether the print data is in document mode or photo mode based on the extension of the original file from which the print data is generated. For example, the determination unit 38 may determine that the print data is in photo mode if the original file has an extension suitable for photos.

[0070] The discrimination unit 38 may discriminate between document mode and photo mode based on the size of the original file from which the print data is generated. For example, the discrimination unit 38 may determine that the print mode is photo mode if the data size per sheet of medium 15 or the data size per unit area of ​​one sheet of medium 15 is larger than a size threshold.

[0071] The discrimination unit 38 may discriminate between the document mode and the photo mode by combining the above-mentioned multiple methods. By combining multiple methods, the discrimination accuracy can be improved. The maintenance unit 18 may perform pressure cleaning, which is cleaning in which the liquid is forcibly discharged from the nozzle 20 by using an external force. The liquid receiving unit 30 may receive the liquid discharged by the pressure cleaning. The maintenance unit 18 may include a pressurizing mechanism that pressurizes the liquid in the liquid discharge unit 21. The maintenance unit 18 may pressurize the liquid in the liquid discharge unit 21 using the pressurizing mechanism, thereby forcibly discharging the liquid from the nozzle 20.

[0072] The maintenance unit 18 may be provided with a liquid receiving unit 30 that receives the liquid discharged by flushing, and a separate liquid receiving unit 30 that receives the liquid discharged by cleaning. The maintenance unit 18 may be provided with a cap that performs capping. The maintenance unit 18 may be provided with a liquid receiving unit 30 that receives the liquid discharged by flushing, and a cap that performs capping and suction cleaning.

[0073] The control unit 36 ​​may change the intensity of the suction cleaning and pressure cleaning by changing the amount of liquid discharged from the nozzle 20. The second-intensity maintenance may discharge a smaller amount of liquid than the first-intensity maintenance. The third-intensity maintenance may discharge a smaller amount of liquid than the second-intensity maintenance. For example, the control unit 36 ​​may reduce the amount of liquid discharged by shortening the time for which cleaning is performed.

[0074] The control unit 36 ​​may change the intensity of the suction cleaning and pressure cleaning by changing the flow rate of the liquid passing through the nozzle 20. The flow rate for the second intensity maintenance may be slower than that for the first intensity maintenance. The flow rate for the third intensity maintenance may be slower than that for the second intensity maintenance.

[0075] The maintenance unit 18 may perform choke cleaning, which is cleaning that forcibly discharges liquid from the nozzle 20 using an external force. Choke cleaning is a cleaning method in which the flow of liquid supplied to the nozzle 20 is restricted and the discharge pump 34 is driven to increase negative pressure, and then the restricted flow of liquid is released to forcefully discharge the liquid. Choke cleaning can perform stronger maintenance than suction cleaning, pressure cleaning, and flushing.

[0076] The control unit 36 ​​may change the type of maintenance depending on the intensity. The control unit 36 ​​may perform choke cleaning as maintenance of a first intensity, suction cleaning as maintenance of a second intensity, and flushing as maintenance of a third intensity.

[0077] The control unit 36 ​​may perform maintenance at the second intensity when the frequency of the ruled line mode is below a specified value, regardless of the frequency of the photo mode, or when the determination result does not include the ruled line mode.

[0078] The liquid ejection device 11 may be a liquid ejection device that ejects or discharges liquids other than ink. The liquid ejected as minute droplets from the liquid ejection device may be in the form of granules, tears, or strings. The liquid referred to here may be any material that can be ejected from the liquid ejection device. For example, the liquid may be in any liquid phase, including fluids such as high or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and metal melts. The liquid may refer not only to a single state of matter, but also to solid functional material particles, such as pigments and metal particles, dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals, as described in the above embodiments. Here, ink encompasses various liquid compositions, such as general water-based inks and oil-based inks, as well as gel inks and hot-melt inks. Specific examples of liquid ejection devices include devices that eject liquids containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters. The liquid ejection device may be a device that ejects bioorganic materials used in biochip manufacture, a device used as a precision pipette to eject sample liquids, a textile printing device, a microdispenser, or the like. The liquid ejection device may be a device that ejects lubricating oil with pinpoint accuracy onto precision machinery such as watches and cameras, or a device that ejects transparent resin liquids such as ultraviolet-curing resins onto substrates to form micro-hemispherical lenses, optical lenses, and the like used in optical communication elements. The liquid ejection device may also be a device that ejects etching liquids such as acids or alkalis to etch substrates, etc.

[0079] [Note] The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below.

[0080] (A) A liquid ejection device includes a liquid ejection unit that prints by ejecting liquid from a nozzle onto a medium, a maintenance unit that performs maintenance on the liquid ejection unit, a discrimination unit that determines whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines, a memory unit that stores the discrimination result by the discrimination unit, and a control unit, and the control unit changes the intensity of the maintenance depending on the frequency of the ruled line mode included in the discrimination result stored in the memory unit.

[0081] With this configuration, the control unit changes the intensity of maintenance depending on the frequency of the ruled line mode. The ruled line mode, which includes vertical lines, requires higher ejection accuracy than the non-ruled line mode, which does not include vertical lines. Therefore, by performing maintenance as needed, liquid consumption can be efficiently reduced.

[0082] (B) In the liquid ejection device, the control unit may perform the maintenance at a first intensity if the discrimination result stored in the memory unit includes the ruled line mode, and may perform the maintenance at a second intensity weaker than the first intensity if the discrimination result stored in the memory unit does not include the ruled line mode.

[0083] According to this configuration, if the determination result does not include the ruled line mode, the control unit performs maintenance at the second intensity that is weaker than the first intensity, thereby reducing the amount of liquid that is wasted.

[0084] (C) In the liquid ejection device, the control unit may perform the maintenance at a first intensity if the frequency of the ruled line mode included in the discrimination result stored in the memory unit is equal to or greater than a specified value, and may perform the maintenance at a second intensity weaker than the first intensity if the frequency of the ruled line mode included in the discrimination result stored in the memory unit is less than the specified value.

[0085] With this configuration, if the frequency of the ruled line mode included in the discrimination result is below a specified value, the control unit performs maintenance at a second intensity that is weaker than the first intensity, thereby reducing unnecessary consumption of liquid.

[0086] (D) In ​​the liquid ejection device, the non-ruled line mode includes a document mode for printing document data and a photo mode for printing photo data, and the control unit may change the intensity of the maintenance performed at the second intensity to a third intensity that is weaker than the second intensity when the frequency of the photo mode is higher than the frequency of the document mode included in the determination result.

[0087] According to this configuration, if the frequency of photo mode is higher than the frequency of document mode among the non-ruled line modes included in the determination result, the control unit performs maintenance at a third intensity, which is weaker than the second intensity. When printing a photo, a larger amount of liquid is used for printing than when printing a document, and the viscosity of the liquid in the liquid ejection unit is less likely to increase. Therefore, by performing maintenance at the third intensity, it is possible to reduce the amount of liquid wasted.

[0088] (E) In the liquid ejection device, the maintenance unit has a liquid receiving portion capable of receiving the liquid ejected by the liquid ejection unit, and the maintenance includes flushing, which ejects the liquid from the liquid ejection unit into the liquid receiving portion, and the control unit may change the intensity of the maintenance by changing the amount of liquid ejected in one flushing.

[0089] According to this configuration, the liquid discharger discharges the liquid whose viscosity has increased by flushing. The control unit changes the intensity of the maintenance by changing the amount of liquid discharged in one flushing. Therefore, the intensity of the maintenance can be easily changed.

[0090] (F) In the liquid ejection device, the maintenance unit may have a cleaning unit capable of performing the maintenance by forcibly discharging the liquid from the nozzle using an external force, and the control unit may change the intensity of the maintenance by changing the frequency of the cleaning.

[0091] According to this configuration, the cleaning unit performs cleaning to remove liquid with increased viscosity and foreign matter such as air bubbles from the liquid ejection unit. The control unit changes the intensity of maintenance by changing the frequency of cleaning. Therefore, the intensity of maintenance can be easily changed.

[0092] (G) A method for controlling a liquid ejection device includes a liquid ejection unit that prints by ejecting liquid from a nozzle onto a medium, a maintenance unit that performs maintenance on the liquid ejection unit, a discrimination unit that determines whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines, and a memory unit that stores the discrimination result by the discrimination unit, and the intensity of the maintenance is changed depending on the frequency of the ruled line mode included in the discrimination result stored in the memory unit.

[0093] According to this method, it is possible to achieve the same effects as those of the liquid ejection device. [Explanation of symbols]

[0094] 11...liquid ejection device, 12...housing, 13...guide shaft, 14...printing unit, 15...medium, 16...medium support unit, 17...conveying unit, 18...maintenance unit, 20...nozzle, 21...liquid ejection unit, 22...carriage, 23...liquid container, 25...driving source, 26...roller, 28...wiping unit, 29...cleaning unit, 30...liquid receiving unit, 31...suction mechanism, 32...waste liquid storage unit, 33...discharge path, 34...discharge pump, 36...control unit, 37...memory unit, 38...discrimination unit, Dm1...first main scanning direction, Dm2...second main scanning direction, Ds...sub-scanning direction.

Claims

1. a liquid ejection unit that performs printing by ejecting liquid from a nozzle onto a medium; a maintenance unit for performing maintenance on the liquid ejection unit; a discrimination unit that discriminates whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines; a storage unit that stores a determination result by the determination unit; A control unit; Equipped with The liquid ejection device, wherein the control unit changes the intensity of the maintenance in accordance with the frequency of the ruled line mode included in the determination result stored in the storage unit.

2. The control unit When the determination result stored in the storage unit includes the ruled line mode, the maintenance is performed at a first intensity; The liquid ejection device according to claim 1, wherein if the ruled line mode is not included in the determination result stored in the memory unit, the maintenance is performed at a second intensity that is weaker than the first intensity.

3. The control unit When the frequency of the ruled line mode included in the determination result stored in the storage unit is equal to or greater than a specified value, the maintenance is performed at a first intensity; The liquid ejection device according to claim 1, characterized in that if the frequency of the ruled line mode included in the discrimination result stored in the memory unit is below the specified value, the maintenance is performed at a second intensity weaker than the first intensity.

4. the non-ruled line mode includes a document mode for printing document data and a photo mode for printing photo data; The control unit A liquid ejection device as described in claim 2 or claim 3, characterized in that if the frequency of the photo mode is higher than the frequency of the document mode included in the discrimination result, the intensity of the maintenance performed at the second intensity is changed to a third intensity that is weaker than the second intensity.

5. the maintenance unit has a liquid receiving unit capable of receiving the liquid ejected by the liquid ejection unit, the maintenance includes flushing, in which the liquid is discharged from the liquid discharge portion to the liquid receiving portion; The liquid ejection device according to any one of claims 1 to 4, characterized in that the control unit changes the intensity of the maintenance by changing the amount of ejection in one flushing.

6. the maintenance unit has a cleaning unit that can perform cleaning as the maintenance by forcibly discharging the liquid from the nozzle by an external force, 6. The liquid ejection device according to claim 1, wherein the control unit changes the intensity of the maintenance by changing the frequency of the cleaning.

7. A control method for a liquid ejection device including a liquid ejection unit that performs printing by ejecting liquid from nozzles onto a medium, a maintenance unit that performs maintenance on the liquid ejection unit, a discrimination unit that discriminates whether the printing mode is a ruled line mode that includes vertical ruled lines or a non-ruled line mode that does not include the vertical ruled lines, and a storage unit that stores a result of discrimination by the discrimination unit, A method for controlling a liquid ejection device, comprising changing the intensity of the maintenance in accordance with the frequency of the ruled line mode included in the determination result stored in the storage unit.

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