JP2009012383A - Fluid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jetting apparatus which solves a malfunction caused by mixing of fluids when the fluid is forcibly sucked from a jetting head. <P>SOLUTION: The fluid jetting apparatus includes a jetting head 13 equipped with a nozzle forming face in which a plurality of the nozzle openings 17 are formed and jetting the fluid from the nozzle openings 17, and a fluid recovering part for recovering the fluid forcibly sucked under a condition that it is brought into contact with the jetting head 13. The fluid recovering part has a lyophilic pattern part 60 provided in accordance with the nozzle openings 17 and exhibiting lyophilic properties to the fluid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus.

As a fluid ejecting apparatus, an ink jet recording apparatus that ejects ink (fluid) onto a recording medium from nozzles formed on a recording head (ejection head) is known. 2. Description of the Related Art Conventionally, in a fluid ejecting apparatus, a capping device including a cap member that is in contact with a recording head so as to surround a nozzle is provided in order to suppress deterioration of nozzle ejection characteristics due to drying or the like.
Further, in the fluid ejecting apparatus, for the purpose of maintaining or restoring the ejection characteristics of the nozzle, the closed space formed by the cap member coming into contact with the recording head is decompressed, and ink is forcibly sucked from the nozzle. (For example, refer to Patent Document 1).
JP 2002-234195 A

By the way, in the above prior art, ink color mixture occurs on the nozzle formation surface during forced suction of ink. Then, after the ink is sucked, the inside of the nozzle is still in a negative pressure state, so the mixed color ink adhering to the nozzle forming surface is drawn into the nozzle, and the ink is mixed in the nozzle. Therefore, there is a possibility that ink of a desired color cannot be ejected from the nozzle. In this case, in order to recover the print quality, it is necessary to perform a so-called flushing process in which ink is ejected from each nozzle, and the ink consumption increases.
In particular, when the recording head is a line head, the number of nozzles is large, so that the possibility that the print quality is deteriorated increases.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a fluid ejecting apparatus that eliminates problems caused by mixing of fluids when the fluid is forcibly sucked from the ejecting head.

  In order to solve the above problems, a fluid ejecting apparatus according to the present invention includes a nozzle forming surface having a plurality of nozzle openings, and ejects a fluid from the nozzle, in a state of being in contact with the ejecting head. In the fluid ejecting apparatus including the fluid recovery unit that recovers the fluid, the fluid recovery unit includes a lyophilic pattern unit that is provided corresponding to the nozzle opening and exhibits lyophilicity with respect to the fluid. Features.

According to the fluid ejecting apparatus of the present invention, the fluid sucked from the nozzles is collected via the corresponding lyophilic pattern portions, so that the fluid sucked from the nozzles is prevented from being mixed.
Therefore, when the fluid recovery member is separated from the ejection head after the suction process, the fluid corresponding to each nozzle is drawn into the negative pressure nozzle.
Therefore, since the mixed fluid does not enter the nozzle during the suction process, a flushing process for recovering the print quality is unnecessary, and it is possible to prevent the fluid from being wasted.

In the fluid ejecting apparatus, it is preferable that the fluid recovery unit includes a liquid repellent pattern portion that exhibits liquid repellency with respect to the fluid between the lyophilic pattern portions.
According to this configuration, the liquid-repellent pattern portion formed between the lyophilic pattern portions functions as a partition wall that repels the fluid, thereby preventing the suctioned fluid from being mixed and recovering well.

In the fluid ejecting apparatus, the fluid recovery part includes an absorbing member that can absorb the fluid, and the lyophilic pattern part and the liquid repellent pattern part are formed on the absorbing member. preferable.
According to this configuration, for example, by providing a fluid absorbing member made of a porous material such as a sponge, mixing can be prevented and fluid can be recovered well.

In the fluid ejecting apparatus, it is preferable that the lyophilic pattern portion is provided corresponding to each nozzle opening.
According to this configuration, it is possible to prevent the fluid from being mixed between the nozzle openings, so that a highly reliable suction process can be performed.

In the fluid ejecting apparatus, it is preferable that the lyophilic pattern portion is provided corresponding to a nozzle row that ejects the same kind of fluid in the nozzle openings.
According to this configuration, it is possible to simplify the structure by forming the lyophilic pattern portion for each nozzle row.

In the fluid ejecting apparatus, the absorbing member is provided with a connecting portion that connects the lyophilic pattern portions at a position separated from the nozzle opening in the thickness direction of the absorbing member. It is preferable that a suction port for sucking the fluid communicates.
According to this configuration, since the fluid can be sucked from each nozzle via one suction port communicating with the connecting portion, the configuration of the suction mechanism can be simplified. Moreover, since the connection part is provided in the position spaced apart from the nozzle, the fluid mixed in the connection part is not drawn into the nozzle.

In the fluid ejecting apparatus, it is preferable that the lyophilic pattern portion is formed in a concave shape with respect to the liquid repellent pattern portion on the surface of the absorbing member that is in contact with the ejecting head.
According to this configuration, the sucked fluid is temporarily accommodated in the recess formed by the lyophilic pattern portion and discharged. Therefore, since the liquid repellent pattern portion functions as a partition wall, the fluid can be favorably flowed into the lyophilic pattern portion, and the fluid recoverability can be improved.

In the fluid ejecting apparatus, the contact angle of the fluid with respect to the nozzle forming surface of the ejecting head is θ, the pitch of the nozzles formed on the nozzle forming surface is W, and the fluid recovery member is disposed on the ejecting head. When the distance between the lyophilic pattern portion and the nozzle forming surface at the time of contact is h, it is preferable that the relationship h ≦ W (1-cos θ) / (2 sin θ) is satisfied.
According to this configuration, the fluid that has flowed out of the nozzle by suction can be brought into contact with the lyophilic pattern portion without contacting the fluid of the adjacent nozzle. Therefore, it is possible to reliably prevent the fluid from being mixed during suction.

In the fluid ejecting apparatus, it is preferable that the ejecting head is a line head.
According to this configuration, as described above, the flushing process for discharging the mixed fluid can be eliminated, so that the fluid consumption can be suppressed in a line head having a large number of nozzles, which is effective.

(First embodiment)
Hereinafter, an embodiment of a fluid ejecting apparatus according to the invention will be described with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In this embodiment, an ink jet printer is exemplified as the fluid ejecting apparatus according to the invention.

FIG. 1 is a schematic configuration diagram of an ink jet printer (hereinafter referred to as an ink jet printer 100) of the present embodiment, FIG. 2 is a plan view of a main part around a line head, and FIG. FIG.
In the present embodiment, the inkjet printer 100 includes a recording unit 10 that performs recording on the recording paper 12 and a maintenance unit 11 that performs maintenance processing on the recording unit 10 as illustrated in FIGS. 1 and 2.

(Recording part)
The recording unit 10 ejects ink droplets to form a line head 13 (ejection head) that forms an image on a recording paper 12 that is a fluid ejection target, a recording paper conveyance mechanism 14 that conveys the recording paper 12, and a line head 13. And an ink reservoir 15 that stores ink (fluid) to be supplied.

The recording paper transport mechanism 14 includes a paper feed motor (not shown), a paper feed roller (platen) 4 that is rotationally driven by the paper feed motor, and the like. 12 are sequentially sent out so as to face the line head 13.

  The ink storage unit 15 is disposed on one side of the printer main body 16 and supplies ink to the line head 13 described later by an ink supply unit (not shown). The ink storage unit 15 is an ink of a color corresponding to each color (yellow (Y), magenta (M), cyan (C), black (K1: dye system), black (K2: pigment system)) of the inkjet printer 100. Ink tanks 15Y, 15M, 15C, 15K1, and 15K2 are stored and communicated with the line head 13 through ink supply means.

  The line head 13 is a line type recording head in which a number of nozzles are arranged over a length (maximum recording paper width P) exceeding at least one side of the maximum size recording paper 12 targeted by the inkjet printer 100. In the present embodiment, at least five printing sections 5Y, 5M, 5C, 5K1, and 5K2 corresponding to each color (Y, M, C, K1, and K2) are provided. Each of the printing units 5Y, 5M, 5C, 5K1, and 5K2 has a nozzle row L (see FIG. 3) in which a large number of nozzles 17 for ejecting ink droplets are arranged and arranged. They are arranged in order along the direction. The nozzle row L is one row line by the nozzle openings 17 or a plurality of lines by the nozzle openings 17, and the number of nozzle openings 17 and the number of lines are appropriately set. FIG. 3 shows an embodiment of the nozzle row L, and shows a plurality of lines by the nozzle openings 17. By increasing the number of lines, a wide range of recording can be performed at once, and the resolution of the image is also increased.

  The line head 13 is arranged such that the length direction corresponding to the maximum recording paper width P is orthogonal to the conveyance direction of the recording paper 12, and ink droplets are ejected from the nozzle openings 17 of the nozzle rows L onto the recording paper 12. Thus, an image is recorded on the recording paper 12.

  The ink supply means that communicates the ink storage unit 15 and the line head 13 has a plurality of ink supply channels, and the respective ink tanks 15Y, 15M, 15C, 15K1, and 15K2 to the respective printing units 5Y, 5M, and 5C. , 5K1 and 5K2 are supplied with ink.

Hereinafter, the configuration of the line head will be described in detail with reference to FIG. FIG. 4 is a cross-sectional view showing a part of the line head.
The line head 13 includes a head main body 18 and a flow path forming unit 22 including a vibration plate 19, a flow path substrate 20, and a nozzle substrate 21. The nozzle openings 17 for ejecting ink are formed in the nozzle substrate 21, and the lower surface of the nozzle substrate 21 is a nozzle formation surface 21A. The flow path forming unit 22 is a unit in which the diaphragm 19, the flow path substrate 20, and the nozzle substrate 21 are laminated and joined together with an adhesive or the like.

  The line head 13 includes an accommodation space 23 formed inside the head body 18 and a drive unit 24 disposed in the accommodation space 23. The drive unit 24 includes, for example, a plurality of piezoelectric elements 25, a fixing member 26 that supports the upper end of the piezoelectric elements 25, and a flexible cable 27 that supplies a drive signal to the piezoelectric elements 25. The piezoelectric element 25 is provided so as to correspond to each of the plurality of nozzle openings 17.

  In addition, an internal flow path 28 that is formed inside the head body 18 and flows ink supplied from the ink tank via the ink supply flow path, and a flow path that includes the vibration plate 19, the flow path substrate 20, and the nozzle substrate 21. A common ink chamber 29 formed by the forming unit 22 and connected to the internal flow path 28, an ink supply port 30 formed by the flow path forming unit 22 and connected to the common ink chamber 29, and the flow path forming unit 22. A pressure chamber 31 formed and connected to the ink supply port 30 is provided. A plurality of pressure chambers 31 are provided so as to correspond to the plurality of nozzle openings 17. Each of the plurality of nozzle openings 17 is connected to each of the plurality of pressure chambers 31.

  The head body 18 is made of synthetic resin. The diaphragm 19 is obtained by laminating an elastic film on a metal support plate such as stainless steel. An island portion 32 joined to the lower end of the piezoelectric element 25 is formed at a portion corresponding to the pressure chamber of the diaphragm 19. At least a part of the diaphragm 19 is elastically deformed according to the driving of the piezoelectric element 25. A compliance portion 33 is formed between the diaphragm 19 and the vicinity of the lower end of the internal flow path 28.

  The flow path substrate 20 has recesses for forming spaces for the common ink chamber 29, the ink supply port 30, and the pressure chamber 31 that connect the lower end of the internal flow path 28 and the nozzle opening 17. In the present embodiment, the flow path substrate 20 is formed by anisotropic etching of silicon.

  The nozzle substrate 21 has a plurality of nozzle openings 17 formed at a predetermined interval (pitch) in a predetermined direction as will be described later. The nozzle substrate 21 of the present embodiment is a plate-like member formed of a metal such as stainless steel.

  The ink supplied from each ink tank through each ink supply channel flows into the upper end of the internal channel 28. The lower end of the internal flow path 28 is connected to the common ink chamber 29, and the ink that has flowed from the ink tank to the upper end of the internal flow path 28 via the ink supply flow path flows through the internal flow path 28 and is then shared. The ink is supplied to the ink chamber 29. The ink supplied to the common ink chamber 29 is supplied through the ink supply port 30 so as to be distributed to each of the plurality of pressure chambers 31.

  When a drive signal is input to the piezoelectric element 25 via the cable 27, the piezoelectric element 25 expands and contracts. As a result, the diaphragm 19 is deformed (moved) in a direction toward and away from the pressure chamber. As a result, the volume of the pressure chamber 31 changes, and the pressure of the pressure chamber 31 containing ink fluctuates. Ink is ejected from the nozzle openings 17 due to this pressure fluctuation.

  As described above, the piezoelectric element 25 (driving element) of the present embodiment ejects ink from the nozzle opening 17, so that the pressure chamber 31 (space) connected to the nozzle opening 17 is based on the input driving signal. Vary the pressure. Then, a desired image is formed on the recording paper 12 by the ink ejected from the nozzle opening 17.

The line head 13 can be moved in the vertical direction by a line head moving mechanism (not shown).
More specifically, the line head 13 is movable in the vertical direction between the printing position and the maintenance position by the line head moving mechanism.
The printing position is a position where recording is performed by ejecting ink from the nozzle openings 17 of the line head 13 to the recording paper 12, and is a position where the line head 13 is relatively moved upward. The maintenance position is a position where the maintenance process of the line head 13 is performed by the maintenance unit 11 described in detail below.

(Maintenance Department)
Next, the configuration of the maintenance unit 11 will be described in detail.
As shown in FIG. 1, the maintenance unit 11 discharges the capping mechanism 40 that prevents the nozzle opening 17 from drying or prevents the ink viscosity from increasing near the nozzle opening 17 and the ink collected in the capping mechanism 40 by forcibly suctioning the ink. A capping maintenance unit 42 (see FIG. 10) including the ink discharge unit 41, a waste ink tank 39 for collecting the ink discharged by the ink discharge unit 41, and the like are provided.

5 is a diagram showing a schematic configuration of the capping mechanism 40, FIG. 5A is a perspective view showing a schematic configuration of the capping mechanism 40, and FIG. 5B is a cross-sectional shape of the capping mechanism 40 in the short side direction. FIG.
As shown in FIG. 5, the capping mechanism 40 includes a cap member (fluid recovery unit) 43 that is molded into a tray shape using a resin or the like. The capping mechanism 40 enables a process of forcibly sucking ink from the line head 13 to maintain or restore the ejection characteristics of the nozzle openings 17. In addition, an ink absorbing member (absorbing member) 65 composed of a sponge-like member or a porous member that can absorb ink is provided inside the cap member 43.

  As for the cap member 43, the peripheral part 43a is shape | molded by the frame shape. The cap member 43 includes a seal portion 80 formed on the peripheral edge portion 43a. The seal portion 80 is formed so as to surround the nozzle formation region when the cap member 43 contacts the nozzle formation surface 21A.

The seal portion 80 is made of, for example, an elastomer. Any other forming material can be used as long as it can be deformed following the surface shape of the line head 13 when pressed.
Such a cap member 43 can form a closed space between the peripheral edge portion 43a (seal portion 80) and the nozzle forming surface 21A by contacting the nozzle forming surface 21A.

  6 is a perspective view showing the configuration of the ink absorbing member 65, FIG. 7 is a plan view showing the configuration of the ink absorbing member 65, and FIG. 8 shows the positional relationship between the lyophilic pattern portion 60 and the nozzle openings 17. FIG.

  As shown in FIG. 6, the ink absorbing member 65 includes the lyophilic pattern portion 60 that exhibits lyophilicity with respect to the ink ejected from the nozzle opening 17, and the ink ejected from the nozzle opening 17. And a liquid repellent pattern 61 exhibiting liquid repellency. As shown in FIG. 7, the lyophilic pattern portion 60 is provided corresponding to the nozzle opening 17, and the lyophobic pattern portion 61 is disposed between the lyophilic patterns 60.

  Here, the lyophilic pattern portion 60 may be formed corresponding to each nozzle opening 17, and the lyophilic pattern portion 60 may be formed for each nozzle row that ejects at least the same color ink. Specifically, in the present embodiment, as shown in FIG. 7, the lyophilic pattern portion 60 is formed so as to correspond to the nozzle row L that ejects the same color ink. That is, in this embodiment, since the line head 13 has five nozzle rows L, the ink absorbing member 65 has five lyophilic pattern portions 60. The lyophilic pattern portion 60 is formed in the thickness direction of the ink absorbing member 65.

  The lyophilic pattern portion 60 is composed of the base material (sponge-like member or porous member) itself that constitutes the ink absorbing member 65. On the other hand, the liquid repellent pattern portion 61 is configured by applying, for example, a fluorine coat to the base material constituting the ink absorbing member 65. Here, the liquid repellency and lyophilicity with respect to the ink are relative, and the liquid repellent pattern portion 61 means a region where the wettability of the ink is relatively lower than that of the lyophilic pattern portion 60. Therefore, the liquid repellent pattern portion 61 to which the fluorine coating is applied has relatively low ink wettability as compared with the lyophilic pattern portion 60.

As shown in FIG. 8, the lyophilic pattern portion 60 is connected to the ink absorbing member 65 at a position away from the nozzle opening 17 in the thickness direction of the ink absorbing member 65 (Z-axis direction in the drawing). A connecting portion 63 is provided. A suction port 67 connected to the capping maintenance unit 42 for forcibly sucking ink accumulated in the capping mechanism 40 communicates with the connecting portion 63.
With such a configuration, the ink sucked by the capping maintenance unit 42 is collected by the connecting unit 63 and then discharged to the outside through the suction port 67.

  FIG. 9 is a diagram showing the positional relationship between the capping mechanism 40 and the line head 13 during maintenance processing (ink suction).

  Here, if the distance between the ink absorbing member 65 and the nozzle forming surface 21 </ b> A is too large, the nozzle openings of the nozzle row L that are being sucked before the ink sucked from the nozzle openings 17 contacts the ink absorbing member 65. There is a possibility that the ink wetted and spread on the nozzle forming surface 21A from 17 and the ink wetted and spread on the nozzle forming surface 21A from the nozzle openings 17 of the other adjacent nozzle rows L may be mixed. As described above, since different colors of ink are ejected from each nozzle row L, ink color mixing occurs on the nozzle forming surface 21A.

  As a means for preventing such ink color mixture, in the ink jet printer 100 according to this embodiment, as shown in FIG. 9, the static contact angle of the ink with respect to the nozzle forming surface 21A of the line head 13 is θ, and the line head The pitch of the 13 nozzle rows L is W, and the distance between the lyophilic pattern portion 60 and the nozzle forming surface 21A when the cap member 43 is brought into contact with the line head 13 is h. Yes.

Hereinafter, the expression 10 will be described.
FIG. 10 shows a state in which ink is drawn from the nozzle opening 17 onto the nozzle formation surface 21A by suction, and is a diagram for explaining Equation 10 that defines the distance between the nozzle formation surface 21A and the lyophilic pattern portion 60. .

  In FIG. 10A, when the ink surface position is expressed in polar coordinates, the following equations 2 and 3 can be defined.

  x = r cos θa (Formula 2)

  y = rsinθa (Formula 3)

  Here, since it is represented by θa = 90 ° −θ, the above formulas 2 and 3 are defined by the following formulas 4 and 5.

  x = rsinθ (Formula 4)

  y = r cos θ (Formula 5)

  As shown in FIG. 10B, assuming that the pitch between the nozzle rows L is W, if the width of the ink droplet is W / 2, ink mixing will not occur. That is, the distance h between the nozzle formation surface 21A and the lyophilic pattern portion 60 (ink absorbing member 65) may be equal to or less than the droplet height when the droplet width is W / 2.

  Here, substituting x = W / 2 into the above equation 4 and developing for r, the following equation 6 is obtained.

  r = W / 2sin θ (Formula 6)

  Further, when the droplet height is Yink, it is defined by the following formula 7.

  Yink = r cos 90 ° −r cos θ (formula 7)

  When this equation 7 is rearranged, the following equation 8 is obtained.

  Yink = r (1-cos θ) (Formula 8)

  Substituting Equation 6 into Equation 8 yields Equation 9 below.

  W (1-cos θ) / (2 sin θ) (Equation 9)

  The droplet height represented by Equation 9 is a gap from the nozzle opening 17 to the lyophilic pattern portion 60 (ink absorbing member 65), and within this gap, no ink color mixing occurs on the nozzle forming surface 21A. Become.

  Therefore, Expression 10, which is a condition for preventing ink color mixing on the nozzle forming surface 21A, is defined.

  h ≦ W (1-cos θ) / (2 sin θ) (Formula 10)

  In the present embodiment, the cap member 43 is brought into contact with the line head 13 so as to satisfy the above formula 10. Therefore, a gap S is generated as shown in FIG. 9 between the ink wetted and spread on the nozzle forming surface 21A from the adjacent nozzle row L (nozzle opening 17) by suction. Therefore, it is possible to prevent ink color mixture from occurring near the nozzle formation surface 21A during ink suction.

  With this configuration, the ink forcibly sucked from the nozzle opening 17 by the capping maintenance unit 42 flows into the lyophilic pattern unit 60. In addition, the liquid repellent pattern portion 61 provided between the lyophilic pattern portions 60 functions as a partition wall for repelling ink, and the inks sucked from different nozzle rows L are prevented from being mixed with each other. It has become.

(Ink discharge part)
Hereinafter, the ink discharging unit will be described in detail with reference to FIG. FIG. 11 is a diagram illustrating a configuration of the suction pump connected to the cap member 43.
The ink discharge unit 41 is connected to the cap member 43 and discharges ink accumulated in the cap member 43, and a suction pump 49 for sucking ink collected in the cap member 43 into the ink discharge channel. Etc.

  On the bottom wall of the cap member 43, a protruding portion 46 for discharging the ink 2 accumulated in the cap member 43 is protruded downward, and a discharge passage 46a is formed inside thereof. One end side of the discharge passage 46 a passes through the cap member 43, and constitutes a suction port 67 that communicates with the connecting portion 63 of the ink absorbing member 65 provided inside the cap member 43.

One end of a discharge tube 47 made of a flexible material or the like that functions as the ink discharge channel is connected to the protrusion 46, and the other end of the discharge tube 47 is inserted into the waste ink tank 39. .
In the waste ink tank 39, a waste ink absorbing material 48 made of a porous member is accommodated, and the ink 2 collected by the waste ink absorbing material 48 is absorbed.

  A tube pump type suction pump 49 is disposed between the cap member 43 and the waste ink tank 39. The suction pump 49 has a cylindrical case 50, and a pump wheel 51 having a circular shape in plan view is rotated around a wheel shaft 52 provided at the axial center of the case 50. Contained as possible. And in this case 50, the intermediate part 47a of the discharge tube 47 is accommodated along the inner peripheral wall 50a of the case 50.

The pump foil 51 is formed with a pair of arcuate roller guide grooves 53 and 54 that swell outward, with the wheel shaft 52 interposed therebetween. One end of each of the roller guide grooves 53 and 54 is positioned on the outer peripheral side of the pump wheel 51, and the other end is positioned on the inner peripheral side of the pump wheel 51. That is, both the roller guide grooves 53 and 54 gradually extend away from the outer peripheral portion of the pump wheel 51 as they go from one end to the other end.
A pair of rollers 55 and 56 as pressing means are inserted and supported in both roller guide grooves 53 and 54 through rotation shafts 55a and 56a, respectively. Both the rotating shafts 55a and 56a are slidable in the roller guide grooves 53 and 54, respectively.

When the pump wheel 51 is rotated in the forward direction (arrow direction), both rollers 55 and 56 move to one end side of both roller guide grooves 53 and 54 (the outer peripheral side of the pump wheel 51), and the discharge tube 47. The intermediate portion 47a is rotated while being sequentially crushed (pressed) from the upstream side to the downstream side. By this rotation, the inside of the discharge tube 47 on the upstream side of the suction pump 49 is decompressed.
As a result, the ink accumulated in the ink absorbing member 65 provided inside the cap member 43 is gradually discharged toward the waste ink tank 39 as the pump wheel 51 rotates in the forward direction. Yes.

  Further, when the pump wheel 51 is rotated in the reverse direction (the direction opposite to the arrow direction), the rollers 55 and 56 move to the other end side of the roller guide grooves 53 and 54 (the inner peripheral side of the pump wheel 51). It is supposed to be. By this movement, both rollers 55 and 56 are in light contact with the intermediate portion 47a of the discharge tube 47, and the reduced pressure state inside the discharge tube 47 is eliminated. The pump wheel 51 is driven to rotate by a paper feed motor of the recording paper transport mechanism 14.

(Maintenance processing)
Hereinafter, a case where maintenance processing is performed on the line head 13 using the maintenance unit 11 in the inkjet printer 100 of the present embodiment will be described with reference to a flowchart shown in FIG.

When print data is transmitted from the outside, a control device (not shown) develops the ejection data corresponding to the dot pattern and transmits it to the line head 13. The line head 13 executes recording (printing / printing) processing, that is, ejection of ink droplets onto the recording paper, based on the received ejection data (step S1).
When a preset time has elapsed (step S2), the periodic maintenance process is started.

  When the maintenance process starts, the control device lowers the line head 13 until the cap member 43 comes into contact with the nozzle forming surface 21 </ b> A, brings the seal portion 80 into close contact with the nozzle forming surface 21 </ b> A, and connects the nozzle forming surface 21 </ b> A and the cap member 43. A space is formed between them (step S3).

Subsequently, the control device drives the suction pump 49 to reduce the space formed between the nozzle-forming surface 21A and the cap member 43 and thereby from the inside of the line head 13 through the nozzle opening 17. A suction operation for forcibly discharging ink is performed (step S4).
At this time, since the space formed between the cap member 43 and the nozzle formation surface 21A is a closed space as described above, the space can be decompressed well by driving the suction pump 49. For this reason, the ink in the line head 13 can be forcedly discharged from the nozzle opening 17 satisfactorily.

  At this time, as described with reference to FIGS. 6 to 9, the ink absorbing member 65 is provided inside the cap member 43. Since the ink absorbing member 65 includes the lyophilic pattern portion 60 corresponding to the nozzle row L of the line head 13 and surrounded by the liquid repellent pattern 61, the liquid repellent pattern portion 61 having relatively low wettability. Functions as a partition wall, and the ink sucked from the nozzle openings 17 flows well in the lyophilic pattern portion 60.

  Therefore, the inks flowing between the adjacent lyophilic pattern portions 60 merge in the connecting portion 63 provided below the thickness direction of the ink absorbing member 65 (in the −Z axis direction in FIG. 6), and then the connecting portion 63. It is discharged to the outside through a suction port 67 communicating with. Therefore, the ink sucked from each nozzle row L does not cause color mixing in the vicinity of the nozzle forming surface 21A. Further, according to the above configuration, since the ink can be sucked from each nozzle opening 17 through one suction port 67 communicating with the connecting portion 63, the configuration of the suction mechanism is simplified.

  Thereafter, the control device reversely drives the suction pump 49 to release the space K formed between the nozzle forming surface 21A and the cap member 43 to the atmosphere (step S5). By reversely driving the suction pump 49, air flows into the space between the nozzle forming surface 21A and the cap member 43, and the space is opened to the atmosphere.

  Then, the control device raises the line head 13 to separate the cap member 43 from the nozzle forming surface 21A (step S6). Specifically, the control device moves the line head 13 to the printing position to separate the cap member 43 from the nozzle forming surface 21A.

  Here, after ink suction, the inside of the nozzle opening 17 is still in a negative pressure state. For this reason, there is a possibility that ink adhering to the nozzle forming surface 21 </ b> A is drawn into the nozzle opening 17. If ink color mixture occurs in the nozzle openings 17, there is a possibility that ink of a desired color cannot be ejected. In order to solve such a problem, it is necessary to discharge the mixed color ink drawn into the nozzle opening 17 by the flushing process. In particular, in the line head 13 having a large number of nozzle openings 17 as in the present embodiment, the amount of ink consumed during the flushing process may increase.

  On the other hand, according to the ink jet printer 100 according to the present embodiment, the ink absorbing member 65 described above prevents ink mixing in the vicinity of the nozzle forming surface 21A, so that the ink drawn into the nozzle opening 17 is of the same color. Because there is no problem. In the present embodiment, the lyophilic pattern portion 60 is formed for each nozzle row that ejects the same type of ink, thereby simplifying the structure, and ink is drawn between the nozzle openings 17 in the same row. Even in this case, the injection characteristics are not impaired. Therefore, it is possible to eliminate a problem (increased ink consumption) caused by color mixing when forcibly sucking ink from the nozzle openings 17 of the line head 13.

(Second embodiment)
Next, a second embodiment of the ink jet printer will be described. In the inkjet printer according to this embodiment, the shape of the ink absorbing member 65 provided inside the cap member 43 is different from that of the first embodiment described above. Therefore, in the following, the same members and configurations as those of the above embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 13 is a diagram illustrating a cross-sectional configuration of the ink absorbing member 65 according to the second embodiment. In the ink absorbing member 65 according to the present embodiment, as shown in FIG. 13, the lyophilic pattern portion 60 is formed in a concave shape with respect to the liquid repellent pattern portion 61 on the surface that contacts the line head 13. ing. In addition, the lyophilic pattern part 60 is formed so as to correspond to the nozzle row L as in the above embodiment. That is, the ink absorbing member 65 has a groove (dent) 70 formed therein.

  When the lyophilic pattern portion 60 is formed in a concave shape with respect to the lyophobic pattern portion 61 as in the present embodiment, the nozzle formation surface 21A and the lyophilic pattern portion 60 satisfy the following relational expression. The ink color mixture is prevented during forced suction.

FIG. 14 is a diagram showing a state in which ink is drawn from the nozzle opening 17 onto the nozzle forming surface 21A by suction.
As shown in FIG. 14, the lower surface of the ink droplet drawn from the nozzle opening 17 enters the groove portion 70. Here, the amount of ink droplets entering the groove portion 70 is t, the pattern width of the lyophilic pattern portion 60 is b, and the distance between the nozzle forming surface 21A and the upper surface of the ink absorbing member 65 is a. Here, the upper surface of the ink absorbing member 65 corresponds to the surface of the liquid repellent pattern portion 61.

  Here, the crossing angle between the line segment connecting the center C of the ink drawn from the nozzle opening 17 and the contact position of the liquid repellent pattern portion 61 and the Y axis (corresponding to the extending direction of the nozzle opening 17) in FIG. In the case of δ, an angular relationship as shown in FIG. 14 is obtained.

  Based on such an angular relationship, the following equation 11 is obtained.

  sin δ = br / 2 (Formula 11)

  When this equation 11 is expanded with respect to δ, the following equation 12 is obtained.

δ = sin ⁻¹ (br / 2) (Formula 12)

  Here, the following formula 13 is obtained by substituting the above formula 6 into the formula 12 and rearranging.

δ = sin ⁻¹ (bsin θ / W) (Formula 13)

Further, the following expression 14 can be defined based on FIG.
tan (δ / 2) = 2t / b (Formula 14)

  Here, when Expression 14 is expanded with respect to t, the following Expression 15 can be defined.

  Further, by substituting the above formula 12 into the formula 15 and rearranging, the following formula 16 can be defined.

  Here, the distance a between the nozzle forming surface 21A and the upper surface of the ink absorbing member 65 may be equal to or less than the value defined by the following equation (17).

  a = rt (formula 17)

  Substituting the above formulas 6 and 16 into the formula 17 and rearranging them can be defined by the following formula (18). In the following formula 18, b ≦ W is satisfied.

  According to the ink absorbing member 65 according to the present embodiment, in addition to the operational effects obtained by the first embodiment, the ink ejected from the nozzle opening 17 is temporarily stored in the groove portion 70 and the lyophilic pattern portion 60. It will surely be discharged to the outside. Therefore, it is possible to satisfactorily prevent the ink from flowing from the lyophilic pattern portion 60 to the lyophobic pattern portion 61 and to improve the ink recoverability.

(Third embodiment)
Next, a third embodiment of the ink jet printer will be described. Unlike the first and second embodiments, the ink jet printer according to this embodiment has a configuration in which the cap member 43 does not have the ink absorbing member 65. In addition, the same code | symbol is attached | subjected about the same member and structure as the said embodiment, and the description is abbreviate | omitted or simplified.

  FIG. 15 is a diagram showing a schematic configuration of the cap member 143 according to the present embodiment. As shown in FIG. 15, the cap member 143 has a lyophilic pattern portion 160 and a liquid repellent pattern portion 161 corresponding to the nozzle row L on its upper surface (the surface that contacts the line head 13) 143a. Is formed. Note that the lyophilic pattern portion 160 and the nozzle formation surface 21A are set so as to satisfy the relationship represented by Expression 10 described with reference to FIG. In addition, the upper surface 143a of the cap member 143 is configured to be slightly inclined toward one direction, thereby allowing the ink ejected on the lyophilic pattern portion 160 to flow in one direction. In addition, an ink discharge port (not shown) is formed at a position where the ink flows on the upper surface 143a of the cap member 143, and the capping maintenance unit 42 (see FIG. 11) connected to the ink discharge port. The ink flowing on each lyophilic pattern portion 160 can be discharged to the outside.

  When the ink is forcibly sucked using the cap member 143 according to the present embodiment, the space formed between the line head 13 and the cap member 143 after the cap member 143 is brought into contact with the line head 13 is described above. The pressure is reduced by the capping maintenance unit 42 (see FIG. 11), and the ink is sucked.

The ink drawn from the nozzle row L by the suction reaches the lyophilic pattern portion 60 provided corresponding to each nozzle row L. Then, the ink wets and spreads only on the lyophilic pattern portion 60, flows out in the inclined direction, and is sucked (discharged) to the outside through an ink discharge port (not shown).
As described above, even when the cap member 143 according to the present embodiment is used, the ink does not mix during the suction process as in the above-described embodiment, and the problem caused by the color mixing is prevented.

(Fourth embodiment)
Next, a fourth embodiment of the ink jet printer will be described. The ink jet printer according to this embodiment is different in only the shape of the cap member 243 in the configuration according to the third embodiment. Therefore, below, the same code | symbol is attached | subjected about the same member and structure as said 3rd embodiment, and the description is abbreviate | omitted or simplified.

  FIG. 16 is a diagram showing a cross-sectional configuration of the cap member 243 according to the present embodiment. As shown in FIG. 16, the cap member 243 is similar to the second embodiment in that the lyophilic pattern portion 260 faces the liquid repellent pattern portion 261 on the side of the cap member 243 that contacts the line head 13. It is formed in a concave shape. In other words, the cap member 243 has a groove (dent) 270 formed thereon, and the upper surface of the lyophilic pattern portion 260 formed in the groove 270 is represented by Equation 18 described with reference to FIG. Thus, the lyophilic pattern portion 260 can prevent ink color mixing during forced suction as in the above embodiment.

  According to the cap member 243 according to the present embodiment, in addition to the operational effects obtained by the third embodiment, the ink ejected from the nozzle opening 17 can be favorably discharged to the outside using the groove portion 270 as a flow path.

  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 maintenance process is performed by moving the line head 13 up and down relative to the maintenance unit 11. However, the present invention is not limited to this. For example, the maintenance is performed up to the standby position of the line head 13. The nozzle forming surface 17a and the maintenance unit 11 may be arranged to face each other by moving the unit 11, and the maintenance process may be performed.

  For example, in the above description of the embodiment, the case where an image is formed on a recording sheet has been described. However, the present invention can also be applied to the case where an image is formed on a roll sheet. As shown in FIG. 17, when printing on the roll paper R, it is difficult to arrange the maintenance unit 11 below the line head 13. In such a case, the maintenance unit 11 is disposed on the side of the line head 13 to raise the line head 13 during the maintenance process, and to face the maintenance unit 11 by rotating the nozzle forming surface 21A in the direction of the arrow in FIG. Then, maintenance processing may be performed.

  The present invention can also be applied to an ink jet printer that performs double-sided printing by feeding a recording sheet between two line heads 13 each having a nozzle forming surface 21A facing each other. In such a case, as shown in FIG. 18, the maintenance units 11 are respectively arranged on the sides of the two line heads, and the line head 13 is moved during the maintenance process as in the above-described double-sided printing, and the nozzle forming surface 21A. May be made to face the maintenance unit 11 by rotating in the direction of the arrow in FIG. Note that only one maintenance unit 11 may be provided, and the maintenance process may be performed on the two line heads 13 by moving the maintenance device up and down.

  In the above embodiment, the configuration in which the lyophilic pattern portions 60, 160, 260 are formed so as to correspond to the nozzle rows L has been described, but the present invention is not limited to this, as shown in FIG. The lyophilic pattern portions 60, 160, and 260 may be formed in correspondence with the nozzle openings 17, respectively. In this way, ink mixing is prevented at each nozzle opening 17, so that more reliable suction processing can be performed.

For example, in the above-described embodiment, a configuration in which a single line head is provided and all types of ink are ejected from the line head has been described. However, the present invention is not limited to this, and a configuration in which a line head is installed for each type of ink may be used. In such a case, the maintenance unit 11 is installed for each line head.
The present invention is not limited to a line head type ink jet printer, and can also be applied to a serial type ink jet printer.

  In the above embodiment, the case where the ink jet recording apparatus is an ink jet printer has been described as an example. However, the present invention is not limited to the ink jet printer, and may be a recording apparatus such as a copying machine or a facsimile.

  In the above embodiment, the piezoelectric element 25 is a laminated type. However, the present invention is not limited to this, and other types (for example, monomorph, unimorph, bimorph, Mooney type, multi-Mooney type, cymbal) are not limited thereto. Type). Furthermore, the drive unit 24 is not limited to the piezo jet type using the piezoelectric element 25 described above, and for example, a thermal method can be adopted. In that case, the fluid discharge amount can be changed by changing the application time.

  In each of the above-described embodiments, the case where the fluid ejecting apparatus is a fluid ejecting apparatus (fluid ejecting apparatus) that ejects a fluid such as ink has been described as an example. The present invention can be applied to a fluid ejecting apparatus that ejects or discharges fluid other than the above. Fluids that can be ejected by the fluid ejecting apparatus include liquids, liquids in which particles of functional material are dispersed or dissolved, gel-like fluids, solids that can be ejected as fluids, and powders (such as toner). .

  Further, the fluid ejecting apparatus may be a fluid ejecting apparatus that ejects a bio-organic matter used for biochip manufacturing, or a fluid ejecting apparatus that ejects a fluid that is used as a precision pipette and serves as a sample.

  In addition, transparent resin liquids such as UV curable resins to form fluid injection devices that inject lubricating oil onto precision machines such as watches and cameras, micro hemispherical lenses (optical lenses) used in optical communication elements, etc. For example, a fluid ejecting apparatus that ejects a liquid onto a substrate, a fluid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, a fluid ejecting apparatus that ejects gel, and a powder such as toner. It may be a toner jet recording apparatus that ejects a solid. The present invention can be applied to any one of these fluid ejecting apparatuses.

It is a schematic block diagram of an inkjet printer. It is a principal part top view of a line head periphery. It is a top view which shows the nozzle formation surface of a line head. It is sectional drawing which shows a part of line head. It is a figure which shows schematic structure of a capping mechanism. It is a perspective view which shows the structure of an ink absorption member. It is a top view which shows the structure of an ink absorption member. It is a cross-sectional block diagram which shows the positional relationship of a lyophilic pattern part and a nozzle. It is a figure which shows the positional relationship of the capping mechanism and head at the time of a maintenance. It is explanatory drawing which prescribes | regulates the positional relationship of a nozzle formation surface and a lyophilic pattern part. It is a figure which shows the structure of an ink discharge part. It is a flowchart figure of the maintenance process with respect to a line head. It is a figure which shows the cross-sectional structure of the ink absorption member which concerns on 2nd embodiment. It is explanatory drawing which prescribes | regulates the positional relationship of a nozzle formation surface and a lyophilic pattern part. It is a figure which shows schematic structure of the cap member which concerns on 3rd embodiment. It is a figure which shows the cross-sectional structure of the capping member which concerns on 4th embodiment. It is a figure which shows the structure which concerns on the modification of an inkjet printer. It is a figure which shows the structure which concerns on the modification of an inkjet printer. It is a figure which shows the structure which concerns on the modification of an inkjet printer.

Explanation of symbols

L ... Nozzle row, 13 ... Line head (jet head), 17 ... Nozzle, 18 ... Head body (holding member), 21 ... Nozzle substrate (nozzle forming member), 21A ... Nozzle forming surface, 43 ... Cap member (fluid recovery) Part), 60 ... lyophilic pattern part, 61 ... lyophobic pattern part, 63 ... coupling part, 65 ... ink absorbing member (absorbing member), 67 ... suction port, 80 ... seal part, 81 ... contact part, 100 ... Inkjet printer (fluid ejecting apparatus), 160 ... lyophilic pattern portion, 161 ... lyophobic pattern portion, 260 ... lyophilic pattern portion, 261 ... lyophobic pattern portion

Claims (9)

In a fluid ejecting apparatus comprising a nozzle forming surface having a plurality of nozzle openings formed therein and ejecting fluid from the nozzle, and a fluid recovery unit that collects the fluid in a state of being in contact with the ejecting head.
The fluid ejecting apparatus according to claim 1, wherein the fluid recovery unit includes a lyophilic pattern unit that is provided corresponding to the nozzle opening and exhibits lyophilicity with respect to the fluid.   2. The fluid ejecting apparatus according to claim 1, wherein the fluid recovery unit includes a liquid repellent pattern portion that exhibits liquid repellency with respect to the fluid between the lyophilic pattern portions.   The fluid recovery unit includes an absorbing member capable of absorbing the fluid, and the lyophilic pattern portion and the liquid repellent pattern portion are formed on the absorbing member. Fluid ejection device.   The fluid ejecting apparatus according to claim 1, wherein the lyophilic pattern portion is provided corresponding to each of the nozzle openings.   4. The fluid ejecting apparatus according to claim 1, wherein the lyophilic pattern portion is provided corresponding to a nozzle row that ejects the same type of fluid in the nozzle openings. 5.   The absorbing member is provided with a connecting portion that connects the lyophilic pattern portions at a position separated from the nozzle opening in the thickness direction of the absorbing member, and the connecting portion has a suction port for sucking the fluid The fluid ejecting apparatus according to claim 3, wherein the fluid ejecting apparatuses are in communication with each other.   7. The absorbent member according to claim 1, wherein the lyophilic pattern portion is formed in a concave shape with respect to the liquid-repellent pattern portion on a surface that is in contact with the ejection head. The fluid ejecting apparatus according to 1. The contact angle of the fluid with respect to the nozzle formation surface of the ejection head is θ, the pitch of the nozzles formed on the nozzle formation surface is W, and the parent when the fluid recovery member is brought into contact with the ejection head When the distance between the liquid pattern portion and the nozzle forming surface is h,
h ≦ W (1-cos θ) / (2 sin θ)
The fluid ejection device according to claim 1, wherein the relationship is satisfied.   The fluid ejecting apparatus according to claim 1, wherein the ejecting head is a line head.

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