JP2011051125A - Liquid jetting apparatus and cleaning method of liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a meniscus to recover utilizing a surface tension of liquid, and to suppress an elongation of a cleaning term. <P>SOLUTION: A cleaning means is provided which completes wiping processing of a large surface tension liquid jetting region (nozzle formation surface 3A set in the large surface tension liquid jetting region in step S1) prior to a small surface tension liquid jetting region (nozzle formation surface 3A set in the small surface tension liquid jetting region in step S1). A control device 37 sets a waiting time after wiping processing when determining that there exists no nozzle formation surface 3A not passed through wiping processing in step S4 (step S5). The control device 37 completes cleaning processing after waiting for a time after the completion of all wiping processing to be the waiting time set in step S5 (step S6). A time up to the completion of wiping processing of the small surface tension liquid jetting region can be assigned to a part of a recovery time of the meniscus in the large surface tension liquid jetting region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus and a cleaning method for the liquid ejecting apparatus.

  The liquid ejecting apparatus includes an ejecting head capable of ejecting liquid, and ejects various liquids from the ejecting head toward a recording material or the like. As a typical liquid ejecting apparatus, for example, an ink jet recording head (hereinafter, simply referred to as a recording head) is provided, and a recording medium such as recording paper using liquid ink (liquid) as ink droplets from nozzles of the recording head. There are inkjet printers that perform recording by forming dots by jetting and landing toward the surface.

  In such a liquid ejecting apparatus, a cleaning process for maintaining or recovering a good ejecting state of the liquid ejected from the nozzle is periodically performed. For example, as one specific cleaning process, a wiping process is performed in which a nozzle forming surface on which nozzle openings are formed is wiped with a wiper.

JP-A-10-128963

However, when the nozzle forming surface is wiped with a wiper, the liquid meniscus formed in the opening portion of the nozzle may be destroyed by interference with the wiper.
When the meniscus is destroyed in this way, there is a case where liquid is not ejected from the nozzle or a flight curve of the ejected liquid may occur, and a good ejection state of the liquid cannot be obtained.

On the other hand, the meniscus gradually recovers due to the surface tension of the liquid. Therefore, it is conceivable to recover the meniscus by securing a certain waiting time after the wiping process.
However, when the surface tension of the liquid is large, a long waiting time (for example, 25 seconds or more) is required until the meniscus once broken is recovered.

  For example, if no standby time is provided as in the case of the current ink jet recording apparatus, the time from the wiping process until printing can be performed is about 5 seconds, including the stop time of the cleaning apparatus and the movement of the recording head. It is. In other words, when the waiting time for meniscus recovery is secured, the cleaning time becomes very long compared to the current state, and the user is allowed to wait for a long time.

  The present invention has been made in view of the above-described problems, and it is an object of the present invention to make it possible to recover a meniscus by utilizing the surface tension of a liquid and to suppress an increase in the cleaning period.

  The present invention adopts the following configuration as means for solving the above-described problems.

  The first invention includes a large surface tension liquid ejecting region in which a nozzle for ejecting a large surface tension liquid that is a liquid having a relatively large surface tension is opened, and a small surface tension liquid that is a liquid having a relatively small surface tension. A liquid ejecting apparatus comprising a small surface tension liquid ejecting region in which a nozzle for ejecting water is opened, and cleaning means for completing a wiping process of the large surface tension liquid ejecting region prior to the small surface tension liquid ejecting region Adopting a configuration comprising

According to the present invention employing such a configuration, the wiping process for the large surface tension liquid ejecting region in which the nozzle for ejecting the large surface tension liquid, which is a liquid having a relatively large surface tension, is opened by the cleaning unit, This is executed so as to be completed prior to the wiping process for the small surface tension liquid ejecting region in which the nozzle for ejecting the small surface tension liquid having a relatively small surface tension is opened.
When the surface tension of the liquid is large, it takes a long time until the meniscus once broken is recovered by the surface tension of the liquid. According to the present invention, the wiping process for the high surface tension liquid ejecting region is first performed. Therefore, the time until the wiping process of the small surface tension liquid jet region is completed can be used as a part of the meniscus recovery time in the large surface tension liquid jet region. When the surface tension of the liquid is small, the meniscus recovers quickly. By adopting the above configuration, the time from the completion of the wiping process to all areas until the meniscus in all areas recovers is minimized. It becomes possible to suppress to.
Therefore, according to the present invention, the meniscus can be recovered by utilizing the surface tension of the liquid, and the cleaning period can be prevented from being prolonged.

  According to a second invention, in the first invention, the cleaning means includes a wiper for wiping the small surface tension liquid ejection region and the large surface tension liquid ejection region, and the small surface tension is reduced according to the surface tension of the liquid. A configuration is adopted in which the moving speed of the wiper with respect to the surface tension liquid ejection region and the large surface tension liquid ejection region is changed.

The probability of the meniscus breaking due to interference with the wiper varies depending on the speed of movement of the wiper relative to the meniscus (i.e., relative to the small surface tension liquid ejection region and the large surface tension liquid ejection region).
According to the present invention employing the above-described configuration, the movement speed of the wiper with respect to the small surface tension liquid jet region and the large surface tension liquid jet region is changed according to the surface tension of the liquid. However, the wiping process time can be shortened.

  According to a third aspect, in the second aspect, the cleaning unit increases the moving speed of the wiper in proportion to the surface tension of the liquid.

The higher the wiper moving speed with respect to the meniscus (that is, with respect to the low surface tension liquid jet region and the large surface tension liquid jet region), the higher the probability of the meniscus breakage. On the other hand, the greater the liquid surface tension, the less likely the meniscus is broken. Become. For this reason, when the surface tension of the liquid is large, even if the moving speed of the wiper is fast, the meniscus destruction probability does not become a large value.
Therefore, by adopting the above configuration, it is possible to shorten the time for the wiping process while efficiently suppressing the meniscus destruction.

  According to a fourth invention, in any one of the first to third inventions, the cleaning unit sets a waiting time after completion of the wiping process in accordance with a surface tension of the liquid.

  According to the present invention employing such a configuration, it is possible to ensure a standby time suitable for the surface tension of the liquid, and to more reliably recover the meniscus.

  According to a fifth aspect of the present invention, there is provided a large surface tension liquid ejecting region in which a nozzle for ejecting a large surface tension liquid that is a liquid having a relatively large surface tension is opened, and a small surface tension liquid that is a liquid having a relatively small surface tension. And a small surface tension liquid ejecting region in which a nozzle for ejecting the liquid is opened, and the wiping process of the large surface tension liquid ejecting region is completed before the small surface tension liquid ejecting region Adopting a configuration to do.

According to the present invention employing such a configuration, the wiping process for the large surface tension liquid ejecting region in which the nozzle for ejecting the large surface tension liquid, which is a liquid having a relatively large surface tension, is opened is relatively performed on the surface. This is executed so as to be completed prior to the wiping process for the small surface tension liquid ejecting region in which the nozzle for ejecting the small surface tension liquid, which is a liquid having a small tension, is opened.
Therefore, like the first invention, according to the present invention, the meniscus can be recovered by utilizing the surface tension of the liquid, and the cleaning period can be prevented from being prolonged.

  According to a sixth invention, in the fifth invention, a wiper that wipes the small surface tension liquid jet region and the large surface tension liquid jet region moves relative to the small surface tension liquid jet region and the large surface tension liquid jet region. A configuration is adopted in which the speed is changed according to the surface tension of the liquid.

  According to the present invention employing such a configuration, the moving speed of the wiper with respect to the small surface tension liquid jet region and the large surface tension liquid jet region is changed according to the surface tension of the liquid, as in the second invention. Therefore, the time for the wiping process can be shortened while suppressing the meniscus destruction.

  According to a seventh invention, in the sixth invention, a configuration is adopted in which the moving speed of the wiper is increased in proportion to the surface tension of the liquid.

  According to the present invention employing such a configuration, the time for the wiping process can be shortened while efficiently preventing the meniscus from being destroyed, as in the third aspect.

  According to an eighth invention, in any of the fifth to seventh inventions, a configuration is adopted in which a standby time after completion of the wiping process is set according to the surface tension of the liquid.

  According to the present invention employing such a configuration, the meniscus can be more reliably recovered as in the fourth aspect.

1 is a plan view schematically showing an internal structure of an ink jet printer according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a schematic configuration of a recording head included in an ink jet printer according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating an arrangement state of recording heads included in the ink jet printer according to the embodiment of the present invention. 1 is a block diagram illustrating an electrical configuration of an inkjet printer according to an embodiment of the present invention. It is the table | surface which visualized the recovery waiting time data memorize | stored in the memory | storage device with which the inkjet printer of one Embodiment of this invention is provided. It is a flowchart for demonstrating the cleaning method containing the wiping process which the inkjet printer of one Embodiment of this invention performs.

  Hereinafter, an embodiment of a liquid ejecting apparatus and a cleaning method for a liquid ejecting apparatus according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size. In the following description, an ink jet printer will be described as an example of the liquid ejecting apparatus of the invention.

FIG. 1 is a plan view schematically showing the internal structure of the ink jet printer 1 of the present embodiment.
As shown in this figure, the ink jet printer 1 of this embodiment includes a printer main body 2 that houses various members. The printer main body 2 includes a head unit moving mechanism 5 that reciprocates a head unit 4 that includes the recording head 3, an ink cartridge 7 that stores ink (liquid) supplied to the recording head 3 via a supply tube 6, and A maintenance device 8 used for a cleaning operation or the like for maintaining the ejection characteristics of the recording head 3 is provided.

  The printer main body 2 is provided with a transport mechanism (not shown) that transports a recording medium. This transport mechanism transports the recording medium in the Y direction. The recording medium is composed of a conveyance motor and a conveyance roller (not shown) that is rotationally driven by the conveyance motor. The recording medium is sequentially fed onto the platen 9 in conjunction with a recording (printing / printing) operation. Examples of the recording medium include paper, PET, and silver PET.

  The head unit moving mechanism 5 includes a guide shaft 10 installed in the width direction of the printer main body 2, a pulse motor 11, a drive pulley 12 connected to a rotation shaft of the pulse motor 11 and driven to rotate by the pulse motor 11. The drive pulley 12 is an idle pulley 13 provided on the opposite side of the printer body 2 in the width direction, and a timing belt 15 that is spanned between the drive pulley 12 and the idle pulley 13 and connected to the carriage 14. It is comprised.

  The head unit 4 includes a recording head 3 that ejects ink toward the recording medium fed onto the platen 9 and a carriage 14 that can move along the width direction of the recording medium.

  The recording head 3 is mounted on the carriage 14. The carriage 14 is connected to the timing belt 15 by attaching a part of the timing belt 15 to a connection portion 16 provided at the center of the side portion. The head unit 4 having such a carriage 14 reciprocates in the main scanning direction along the guide shaft 10 according to the movement of the timing belt 15 that is rotated by driving the pulse motor 11.

  As shown in FIG. 1, the maintenance device 8 includes a capping mechanism 18 that is used for a suction operation for sucking thickened ink from each nozzle 17 (see FIG. 2 or 3) of the recording head 3, and nozzles of the recording head 3. It has a wiping mechanism 20 used for a wiping process for wiping the ink adhering to the formation surface 3A (see FIG. 2 or FIG. 3) with a wiper 19, and is disposed at the home position. Here, the home position is set in an end area within the movement range of the head unit 4 and outside the recording area. When the power is turned off or when recording is not performed for a long time, the head unit 4 is set. Is the place to move.

  When the head unit 4 is positioned at the home position, maintenance processing (ink suction operation, wiping processing, etc.) is performed on the recording head 3 by the maintenance device 8 under the control of the control device 37 described later. Waste ink discharged from the recording head 3 to the maintenance device 8 is collected by a waste liquid collection mechanism (not shown).

FIG. 2 is a cross-sectional view showing a schematic configuration of the recording head 3.
As shown in the figure, the recording head 3 has a head case 21, a flow path unit 22, and an actuator unit 23.

  The head case 21 is a hollow box-shaped member made of synthetic resin, and a case flow path 24 and an accommodation space 25 are formed inside the head case 21. The case channel 24 is formed so as to penetrate the height direction of the head case 21. The upper end of the case channel 24 is connected to an introduction needle unit (not shown). The lower end of the case flow path 24 communicates with the common ink chamber 26 in the flow path unit 22.

  The actuator unit 23 is housed in the housing space 25. The actuator unit 23 includes a plurality of piezoelectric vibrators 27 arranged in a comb shape, a fixing plate 28 to which the piezoelectric vibrators 27 are joined, and wiring for supplying a drive signal from the printer body to the piezoelectric vibrator 27. It is comprised from the flexible cable 29 as a member. Each piezoelectric vibrator 27 has a fixed end portion bonded to a fixed plate 28 and a free end portion protruding outward from the front end surface of the fixed plate 28, and is attached to the fixed plate 28 in a so-called cantilever state. Yes. The actuator unit 23 is housed and fixed in the housing space 25 by bonding the back surface of the fixing plate 28 to the inner wall surface of the case that defines the housing space 25.

  The flow path unit 22 includes a vibration plate 30, a flow path substrate 31, and a nozzle plate 32. The vibration plate 30, the flow path substrate 31, and the nozzle plate 32 are laminated in this order, and are joined and integrated with an adhesive (not shown). The vibration plate 30, the flow path substrate 31, and the nozzle plate 32 are members that form a series of ink flow paths from the common ink chamber 26 through the ink supply port 33 and the pressure chamber 34 to the nozzle 17.

  The pressure chamber 34 is formed as an elongated space in a direction orthogonal to the arrangement direction of the nozzles 17. The common ink chamber 26 communicates with the case flow path 24 and is a space into which ink supplied from the ink cartridge 7 through the supply tube 6 is introduced. The ink introduced into the common ink chamber 26 is distributed to each pressure chamber 34 through the ink supply port 33.

  The flow path substrate 31 disposed between the nozzle plate 32 and the vibration plate 30 is a flow path portion that becomes an ink flow path, specifically, a common ink chamber 26, an ink supply port 33, and an empty space that becomes a pressure chamber 34. It is a plate-like member in which a section is formed. The flow path substrate 31 is produced, for example, by subjecting a silicon wafer, which is a crystalline base material, to anisotropic etching.

  The diaphragm 30 is a double-structured composite plate material in which an elastic film is laminated on a metal support plate such as stainless steel. At a portion corresponding to the pressure chamber 34 of the vibration plate 30, an island portion 35 to which the tip surface of the piezoelectric vibrator 27 is joined is formed by removing the support plate in an annular shape by etching or the like. This island part 35 functions as a diaphragm part.

  The diaphragm 30 is configured such that the elastic film around the island portion 35 is elastically deformed in response to the operation of the piezoelectric vibrator 27, seals one opening surface of the flow path substrate 31, and the compliance portion 36. It has come to function as. As for the portion corresponding to the compliance portion 36, the support plate is removed by etching or the like as in the diaphragm portion, and only the elastic film remains.

  The nozzle plate 32 is a plate material made of a metal such as stainless steel, for example, and a plurality of nozzles 17 arranged at a pitch (for example, 180 dpi) corresponding to the dot formation density are formed. That is, the nozzle 17 is opened on the nozzle forming surface 3 </ b> A of the nozzle plate 32.

In the inkjet printer 1 of the present embodiment, as shown in FIG. 3, a plurality (four) of recording heads 3 (3 a to 3 d) are installed with respect to the carriage 14.
In the present embodiment, the recording heads 3a to 3d eject different types of ink described later. More specifically, the recording head 3a ejects yellow ink, the recording head 3b ejects magenta ink, the recording head 3c ejects cyan ink, and the recording head 3d ejects black ink.

Ink of different colors (that is, different types of ink) has different ink compositions and different surface tensions. That is, inks having different surface tensions are ejected from the recording heads 3a to 3d.
For this reason, the nozzle formation surface 3A of each of the recording heads 3a to 3d is a “liquid (ink) having a relatively large surface tension” according to the present invention due to the relationship with the surface tension of the ink ejected from the other recording heads 3. "Large surface tension liquid ejection region in which a nozzle for ejecting a certain large surface tension liquid is opened" or "Small surface tension liquid ejection region in which a nozzle for ejecting a small surface tension liquid having a relatively small surface tension is opened""
Similarly to the nozzle formation surface 3A, each nozzle 17 also has a “high surface tension liquid that is a liquid having a relatively large surface tension” according to the present invention due to the relationship with the surface tension of the ink ejected from the ejecting nozzle 17. Or a “nozzle for ejecting a small surface tension liquid that is a liquid having a relatively small surface tension”.
That is, the inkjet printer 1 of the present embodiment includes a large surface tension liquid ejecting region in which a nozzle that ejects a large surface tension liquid that is a liquid having a relatively large surface tension and a liquid having a relatively small surface tension. And a small surface tension liquid ejecting region in which a nozzle for ejecting a certain small surface tension liquid is opened.

The ink cartridge 7 stores a yellow ink cartridge for storing yellow ink to be supplied to the recording head 3a, a magenta ink cartridge for storing magenta ink to be supplied to the recording head 3b, and cyan ink to be supplied to the recording head 3c. And a black ink cartridge for storing black ink to be supplied to the recording head 3d.
The ink cartridge 7 is connected to each recording head 3 via a supply tube 6.

FIG. 4 is a block diagram illustrating an electrical configuration of the inkjet printer 1.
As shown in FIG. 4, the inkjet printer 1 according to the present embodiment includes a control device 37 that controls the entire operation, an input device 38, a storage device 39, a recording medium transport mechanism 40, a recording head 3, a head unit moving mechanism 5, A maintenance device 8 and the like are provided.

  The control device 37 electrically controls the operation of various components, and includes an input device 38 that inputs various information related to the operation of the ink jet printer 1, a storage device 39 that stores various information related to the operation of the ink jet printer 1, Various input interface circuits for transmitting / receiving data to / from the recording medium transport mechanism 40 for transporting the recording medium, the maintenance device 8 for performing maintenance processing on the recording head 3, etc., and predetermined arithmetic processing based on this data CPU etc. which perform.

The storage device 39 stores surface tension data indicating the surface tension of the ink input from the input device 38 and the like, recovery waiting time data indicating the relationship between the ink surface tension and the waiting time, and the like.
Here, the waiting time is a time until the meniscus once broken is recovered by the surface tension of the ink.

  FIG. 5 is a table visualizing the recovery waiting time data stored in the storage device 39. As shown in this figure, in the recovery waiting time data, the relationship between the ink surface tension and the waiting time is indicated by the recovery probability.

In the inkjet printer 1 of the present embodiment, the control device 37, the storage device 39, the head unit moving mechanism 5, and the maintenance device 8 constitute a cleaning device 100 (cleaning means). The cleaning device 100 completes the wiping process for the large surface tension liquid ejection region prior to the above-described small surface tension liquid ejection region.
More specifically, the cleaning device 100 determines whether the nozzle forming surface 3A of the recording head 3a is a small surface tension liquid ejection region based on the surface tension of the ink stored in the storage device 39 by the control device 37. It is determined whether it is a surface tension liquid ejection region. Subsequently, the cleaning device 100 causes the control unit 37 to complete the wiping process for the large surface tension liquid ejection region before the small surface tension liquid ejection region based on the determination result. The maintenance device 8 is driven.

In the inkjet printer 1 of the present embodiment, the cleaning device 100 changes the moving speed of the wiper 19 relative to the nozzle formation surface 3A of the recording head 3 according to the type of ink to be ejected.
More specifically, the cleaning device 100 determines the moving speed of the wiper 19 based on the surface tension data stored in the storage device 39, and moves the wiper 19 based on the moving speed. Here, the cleaning device 100 increases the moving speed of the wiper 19 as the value of the surface tension data increases. That is, the cleaning device 100 increases the moving speed of the wiper 19 in proportion to the surface tension of the ink.

Further, in the inkjet printer 1 of the present embodiment, the cleaning device 100 sets a waiting time after completion of the wiping process according to the surface tension of the ink.
More specifically, the cleaning device 100 is suitable for the ink ejected from the nozzle forming surface 3A based on the surface tension of the ink ejected from the nozzle forming surface 3A that performs the wiping process based on the recovery waiting time data. The waiting time is acquired, and this waiting time is set as a waiting time after completion of the wiping process.

Next, a cleaning method including a wiping process in the inkjet printer 1 configured as described above will be described with reference to a flowchart of FIG.
This wiping process is performed when the nozzle forming surface 3A is soiled with ink or the like. For example, the wiping process is performed after the suction process for forcibly discharging the ink via the nozzle 17 is completed.
Further, the wiping process is mainly performed by the control device 37 that functions as one configuration of the cleaning device 100. For this reason, in the following description, it demonstrates focusing on the control apparatus 37.

When executing the wiping process, the control device 37 first sets the large surface tension liquid ejection region and the small surface tension liquid ejection region (step S1).
Specifically, the control device 37 uses the surface tension data stored in the storage device 39 to eject the nozzle having the highest surface tension from the nozzle formation surface 3A that has not been subjected to the wiping process. The formation surface 3A is set in the large surface tension liquid ejection region, and the other nozzle formation surface 3A is set in the small surface tension liquid ejection region.

Subsequently, the control device 37 sets the moving speed of the wiper 19 with respect to the nozzle forming surface 3A set in the large surface tension liquid ejection region in step S1 (step S2).
Specifically, the control device 37 acquires the surface tension of the ink ejected from the large surface tension liquid ejection region from the surface tension data stored in the storage device 39, and is proportional to the acquired surface tension. The moving speed of the wiper 19 is set.

Subsequently, the control device 37 executes a wiping process for the nozzle forming surface 3A set in the large surface tension liquid ejection region in step S1 (step S3).
Specifically, the control device 37 controls the head unit moving mechanism 5 so that the wiper 19 is moved with respect to the nozzle forming surface 3A at the moving speed set in step S2.

  Subsequently, the control device 37 determines whether or not the nozzle forming surface 3A that has not been subjected to the wiping process exists (step S4), and if it exists, performs step S1 again.

On the other hand, when it is determined in step S4 that there is no nozzle forming surface 3A that has not been subjected to the wiping process, the control device 37 sets a waiting time after the wiping process (step S5).
Specifically, the control device 37 determines the waiting time after the wiping process from the surface tension of the ink ejected from the nozzle forming surface that has been wiped last and the recovery waiting time data stored in the storage device 39. Set.
The standby time is preferably changed according to the use environment (setting mode) requested by the user. For example, when the user does not require high-definition printing and wants to start printing quickly, the control device 37 determines the area indicated by “Δ” from the recovery waiting time data (an area with a recovery rate of 70 to 80%). ) Value to set the waiting time. On the other hand, when the user desires high-definition printing, the control device 37 selects a value of an area indicated by “◯” (an area with a recovery rate of 90 to 100%) from the recovery waiting time data. Set the waiting time.

  Then, the control device 37 completes the cleaning process after waiting for the time after completion of all the wiping processes to reach the standby time set in step S5 (step S6).

According to the inkjet printer 1 of the present embodiment as described above, the cleaning device 100 performs the wiping process on the large surface tension liquid ejection region (the nozzle formation surface 3A set in the large surface tension liquid ejection region in Step S1). This is executed so as to be completed before the wiping process for the small surface tension liquid ejecting region (the nozzle forming surface 3A set in the small surface tension liquid ejecting region in step S1).
When the surface tension of the ink is large, it takes a long time until the meniscus once broken is recovered by the surface tension of the ink. However, according to the ink jet printer 1 of the present embodiment, the liquid having the large surface tension is first used. Since the wiping process for the ejection region is completed, the time until the wiping process for the small surface tension liquid ejection region is completed can be used as a part of the meniscus recovery time in the large surface tension liquid ejection region. On the other hand, since the meniscus recovers quickly when the surface tension of the ink is small, by adopting the above configuration, after the wiping process for all the nozzle formation surfaces 3A is completed, the meniscuses on all the nozzle formation surfaces 3A It is possible to minimize the time until recovery.
Therefore, according to the inkjet printer 1 of the present embodiment, the meniscus can be recovered using the surface tension of the liquid, and the cleaning period can be prevented from being prolonged.

Further, in the ink jet printer 1 of the present embodiment, the wiper 19 moves relative to the nozzle forming surface 3A (the small surface tension liquid ejecting region and the large surface tension liquid ejecting region) according to the surface tension of the ejected ink. Change the speed.
The probability of the meniscus breaking due to interference with the wiper 19 varies depending on the moving speed of the wiper 19 relative to the meniscus (ie, relative to the small surface tension liquid ejection region and the large surface tension liquid ejection region).
According to the inkjet printer 1 of the present embodiment, the movement speed of the wiper 19 with respect to the small surface tension liquid ejection region and the large surface tension liquid ejection region is changed according to the surface tension of the ejected ink. The time for the wiping process can be shortened while suppressing destruction.

In the inkjet printer 1 of the present embodiment, the moving speed of the wiper 19 is increased in proportion to the surface tension of the ink.
As the moving speed of the wiper 19 with respect to the meniscus (that is, with respect to the low surface tension liquid ejection region and the large surface tension liquid ejection region) increases, the probability of the meniscus destruction increases. On the other hand, as the surface tension of the ink increases, the meniscus is destroyed. It becomes difficult. For this reason, when the surface tension of the ink is large, even if the moving speed of the wiper 19 is fast, the meniscus destruction probability does not become a large value.
Therefore, in the inkjet printer 1 of the present embodiment, the time for the wiping process can be shortened while efficiently suppressing the meniscus destruction.

Further, in the ink jet printer 1 of the present embodiment, the standby time after completion of the wiping process is set according to the surface tension of the ink. Here, the waiting time after completion of the wiping process is a time from when the wiping process to all the nozzle formation surfaces 3A is completed until printing is possible.
According to such an ink jet printer 1 of the present embodiment, it is possible to ensure a standby time suitable for the surface tension of the ink, and to recover the meniscus more reliably.

  The preferred embodiments according to the present invention have been described above with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to such examples, and the above embodiments may be combined. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

For example, in the above-described embodiment, the configuration has been described in which the recording heads 3 each eject one type of ink and the recording heads 3 are provided by the number of ink types.
However, the present invention is not limited to this, and a configuration in which a plurality of types of ink are ejected from a single recording head can also be employed. In such a case, a nozzle provided for each type of ink is opened on the nozzle forming surface of the recording head. Therefore, the nozzle formation surface of a single recording head is virtually divided into a plurality of areas corresponding to the type of ink to be ejected, and each divided area is set as a large surface tension liquid ejection area or a small surface tension liquid ejection area. Will be. Then, a wiping process is performed on each divided region. Note that a region where nozzle openings for ejecting the same type of ink are formed may be virtually divided into a plurality.

In the above embodiment, the configuration in which the moving speed of the wiper 19 with respect to the nozzle forming surface 3A is changed according to the surface tension of the ink has been described.
However, the present invention is not limited to this, and the moving speed of the wiper 19 relative to the nozzle forming surface 3A may be constant.

Further, in the above-described embodiment, when the surface tensions of two inks are slightly different, a configuration is described in which areas for ejecting these inks are classified into a large surface tension liquid ejecting area and a small surface tension liquid ejecting area. did.
However, for example, when there is no significant difference in surface tension, the effect of the present invention is diminished because there is no significant difference in recovery waiting time. For this reason, in the present invention, for example, when the surface tension falls within a preset range, the order of the wiping process may be determined based on other conditions (such as the arrangement relationship of the recording heads).
As a result, when only one of the inks has a large surface tension, only the nozzle forming surface on which the ink is ejected is preferentially wiped, and the other nozzle forming surfaces are wiped in the arrangement order. A wiping process can be performed.

Moreover, in the said embodiment, the structure which wipes all the nozzle formation surfaces 3A was demonstrated.
However, the present invention is not limited to this, and prior to the wiping process, the ink ejection characteristics may be acquired, and only the nozzle formation surface on which dot missing or the like has been confirmed may be subjected to the wiping process.

  In the ink jet printer 1 of the present embodiment, the wiping process is performed in order from the nozzle forming surface 3A on which ink having a large surface tension is ejected, and therefore the surface tension of the ink ejected from the recording head 3 in advance is large. By arranging in order, the moving distance of the head unit by the head unit moving mechanism 5 can be shortened, and the time required for the wiping process can be shortened.

Moreover, in the inkjet printer 1 of this embodiment, the structure which memorize | stores the value of surface tension directly in the memory | storage device 39 was demonstrated.
However, the present invention is not limited to this, and the value of the interfacial tension of the ink with respect to the recording head forming material and the value of the contact angle are stored as values indicating the magnitude of the surface tension of the ink. A configuration may be used in which the surface tension of the ink is acquired based on the value.

Moreover, in the said embodiment, the liquid ejecting apparatus of this invention demonstrated the structure which is what is called a serial type inkjet printer 1. FIG.
However, the present invention is not limited to this, and can be applied to a so-called line-type inkjet printer.

Moreover, in the said embodiment, the case where the liquid ejecting apparatus of this invention was applied to the inkjet printer 1 was illustrated and demonstrated.
However, the present invention is not limited to this, and can be applied to various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be a material that can be ejected by the liquid ejecting apparatus. For example, it may be in the state when the substance is in a liquid phase, and may be in a liquid state with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts) ) And a liquid as one state of the substance, as well as particles in which functional material particles made of solid materials such as pigments and metal particles are dissolved, dispersed or mixed in a solvent.

  In addition, as a typical example of the liquid, ink or liquid crystal as described in the above embodiment can be given. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot-melt inks.

  As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a coloring material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid used as a precision pipette, a printing apparatus, a microdispenser, or the like.

  In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate, or a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate or the like may be employed.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer (liquid ejecting apparatus), 3 ... Recording head, 3A ... Nozzle formation surface (large surface tension ejecting area, small surface tension ejecting area), 5 ... Head unit moving mechanism, 8 ... Maintenance apparatus , 17 ... Nozzle, 19 ... Wiper, 20 ... Wiping mechanism, 37 ... Control device, 39 ... Storage device, 100 ... Cleaning device

Claims (8)

A large surface tension liquid ejecting area in which a nozzle that ejects a large surface tension liquid that has a relatively large surface tension is opened, and a nozzle that ejects a small surface tension liquid that has a relatively small surface tension. A liquid ejecting apparatus comprising a small surface tension liquid ejecting region,
A liquid ejecting apparatus comprising: a cleaning unit that completes a wiping process of the large surface tension liquid ejecting region before the small surface tension liquid ejecting region.   The cleaning means includes a wiper for wiping the small surface tension liquid ejection area and the large surface tension liquid ejection area, and the small surface tension liquid ejection area and the large surface tension liquid ejection area according to the surface tension of the liquid. The liquid ejecting apparatus according to claim 1, wherein a moving speed of the wiper with respect to the is changed.   The liquid ejecting apparatus according to claim 2, wherein the cleaning unit increases a moving speed of the wiper in proportion to a surface tension of the liquid.   The liquid ejecting apparatus according to claim 1, wherein the cleaning unit sets a waiting time after completion of the wiping process according to a surface tension of the liquid. A large surface tension liquid ejecting area in which a nozzle that ejects a large surface tension liquid that has a relatively large surface tension is opened, and a nozzle that ejects a small surface tension liquid that has a relatively small surface tension. A method for cleaning a liquid ejecting apparatus comprising a small surface tension liquid ejecting region,
A cleaning method for a liquid ejecting apparatus, wherein a wiping process for the large surface tension liquid ejecting region is completed before the small surface tension liquid ejecting region.   The moving speed of the wiper that wipes the small surface tension liquid jet region and the large surface tension liquid jet region with respect to the small surface tension liquid jet region and the large surface tension liquid jet region is changed according to the surface tension of the liquid. The method for cleaning a liquid ejecting apparatus according to claim 5.   The method of cleaning a liquid ejecting apparatus according to claim 6, wherein the moving speed of the wiper is increased in proportion to the surface tension of the liquid.   The cleaning method for a liquid ejecting apparatus according to claim 5, wherein a waiting time after completion of the wiping process is set according to a surface tension of the liquid.

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