Liquid ejecting apparatus

A liquid ejecting apparatus includes a head that ejects an ink while moving in an X direction, a plurality of liquid retention portions that are arranged in a direction that intersects the X direction and retain the ink, a mounting portion in which the plurality of liquid retention portions are mounted, and a plurality of flow channels that are provided in the mounting portion and supply the ink to the head from the plurality of liquid retention portions, in which the plurality of liquid retention portions include a liquid retention portion that retains a black ink, and, among flow channel lengths of the plurality of flow channels, the flow channel length of a flow channel that supplies the black ink is shortest.

This application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2016-140026 filed on Jul. 15, 2016, the entire disclosure of which is expressly incorporated by reference herein.

BACKGROUND

1. Technical Field

The present invention relates to a liquid ejecting apparatus.

2. Related Art

A liquid ejecting apparatus that ejects a liquid such as ink, which is supplied from a liquid container (a cartridge), from a nozzle has been proposed in the related art. For example, JP-A-2015-123677 discloses a serial type liquid ejecting apparatus in which a liquid container is mounted in a box form carriage in which a liquid ejecting head is installed, and the carriage is caused to reciprocate with respect to a medium such as printing paper.

Furthermore, a liquid ejecting head provided with a liquid ejecting portion, a plurality of cartridges that store ink, a fixing body that fixes the cartridges, and a flow channel plate that forms a flow channel of liquid with a fixing plate has been disclosed as a liquid ejecting head that is suitable in a liquid ejecting apparatus (for example, JP-A-2015-223774).

The liquid ejecting head disclosed in JP-A-2015-223774 can rapidly discharge a liquid that flows out from the cartridges, and is reduced in size as a result of disposing the cartridges in a two-dimensional manner.

However, in a liquid ejecting apparatus in which the liquid ejecting head (liquid ejecting head unit) disclosed in JP-A-2015-223774 is mounted, flow channels of liquid that run from the cartridges to the liquid ejecting portion (head) are not optimized, and therefore, there is a concern that defects (for example, the omission of dots) will occur as a result of the fact that the flow channels of liquid are not optimized.

SUMMARY

The invention can be realized as the following aspects or application examples.

Application Example 1

According to this application example, there is provided a liquid ejecting apparatus including a head that ejects a liquid while moving in a scanning direction, a plurality of liquid retention portions that are arranged in a direction that intersects the scanning direction and retain the liquid, a mounting portion in which the plurality of liquid retention portions are mounted, and a plurality of flow channels that are provided in the mounting portion and supply the liquid to the head from the plurality of liquid retention portions, in which the plurality of liquid retention portions include a black liquid retention portion that retains a black liquid, and, among flow channel lengths of the plurality of flow channels, a flow channel length of a flow channel that supplies the black liquid is shortest.

According to this application example, the liquid ejecting apparatus records (prints) a desired image on a medium by forming dots on the medium as a result of ejecting the liquid from the head. In addition, in comparison with dots formed using other colors, black dots formed using the black liquid are easier to recognize visually, stand out more as a result. Therefore, if it is likely that a defect (for example, the omission of dots) will occur in the black dots formed on the medium as a result of the head ejecting the black liquid, it is likely that the defect will lead to a deterioration in the appearance quality of an image recorded on the medium. Meanwhile, when it is unlikely that a defect will occur in the black dots formed on the medium as a result of the head ejecting the black liquid, it is possible to enhance the appearance quality of an image recorded on the medium.

Furthermore, if a flow channel that supplies the liquid is long and the flow channel resistance of a flow channel that supplies the liquid is high, since it is unlikely that the liquid will be ejected from the head, it is likely that a defect (for example, the omission of dots) will occur as a result of the liquid not being ejected from the head properly. When the flow channel resistance of a flow channel that supplies the liquid is low, since it is likely that the liquid will be ejected from the head properly, it is unlikely that a defect will occur as a result of the liquid not being ejected from the head properly.

According to the application example, since the flow channel length of the flow channel that supplies the black liquid is the shortest, and therefore, the flow channel resistance of the flow channel that supplies the black liquid is the lowest, it is likely that the black liquid will be ejected from the head properly, it is unlikely that a defect (for example, the omission of black dots) will occur as a result of the black liquid not being ejected from the head properly, and therefore, it is possible to enhance the appearance quality of an image recorded on the medium.

Application Example 2

In the liquid ejecting apparatus according to the application example, it is preferable that at least a portion of the black liquid retention portion be disposed so as to overlap with the head when viewed in a planar manner.

If at least a portion of a black liquid retention portion is disposed so as to overlap with the head when viewed in a planar manner, it is possible to dispose a discharge opening for black liquid of the black liquid retention portion and an introduction opening for black liquid of the head so as to overlap with one another when viewed in a planar manner, and therefore, it is possible to reduce the flow channel length of the flow channel that runs from the discharge opening to the introduction opening in comparison with a case in which the discharge opening and the introduction opening do not overlap with one another when viewed in a planar manner.

That is, if a discharge opening and an introduction opening are disposed so as to overlap with one another when viewed in a planar manner, it is possible to make the flow channel length of a flow channel of the black liquid that runs from the discharge opening to the introduction opening the shortest.

Application Example 3

According to another application example, there is provided a liquid ejecting apparatus including a head that ejects a liquid while moving in a scanning direction, a plurality of liquid retention portions having different retention capacities that are arranged in a direction that intersects the scanning direction and retain the liquid, a mounting portion in which the plurality of liquid retention portions are mounted, and a plurality of flow channels that are provided in the mounting portion and supply the liquid to the head from the plurality of liquid retention portions, in which, among flow channel lengths of the plurality of flow channels, a flow channel length of a flow channel that supplies a liquid retained in a liquid retention portion having a greatest retention capacity is shortest.

The liquid retained in the liquid retention portion having the greatest retention capacity is a liquid having a high frequency of use that is often ejected from the head and that is often consumed. Furthermore, when the frequency of use of a liquid is high, in comparison with a case in which the frequency of use of a liquid is low, it is likely that defects will occur in the dots formed by the liquid. Therefore, if it is likely that a defect (for example, the omission of dots) will occur in the dots formed on the medium as a result of the head ejecting a liquid retained in a liquid retention portion having the greatest retention capacity (hereinafter, referred to as a liquid having a high frequency of use), it is likely that the defect will lead to a deterioration in the appearance quality of an image recorded on the medium. Meanwhile, if it is unlikely that a defect will occur in the dots formed on the medium even if the head ejects a liquid having a high frequency of use, it is possible to enhance the appearance quality of an image recorded on the medium.

According to the application example, since the flow channel length of the flow channel that supplies the liquid having a high frequency of use is the shortest, and therefore, the flow channel resistance of the flow channel that supplies the liquid having a high frequency of use is the lowest, it is most likely that the liquid having a high frequency of use will be ejected from the head, it is unlikely that a defect (for example, the omission of dots) will occur as a result of the liquid having a high frequency of use not being ejected from the head properly, and therefore, it is possible to enhance the appearance quality of an image recorded on the medium.

Application Example 4

In the liquid ejecting apparatus according to the application example, it is preferable that at least a portion of the liquid retention portion having the greatest retention capacity is disposed so as to overlap with the head when viewed in a planar manner.

If at least a portion of a liquid retention portion that retains a liquid having a high frequency of use is disposed so as to overlap with the head when viewed in a planar manner, it is possible to dispose a discharge opening for the liquid having a high frequency of use of the liquid retention portion and an introduction opening for the liquid having a high frequency of use of the head so as to overlap with one another when viewed in a planar manner, and therefore, it is possible to reduce the flow channel length of the flow channel that runs from the discharge opening to the introduction opening in comparison with a case in which the discharge opening and the introduction opening do not overlap with one another when viewed in a planar manner.

That is, if a discharge opening and an introduction opening are disposed so as to overlap with one another when viewed in a planar manner, it is possible to make the flow channel length of a flow channel of the liquid having a high frequency of use that runs from the discharge opening to the introduction opening the shortest.

Application Example 5

According to still another application example, there is provided a liquid ejecting apparatus including a head that ejects a liquid while moving in a scanning direction, a plurality of liquid retention portions that are arranged in a direction that intersects the scanning direction and retain the liquid, a mounting portion in which the plurality of liquid retention portions are mounted, and a plurality of flow channels that are provided in the mounting portion and supply the liquid to the head from the plurality of liquid retention portions, in which, among flow channel lengths of the plurality of flow channels, a flow channel length of a flow channel that supplies a liquid having a greatest consumption amount among liquids retained in the plurality of liquid retention portions, is shortest.

The liquid having the greatest consumption amount is a liquid having the highest frequency of use. Furthermore, when the frequency of use of a liquid is high, in comparison with a case in which the frequency of use of a liquid is low, it is likely that defects will occur in the dots formed by the liquid. Therefore, if it is likely that a defect (for example, the omission of dots) will occur in the dots formed on the medium as a result of the head ejecting the liquid having the highest consumption amount, it is likely that the defect will lead to a deterioration in the appearance quality of an image recorded on the medium. Meanwhile, if it is unlikely that a defect will occur in the dots formed on the medium even if the head ejects the liquid having the highest consumption amount, it is possible to enhance the appearance quality of an image recorded on the medium.

According to the application example, since the flow channel length of the flow channel that supplies the liquid having the highest consumption amount is the shortest, and therefore, the flow channel resistance of the flow channel that supplies the liquid having the highest consumption amount is the lowest, it is most likely that the liquid having the highest consumption amount will be ejected from the head, it is unlikely that a defect (for example, the omission of dots) will occur as a result of the liquid having the highest consumption amount not being ejected from the head properly, and therefore, it is possible to enhance the appearance quality of an image.

Application Example 6

In the liquid ejecting apparatus according to the application example, it is preferable that at least a portion of a liquid retention portion that retains the liquid for which the consumption amount is greatest be disposed so as to overlap with the head when viewed in a planar manner.

If at least a portion of a liquid retention portion that retains the liquid having the highest consumption amount is disposed so as to overlap with the head when viewed in a planar manner, it is possible to dispose a discharge opening for the liquid having the highest consumption amount of the liquid retention portion and an introduction opening for the liquid having the highest consumption amount of the head so as to overlap with one another when viewed in a planar manner, and therefore, it is possible to reduce the flow channel length of the flow channel that runs from the discharge opening to the introduction opening in comparison with a case in which the discharge opening and the introduction opening do not overlap with one another when viewed in a planar manner.

That is, if a discharge opening and an introduction opening are disposed so as to overlap with one another when viewed in a planar manner, it is possible to make the flow channel length of a flow channel of the liquid having the highest consumption amount that runs from the discharge opening to the introduction opening the shortest.

Application Example 7

It is preferable that the liquid ejecting apparatus according to the application example further include a support body that supports the head, and a guide shaft that supports the support body and sets the support body to be capable of moving in the scanning direction, and that, in the support body, the head be supported on a side that is close to the guide shaft.

If an excessive force is applied to the support body or the head, the support body supported by the guide shaft rotates with the guide shaft as a pivot point thereof, and the position of the support body changes. Furthermore, the head supported by the support body also rotates with the guide shaft as a pivot point thereof, and the position of the head changes.

If the head is supported on a side that is close to the guide shaft in a case in which the head rotates with the guide shaft as a pivot point thereof due to an excessive force, in comparison with a case in which the head is supported on a side that is far from the guide shaft, it is possible to reduce a change in the position of the head that arises due to rotation with the guide shaft as a pivot point thereof.

If the change in the position of the head is reduced, positional shift of liquid droplets to be deposited on the medium as a result of being ejected from the head is reduced, and therefore, it is possible to enhance the appearance quality of an image formed on the medium.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Description of Embodiments

Hereinafter, embodiments of the invention will be described with reference to the drawings. The embodiments illustrate aspects of the invention, but do not limit the invention, and can be changed arbitrarily within a range of the technical idea of the invention. In addition, in each of the drawings below, the scales are altered for each layer and each location in order to make each layer and each location have a size that is easy to understand in the drawings.

FIG. 1is a configuration view of a liquid ejecting apparatus according to Embodiment 1.

A liquid ejecting apparatus1according to the present embodiment is an ink jet type printing apparatus that ejects an ink15, which is one example of a “liquid”, onto a medium12. A typical example of the medium12is printing paper, but it is also possible to use various media such as a fabric or a resin film.

As shown inFIG. 1, the liquid ejecting apparatus1is provided with a control unit20, a transport mechanism30, a liquid ejecting unit40, and a movement mechanism50. For example, the control unit20is configured to include a control device such as a central processing unit (CPU) and a storage circuit such as semiconductor memory (not illustrated in the drawings), and controls each component of the liquid ejecting apparatus1in an integral manner as a result of the control device executing a program stored in a storage circuit.

The transport mechanism30transports the medium12in a Y direction on the basis of the control by the control unit20. The transport mechanism30includes a supply side transport mechanism32and a discharge side transport mechanism34. The transport mechanism32is installed on an upstream side (the negative side in the Y direction) of the transport mechanism34and supplies the medium12to the transport mechanism34side, and the transport mechanism34discharges the medium12supplied from the transport mechanism32to a downstream side (the positive side in the Y direction).

Additionally, the Y direction is a transport direction of the medium12, and is an example of “a direction that intersects a scanning direction”.

The liquid ejecting unit40is a component that ejects a plurality of types of ink15onto the medium12, and includes a support body60, a mounting portion70, and a head80. The support body60is a substantially box form housing (carriage) that supports the mounting portion70and the head80. The mounting portion70holds a plurality of liquid retention portions14, which retain different types of ink (the plurality of types of ink).

For example, the liquid retention portions14are cartridges (liquid containers) that retain the ink15. Six types (six colors) of the ink15are used in the present embodiment. To explain in more detail, the ink15used in the present embodiment is configured by a cyan (C) ink15C, a magenta (M) ink15M, a yellow (Y) ink15Y, a black (B) ink15B, a light cyan (LC) ink15LC, and a light magenta (LM) ink15LM.

Additionally, the black (B) ink15B is an example of “a black liquid”. Furthermore, from this point onwards, there are cases in which the types of ink15C,15M,15Y,15B,15LC, and15LM will be referred to collectively as the ink15. In addition, more than six types of the ink15may be used, or less than six types of the ink15may be used.

The ink15includes a color material, a solvent in which a color material is dispersed (or dissolved), or the like. For example, the color material is a pigment or a dye. For example, the solvent is a water-based medium or an organic solvent. Furthermore, in addition to a color material and a solvent, the ink15may include a basic catalyst, a surfactant, a tertiary amine, a resin, a pH adjusting agent, a buffer solution, a fixing agent, an antiseptic, an antioxidant or an ultraviolet absorber, a chelating agent, an oxygen absorber, or the like.

A liquid retention portion14A in which the magenta (M) ink15M is retained, a liquid retention portion14B in which the black (B) ink15B is retained, a liquid retention portion14C in which the light cyan (LC) ink15LC is retained, a liquid retention portion14D in which the cyan (C) ink15C is retained, a liquid retention portion14E in which the yellow (Y) ink15Y is retained, and a liquid retention portion14F in which the light magenta (LM) ink15LM is retained are mounted in the mounting portion70, arranged along the Y direction. Each of the liquid retention portions14A,14B,14C,14D,14E, and14F can be attached and detached to and from the mounting portion70in an individual manner.

Additionally, the liquid retention portion14B that retains the black (B) ink15B is an example of “a black liquid retention portion”. Furthermore, there are cases in which the liquid retention portions14A,14B,14C,14D,14E, and14F will simply be referred to as the liquid retention portions14.

As a result of arranging the six liquid retention portions14A,14B,14C,14D,14E, and14F in the Y direction (the transport direction of the medium12), in comparison with a case in which the six liquid retention portions14A,14B,14C,14D,14E, and14F are arranged in an X direction (the width direction of the medium12), the dimension of the liquid ejecting apparatus1in the X direction (the dimension in the width direction) is smaller, and therefore, it is possible to reduce the size of the liquid ejecting apparatus1.

Nozzles N that eject the ink15onto the medium12are provided in the head80. To explain in more detail, a nozzle N that ejects the magenta (M) ink15M, a nozzle N that ejects the black (B) ink15B, a nozzle N that ejects the light cyan (LC) ink15LC, a nozzle N that ejects the cyan (C) ink15C, a nozzle N that ejects the yellow (Y) ink15Y, and a nozzle N that ejects the light magenta (LM) ink15LM are provided in the head80.

The head80records (prints) text (characters), images, and the like on the medium12by forming dots of colors that correspond to the types of ink15C,15M,15Y,15B,15LC, and15LM on the medium12as a result of ejecting the types of ink15C,15M,15Y,15B,15LC, and15LM from the nozzles N.

In the liquid ejecting apparatus1, since text printing, black and white printing, and the like, are executed often, the consumption amount of the black (B) ink15B is the greatest. Therefore, the black (B) ink15B is an example of “a liquid having the greatest consumption amount”.

The movement mechanism50is a mechanism that causes the liquid ejecting unit40to reciprocate in the X direction on the basis of the control by the control unit20. The X direction is a direction in which the liquid ejecting unit40moves, is an example of “a scanning direction”, and intersects the Y direction in which the medium12is transported. The movement mechanism50includes a transport belt52, a guide shaft54, and a driving motor (not illustrated in the drawings). The transport belt52is an endless belt that is provided in a hanging manner that is longitudinal in the X direction, and rotates as a result of the motive power of the driving motor. The support body60of the liquid ejecting unit40is fixed to the transport belt52. The guide shaft54is a shaft body that is inserted through the support body60and extends in the X direction. The guide shaft54supports the support body60, and is capable of moving the support body60in the X direction.

That is, the support body60is supported by the guide shaft54, and reciprocates between the positive side and the negative side in the X direction due to the movement mechanism50(the transport belt52, the guide shaft54, the driving motor (not illustrated in the drawings), and the like).

The head80is supported by the support body60. The head80moves together with the support body60, and therefore, is capable of moving in the X direction. The head80records characters, images, and the like on the medium12by ejecting the ink15onto the medium12while moving in the X direction (the scanning direction).

To explain in more detail, characters, images, and the like, are recorded on the medium12by aligning rows of dots (raster lines) arranged in the X direction (the scanning direction) in the Y direction (the transport direction) as a result of alternately repeating an ink ejection operation in which the ink15is ejected in the head80while moving in which X direction (the scanning direction), and a transport operation in which the transport mechanism32feeds the medium12in the Y direction (the transport direction).

In other words, desired characters, images, and the like, are formed on the medium12as a result of the head80ejecting the ink15as ink droplets and causing the ink droplets to be deposited in reference positions on the medium12.

In this manner, the liquid ejecting apparatus1is provided with the head80that ejects the ink15while moving in the X direction, the plurality of the liquid retention portions14that are arranged in a direction (the Y direction) that intersects the X direction and retain the ink15, and the mounting portion70in which the plurality of liquid retention portions14are mounted.

In addition, from this point onwards, a direction perpendicular to an X-Y plane will be set as a Z direction. The ink15(ink droplets) ejected from the head80(the nozzles N) is deposited on the outer surface of the medium12as a result of traveling to the positive side in the Z direction.

FIG. 2is a cross-sectional view along a line II-II inFIG. 1(a cross-section that is parallel to a Y-Z plane).

As shown inFIG. 2, the transport mechanism32includes a supply roller322and a supply roller324in which the central axes are parallel to the X direction. The medium12is transported in the Y direction passing through both the supply roller322and the supply roller324due to rotation of one or both of these rollers.

The transport mechanism34includes a discharge roller342and a discharge roller344in which the central axes are parallel to the X direction, a structural body346(a frame) that supports the discharge roller342and the discharge roller344, and a regulation roller348that is supported by the structural body346and regulates uplift of the medium12. The medium12supplied from the transport mechanism32reaches the transport mechanism34passing through a space below the head80, and is discharged to the downstream side passing through both the discharge roller342and the discharge roller344as a result of rotation of one or both of these rollers.

The support body60is a substantially box form structural body that includes a bottom surface portion62and a peripheral wall portion64, and for example, is formed by injection molding of a resin material. An insertion hole642, through which the guide shaft54is inserted, is formed in the peripheral wall portion64. The support body60is supported by the guide shaft54as a result of inserting the guide shaft54into the insertion holes642.

The head80is fixed to the bottom surface portion62of the support body60. In the support body60, the head80is supported on a side that is close to the guide shaft54.

In this manner, the liquid ejecting apparatus1is further provided with the support body60that supports the head80, and the guide shaft54that supports the support body60and is capable of moving the support body60in the X direction, and in the support body60, the head80is supported on the side that is close to the guide shaft54.

If an excessive force is applied to the support body60or the head80, the support body60supported by the guide shaft54rotates with the guide shaft54as a pivot point thereof, and the position of the support body60changes. Furthermore, the head80supported by the support body60also rotates with the guide shaft54as a pivot point thereof, and the position of the head80changes.

Furthermore, if the head80is supported on a side that is close to the guide shaft54in a case in which the head80rotates with the guide shaft54as a pivot point thereof due to an excessive force being applied to the support body60or the head80, in comparison with a case in which the head80is supported on a side that is far from the guide shaft54, it is possible to reduce a change in the position of the head80that arises due to rotation with the guide shaft54as a pivot point thereof. Further, if the change in the position of the head80is reduced, the ink15(ink droplets) ejected from the head80are accurately deposited in reference positions on the medium12, and therefore, it is possible to enhance the appearance quality of an image recorded on the medium12.

FIG. 3is a cross-sectional view focusing on a single arbitrary nozzle among the nozzles formed in the head.

As shown inFIG. 3, the head80is a structural body in which a pressure chamber substrate82, a vibration plate83, a piezoelectric element84, and a housing portion85are disposed on one side of a flow channel substrate81, and a nozzle plate86is disposed on the other side. For example, the flow channel substrate81, the pressure chamber substrate82, and the nozzle plate86are formed by a silicon flat plate material, and, for example, the housing portion85is formed by injection molding of a resin material.

The plurality of nozzles N are formed in the nozzle plate86. The respective plurality of nozzles N are cross-sectionally circular through holes having the Z direction as the axial direction (the direction of the central axis) thereof. Nozzle rows (refer toFIG. 1) in which a plurality of nozzles N that eject a single type of the ink15, which is supplied from a single arbitrary liquid retention portion14, are arranged in the Y direction, are arranged in the X direction mutually spaced apart in the plurality of liquid retention portions14.

An opening portion812, a branched flow channel (a narrowing flow channel)814, and a communication flow channel816are formed in the flow channel substrate81. The branched flow channel814and the communication flow channel816are through holes that are formed for each nozzle N, and the opening portion812is an opening that is continuous throughout the plurality of nozzles N. A space that is mutually in communication with an accommodation portion (a concave portion)852formed in the housing portion85, and the opening portion812of the flow channel substrate81, functions as a common liquid chamber (a reservoir) R that retains the ink15supplied from the liquid retention portions14via an introduction opening854of the housing portion85.

An opening portion822is formed in the pressure chamber substrate82for each nozzle N. The vibration plate83is a flat plate material that is installed on the outer surface of a side of the pressure chamber substrate82that is opposite to the flow channel substrate81and is capable of elastic deformation. A space that is interposed between the vibration plate83and the flow channel substrate81on the inner side of each opening portion822of the pressure chamber substrate82, functions as a pressure chamber (cavity) C filled with the ink15supplied from the common liquid chamber R via the branched flow channel814. Each pressure chamber C is in communication with a nozzle N via the communication flow channel816of the flow channel substrate81.

The piezoelectric element84is formed for each nozzle N on the outer surface of the vibration plate83on a side that is opposite to the pressure chamber substrate82. Each piezoelectric element84is a driving element in which a piezoelectric body is interposed between a pair of electrodes that face one another. When the vibration plate83vibrates as a result of the piezoelectric element84deforming due to the supply of a driving signal, the pressure inside the pressure chamber C fluctuates, and the ink15inside the pressure chamber C is ejected from the nozzle N. Additionally, in the present embodiment, a piezoelectric type head80that uses the piezoelectric element84, which applies mechanical vibrations to the pressure chamber C is illustrated by way of example, but it is also possible to adopt a heat-emitting element that generates air bubbles in an inner portion of a pressure chamber due to heating, as a driving element.

FIG. 4is an exploded perspective view of a liquid ejecting unit.

As shown inFIGS. 2 and 4, the mounting portion70includes a main body portion72and a sealing portion74. For example, the main body portion72and the sealing portion74are mutually formed in an individual manner using injection molding of a resin material.

The main body portion72is a structural body in which the plurality of liquid retention portions14are mounted, and includes a base portion722, a side wall portion724, and a plurality of dividing wall portions726. The base portion722is a substantially flat plate form section that includes an outer surface (hereinafter, referred to as a “mounting surface”) SA1onto which the plurality of liquid retention portions14are mounted, and an outer surface (hereinafter, referred to as a “fixing surface”) SA2on a side opposite to the mounting surface SA1. The side wall portion724is a wall form section that projects along the peripheral edge of the base portion722from the mounting surface SA1. The plurality of dividing wall portions726are dividing walls that project from the mounting surface SA1of the base portion722in a manner that partitions spaces in which each liquid retention portion14is mounted.

A plurality of introduction openings732A,732B,732C,732D,732E, and732F (referred to simply as introduction openings732in some cases from this point onwards), which correspond to the different liquid retention portions14, are formed in the base portion722. The plurality of liquid retention portions14are mounted and held on the mounting surface SA1in a manner in which discharge openings (not illustrated in the drawings) of the ink15the liquid retention portions14are in communication with the introduction openings732. The ink15discharged from the discharge openings of the liquid retention portion14is introduced into the introduction openings732of the base portion722.

A plurality of through holes734, through which screws76for fixing the main body portion72to the support body60are inserted, are formed in each corner portion (the four corners) of the base portion722of the mounting portion70. Furthermore, through holes624, through which the screws76are inserted, are formed in each corner portion (the four corners) of the bottom surface portion62of the support body60.

The mounting portion70is fixed to the support body60as a result of four of the screws76being inserted into each through hole734of the base portion722of the mounting portion70and each through hole624formed in the corner portions of the bottom surface portion62of the support body60.

Additionally, the structure (the connection portions) for mutually fixing the mounting portion70and the support body60is not limited to the above-mentioned illustrative example. For example, it is also possible to adopt a configuration in which the mounting portion70is fixed to the support body60using an adhesive, or a configuration in which the mounting portion70is fixed to the support body60by causing deformation (for example, thermal caulking) after inserting caulking pins formed in one of the mounting portion70and the support body60into the other.

The sealing portion74is a substantially flat plate form member that includes an outer surface (hereinafter, referred to as a “flow channel surface”) SB1facing the base portion722of the main body portion72, and an outer surface (hereinafter, referred to as an “exterior outer surface”) SB2on a side opposite to the flow channel surface SB1. The sealing portion74is fixed to the base portion722in a state in which the flow channel surface SB1of the sealing portion74is adhered to the fixing surface SA2of the base portion722. A plurality of attachment portions742are formed on the outer peripheral surface of the sealing portion74.

The sealing portion74is fixed to the main body portion72(the base portion722) using an arbitrary fixing method such as thermal caulking that causes thermal deformation in a state in which the projections of the fixing surface SA2are inserted into the through holes formed in each attachment portion742, or screwing by using screws inserted into the through holes of the attachment portions742.

As shown inFIG. 4, a plurality of introduction openings743, a plurality of groove portions746A,746C,746D,746E, and746F (referred to simply as groove portions746in some cases from this point onwards), and a plurality of communication openings744A,744B,744C,744D,744E, and744F (referred to simply as communication openings744in some cases from this point onwards) are formed on the flow channel surface SB1of the sealing portion74.

The introduction openings743are circular indentations that are in communication with the introduction openings732of the base portion722. The groove portions746are linear (straight line form or curved line form) indentations that link the introduction openings743and the communication openings744. The communication openings744are through holes that pass through the sealing portion74, and are supply openings of the ink15that supply the ink15to the introduction openings854of the head80.

As shown inFIG. 2, in a state in which the sealing portion74is fixed to the main body portion72, six flow channels7A,7B,7C,7D,7E, and7F (simply referred to as flow channels7in some cases from this point onwards) through which the ink15flows, are formed in portions surrounded by the flow channel surface SB1of the sealing portion74and the fixing surface SA2of the base portion722. That is, the flow channels7are flow channels of the ink15that are provided in the mounting portion70and supply the ink15to the head80from the liquid retention portions14.

The flow channel7A is a flow channel of the ink15M that supplies the ink15M to the head80from the liquid retention portion14A. The flow channel7B is a flow channel of the ink15B that supplies the ink15B to the head80from the liquid retention portion14B. The flow channel7C is a flow channel of the ink15LC that supplies the ink15LC to the head80from the liquid retention portion14C. The flow channel7D is a flow channel of the ink15C that supplies the ink15C to the head80from the liquid retention portion14D. The flow channel7E is a flow channel of the ink15Y that supplies the ink15Y to the head80from the liquid retention portion14E. The flow channel7F is a flow channel of the ink15LM that supplies the ink15LM to the head80from the liquid retention portion14F.

In the present embodiment, at least a portion of the liquid retention portion14B is disposed so as to overlap with the head80when viewed in a planar manner so that the discharge opening of the ink15B in the liquid retention portion14B, the introduction opening732B, the communication opening744B, and the corresponding introduction opening854of the head80overlap when viewed in a planar manner.

As a result of this, the ink15B retained in the liquid retention portion14B is supplied to the head80via the discharge opening of the ink15B in the liquid retention portion14B, the introduction opening732B and the communication opening744B of the mounting portion70, and the introduction opening854of the head80. Further, the flow channel7B provided in the mounting portion70is configured to include the introduction opening732B and the communication opening744B but does not include an introduction opening743and a groove portion746.

On the other hand, at least a portion of each of the liquid retention portions14A,14C,14D,14E, and14F is disposed so as to not overlap with the head80when viewed in a planar manner. Further, the discharge openings of the types of ink15M,15LC,15C,15Y, and15LM of the liquid retention portions14A,14C,14D,14E, and14F, the communication openings744A,744C,744D,744E, and744F, and the corresponding introduction openings854of the head80are disposed so as to not overlap with one another when viewed in a planar manner.

As a result of this, the ink15M retained in the liquid retention portion14A is supplied to an introduction opening854of the head80via the discharge opening of the ink15M in the liquid retention portion14A, the introduction opening732A, an introduction opening743, the groove portion746A, and the communication opening744A of the mounting portion70. Further, the flow channel7A provided in the mounting portion70is configured to include the introduction opening732A, an introduction opening743, the groove portion746A and the communication opening744A.

The ink15LC retained in the liquid retention portion14C is supplied to an introduction opening854of the head80via the discharge opening of the ink15LC in the liquid retention portion14C, the introduction opening732C, an introduction opening743, the groove portion746C, and the communication opening744C of the mounting portion70. Further, the flow channel7C provided in the mounting portion70is configured to include the introduction opening732C, an introduction opening743, the groove portion746C and the communication opening744C.

The ink15C retained in the liquid retention portion14D is supplied to an introduction opening854of the head80via the discharge opening of the ink15C in the liquid retention portion14D, the introduction opening732D, an introduction opening743, the groove portion746D, and the communication opening744D of the mounting portion70. Further, the flow channel7D provided in the mounting portion70is configured to include the introduction opening732D, an introduction opening743, the groove portion746D and the communication opening744D.

The ink15Y retained in the liquid retention portion14E is supplied to an introduction opening854of the head80via the discharge opening of the ink15Y in the liquid retention portion14E, the introduction opening732E, an introduction opening743, the groove portion746E, and the communication opening744E of the mounting portion70. Further, the flow channel7E provided in the mounting portion70is configured to include the introduction opening732E, an introduction opening743, the groove portion746E and the communication opening744E.

The ink15LM retained in the liquid retention portion14F is supplied to an introduction opening854of the head80via the discharge opening of the ink15LM in the liquid retention portion14F, the introduction opening732F, an introduction opening743, the groove portion746F, and the communication opening744F of the mounting portion70. Further, the flow channel7F provided in the mounting portion70is configured to include the introduction opening732F, an introduction opening743, the groove portion746F and the communication opening744F.

Since the flow channel7B provided in the mounting portion70does not include an introduction opening743and a groove portion746and the flow channels7A,7C,7D,7E, and7F provided in the mounting portion70include an introduction opening743and a groove portion746, the flow channel length of the flow channel7B is the shortest among the flow channel lengths of the plurality of flow channels7A,7B,7C,7D,7E, and7F.

That is, the present embodiment has a configuration in which the flow channel length of the flow channel7B that supplies the black (B) ink15B is the shortest among the flow channel lengths of the plurality of flow channels7A,7B,7C,7D,7E, and7F.

In the above-mentioned manner, since the consumption amount of the black (B) ink15B is the greatest, the present embodiment has a configuration in which, among the flow channel lengths of the plurality of flow channels7A,7B,7C,7D,7E, and7F, the flow channel length of the flow channel7B that supplies the black (B) ink15B having the greatest consumption amount among the types of ink15M,15B,15LC,15C,15Y, and15LM retained in the plurality of liquid retention portions14A,14B,14C,14D,14E, and14F is the shortest.

Furthermore, the flow channel lengths of the flow channels7A,7C,7D,7E, and7F depend on the lengths of the groove portions746A,746C,746D,746E, and746F. In the present embodiment, since the groove portions increase in length in the order of the groove portion746C, the groove portion746A, the groove portion746D, the groove portion746E, and the groove portion746F, the flow channel lengths increase in the order of the flow channel7C, the flow channel7A, the flow channel7D, the flow channel7E, and the flow channel7F.

That is, in the present embodiment, the flow channel lengths increase in the order of the flow channel7B, the flow channel7C, the flow channel7A, the flow channel7D, the flow channel7E, and the flow channel7F.

Since the consumption amount of the ink15B is greater than those of the other types of ink15C,15M,15Y,15LC, and15LM, the number of times that the ink15B is ejected (referred to as the frequency of use from this point onwards) in the head80is the greatest. That is, in the liquid ejecting unit40, the frequency of use of the ink15B is the highest.

If the frequency of use of an ink15in the liquid ejecting unit40is high, in comparison with a case in which the frequency of use of an ink15is low, it is likely that air bubbles will occur in the flow channel of the ink15that runs from a liquid retention portion14to a nozzle N of the head80.

In the liquid ejecting apparatus1, air bubbles that occur in a flow channel of an ink15that runs from a liquid retention portion14to a nozzle N of the head80are forcibly discharged to an outer portion from the nozzle N by carrying out a maintenance process (for example, a flushing process) at regular intervals.

If air bubbles remain in a flow channel of an ink15that runs from a liquid retention portion14to a nozzle N of the head80, the ink15is not ejected properly from the nozzle N, and a defect in which a dot to be formed by the ink15is not formed occurs (dot omission).

Since the frequency of use of the black (B) ink15B is the highest, it is most likely that air bubbles will occur in the flow channel of the ink15B that runs from a liquid retention portion14to a nozzle N of the head80.

Furthermore, since it is easier to visually recognize dots formed by the black (B) ink15B than dots formed by the other types of ink15C,15M,15Y,15LC, and15LM, dot omission of the ink15B stands out more than dot omission of the other types of ink15C,15M,15Y,15LC, and15LM.

Therefore, if a defect (dot omission of the ink15B) caused by air bubbles occurs in the black (B) ink15B, the defect leads to a deterioration in the appearance quality of characters, images, and the like, recorded on the medium12. On the other hand, if it is unlikely that a defect (dot omission of the ink15B) caused by air bubbles will occur in the black (B) ink15B, it is possible to enhance the appearance quality of characters, images, and the like, recorded on the medium12.

In the present embodiment, since the flow channel length of the flow channel of the ink15is shorter than those of the other types of ink15M,15LC,15C,15Y, and15LM, in the black (B) ink15B in which defects stand out the most (the ink15B having the highest frequency of use), air bubbles occur on a side that is close to a nozzle N. If air bubbles occur on a side that is close to a nozzle N, it is easier to discharge the air bubbles from the nozzle N than in a case in which air bubbles occur on a side that is far from a nozzle N.

Since the flow channel length of the flow channel7B of the black (B) ink15B in which defects stand out the most is the shortest, it is unlikely that a defect (dot omission of the ink15B) will occur as a result of air bubbles in the ink15B since it is likely that air bubbles will be discharged from the nozzle N due to the air bubbles occurring on a side that is close to the nozzle N.

Furthermore, if the flow channel of the ink15B inside the liquid ejecting unit40is short, the flow channel resistance in the flow channel of the ink15B is low, and therefore, it is likely that the ink15B will be ejected from a nozzle N in comparison with a case in which the flow channel resistance is high. Accordingly, it is unlikely that a defect (dot omission of the ink15B) will occur as a result of the flow channel resistance of the ink15B being high.

In this manner, as a result of making the flow channel length of the flow channel7B of the black (B) ink15B in which defects stand out the most (the ink15B having the highest frequency of use) the shortest, it is unlikely that a defect (dot omission of the ink15B) caused by air bubbles in the ink15B or a defect (dot omission of the ink15B) will occur as a result of the flow channel resistance of the ink15B being high, and therefore, it is possible to enhance the appearance quality of characters, images, and the like recorded on the medium12.

FIG. 5is a view that corresponds toFIG. 1, and is a configuration view of a liquid ejecting apparatus according to Embodiment 2.FIG. 6is a view that corresponds toFIG. 2, and is cross-sectional view along a line VI-VI inFIG. 5.FIG. 7is a view that corresponds toFIG. 4, and is an exploded perspective view of a liquid ejecting unit.

Hereinafter, an outline of a liquid ejecting apparatus1A according to the present embodiment will be described focusing on the differences from Embodiment 1 with reference toFIGS. 5 to 7. In addition, constituent sites that are the same as those of Embodiment 1 will be given the same reference numerals, and overlapping descriptions thereof will be omitted.

As shown inFIG. 5, five types (five colors) of ink15are used by the present embodiment and this is a difference from Embodiment 1. To explain in more detail, the ink15used in the present embodiment is configured by a photo black (PB) ink15PB, a matte black (MB) ink15MB, a cyan (C) ink15C, a magenta (M) ink15M, and a yellow (Y) ink15Y.

The photo black (PB) ink15PB includes a black dye as a color material. The matte black (MB) ink15MB includes a black pigment as a color material. The matte black (MB) ink15MB can reproduce a more complete black than the photo black (PB) ink15PB. In comparison with the matte black (MB) ink15MB, the photo black (PB) ink15PB can reproduce a variety of concentrations (reflectances) of black such as grey, for example.

In the liquid ejecting apparatus1A, the reproduction of a more complete black is required, and therefore, the consumption amount of the matte black (MB) ink15MB is the greatest. That is, the matte black (MB) ink15MB is an example of “a liquid having the greatest consumption amount”.

A liquid retention portion14G in which the magenta photo black (PB) ink15PB is retained, a liquid retention portion14H in which the matte black (MB) ink15MB is retained, a liquid retention portion14A in which the magenta (M) ink15M is retained, a liquid retention portion14D in which the cyan (C) ink15C is retained, and a liquid retention portion14E in which the yellow (Y) ink15Y is retained are mounted in a mounting portion70, arranged along a Y direction. Each of the liquid retention portions14G,14H,14A,14D, and14E can be attached and detached to and from the mounting portion70in an individual manner.

The retention capacities of the ink15in the liquid retention portions14G,14A,14D, and14E are all the same, and are the same retention capacity as that of Embodiment 1. The retention capacity of the ink15MB in the liquid retention portion14H is greater than the retention capacity of the ink15of the liquid retention portions14G,14A,14D, and14E, and is twice the retention capacity of the ink15of the liquid retention portions14G,14A,14D, and14E. This feature is a difference from Embodiment 1.

That is, the liquid retention portion14H is an example of “a liquid retention portion having the greatest retention capacity”.

In a state in which a sealing portion74is fixed to a main body portion72, five flow channels7A,7B,7D,7E, and7F (simply referred to as flow channels7in some cases from this point onwards) through which the ink15flows, are formed in portions surrounded by a flow channel surface SB1of the sealing portion74and a fixing surface SA2of a base portion722.

In a state in which the sealing portion74is fixed to the main body portion72, five flow channels7A,7B,7D,7E, and7F are formed in the present embodiment, and six flow channels7A,7B,7C,7D,7E, and7F are formed in Embodiment 1. This feature is a difference between the present embodiment and Embodiment 1. In other words, the flow channel7according to the present embodiment has a configuration in which the flow channel7C has been omitted from the flow channels7according to Embodiment 1.

The flow channel7A is a flow channel of the ink15PB that supplies the ink15PB to a head80from the liquid retention portion14G. The flow channel7B is a flow channel of the ink15MB that supplies the ink15MB to the head80from the liquid retention portion14H. The flow channel7D is a flow channel of the ink15M that supplies the ink15M to the head80from the liquid retention portion14A. The flow channel7E is a flow channel of the ink15C that supplies the ink15C to the head80from the liquid retention portion14D. The flow channel7F is a flow channel of the ink15Y that supplies the ink15Y to the head80from the liquid retention portion14E.

In the present embodiment, among flow channel lengths of the plurality of flow channels7A,7B,7D,7E, and7F, a flow channel length of the flow channel7B that supplies the ink15MB, which is retained in the liquid retention portion14H that has the greatest retention capacity is shortest.

In the present embodiment, a discharge opening of the ink15MB in the liquid retention portion14H, a communication opening744B, and a corresponding introduction opening854are disposed so as to overlap with one another when viewed in a planar manner so that the flow channel length of the flow channel7B of the matte black (MB) ink15MB is the shortest. That is, at least a portion of the liquid retention portion14H, which has the greatest retention capacity, is disposed so as to overlap with the head80when viewed in a planar manner so that the flow channel length of the flow channel7B of the matte black (MB) ink15MB is the shortest.

Since it is easier to visually recognize dots formed by the matte black (MB) ink15MB than dots formed by the other types of ink15PB,15M,15C, and15Y, dot omission of the ink15MB stands out more than dot omission of the other types of ink15PB,15M,15C, and15Y.

Therefore, if it is unlikely that a defect (dot omission of the ink15MB) caused by air bubbles and a defect (dot omission of the ink15MB) will occur in the matte black (MB) ink15MB as a result of the flow channel resistance being high, it is possible to enhance the appearance quality of characters, images, and the like, recorded on the medium12.

In the present embodiment, since the flow channel length of the flow channel7B of the matte black (MB) ink15MB in which defects stand out the most is the shortest, it is unlikely that air bubbles will remain in the flow channel of the ink15MB that runs from a liquid retention portion14to the nozzle N of the head80, and therefore, it is unlikely that a defect (dot omission of the ink15MB) will occur as a result of air bubbles in the ink15MB.

Furthermore, in the present embodiment, since the flow channel length of the flow channel7B of the matte black (MB) ink15MB is the shortest and the flow channel resistance of the matte black (MB) ink15MB is the lowest as a result, it is unlikely that a defect (dot omission of the ink15MB) will occur as a result of the flow channel resistance of the ink15MB being high.

Accordingly, as a result of making the flow channel length of the flow channel7B of the matte black (MB) ink15MB in which defects stand out the most the shortest, it is unlikely that either one of a defect (dot omission of the ink15MB) caused by air bubbles in the ink15MB or a defect (dot omission of the ink15MB) will occur as a result of the flow channel resistance of the ink15MB being high, and therefore, it is possible to enhance the appearance quality of characters, images, and the like recorded on the medium12.

FIG. 8is a view that corresponds toFIG. 1, and is a configuration view of a liquid ejecting apparatus according to Embodiment 3.FIG. 9is a view that corresponds toFIG. 2, and is cross-sectional view along a line IX-IX inFIG. 8.FIG. 10is a view that corresponds toFIG. 4, and is an exploded perspective view of a liquid ejecting unit.FIG. 11is a schematic view of the main components of a valve unit. That is,FIG. 11is a schematic view of a flow pressure adjustment portion133built into a valve unit17.

Hereinafter, an outline of a liquid ejecting apparatus1B according to the present embodiment will be described focusing on the differences from Embodiment 1 with reference toFIGS. 8 to 11. In addition, constituent sites that are the same as those of Embodiment 1 will be given the same reference numerals, and overlapping descriptions thereof will be omitted.

As shown inFIG. 8, the liquid ejecting apparatus1B according to the present embodiment is an off-carriage type printing apparatus in which ink tanks16A,16B,16C,16D,16E, and16F (simply referred to as ink tanks16in some cases from this point onwards), in which types of ink15M,15B,15LC,15C,15Y, and15LM are retained, are disposed in locations that are separate from a support body60(a carriage). On the other hand, the liquid ejecting apparatus1according to Embodiment 1 is an on-carriage type printing apparatus in which the liquid retention portions14, in which the ink15is retained, are disposed in the support body60(a carriage).

This feature is a difference between the present embodiment and Embodiment 1.

Magenta (M) ink15M is retained in the ink tank16A, black (B) ink15B is retained in the ink tank16B, light cyan (LC) ink15LC is retained in the ink tank16C, cyan (C) ink15C is retained in the ink tank16D, yellow (Y) ink15Y is retained in the ink tank16E, and light magenta (LM) ink15LM is retained in the ink tank16F.

The six types (six colors) of the ink15retained in the ink tanks16are respectively pressurized by a pressurization portion18, and are supplied to a head80via six ink supply tubes19, and six valve units17A,17B,17C,17D,17E, and17F (referred to as valve units17in some cases from this point onwards).

A feature of the valve units17being disposed on an upstream side in a flow direction of the ink15with respect to the head80is a difference between the present embodiment and Embodiment 1.

The valve units17adjust the flow pressure of the ink15supplied to the head80so that the ink15is ejected stably from the nozzles N of the head80. That is, the flow pressure of the ink15supplied to the head80is adjusted by flow pressure adjustment portions133provided in flow channels (referred to as liquid flow channels from this point onwards) of the ink15inside the valve units17.

In the present embodiment, a single flow pressure adjustment portion133is built-into each valve unit17so that it is possible to adjust the flow pressure of the ink15of a single color by using a valve unit17. Therefore, the valve units17are respectively connected to six ink supply tubes19.

Additionally, the valve units17may also have a configuration that includes a plurality of flow pressure adjustment portions133that adjust the flow pressure of a plurality of colors of the ink15.

The flow pressure adjustment portions133include an ink introduction channel134, an ink supply chamber135in which the ink15is retained, a filter136provided inside the ink supply chamber135, a valve body137, a pressure chamber138in which the ink15is retained, and an ink lead-through channel139. The ink15supplied in a pressurized manner by the pressurization portion18is supplied to the head80as a result of passing through the ink introduction channel134, the ink supply chamber135, the valve body137, the pressure chamber138, and the ink lead-through channel139.

In this manner, the valve units17, in which the ink15is retained in the inner portion (the flow pressure adjustment portions133) thereof, are an example of “a liquid retention portion”.

The ink15is supplied to the ink supply chamber135in a pressurized state. The valve body137is disposed between the ink supply chamber135and the pressure chamber138, and opens and closes a liquid flow channel between the ink supply chamber135and the pressure chamber138. The ink supply chamber135is disposed on an upstream side of the liquid flow channel with respect to the valve body137, and the pressure chamber138is disposed on the downstream side of the liquid flow channel with respect to the valve body137.

During a printing operation, the pressure chamber138is sequentially replenished with the ink15from the ink supply chamber135while the valve body137opens slightly in accordance with consumption of ink15. Furthermore, pressure fluctuations in the ink15inside the ink supply chamber135on the upstream side of the liquid flow channel are isolated from pressure changes of the ink15inside the pressure chamber138on the downstream side of the liquid flow channel as a result of being restricted to be within a given predetermined range due to opening and closing of the valve body137. Accordingly, even if a pressure change occurs further on the upstream side of the liquid flow channel than the valve body137, the downstream side of the liquid flow channel is not subjected to the effects thereof. Therefore, the flow pressure of the ink15supplied to the head80is adjusted as a result of the pressure that acts on the ink15inside the pressure chamber138of the flow pressure adjustment portion133(the valve unit17) being controlled to be in a predetermined range.

To explain in more detail, the valve units17adjust the pressure of the ink15supplied to the head80so that negative pressure is applied to the ink supplied to the nozzles N in order for the ink to be ejected properly from the nozzles N during printing without the ink15leaking out from the nozzles N of the head80during non-printing.

The ink15M is supplied to a corresponding introduction opening854of the head80via the valve unit17A and the flow channel7A. The ink15B is supplied to a corresponding introduction opening854of the head80via the valve unit17B and the flow channel7B. The ink15LC is supplied to a corresponding introduction opening854of the head80via the valve unit17C and the flow channel7C. The ink15C is supplied to a corresponding introduction opening854of the head80via the valve unit17D and the flow channel7D. The ink15Y is supplied to a corresponding introduction opening854of the head80via the valve unit17E and the flow channel7E. The ink15LM is supplied to a corresponding introduction opening854of the head80via the valve unit17F and the flow channel7F.

The present embodiment has a configuration in which the flow channel length of the flow channel7B of the black (B) ink15B in which defects stand out the most is the shortest.

As a result of making the flow channel length of the flow channel7B of the black (B) ink15B in which defects stand out the most the shortest, it is unlikely that air bubbles will remain in the flow channel of the ink15B that runs from the valve unit17to the nozzle N of the head80, and therefore, it is unlikely that a defect (dot omission of the ink15B) caused by air bubbles in the ink15B.

Furthermore, the flow channel resistance of the black (B) ink15B is the lowest, and therefore, it is unlikely that a defect (dot omission of the ink15B) will occur as a result of the flow channel resistance of the ink15B being high.

Accordingly, as a result of making the flow channel length of the flow channel7B of the black (B) ink15B in which defects stand out the most the shortest, it is unlikely that either one of a defect (dot omission of the ink15B) caused by air bubbles in the ink15B or a defect (dot omission of the ink15B) will occur as a result of the flow channel resistance of the ink15B being high, and therefore, it is possible to enhance the appearance quality of characters, images, and the like recorded on the medium12.

The present invention is not limited to the abovementioned embodiments, can be changed as appropriate within a range that does not depart from the scope or the idea of the invention that can be understood from the claims and the entirety of the specification, and it is possible to consider various modification examples in addition to the above-mentioned embodiments. Hereinafter, modification examples will be described.

Modification Example 1

It is more likely that a defect such as dot omission will occur in an ink having a high frequency of use (an ink for which there are a large number of repetitions of being ejected from a head) than in an ink having a low frequency of use (an ink for which there are a small number of repetitions of being ejected from the head). Furthermore, it is important for it to be more unlikely for a dot defect to occur in an ink for which it is likely that a dot defect will stand out than in an ink for which it is unlikely that a dot defect will stand out. Therefore, it is preferable that the flow channel length of a flow channel that supplies an ink having a high frequency of use and an ink for which it is likely that a dot defect will stand out be short.

For example, in a case in which there is a difference in the frequency of use and the likelihood that defects will stand out in the inks that are used in a liquid ejecting apparatus, it is preferable that ink having a high frequency of use and ink for which it is likely that defects will stand out be supplied via flow channels for which the flow channel length is short, and that ink having a low frequency of use and ink for which it is unlikely that defects will stand out be supplied via flow channels for which the flow channel length is long.

For example, in Embodiment 1, the flow channel lengths increase in the order of the flow channel7B, the flow channel7C, the flow channel7A, the flow channel7D, the flow channel7E, and the flow channel7F. In the above-mentioned manner, it is preferable that the ink15having the highest frequency of use (the ink15B) be supplied via the flow channel7B for which the flow channel length is the shortest. It is preferable that the ink15having the next highest frequency of use be supplied via the flow channel7C for which the flow channel length is the next shortest. It is preferable that the ink15having the next highest frequency of use be supplied via the flow channel7A for which the flow channel length is the next shortest. It is preferable that the ink15having the next highest frequency of use be supplied via the flow channel7D for which the flow channel length is the next shortest. It is preferable that the ink15having the next highest frequency of use be supplied via the flow channel7E for which the flow channel length is the next shortest. Further, it is preferable that the ink15having the lowest frequency of use be supplied via the flow channel7F for which the flow channel length is the longest, that is, it is preferable that the flow channels that supply the ink be selected depending on the frequency of use and the likelihood that defects will stand out.

Modification Example 2

In addition to machines that are dedicated to printing, a similar configuration to that of the liquid ejecting apparatuses1,1A, and1B illustrated by way of example in the above-mentioned embodiments can be applied to various machines such as facsimile apparatuses and copy machines.

Furthermore, the applications of the liquid ejecting apparatus of the invention are not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a color material can be used as a manufacturing apparatus that forms color filters of a liquid crystal display apparatus. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material can be used as a manufacturing apparatus that forms wiring substrates and electrodes.