JP6852774B2 - Liquid injection device and cleaning device - Google Patents

Description

The present invention relates to a liquid injection device such as an inkjet printer and a cleaning device.

Conventionally, as a kind of liquid injection device, an inkjet printer that prints by ejecting ink onto paper from a nozzle ink ejection port formed on an ink ejection surface of a recording head has been known. Some such printers are provided with a head maintenance device that wipes the ink ejection surface with a long sheet-shaped ink absorbing member (see, for example, Patent Document 1).

Such a head maintenance device includes an ink absorbing member that absorbs ink, and a pressing member that presses the ink absorbing member from a side opposite to the side in contact with the ink ejection surface to bring it into contact with the ink ejection surface. The pressing member includes a roller member formed of an elastic material and having a groove on a contact surface with the ink absorbing member and rotatably configured, and a shaft member that pivotally supports the roller member.

Then, the ink absorbing member is pressed by the roller member from the side opposite to the side of the recording head in contact with the ink ejection surface, so that the roller member is brought into close contact with one end of the ink ejection surface. By moving it to the other end, the ink on the entire surface of the ink ejection surface is wiped off. In this case, the groove portion of the roller member is arranged so as to avoid the position corresponding to the ink ejection port of the nozzle.

Japanese Unexamined Patent Publication No. 2008-229962

By the way, in the head maintenance device of the printer as described above, when the ink ejection surface has irregularities (steps), if the pressing force of the roller member on the ink absorbing member is increased in order to improve the ink wiping property of the ink ejection surface, There is a problem that the ink ejection surface is damaged and easily deteriorates. In this case, since the groove portion of the roller member is arranged so as to avoid the position corresponding to the ink ejection port, the pressing force applied to the ink ejection port peripheral region including the ink ejection port region on the ink ejection surface becomes high. The area is particularly prone to deterioration.

Note that these problems are not limited to inkjet printers that print by injecting ink from the nozzles, but the sheet-like liquid absorbing member is pressed against the nozzle surface where the nozzles are arranged by an elastic body such as rubber. The liquid injection device provided with the head maintenance device for wiping off the adhering liquid is generally common.

The present invention has focused on such problems existing in the prior art. An object of the present invention is to provide a liquid injection device and a cleaning device capable of suppressing deterioration of a nozzle region including a nozzle opening region due to wiping of a nozzle surface on which a nozzle for ejecting a liquid is arranged. ..

Hereinafter, means for solving the above problems and their actions and effects will be described.
The liquid injection device that solves the above problems includes a liquid injection head that injects liquid from a nozzle arranged on the nozzle surface, an absorption member that comes into contact with the nozzle surface and can absorb the liquid adhering to the nozzle surface. The absorbing member includes a wiper unit having a pressing portion that presses the absorbing member from a side opposite to the side that contacts the nozzle surface to bring the absorbing member into contact with the nozzle surface, and the pressing portion is provided. , The direction in which the absorbing member intersects the direction in which the absorbing member moves with respect to the liquid injection head in the direction along the nozzle surface is the axial direction, and the portion of the pressing portion that can press the absorbing member is convex. In the case of a portion, the concave-convex region having a plurality of the convex portions formed at intervals in the axial direction and the concave portion formed between the convex portions, and the absorbing member without the concave portion can be pressed. A flat region and a region for pressing the absorbent member in a contact operation of bringing the absorbent member into contact with the nozzle surface by rotating the pressing portion are defined as a concave-convex region and the flat region. It is possible to switch to.
The liquid injection device that solves the above problems includes a liquid injection head that injects liquid from a nozzle arranged on the nozzle surface, an absorption member that comes into contact with the nozzle surface and can absorb the liquid adhering to the nozzle surface. The absorbing member is provided with a pressing portion that presses the absorbing member from a side opposite to the side of the absorbing member that contacts the nozzle surface to bring the absorbing member into contact with the nozzle surface, and the absorbing member pressed by the pressing portion. The first contact operation of bringing the nozzle surface into contact with the nozzle surface at a position corresponding to the nozzle region including the nozzle opening region, and the absorbing member pressed by the pressing portion of the nozzle surface. It is possible to perform the second contact operation of contacting the nozzle surface at a position corresponding to the non-nozzle region, which is a region other than the nozzle region.

According to this configuration, in particular, by selectively wiping the nozzle surface by contacting the absorbing member by the second contact operation, the nozzle surface is wiped while reducing the pressing force applied to the nozzle region by the wiping. be able to. Therefore, it is possible to suppress deterioration of the nozzle region including the nozzle opening region due to wiping of the nozzle surface on which the nozzle on which the liquid is ejected is arranged.

In the liquid injection device, in the contact of the absorbing member by the second contact operation, the pressing force applied to the nozzle region by the contact of the absorbing member is applied to the non-nozzle region by the contact of the absorbing member. It is preferably smaller than the pressing force.

According to this configuration, the liquid adhering to the nozzle surface can be suitably absorbed and removed by the absorbing member while reducing the damage given to the nozzle region.
In the liquid injection device, the compression rate of the portion of the absorbing member pressed against the nozzle region is preferably smaller than the compressibility of the portion of the absorbing member pressed against the non-nozzle region.

According to this configuration, the liquid adhering to the nozzle surface can be suitably absorbed and removed by the absorbing member while reducing the damage given to the nozzle region.
In the liquid injection device, the non-nozzle region is a protruding surface that protrudes from the nozzle region, and the protruding surface preferably has a lower liquid repellency than the nozzle region.

According to this configuration, the liquid easily wets and spreads on the protruding surface having a relatively low liquid repellency, so that the liquid on the protruding surface can be efficiently absorbed and removed by the absorbing member.
In the liquid injection device, the non-nozzle region is a protruding surface protruding from the nozzle region, and the absorbing member moves relative to the liquid injection head in a direction along the nozzle surface in a state of being in contact with the nozzle surface. In the wiping operation, the last region on the nozzle surface, which is the region where the absorbing member finally contacts, is formed by the protruding surface, and is applied to the last region in the contact of the absorbing member by the second contact operation. The pressing force applied is preferably larger than the pressing force applied to the nozzle region when the absorbing member comes into contact with both the nozzle region and the protruding surface.

According to this configuration, when the absorbing member changes from the state of being in contact with both the protruding surface and the nozzle region to the state of being in contact with only the protruding surface of the last region, the portion of the absorbing member that is in contact with the nozzle region The pressure rises. Therefore, it is possible to prevent the absorbing member from wiping the liquid on the protruding surface in the final region.

In the liquid injection device, the surface of the liquid injection head having the nozzle is preferably covered with a cover member having a through hole for exposing the nozzle region in a portion corresponding to the nozzle region.

According to this configuration, the pressing force applied to the nozzle region and the non-nozzle region when the nozzle surface is wiped can be made different from each other with a relatively simple configuration in which the cover member is simply attached to the liquid injection head.

In the liquid injection device, the pressing portion has a convex portion capable of pressing the absorbing member, and moves relative to the liquid injection head in a direction along the nozzle surface in a state where the absorbing member is in contact with the nozzle surface. It is preferable that the dimension of the convex portion in the direction intersecting with the direction of crossing is shorter than the dimension of the nozzle region in the direction of intersection.

According to this configuration, the absorbing member can be effectively pressed by the convex portion of the pressing portion so that the absorbing member makes suitable contact with the nozzle region.
A cleaning device that solves the above problems includes an absorbing member capable of absorbing the liquid adhering to the nozzle surface in contact with the nozzle surface on which the liquid injection head injects the liquid is arranged, and the nozzle in the absorbing member. A pressing portion that presses the absorbing member from a side opposite to the side that contacts the surface to bring the absorbing member into contact with the nozzle surface is provided, and the pressing portion is provided in a direction in which the absorbing member is along the nozzle surface. It is rotatable with the direction intersecting the moving direction with respect to the liquid injection head as the axial direction, and when the portion of the pressing portion that can press the absorbing member is a convex portion, the interval is set in the axial direction. The peripheral surface has a concavo-convex region having a plurality of the convex portions formed therein and a concave portion formed between the convex portions, and a flat region having no concave portion and capable of pressing the absorbing member. By rotating the pressing portion, it is possible to switch the region for pressing the absorbing member between the uneven region and the flat region in the contact operation of bringing the absorbing member into contact with the nozzle surface.
A cleaning device that solves the above problems includes an absorbing member capable of absorbing the liquid adhering to the nozzle surface in contact with the nozzle surface of a liquid injection head that injects liquid from a nozzle arranged on the nozzle surface, and the absorbing member. The absorbing member is provided with a pressing portion that presses the absorbing member from a side opposite to the side of the member that contacts the nozzle surface to bring the absorbing member into contact with the nozzle surface, and the absorbing member pressed by the pressing portion is provided. The first contact operation of contacting the nozzle surface at a position corresponding to the nozzle region including the nozzle opening region of the nozzle surface and the absorbing member pressed by the pressing portion are subjected to the nozzle of the nozzle surface. It is possible to perform the second contact operation of contacting the nozzle surface at a position corresponding to the non-nozzle region, which is a region other than the region.

According to this configuration, in particular, by selectively wiping the nozzle surface by the second contact operation, it is possible to wipe the nozzle surface while reducing the pressing force applied to the nozzle region by the wiping. Therefore, it is possible to suppress deterioration of the nozzle region including the nozzle opening region due to wiping of the nozzle surface on which the nozzle on which the liquid is ejected is arranged.

The schematic diagram which shows the schematic structure of the inkjet printer of one Embodiment. A schematic plan view showing the positional relationship between the support base and the maintenance mechanism. Perspective view of the head unit. Schematic diagram of the nozzle surface. FIG. 3 is a schematic cross-sectional view of FIG. Schematic diagram of the side surface of the wiper unit. The perspective view which shows the main part of FIG. The cross-sectional schematic diagram which shows the 2nd contact operation. A side schematic diagram showing a state when the nozzle surface is wiped. The schematic diagram which shows the state when wiping a nozzle surface is seen from the nozzle surface side. The cross-sectional schematic diagram which shows the 1st contact operation. FIG. 6 is a schematic cross-sectional view showing a first contact operation in a modified example. FIG. 12 is an enlarged cross-sectional view of a main part of FIG. FIG. 6 is a schematic cross-sectional view showing a second contact operation in the modified example. FIG. 14 is an enlarged cross-sectional view of a main part of FIG. FIG. 6 is a schematic cross-sectional view showing a first contact operation in another modified example. In still another modified example, a schematic cross-sectional view showing a configuration when two different types of pressing rollers for pressing the cloth sheets are adopted. FIG. 6 is a schematic cross-sectional view showing a second contact operation in still another modified example.

Hereinafter, an embodiment of the liquid injection device will be described with reference to the drawings.
As shown in FIG. 1, an inkjet printer 11 as an example of a liquid injection device is a transport unit that transports a recording medium 13 such as paper supported by a support base 12 in a transport direction Y along the surface of the support base 12. A printing unit 15 for printing by injecting ink as an example of a liquid onto a recording medium 13 to be conveyed is provided.

The support base 12, the transport unit 14, and the printing unit 15 are assembled to the printer main body 16 including a housing, a frame, and the like. In the inkjet printer 11, the support base 12 extends in the width direction of the recording medium 13 (the direction orthogonal to the paper surface in FIG. 1). Further, a cover 17 is attached to the printer main body 16 so as to be openable and closable.

The transport unit 14 is arranged on the upstream side and the downstream side of the support base 12 in the transport direction Y, respectively, and the recording medium 13 is arranged on the downstream side of the transport roller pair 19 in the transport direction Y. It is provided with a guide plate 20 that guides while supporting. Then, the transport unit 14 rotates along the surface of the support base 12 and the surface of the guide plate 20 by rotating the transport roller pairs 18 and 19 while sandwiching the recording medium 13 by being driven by a transport motor (not shown). The recording medium 13 is conveyed in the transfer direction Y.

The printing unit 15 is attached to the guide shafts 22 and 23 extending along the scanning direction X which is the width direction of the recording medium 13 orthogonal (intersecting) with the transport direction Y of the recording medium 13 and the guide shafts 22 and 23. It includes a carriage 25 that is guided and can reciprocate in the scanning direction X. The carriage 25 reciprocates in the scanning direction X as the carriage motor 24 (see FIG. 2) is driven.

At least one liquid injection head 27 (two in this embodiment) having a nozzle 26 for injecting ink is attached to the lower end portion of the carriage 25. That is, the liquid injection head 27 is attached to the carriage 25 in a posture in which its lower surface faces the support base 12 at a predetermined distance in the vertical direction Z, and together with the carriage 25 as the carriage motor 24 (see FIG. 2) is driven. It reciprocates in the scanning direction X. The liquid injection heads 27 are arranged so as to be separated from each other by a predetermined distance in the scanning direction X and deviated by a predetermined distance in the transport direction Y.

On the other hand, a part of the supply mechanism 31 that supplies ink from the ink cartridge 30 to the liquid injection head 27 is attached to the upper side of the carriage 25. The supply mechanism 31 causes the ink to flow along the supply direction A from the upstream side on the ink cartridge 30 side to the downstream side on the liquid injection head 27 side. At least one set (five sets in this embodiment) of the ink cartridge 30 and the supply mechanism 31 is provided for each type of ink.

The five ink cartridges 30 are detachably mounted on a plurality of (five in this embodiment) mounting portions 32, and each of the five ink cartridges 30 contains inks of different colors (types). As an example, inks of each color of cyan (C), magenta (M), yellow (Y), black (K), and white (W) are contained in each ink cartridge 30. By injecting the ink supplied from each ink cartridge 30 from the liquid injection head 27, color printing or the like on the recording medium 13 is performed. As an example, in the case of the dark color recording medium 13, white printing (base printing) is performed, and then color printing is performed on the white printing medium 13.

The supply mechanism 31 includes a supply path 33 for supplying ink from the ink cartridge 30 to the liquid injection head 27. In the supply path 33, the supply pump 34 that flows ink in the supply direction A, the filter unit 35 that captures air bubbles and foreign substances in the ink, and the ink flow that flows through the supply path 33 are changed in order from the upstream side to supply ink. A static mixer 36 for stirring, a liquid storage chamber 37 for storing ink, and a pressure adjusting unit 38 for adjusting the pressure of ink are provided.

The supply pump 34 includes a diaphragm pump 40 having a variable pump chamber volume, a suction valve 41 arranged on the upstream side of the diaphragm pump 40, and a discharge valve 42 arranged on the downstream side of the diaphragm pump 40. are doing. The suction valve 41 and the discharge valve 42 are composed of a one-way valve that allows the flow of ink to the downstream side while obstructing the flow of ink to the upstream side.

Therefore, the supply pump 34 sucks ink from the ink cartridge 30 side through the suction valve 41 as the volume of the pump chamber of the diaphragm pump 40 increases, and as the volume of the pump chamber decreases. Ink is ejected to the liquid injection head 27 side via the ejection valve 42. Further, the filter unit 35 is arranged at a position corresponding to the cover 17 of the printer main body 16, and is detachably attached to the supply path 33. The filter unit 35 can be replaced by opening the cover 17.

The inkjet printer 11 controls drive of a transfer motor (not shown), a carriage motor 24 (see FIG. 2), a supply pump 34, and the like for driving the transfer roller pairs 18 and 19, and each nozzle of the liquid injection head 27. A control unit 39 that controls injection of ink from the 26 is provided. Then, the liquid injection head 27 ejects ink from each nozzle 26 onto the recording medium 13 conveyed on the support base 12 while reciprocating in the scanning direction X together with the carriage 25 as the carriage motor 24 is driven. Print.

As shown in FIG. 2, a maintenance mechanism 43 for performing maintenance of the liquid injection head 27 is provided at a position adjacent to one end of the support base 12 in the scanning direction X. In the present embodiment, the region where the liquid injection head 27 ejects ink to the recording medium 13 for printing and the region where the recording medium 13 may be conveyed is referred to as a transfer region PA. In this case, the maintenance mechanism 43 is arranged within the scanning range of the carriage 25 in the scanning direction X and outside the transport region PA (on the right side in FIG. 2).

The maintenance mechanism 43 has a flushing unit 45 having a liquid receiving portion 44 arranged in order from a position closest to the transport region PA in the scanning direction X, a wiper unit 46 as an example of a cleaning device, and an upper end opened. A cap unit 48 having two cap portions 47 having a bottomed square box shape is provided.

The carriage 25 and the liquid injection head 27 stand by at the home position HP where the cap unit 48 is arranged when printing is not performed or when the power is turned off. That is, the liquid injection head 27 can move between the transport region PA and the home position HP in the scanning direction X orthogonal (intersecting) with the transport direction Y.

When the two liquid injection heads 27 are moved to the home position HP, the two cap portions 47 face the two liquid injection heads 27 in the vertical direction. Each cap portion 47 is moved up and down between a position where it can come into contact with each liquid injection head 27 and a position away from each liquid injection head 27 by driving the capping motor 49.

Each cap portion 47 contacts each liquid injection head 27 so as to surround the plurality of nozzles 26 to form a closed space with each liquid injection head 27, thereby drying the ink in each nozzle 26. Suppress. Each liquid injection head 27 is capped by each cap portion 47 at the home position HP, such as when printing is not performed.

The inside of each cap portion 47 can be sucked by a suction pump 50 via a suction tube (not shown) whose one end side is connected to each cap portion 47. Then, each liquid injection head 27 is capped by each cap portion 47 at the home position HP, and by driving the suction pump 50 to suck the inside of each cap portion 47 (closed space), each nozzle 26 The so-called head cleaning is performed in which the thickening ink and air bubbles in each liquid injection head 27 are discharged into each cap portion 47. The capping motor 49 and the suction pump 50 are driven and controlled by the control unit 39 (see FIG. 1).

The wiper unit 46 has an opening of a wiper cassette 52 equipped with a cloth sheet 51 as an example of an absorbing member capable of abutting the lower surface of the liquid injection head 27 and absorbing ink, and an upper end to which the wiper cassette 52 is detachably mounted. It is provided with a bottomed square box-shaped wiper holder 53. The wiper unit 46 is guided by a pair of rail portions 54 so as to be reciprocally movable along the transport direction Y.

Further, the flushing unit 45 liquid-receives the flushing ink ejected at the time of so-called flushing, in which ink droplets are ejected from each nozzle 26 independently of printing for the purpose of preventing or eliminating clogging of each nozzle 26. Accept in part 44. The flushing unit 45 is arranged so that when the liquid injection head 27 on the right side in FIG. 2 is located above the wiper unit 46, the liquid receiving portion 44 is located below the liquid injection head 27 on the left side in FIG. Has been done.

As shown in FIG. 3, the head unit 55 is attached to the lower surface portion of the carriage 25, and includes a bracket portion 56 for attaching to the carriage 25 and a rectangular parallelepiped liquid injection head 27 projecting downward from the bracket portion 56. It has. The liquid injection head 27 includes a rectangular parallelepiped-shaped flow path forming portion 57 projecting downward from the bracket portion 56, and a rectangular plate-shaped head main body 58 fixed to the lower side of the flow path forming portion 57. On the lower surface of the head body 58 in FIG. 3, a plurality of rows (10 rows as an example) of nozzle rows 59 are formed.

Further, on the lower surface side of the head body 58, a plate-shaped cover member 60 having a plurality of (five as an example) through holes 60a is provided, and nozzles 26 (see FIG. 4) forming the nozzle row 59 are opened. It is attached so as to cover a part of the opening surface 61 (lower surface in this example). The plurality of nozzle rows 59 are exposed in one through hole 60a by a predetermined number of rows (two rows as an example). Of course, through holes 60a may be provided for each row of the nozzle rows 59.

In this example, the area of the nozzle opening surface 61 exposed by the through hole 60a is the nozzle area 62. That is, the surface of the liquid injection head 27 having the nozzle 26 has a cover member 60 having a through hole 60a for exposing the nozzle region 62 in a portion corresponding to the nozzle region 62 which is an outer region adjacent to the opening region of the nozzle 26. Covered by. The nozzle region 62 includes an opening region of each nozzle 26 (see FIG. 4).

As shown in FIGS. 4 and 5, the cover member 60 covers a portion of the nozzle opening surface 61 other than the nozzle region 62 exposed by the through hole 60a, and the liquid injection head 27 has a fixed structure such as locking. It is fixed to. Then, as shown in FIG. 3, the entire bottom surface of the liquid injection head 27 is the nozzle surface 63 to be wiped by the wiper unit 46. The nozzle surface 63 is a non-nozzle region that is a region other than the nozzle region 62 (that is, the region in the through hole 60a) and the nozzle region 62, and the thickness of the cover member 60 is greater than that of the nozzle region 62 (in this example, 0. It is provided with a protruding surface 64 that protrudes by 1 mm).

Therefore, there is a step 65 between the nozzle region 62 and the protruding surface 64 (non-nozzle region). That is, the nozzle surface 63 is composed of an uneven surface that becomes a concave portion in the nozzle region 62 and a convex portion in the protruding surface 64. The cover member 60 is made of, for example, metal (for example, stainless steel or the like).

As shown in FIG. 4, the nozzle row 59 includes a large number (for example, 180 or 360) of nozzles 26 arranged at a constant pitch along the transport direction Y. Each nozzle row 59 ejects one color of ink corresponding to the ink color of the ink cartridge 30 (see FIG. 1). Of course, inks of colors other than the four colors of CMYK and white (W) may be sprayed, and inks of colors such as light magenta, light cyan, light yellow, gray, and orange may be sprayed. The number of colors of the liquid injection head 27 may be CMYK 4 colors, CMY 3 colors, black 1 color, or the like. Further, there may be an unused nozzle row in which the ink is not ejected in the plurality of nozzle rows 59.

Further, the nozzle opening surface 61 is subjected to a liquid repellent treatment (ink repellent treatment) that easily repels ink, and a liquid repellent film 66 (ink repellent film) is formed on the surface thereof. The ink used in this embodiment is, for example, a pigment ink. In pigment ink, a large number of pigment particles are dispersed in a liquid used as a dispersion medium. Cyan, magenta, and yellow pigments are organic pigments with an average particle size of about 100 nm, black pigments are carbon black (inorganic pigments) with an average particle size of about 120 nm, and white pigments are titanium oxide with an average particle size of about 320 nm. (Inorganic pigment) etc. are adopted.

The ink of this example is a water-based ink, and a large number of pigment particles are dispersed in water, which is a dispersion medium. Therefore, in this example, the liquid-repellent film 66 is a water-repellent film having a function of repelling water-based ink. The liquid-repellent film 66 may be composed of, for example, a thin film base layer mainly made of polyorganosiloxane containing an alkyl group and a liquid-repellent film layer made of a metal alkoxide having a long-chain polymer group containing fluorine. The liquid-repellent film 66 is gradually worn by repeatedly wiping the nozzle opening surface 61, and when the liquid-repellent film 66 is worn more than a certain amount, its liquid-repellent property is lowered. The liquid-repellent film 66 may be a liquid-repellent coating film or a liquid-repellent monolayer, and the film thickness and the liquid-repellent treatment method can be arbitrarily selected.

When the liquid repellent property of the liquid repellent film 66 is lowered, the wetting angle (contact angle) of a liquid such as ink mist with respect to the nozzle region 62 becomes small. Therefore, the plurality of ink mists adhering to the nozzle region 62 are wet and spread, and easily grow into one relatively wide ink droplet (adhered ink). Therefore, such adhered ink may be present in the vicinity of the nozzle 26, block the opening of a part of the nozzle 26, or may flow into the nozzle 26.

Further, when ink droplets are ejected from the nozzle 26 in the state where the adhered ink is present in the vicinity of the nozzle 26, the ejected ink droplets come into contact with the adhered ink and induce flying bending of the ink droplets. Such flying and bending of the ink droplets causes the landing position of the ink droplets on the recording medium 13 (that is, the print dot formation position) to deviate from the assumed position, resulting in deterioration of the print image quality. For this reason, it is necessary to suppress the wear of the liquid repellent film 66 due to wiping as much as possible.

On the other hand, the cover member 60 is manufactured by processing a metal plate into a predetermined shape, and the surface of the cover member 60 is not subjected to a liquid repellent treatment. Therefore, the protruding surface 64 (non-nozzle region) has a lower liquid repellency than the nozzle region 62. That is, the wetting angle of the ink with respect to the protruding surface 64 is smaller than the wetting angle of the ink with respect to the nozzle region 62.

As shown in FIG. 5, the liquid injection head 27 has a plurality of (for example, five in this embodiment) recording heads 67 (unit heads) arranged in parallel at a constant pitch in the scanning direction X. The peripheral edge of the nozzle opening surface 61, which is the lower surface of the recording head 67, is covered with the cover member 60, and the nozzle region 62 including the nozzles 26 for two rows is exposed from the through hole 60a formed in the cover member 60. ..

Each nozzle 26 communicates with each ink flow path 57a passing through the flow path forming portion 57, and each ink flow path 57a protrudes upward from the upper surface of the flow path forming portion 57 through a flow path (not shown). It communicates with 55a. Each supply pipe portion 55a communicates with the supply port of the pressure adjusting unit 38 (see FIG. 1) mounted on the carriage 25 via a flow path (not shown).

Therefore, from each pressure adjusting unit 38 (see FIG. 1), ink of each corresponding color is supplied to the nozzle 26 of the corresponding recording head 67 through each supply pipe portion 55a, each ink flow path 57a, and the like. The liquid injection head 27 may be configured to include one head having three or more rows of nozzles.

Next, the configuration of the wiper unit 46 will be described in detail.
As shown in FIG. 6, the wiper unit 46 includes a wiper cassette 52 equipped with a cloth sheet 51 that comes into contact with the nozzle surface 63 of the liquid injection head 27 and can absorb ink adhering to the nozzle surface 63, and the wiper cassette 52. It is equipped with a wiper holder 53 that can be attached and detached. As the cloth sheet 51 of the present embodiment, a cloth sheet 51 having a thickness of 0.34 mm to 0.41 mm is adopted.

The wiper unit 46 is guided along a pair of rail portions 54 via a guide portion 68 fixed to the lower portion thereof, and can reciprocate along the transport direction Y. An electric motor 69 as a power source and a power transmission mechanism 70 for transmitting the power of the electric motor 69 are provided on the printer main body 16 (see FIG. 1) side.

A rack and pinion mechanism 71 is provided on the side of the wiper unit 46. The rack and pinion mechanism 71 meshes with the rack gear portion 71a fixed to the side surface of the wiper holder 53 in a direction whose longitudinal direction coincides with the transport direction Y, and meshes with the rack gear portion 71a and via the power transmission mechanism 70. It has a pinion gear portion 71b that rotates by the transmitted power.

Then, when the electric motor 69 is driven to rotate in the forward direction, the pinion gear portion 71b rotates in the forward direction, and the wiper unit 46 moves forward together with the rack gear portion 71a from the retracted position shown in FIG. 6 to the downstream side in the transport direction Y (to the left in FIG. 6). To do. When the electric motor 69 that has stopped after this movement is driven in reverse, the pinion gear portion 71b that meshes with the rack gear portion 71a reverses, and the wiper unit 46 returns to the upstream side in the transport direction Y (to the right in FIG. 6). It returns to the retracted position shown in FIG.

In the wiper cassette 52, the feeding shaft 72 and the winding shaft 73 are pivotally supported in a state of being separated by a predetermined distance in the transport direction Y. An unused cloth sheet 51 is supported on the feeding shaft 72 in a wound state, and a used cloth sheet 51 unwound from the feeding shaft 72 is wound on the winding shaft 73. Be supported. The unused cloth sheet 51 is pre-impregnated with a cleaning liquid (for example, water) for improving the wiping property against the nozzle surface 63. Of course, the cloth sheet 51 may not be impregnated with the cleaning liquid in advance, and the cleaning liquid may be applied to the unused cloth sheet 51 before wiping the nozzle surface 63.

As shown in FIGS. 6 and 7, the cloth sheet 51 on the way from the feeding shaft 72 to the winding shaft 73 is moved upward from the rectangular opening 52a formed in the center of the upper surface of the wiper cassette 52. It is wound from above on the outer peripheral surface of the pressing roller 74 as an example of the partially protruding pressing portion.

The pressing roller 74 is an annular shape of a round bar-shaped support shaft 75 and a plurality of (six in the present embodiment) as an example of convex portions formed on the peripheral surface of the support shaft 75 at equal intervals in the axial direction. A plurality of (five in this embodiment) annular small diameter portions having an outer diameter smaller than that of the large diameter portion 76 formed between the large diameter portion 76 and the large diameter portion 76 on the peripheral surface of the support shaft 75. It has 77 and. Therefore, the peripheral surface of the pressing roller 74 is composed of an uneven surface having a step. In this case, the difference in height from the peripheral surface of the support shaft 75 between each large diameter portion 76 and each small diameter portion 77 (step on the peripheral surface of the pressing roller 74) is 0.6 mm ± 0.1 mm in the present embodiment. Is set to.

The support shaft 75 is made of a hard material such as metal or a hard synthetic resin, and each large diameter portion 76 and each small diameter portion 77 are made of an elastic material such as rubber. The large-diameter portions 76 and the small-diameter portions 77 are alternately arranged without gaps in the axial direction of the support shaft 75, and are integrally formed. Then, the pressing roller 74 is urged upward by the spring 78 on the support shaft 75, and each large diameter portion 76 of the pressing roller 74 is in a state of pressing the cloth sheet 51 upward.

Therefore, the pressing roller 74 can press the cloth sheet 51 from the side opposite to the side of the cloth sheet 51 that comes into contact with the nozzle surface 63 to bring the cloth sheet 51 into contact with the nozzle surface 63. Further, the width of the cloth sheet 51 in the scanning direction X (the axial direction of the support shaft 75) is slightly wider than the width of the nozzle surface 63 of the liquid injection head 27 in the scanning direction X. Therefore, the cloth sheet 51 can wipe the entire nozzle surface 63. As the cloth sheet 51 of the present embodiment, a cloth sheet 51 capable of absorbing and holding a liquid (ink and cleaning liquid) of 350% by weight is adopted.

Further, in the state where the wiper unit 46 is in the forward movement end position, for example, the power transmission to the pinion gear portion 71b is cut off by the clutch mechanism (not shown) in the power transmission mechanism 70, and the take-up shaft 73 transmits the power. It is connected to the mechanism 70 so as to be able to transmit power. In this state, the take-up shaft 73 is rotated by the power transmitted from the electric motor 69 via the power transmission mechanism 70, and the unused cloth sheet 51 is unwound from the feeding shaft 72 and the used cloth sheet is used. 51 is wound by the winding shaft 73.

During this time, the carriage 25 (see FIG. 2) retracts from the position where the nozzle surface 63 of the liquid injection head 27 is wiped by the wiper unit 46. Then, when the electric motor 69 reversely drives after the wiping operation by the wiper unit 46 is completed, the wiper unit 46 reactivates and returns to the retracted position shown in FIG.

As shown in FIG. 8, the dimension M of the large diameter portion 76 in the direction intersecting the direction of relative movement with the liquid injection head 27 in the direction along the nozzle surface 63 with the cloth sheet 51 in contact with the nozzle surface 63 is the said. It is shorter than the dimension L of the nozzle region 62 in the intersecting direction. That is, the dimension M of the large diameter portion 76 in the scanning direction X, which is the direction orthogonal to the transport direction Y, which is the direction in which the cloth sheet 51 moves when wiping the nozzle surface 63, is the dimension of the nozzle region 62 in the scanning direction X. It is shorter than L.

In this case, the dimension L of the nozzle region 62 in the scanning direction X is slightly longer than the sum of the dimension of the large diameter portion 76 in the scanning direction X and the dimension corresponding to twice the thickness of the cloth sheet 51. Is preferable. Further, the dimension L of the nozzle region 62 in the scanning direction X, the dimension of the through hole 60a in the scanning direction X, and the dimension of the small diameter portion 77 of the pressing roller 74 in the scanning direction X are the same. In the present embodiment, the dimension L of the nozzle region 62 in the scanning direction X is set to 6.58 mm.

Further, the dimension of the portion of the cover member 60 sandwiched between the nozzle regions 62 in the scanning direction X, that is, the distance between the nozzle regions 62 in the scanning direction X is the same as the dimension M of the large diameter portion 76 in the scanning direction X. ing. Therefore, the six large diameter portions 76 of the pressing roller 74 are arranged in the scanning direction X with an interval of the dimension L of the nozzle region 62 in the scanning direction X, and the five nozzle regions 62 are the large diameter portions 76 in the scanning direction X. They are arranged in the scanning direction X with an interval of M minutes.

With this configuration, the liquid injection head 27 side is moved in the scanning direction X to adjust the positions of the nozzle surface 63 and the large diameter portion 76 of the pressing roller 74 in the scanning direction X, whereby the pressing roller 74 on the cloth sheet 51 It is possible to selectively press (contact) the portion wound around the large diameter portion 76 against the nozzle region 62 and the protruding surface 64 (non-nozzle region) of the nozzle surface 63. ..

In this case, as shown in FIG. 11, the operation of bringing the cloth sheet 51 pressed by the large diameter portion 76 of the pressing roller 74 into contact with the nozzle surface 63 at a position corresponding to the nozzle region 62 in the nozzle surface 63 is the operation. It is a one-contact operation. On the other hand, as shown in FIG. 8, the cloth sheet 51 pressed by the large diameter portion 76 of the pressing roller 74 corresponds to a non-nozzle region (protruding surface 64) which is a region other than the nozzle region 62 in the nozzle surface 63. The operation of contacting the nozzle surface 63 at the position is referred to as a second contact operation.

Next, the operation of the inkjet printer 11 will be described.
In the inkjet printer 11, a printing operation of ejecting ink droplets from each nozzle 26 of the liquid injection head 27 while the carriage 25 is moving in the scanning direction X to record one scan on the recording medium 13 and a recording medium 13 The printing on the recording medium 13 is advanced by alternately repeating the transport operation of transporting the image to the next printing position. During this printing, the wiper unit 46 stands by at the retracted position shown in FIG.

Then, in the inkjet printer 11, the ink in the liquid injection head 27 is forced from the nozzle 26 at a predetermined timing (when the ink cartridge 30 is replaced, when the ink injection failure from the nozzle 26 occurs, before printing, etc.). Head cleaning is performed by sucking and discharging the ink. When performing this head cleaning, first, the carriage 25 and the liquid injection head 27 are moved to the home position HP where the cap unit 48 is arranged by driving the carriage motor 24, and then the capping motor 49 is driven to drive the cap portion. By raising 47, the liquid injection head 27 is capped by the cap portion 47.

Subsequently, when the inside of the cap portion 47 (closed space) is sucked by driving the suction pump 50, the thickening ink and air bubbles in the liquid injection head 27 are discharged from each nozzle 26 into the cap portion 47. At this time, since the inside of the cap portion 47 is filled with the ink discharged from each nozzle 26, the region corresponding to the inside of the cap portion 47 on the nozzle surface 63 is immersed in the ink.

Then, when a predetermined amount of ink is discharged from each nozzle 26, the suction pump 50 is stopped. Subsequently, when the air release valve (not shown) provided in the cap portion 47 is opened, the inside of the cap portion 47 is opened to the atmosphere. Subsequently, when the cap portion 47 is lowered by driving the capping motor 49, the cap portion 47 is separated from the liquid injection head 27.

After that, the suction pump 50 is driven for a predetermined time to perform air suction in the cap portion 47, so that the ink remaining in the cap portion 47 is discharged. This completes the head cleaning. After the head cleaning is completed, the area corresponding to the inside of the cap portion 47 on the nozzle surface 63 is sufficiently wet with ink, so the nozzle surface 63 is wiped with the wiper unit 46 to remove this ink. There is a need.

In this case, since the nozzle opening surface 61, that is, the nozzle region 62 is covered with the liquid repellent film 66, small ink droplets (ink droplets smaller than the step 65 of 0.1 mm) adhering to the nozzle region 62 are ejected as liquid. It flows when the cap portion 47 separates from the head 27. Therefore, large ink droplets (large ink droplets having a step of 0.1 mm or more of 65 or more) remain attached to the nozzle region 62.

When the wiper unit 46 wipes the nozzle surface 63, first, the carriage motor 24 drives the carriage 25 to move the carriage 25 to a position where the nozzle surface 63 of the liquid injection head 27 is wiped by the wiper unit 46. In this case, the cloth sheet 51 pressed by the large diameter portion 76 of the pressing roller 74 is placed on the nozzle surface 63 at a position corresponding to the non-nozzle region (protruding surface 64) which is a region other than the nozzle region 62 in the nozzle surface 63. The carriage 25 is moved to a position where the cloth sheet 51 can be contacted by the second contact operation.

Subsequently, when the wiper unit 46 is moved forward from the retracted position in the transport direction Y, the cloth sheet 51 moves in the order of Pa position, Pb position, Pc position, and Pd position as shown in FIGS. 9 and 10. Wipe the entire nozzle surface 63. At this time, since the portion pressed by the large diameter portion 76 of the pressing roller 74 of the cloth sheet 51 is pressed against the protruding surface 64 with a relatively large pressure, the adhered ink on the protruding surface 64 is absorbed by the cloth sheet 51. It will almost certainly be wiped off.

At this time, the load applied to the pressing roller 74 is 3.43N, and the contact area when the pressing roller 74 elastically deforms and comes into contact with the cloth sheet 51 is 132.8 mm ² , so that the pressing roller 74 is a cloth sheet. The pressure when the 51 is pressed against the protruding surface 64 is 25.8 kPa. Further, at this time, when the cloth sheet 51 having a thickness of 0.34 mm to 0.41 mm is pressed against the protruding surface 64 by the pressing roller 74, the amount of compression of the cloth sheet 51 is 0.07 mm to 0.08 mm. The thickness of the cloth sheet 51 when the protruding surface 64 is wiped off is 0.26 mm to 0.34 mm.

Further, at this time, as shown in FIG. 8, the portion of the pressing roller 74 corresponding to the through hole 60a is a small diameter portion 77, and the portion corresponding to the nozzle region 62 of the cloth sheet 51 is almost entirely formed by the pressing roller 74. It is avoided that the material is not pressed and is pushed into the through hole 60a by a strong pressing force.

As a result, the portion of the cloth sheet 51 corresponding to the through hole 60a contacts the nozzle region 62 with a pressure smaller than the pressure (wiping pressure) at which the portion of the cloth sheet 51 corresponding to the protruding surface 64 contacts the protruding surface 64. .. That is, in the contact of the cloth sheet 51 by the second contact operation, the pressing force applied to the nozzle region 62 by the contact of the cloth sheet 51 is applied to the protruding surface 64 (non-nozzle region) by the contact of the cloth sheet 51. Less than pressure.

At this time, the compression ratio of the portion of the cloth sheet 51 pressed against the nozzle region 62 is smaller than the compression ratio of the portion pressed against the protruding surface 64 (non-nozzle region) of the cloth sheet 51. Then, the cloth sheet 51 moves in the transport direction Y, which is also the wiping direction, in a state where the cloth sheet 51 is in contact with the pressures P1 and P2 shown in the position Pc of FIG. Wipe off.

Here, for example, when the cloth sheet 51 wipes the nozzle surface 63 in the contact of the cloth sheet 51 by the second contact operation, the cloth sheet 51 may not contact the nozzle area 62 at all, but the nozzle area 62 Since the size of the adhered ink droplets is a step of 65 (0.1 mm) or more, the cloth sheet 51 surely contacts the ink droplets adhering to the nozzle region 62 even in such a case. Therefore, the ink droplets adhering to the nozzle region 62 are surely absorbed and removed by the cloth sheet 51.

Further, when the nozzle surface 63 is wiped with the cloth sheet 51, pigment particles are present in the ink absorbed by the cloth sheet 51, so that the cloth sheet 51 being wiped comes into contact with the nozzle region 62 with a strong pressure. If the pigment particles move in this state, the nozzle region 62 will be damaged due to the pigment particles functioning as abrasive particles. If the liquid repellency of the nozzle region 62 is deteriorated by repeatedly wiping the nozzle region 62 due to such damage, the ink droplets may be caused to fly and bend, resulting in deterioration of the print image quality.

In this respect, in the present embodiment, as shown in FIG. 8, the nozzle surface 63 is usually wiped off by the cloth sheet 51 in the contact of the cloth sheet 51 by the second contact operation, that is, the cloth sheet 51 is the protruding surface 64. The nozzle region 62 is wiped with a pressure smaller than the pressure against. Therefore, even if the nozzle surface 63 is repeatedly wiped by the contact of the cloth sheet 51 by the second contact operation, the liquid repellency of the nozzle region 62 is unlikely to decrease. As a result, the ink droplets ejected from each nozzle 26 are less likely to be bent during printing, and high print quality can be printed for a relatively long period of time.

Since ink mist generated during printing adheres to the nozzle surface 63, wiping the nozzle surface 63 with the cloth sheet 51 by the second contact operation is performed on the cloth sheet 51 not only after head cleaning but also during printing. The contact is performed at a predetermined timing.

Further, as shown by the position Pc in FIG. 10, in the area where the cloth sheet 51 contacts both the nozzle area 62 and the protruding surface 64 in the wiping operation of wiping the nozzle surface 63 with the cloth sheet 51, the cloth sheet 51 is used. It moves in the transport direction Y in a state where it is in contact with the protruding surface 64 at a pressure P1 and is in contact with the nozzle region 62 at a pressure P2 smaller than the pressure P1. Then, at the position Pd shown in FIG. 10, where the cloth sheet 51 finally contacts the nozzle surface 63 after wiping the area where the cloth sheet 51 contacts both the nozzle region 62 and the protruding surface 64, the nozzle surface The entire last region, which is the region where the cloth sheet 51 finally contacts in 63, becomes the protruding surface 64.

Therefore, the pressure P2 in which the cloth sheet 51 has pressed the nozzle region 62 up to that point changes to a higher pressure P3. That is, in the contact of the cloth sheet 51 by the second contact operation, the pressing force applied to the last region on the nozzle surface 63 is the nozzle region 62 when the cloth sheet 51 contacts both the nozzle region 62 and the protruding surface 64. It becomes larger than the pressing force applied to.

That is, when the cloth sheet 51 is in contact with both the protruding surface 64 and the nozzle region 62 and is in contact with only the protruding surface 64 of the last region, the cloth sheet 51 is in contact with the nozzle region 62 of the cloth sheet 51. The pressure of the part rises. Therefore, it is possible to prevent the cloth sheet 51 from wiping off the ink on the protruding surface 64 in the final region.

Further, since the protruding surface 64 has a lower liquid repellency to ink than the nozzle region 62, the adhered ink on the protruding surface 64 is relatively easy to get wet and spread. Therefore, the ink on the protruding surface 64 is effectively absorbed by using the wide area of the cloth sheet 51. Incidentally, when the liquid repellency of the protruding surface 64 is higher than that of the nozzle region 62, the ink that has moved from the nozzle region 62 along the step 65 (inner wall surface of the through hole 60a) to the protruding surface 64 side does not get wet and spread. Concentrate near the step 65.

For this reason, the ink is intensively absorbed in the local area corresponding to the step 65 in the cloth sheet 51, so that the ink absorption performance in this area tends to deteriorate, and the ink remaining in the vicinity of the step 65 is left unwiped. It will be easier. In this respect, in the present embodiment, since the ink on the protruding surface 64, which has lower liquid repellency than the nozzle region 62, easily wets and spreads, the wet and spread ink is widely absorbed by the cloth sheet 51. As a result, it becomes difficult for the ink to be left unwiped near the step 65 on the nozzle surface 63.

Further, in rare cases, foreign matter such as fine fluff may pierce the nozzle region 62 so as to pierce the nozzle region 62. In such a case, the foreign matter is wiped off the nozzle surface 63 by the contact of the cloth sheet 51 by the second contact operation. Cannot be removed. Therefore, in such a case, the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the first contact operation.

In this case, first, the cloth sheet 51 pressed by the large diameter portion 76 of the pressing roller 74 is brought into contact with the nozzle surface 63 at a position corresponding to the nozzle region 62 on the nozzle surface 63, and the cloth sheet by the first contact operation is performed. The carriage 25 is moved to a position where the 51 can be contacted. Subsequently, when the wiper unit 46 is moved forward from the retracted position in the transport direction Y, the cloth sheet 51 moves in the order of position Pa, position Pb, position Pc, and position Pd, as shown in FIGS. 9 and 10. Wipe the entire nozzle surface 63.

At this time, as shown in FIG. 11, the portion of the cloth sheet 51 pressed by the large diameter portion 76 of the pressing roller 74 is pressed against the nozzle region 62 with a relatively large pressure. In this case, since the dimension M of the large diameter portion 76 in the scanning direction X is shorter than the dimension L of the nozzle region 62 in the scanning direction X, the portion pressed by the large diameter portion 76 in the cloth sheet 51 is the nozzle region. It is surely pressed against 62. As a result, the foreign matter on the nozzle region 62 is almost certainly wiped off together with the adhered ink.

As described above, in the inkjet printer 11, the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the first contact operation and the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the second contact operation. be able to. In particular, the frequency of wiping the nozzle surface 63 by the contact of the cloth sheet 51 by the first contact operation is much less than the frequency of wiping the nozzle surface 63 by the contact of the cloth sheet 51 by the second contact operation. Therefore, deterioration of the nozzle region 62 due to wiping of the nozzle surface 63 can be suppressed.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The inkjet printer 11 selectively wipes the nozzle surface 63 by the contact of the cloth sheet 51 by the first contact operation and the nozzle surface 63 by the contact of the cloth sheet 51 by the second contact operation. Can be done. Therefore, in particular, by selectively wiping the nozzle surface 63 by contacting the cloth sheet 51 by the second contact operation, the nozzle surface 63 can be wiped while reducing the pressing force applied to the nozzle region 62 by the wiping. It can be carried out. Therefore, deterioration of the nozzle region 62 including the opening region of the nozzle 26 due to wiping of the nozzle surface 63 on which the nozzle 26 on which the ink is ejected is arranged can be suppressed.

(2) In the inkjet printer 11, in the contact of the cloth sheet 51 by the second contact operation, the pressing force applied to the nozzle region 62 by the contact of the cloth sheet 51 is the protruding surface 64 (non-nozzle) by the contact of the cloth sheet 51. It is smaller than the pressing force applied to the area). Therefore, the ink adhering to the nozzle surface 63 can be suitably absorbed and removed by the cloth sheet 51 while reducing the damage given to the nozzle region 62.

(3) In the inkjet printer 11, the compression ratio of the portion of the cloth sheet 51 pressed against the nozzle region 62 is smaller than the compression ratio of the portion of the cloth sheet 51 pressed against the protruding surface 64. Therefore, the ink adhering to the nozzle surface 63 can be suitably absorbed and removed by the cloth sheet 51 while reducing the damage given to the nozzle region 62.

(4) In the inkjet printer 11, the protruding surface 64 has a lower liquid repellency than the nozzle region 62. Therefore, since the ink tends to get wet and spread on the protruding surface 64 having a relatively low liquid repellency, the cloth sheet 51 can efficiently absorb and remove the ink on the protruding surface 64.

(5) In the inkjet printer 11, when the cloth sheet 51 is contacted by the second contact operation, the pressing force applied to the last region of the protruding surface 64 is applied to both the nozzle region 62 and the protruding surface 64 of the cloth sheet 51. It is larger than the pressing force applied to the nozzle region 62 at the time of contact. Therefore, when the cloth sheet 51 is in contact with both the protruding surface 64 and the nozzle region 62 and is in contact with only the protruding surface 64 of the last region, the cloth sheet 51 is in contact with the nozzle region 62 of the cloth sheet 51. The pressure of the part rises. Therefore, it is possible to prevent the cloth sheet 51 from wiping off the ink on the protruding surface 64 in the final region.

(6) In the inkjet printer 11, the surface of the liquid injection head 27 having the nozzle 26 is covered with a cover member 60 having a through hole 60a that exposes the nozzle region 62 in a portion corresponding to the nozzle region 62. Therefore, with a relatively simple configuration in which the cover member 60 is simply attached to the liquid injection head 27, the pressing forces applied to the nozzle region 62 and the protruding surface 64 when the nozzle surface 63 is wiped can be made different from each other. ..

(7) In the inkjet printer 11, the pressing roller 74 has a large diameter portion 76 capable of pressing the cloth sheet 51, and the dimension M of the large diameter portion 76 in the scanning direction X is the nozzle region 62 in the scanning direction X. It is shorter than the dimension L. Therefore, in the contact of the cloth sheet 51 by the first contact operation, the cloth sheet 51 is effectively pressed by the large diameter portion 76 of the pressing roller 74 so that the cloth sheet 51 makes a suitable contact with the nozzle region 62. be able to.

(Change example)
The above embodiment may be changed as follows.
As shown in FIGS. 12 and 13, a rubber roller 80 may be used as the pressing portion instead of the pressing roller 74. The rubber roller 80 is formed by cutting out a portion of the peripheral surface of the cylindrical rubber corresponding to the protruding surface 64 of the nozzle surface 63 in the circumferential direction to provide a plurality of recesses 80a. Therefore, concave portions 80a and convex portions 80b are alternately formed on a part of the peripheral surface of the rubber roller 80 in the circumferential direction in the axial direction thereof. That is, unevenness is formed on a part of the peripheral surface of the rubber roller 80 in the circumferential direction, and the portion other than the portion where the unevenness is formed on the peripheral surface of the rubber roller 80 is flat without unevenness. Then, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the first contact operation, as shown in FIGS. 12 and 13, the cloth sheet 51 is moved to the nozzle surface 63 by the convex portion 80b of the rubber roller 80. Press against the nozzle area 62. On the other hand, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the second contact operation, the rubber roller 80 is rotated by, for example, 180 ° from the state of the first contact operation (the state shown in FIGS. 12 and 13). As shown in FIGS. 14 and 15, the cloth sheet 51 is pressed against the protruding surface 64 of the nozzle surface 63 by the flat portion of the rubber roller 80.

As shown in FIG. 16, a small large diameter portion 76A having an outer diameter slightly smaller than that of the large diameter portion 76 of the pressing roller 74 may be added to the end portion of the pressing roller 74. Then, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the first contact operation, the nozzle region 62 in which the nozzle row 59 into which the ink containing an inorganic pigment such as carbon black or titanium oxide is ejected is formed. The cloth sheet 51 is pressed by the small large diameter portion 76A. By doing so, it is possible to reduce the damage caused to the nozzle region 62 by the inorganic pigment when the nozzle region 62 is wiped. Further, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the second contact operation, if it is desired to surely wipe the protruding surface 64, the small large diameter portion 76A may not be used. That is, the position of the pressing roller 74 in the axial direction may be adjusted so that the cloth sheet 51 is pressed against the protruding surface 64 by the large diameter portion 76 other than the small large diameter portion 76A.

A soft large diameter portion having the same shape as the large diameter portion 76 and having a hardness lower than that of the large diameter portion 76 may be added to the end portion of the pressing roller 74. Then, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the first contact operation, the nozzle region 62 in which the nozzle row 59 into which the ink containing an inorganic pigment such as carbon black or titanium oxide is ejected is formed. The cloth sheet 51 is pressed by the soft large diameter portion. By doing so, it is possible to reduce the damage caused to the nozzle region 62 by the inorganic pigment when the nozzle region 62 is wiped. Further, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the second contact operation, if it is desired to surely wipe the protruding surface 64, the soft large diameter portion may not be used. That is, the position of the pressing roller 74 in the axial direction may be adjusted so that the cloth sheet 51 is pressed against the protruding surface 64 by the large diameter portion 76 other than the soft large diameter portion.

As shown in FIG. 17, the wiper unit 46 having the pressing roller 74 and the wiper unit in which the pressing roller 74 of the wiper unit 46 is changed to the small pressing roller 74A are arranged side by side in the scanning direction X. You may. In this case, the small pressing roller 74A is obtained by changing the large diameter portion 76 of the pressing roller 74 to a small large diameter portion 76A whose outer diameter is slightly smaller than that of the large diameter portion 76. Then, when wiping the nozzle region 62 in which the nozzle row 59 in which the ink containing the inorganic pigment is ejected is formed, a wiper unit having a small pressing roller 74A is used to eject the ink not containing the inorganic pigment. When wiping the nozzle region 62 in which the rows 59 are formed, a wiper unit 46 having a pressing roller 74 is used.

As shown in FIG. 18, when the nozzle surface 63 is wiped by the contact of the cloth sheet 51 by the second contact operation, the area where the large diameter portion 76 of the pressing roller 74 is separated from the nozzle surface 63 of the cloth sheet 51 is formed. You may press it. In this case, one large diameter portion 76 of the pressing roller 74 is arranged at both ends, and the distance between these two large diameter portions 76 is slightly wider than the width of the nozzle surface 63.

The nozzle surface 63 may be wiped by a third contact operation in which a portion of the cloth sheet 51 that is not pressed by the pressing portion is brought into contact with the nozzle surface 63.
-The pressing portion is not limited to a cylindrical shape, and may be formed of a strip-shaped member having a convex portion. That is, the pressing portion may be formed of, for example, a member having a convex portion formed on one surface of the flat plate.

The dimension M of the large diameter portion 76 in the scanning direction X does not necessarily have to be shorter than the dimension L of the nozzle region 62 in the scanning direction X.
The protruding surface 64 may be formed so as to be integrally formed with the liquid injection head 27 without using the cover member 60. In this case, the nozzle opening surface 61 is composed of an uneven surface.

A liquid repellent treatment is applied to an outer region (a region corresponding to the nozzle region 62 of the above embodiment) adjacent to the opening region of the nozzle 26 of the nozzle opening surface 61 without providing the protruding surface 64, and the outer region (the above). The liquid repellent treatment may not be applied to the region corresponding to the non-nozzle region of the embodiment). In this case, the nozzle opening surface 61 corresponds to the nozzle surface 63 to be wiped from the wiper unit 46 in the above embodiment.

In the contact of the cloth sheet 51 by the second contact operation, the pressing force applied to the last region of the protruding surface 64 is not necessarily the nozzle region 62 when the cloth sheet 51 contacts both the nozzle region 62 and the protruding surface 64. It does not have to be greater than the pressing force applied to.

The liquid repellency of the protruding surface 64 does not necessarily have to be lower than the liquid repellency of the nozzle region 62.
In the contact of the cloth sheet 51 by the second contact operation, the compression rate of the portion of the cloth sheet 51 pressed against the nozzle region 62 is not necessarily smaller than the compression rate of the portion pressed by the protruding surface 64 of the cloth sheet 51. No need.

In the contact of the cloth sheet 51 by the second contact operation, the pressing force applied to the nozzle region 62 by the contact of the cloth sheet 51 is not necessarily applied to the protruding surface 64 (non-nozzle region) by the contact of the cloth sheet 51. It does not have to be less than the pressure.

-The liquid injection head 27 may be capped for each nozzle row 59 to perform head cleaning. In this way, the cap portion can be made smaller than in the case where all the nozzle rows 59 are capped by the cap portion 47 and the head cleaning is performed, so that the amount of ink consumed during the head cleaning can be reduced.

-Without impregnating the unused cloth sheet 51 with the cleaning liquid in advance, a cleaning liquid application mechanism such as an injection nozzle is provided, the cleaning liquid is applied to the nozzle surface 63, and the nozzle surface 63 is wiped with the cloth sheet 51. You may.

-Ink is applied from the nozzle 26 of the liquid injection head 27 to the used area of the cloth sheet 51 (the area where the nozzle surface 63 is wiped off) in the wiper unit 46 for the purpose of eliminating clogging of the nozzle 26 regardless of printing. Flushing to discharge may be performed.

The wiper unit 46 may wipe the nozzle surface 63 by moving the nozzle surface 63 while the wiper unit 46 is stopped, or by moving both the wiper unit 46 and the nozzle surface 63. May be good.

The inkjet printer 11 may be a line head type printer that does not include a carriage 25 that supports the liquid injection head 27 and has a line head whose printing range covers the entire width of the recording medium 13. In this case, since the line head is fixed and does not move, the nozzle surface is wiped by moving the wiper unit.

-The ink may be a non-aqueous ink.
Non-aqueous inks will be described in detail below.
The non-aqueous ink used in the liquid injection device contains a resin in composition and substantially does not contain glycerin having a boiling point of 290 ° C. at 1 atm. If the ink contains substantially glycerin, the dryness of the ink is significantly reduced. As a result, in various media, particularly ink non-absorbent or low-absorbent media, not only the unevenness of light and shade of the image is conspicuous, but also the fixability of the ink cannot be obtained. Further, it is preferable that the ink substantially does not contain alkyl polyols (excluding the above-mentioned glycerin) having a boiling point of 280 ° C. or higher at 1 atm.

Here, "substantially not contained" in the present specification means that the content is not contained in an amount that sufficiently exerts the significance of addition. Quantitatively speaking, it is preferable that glycerin is not contained in an amount of 1.0% by mass or more, more preferably 0.5% by mass or more, and 0, based on the total mass (100% by mass) of the ink. . It is more preferably not contained in an amount of 1% by mass or more, further preferably not contained in an amount of 0.05% by mass or more, and particularly preferably not containing 0.01% by mass or more. Most preferably, it does not contain 0.001% by mass or more of glycerin.

Next, the additives (components) contained or may be contained in the ink will be described.
[1. Color material]
The ink may contain a coloring material. The coloring material is selected from pigments and dyes.

[1-1. Pigment]
By using a pigment as a coloring material, the light resistance of the ink can be improved. As the pigment, either an inorganic pigment or an organic pigment can be used. The inorganic pigment is not particularly limited, and examples thereof include carbon black, iron oxide, titanium oxide, and silica oxide.

The organic pigment is not particularly limited, but for example, quinacridone pigment, quinacridone quinone pigment, dioxazine pigment, phthalocyanine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanslon pigment, flavanthron pigment, etc. Examples thereof include perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. .. Specific examples of the organic pigment include the following.

Examples of the pigment used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15:34, 16, 18, 22, 60, 65, 66, C.I. I. Bat blue 4, 60 can be mentioned. Above all, C.I. I. Pigment Blue 15: 3 or 15: 4 is preferred.

Pigments used in magenta ink include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 , 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50. Above all, C.I. I. Pigment Red 122, C.I. I. Pigment Red 202, and C.I. I. One or more selected from the group consisting of pigment violet 19 is preferable.

Examples of the pigment used in the yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180, 185, 213 and the like. Above all, C.I. I. One or more selected from the group consisting of Pigment Yellow 74, 155, and 213 is preferable.

Examples of pigments used for inks of colors other than the above, such as green ink and orange ink, include conventionally known pigments.
The average particle size of the pigment is preferably 250 nm or less because clogging in the nozzle can be suppressed and the ejection stability is further improved. The average particle size in the present specification is based on the volume. As a measuring method, for example, it can be measured by a particle size distribution measuring device based on a laser diffraction / scattering method. Examples of the particle size distribution measuring device include a particle size distribution meter based on a dynamic light scattering method (for example, Microtrack UPA manufactured by Nikkiso Co., Ltd.).

[1-2. dye]
A dye can be used as the coloring material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. The content of the coloring material is preferably 0.4 to 12% by mass, more preferably 2% by mass or more and 5% by mass or less, based on the total mass (100% by mass) of the ink.

[2. resin]
The ink contains a resin. When the ink contains a resin, a resin film is formed on the medium, and as a result, the ink is sufficiently fixed on the medium, and the effect of mainly improving the scratch resistance of the image is exhibited. Therefore, the resin emulsion is preferably a thermoplastic resin. The thermal deformation temperature of the resin is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, because it is less likely to cause clogging of the nozzle and has an advantageous effect of imparting abrasion resistance to the medium. preferable.

Here, the "thermal deformation temperature" in the present specification is a temperature value represented by a glass transition temperature (Tg) or a minimum film forming temperature (MFT). That is, "the thermal deformation temperature is 40 ° C. or higher" means that either Tg or MFT may be 40 ° C. or higher. Since it is easier to grasp the superiority or inferiority of the redispersibility of the resin in MFT than in Tg, the thermal deformation temperature is preferably a temperature value represented by MFT. If the ink has excellent redispersibility of the resin, the ink does not stick to the ink, so that the nozzle is less likely to be clogged.

Specific examples of the thermoplastic resin are not particularly limited, but are poly (meth) acrylic acid ester or a copolymer thereof, polyacrylonitrile or a copolymer thereof, polycyanoacrylate, polyacrylamide, poly (meth) acrylic acid and the like. (Meta) acrylic polymers, polyethylene, polypropylene, polybutene, polyisobutylene, and polystyrene, and their copolymers, and polyolefin-based polymers such as petroleum resin, kumaron-inden resin, and terpene resin, polyvinyl acetate. Or its copolymer, polyvinyl alcohol, polyvinyl acetal, and vinyl acetate-based or vinyl alcohol-based polymer such as polyvinyl ether, polyvinyl chloride or its copolymer, polyvinylidene chloride, fluororesin, and halogen-containing such as fluororubber. System polymers, polyvinylcarbazole, polyvinylpyrrolidone or copolymers thereof, nitrogen-containing vinyl polymers such as polyvinylpyridine, and polyvinylimidazole, polybutadienes or copolymers thereof, polychloroprenes, and dienes such as polyisoprene (butyl rubber). Examples include polymers and other ring-opening polymerized resins, condensation polymerized resins, and natural polymer resins.

The content of the resin is preferably 1 to 30% by mass, more preferably 1 to 5% by mass, based on the total mass (100% by mass) of the ink. When the content is within the above range, the glossiness and scratch resistance of the formed topcoat image can be further improved. Examples of the resin that may be contained in the ink include a resin dispersant, a resin emulsion, and wax.

[2-1. Resin emulsion]
The ink may include a resin emulsion. When the medium is heated, the resin emulsion preferably forms a resin film together with wax (emulsion), so that the ink is sufficiently fixed on the medium and the scratch resistance of the image is improved. When the medium is printed with an ink containing a resin emulsion due to the above effects, the ink becomes excellent in abrasion resistance particularly on a medium having non-absorbency or low absorbency.

Further, the resin emulsion that functions as a binder is contained in the ink in an emulsion state. By containing a resin that functions as a binder in the ink in an emulsion state, it is easy to adjust the viscosity of the ink to an appropriate range in the inkjet recording method, and it is possible to improve the storage stability and ejection stability of the ink.

Resin emulsions include, but are not limited to, (meth) acrylic acid, (meth) acrylic acid ester, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether, and vinylpyrrolidone. , Vinylpyridine, vinylcarbazole, vinylimidazole, and vinylidene chloride homopolymers or copolymers, fluororesins, and natural resins. Among them, either a methacrylic acid-based resin or a styrene-methacrylic acid copolymer-based resin is preferable, and any of an acrylic-based resin and a styrene-acrylic acid copolymer-based resin is more preferable, and a styrene-acrylic acid copolymer-based resin is more preferable. Even more preferable. The above-mentioned copolymer may be in any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer.

The average particle size of the resin emulsion is preferably in the range of 5 nm to 400 nm, more preferably in the range of 20 nm to 300 nm, in order to further improve the storage stability and ejection stability of the ink. Among the resins, the content of the resin emulsion is preferably in the range of 0.5 to 7% by mass with respect to the total mass (100% by mass) of the ink. When the content is within the above range, the solid content concentration can be lowered, so that the discharge stability can be further improved.

[2-2. wax]
The ink may contain wax. When the ink contains wax, the fixability of the ink on the non-ink-absorbing and low-absorbing medium becomes more excellent. The wax is more preferably an emulsion type. The wax is not limited to the following, and examples thereof include polyethylene wax, paraffin wax, and polyolefin wax, and among them, polyethylene wax described later is preferable. In addition, in this specification, "wax" mainly means the thing which solid wax particles were dispersed in water by using the surfactant which will be described later.

When the ink contains polyethylene wax, the scratch resistance of the ink can be improved. The average particle size of the polyethylene wax is preferably in the range of 5 nm to 400 nm, more preferably in the range of 50 nm to 200 nm, in order to further improve the storage stability and ejection stability of the ink.

The content of the polyethylene wax (in terms of solid content) is preferably in the range of 0.1 to 3% by mass, and 0.3 to 3% by mass, based on the total mass of the ink (100% by mass) independently of each other. It is more preferably in the range of% by mass, and even more preferably in the range of 0.3 to 1.5% by mass. When the content is within the above range, the ink can be satisfactorily solidified and fixed even on a medium that does not absorb ink or has low absorbency, and the storage stability and ejection stability of the ink are further improved. Can be.

[3. Surfactant]
The ink may contain a surfactant. Examples of the surfactant include, but are not limited to, nonionic surfactants. The nonionic surfactant has the effect of spreading the ink uniformly on the medium. Therefore, when printing is performed using an ink containing a nonionic surfactant, a high-definition image with almost no bleeding can be obtained. Such nonionic surfactants are not limited to the following, but are, for example, silicon-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivatives, and fluorine-based interfaces. Activators can be mentioned, and among them, silicon-based surfactants are preferable.

The content of the surfactant is 0.1% by mass or more and 3% by mass or less with respect to the total mass (100% by mass) of the ink because the storage stability and ejection stability of the ink are further improved. It is preferably in the range.

[4. Organic solvent]
The ink may contain a known volatile water-soluble organic solvent. However, as described above, the ink substantially does not contain glycerin (boiling point at 1 atm is 290 ° C), which is a kind of organic solvent, and alkyl polyols having a boiling point at 280 ° C or higher at 1 atm. It is preferable that (excluding the above-mentioned glycerin) is substantially not contained.

[5. Aprotic polar solvent]
The ink may contain an aprotic polar solvent. By containing the aprotic polar solvent in the ink, the above-mentioned resin particles contained in the ink are dissolved, so that clogging of the nozzles can be effectively suppressed during printing. Further, since it has a property of dissolving a medium such as vinyl chloride, the adhesion of the image is improved.

The aprotic polar solvent is not particularly limited, but is one or more selected from pyrrolidones, lactones, sulfoxides, imidazolidinones, sulfolanes, urea derivatives, dialkylamides, cyclic ethers, and amide ethers. Is preferably included. Representative examples of pyrrolidones include 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone, and typical examples of lactones are γ-butyrolactone, γ-valerolactone, and ε-caprolactone. Typical examples of sulfoxides are dimethyl sulfoxide and tetramethylene sulfoxide.

Representative examples of imidazolidinones include 1,3-dimethyl-2-imidazolidinone, representative examples of sulfolanes include sulfolanes and dimethylsulfolanes, and representative examples of urea derivatives include dimethylurea. There are 1,1,3,3-tetramethylurea. Representative examples of dialkylamides include dimethylformamide and dimethylacetamide, and typical examples of cyclic ethers include 1,4-dioxane and tetrahydrofuran.

Among them, pyrrolidones, lactones, sulfoxides, and amide ethers are particularly preferable, and 2-pyrrolidone is most preferable from the viewpoint of the above-mentioned effects. The content of the aprotic polar solvent is preferably in the range of 3 to 30% by mass, more preferably in the range of 8 to 20% by mass, based on the total mass (100% by mass) of the ink. preferable.

[6. Other ingredients]
In addition to the above components, the ink may further contain a fungicide, a rust inhibitor, a chelating agent, and the like.

Next, the components of the surfactant to be mixed with the second liquid will be described.
Surfactants include cationic surfactants such as alkylamine salts and quaternary ammonium salts; anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; alkyldimethylamine oxide. , Alkylcarboxybetaine and other amphoteric surfactants; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene / polyoxypropylene block copolymers. Etc. can be used, but among these, an anionic surfactant or a nonionic surfactant is particularly preferable.

The content of the surfactant is preferably 0.1 to 5.0% by mass with respect to the total mass of the second liquid. Further, from the viewpoint of foaming property and defoaming property after bubbles, the content of the surfactant is preferably 0.5 to 1.5% by mass with respect to the total mass of the second liquid. The surfactant may be only one type or two or more types. Further, the surfactant contained in the second liquid is preferably the same as the surfactant contained in the ink (first liquid), for example, the surfactant contained in the ink (first liquid). When is a nonionic surfactant, the nonionic surfactant is not limited to the following, but is, for example, silicon-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivative. , And fluorine-based surfactants, and among them, silicon-based surfactants are preferable.

In particular, the foam height immediately after foaming and 5 minutes after foaming using the Rosmiles method is within the above range (the foam height immediately after foaming is 50 mm or more, and the foam height after 5 minutes of foaming is 5 mm or less). In order to achieve this, an adduct in which ethylene oxide (EO) is added to acetylene diol with an addition molar number of 4 to 30 is used as a surfactant, and the content of the adduct is set to 0 with respect to the total weight of the cleaning solution. It is preferably 1 to 3.0% by weight. Further, the foam height immediately after foaming and 5 minutes after foaming using the Rosmiles method is within the above preferable range (the foam height immediately after foaming is 100 mm or more, and the foam height 5 minutes after foaming is 5 mm or less). In order to obtain the above, an adduct in which ethylene oxide (EO) is added to acetylene diol with an addition molar number of 10 to 20 is used, and the content of the adduct is 0.5 to 1 with respect to the total weight of the cleaning liquid. It is preferably 5.5% by weight. However, if the content of the ethylene oxide adduct of acetylene diol is too large, the critical micelle concentration may be reached and an emulsion may be formed.

The surfactant has a function of making the water-based ink wet and spread easily on the recording medium. The surfactant that can be used in the present invention is not particularly limited, and is an anionic surfactant such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl. Nonionic surfactants such as ethers, acetylene glycols, and polyoxyethylene / polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone-based surfactants; Fluorine-based surfactants and the like can be used.

The surfactant has the effect of subdividing and dispersing the agglomerates due to the interfacial active effect between the cleaning liquid (second liquid) and the agglomerates. Further, since it has a function of lowering the surface tension of the cleaning liquid, the cleaning liquid easily penetrates between the agglomerate and the liquid injection surface, and has an effect of facilitating the agglomeration from being separated from the liquid injection surface.

As the surfactant, any compound having a hydrophilic portion and a hydrophobic portion in the same molecule can be preferably used. As a specific example, those represented by the following formulas (I) to (IV) are preferable. That is, the polyoxyethylene alkyl phenyl ether-based surfactant of the following formula (I), the acetylene glycol-based surfactant of the formula (II), the polyoxyethylene alkyl ether-based surfactant of the following formula (III), and the formula (IV). ) Polyoxyethylene polyoxypropylene alkyl ether-based surfactant.

（Ｒは分岐していても良い炭素数６〜１４の炭化水素鎖、ｋ：５〜２０）

(R is a hydrocarbon chain having 6 to 14 carbon atoms which may be branched, k: 5 to 20)

（ｍ、ｎ≦２０，０＜ｍ＋ｎ≦４０）

(M, n ≦ 20,0 <m + n ≦ 40)

（Ｒは分岐してもよい炭素数６〜１４の炭化水素鎖、ｎは５〜２０）

(R is a hydrocarbon chain having 6 to 14 carbon atoms which may be branched, n is 5 to 20)

（Ｒは炭素数６〜１４の炭化水素鎖、ｍ、ｎは２０以下の数）
前記式（Ｉ）〜（IV）の化合物以外では、例えばジエチレングリコールモノフェニルエーテル、エチレングリコールモノフェニルエーテル、エチレングリコールモノアリルエーテル、ジエチレングリコールモノフェニルエーテル、ジエチレングリコールモノブチルエーテル、プロピレングリコールモノブチルエーテル、テトラエチレングリコールクロロフェニルエーテル等の多価アルコールのアルキル及びアリールエーテル類、ポリオキシエチレンポリオキシプロピレンブロック共重合体等のノニオン系界面活性剤、フッ素系界面活性剤、エタノール、２−プロパノール等の低級アルコール類を用いることができるが、特にジエチレングリコールモノブチルエーテルが好ましい。

(R is a hydrocarbon chain having 6 to 14 carbon atoms, and m and n are numbers of 20 or less)
Other than the compounds of the formulas (I) to (IV), for example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl Use alkyl and aryl ethers of polyhydric alcohols such as ethers, nonionic surfactants such as polyoxyethylene polyoxypropylene block copolymers, fluorine-based surfactants, and lower alcohols such as ethanol and 2-propanol. However, diethylene glycol monobutyl ether is particularly preferable.

-In the above embodiment, the liquid injection device may be a liquid injection device that injects or ejects a liquid other than ink. The state of the liquid discharged as a minute amount of droplets from the liquid injection device includes those having a granular, tear-like, or thread-like tail. Further, the liquid referred to here may be any material that can be injected from a liquid injection device. For example, the substance may be in a liquid phase, and may be a highly viscous or low-viscosity liquid, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts). ) Shall include a flowing body. Further, it includes not only a liquid as a state of a substance but also a particle of a functional material made of a solid substance such as a pigment or a metal particle dissolved, dispersed or mixed in a solvent. Typical examples of the liquid include various liquid compositions such as water-based ink, non-water-based ink, oil-based ink, gel ink, hot melt ink, and liquid crystal as described in the above-described embodiment. Specific examples of the liquid injection device include liquids containing materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, surface emitting displays, color filters, etc. in the form of dispersion or dissolution. There is a liquid injection device that injects. Further, a liquid injection device for injecting a bioorganic substance used for producing a biochip, a liquid injection device for injecting a liquid as a sample used as a precision pipette, a printing device, a microdispenser, or the like may be used. Furthermore, a transparent resin liquid such as an ultraviolet curable resin is used to form a liquid injection device that injects lubricating oil pinpointly into precision machines such as watches and cameras, and a microhemispherical lens (optical lens) used for optical communication elements. May be a liquid injection device that injects Further, it may be a liquid injection device that injects an etching solution such as an acid or an alkali to etch a substrate or the like.

11 ... Inkjet printer as an example of a liquid injection device, 12 ... Support stand, 13 ... Recording medium, 14 ... Conveying unit, 15 ... Printing unit, 16 ... Printer body, 17 ... Cover, 18 ... Conveying roller pair, 19 ... Conveyor roller pair, 20 ... guide plate, 22 ... guide shaft, 23 ... guide shaft, 24 ... carriage motor, 25 ... carriage, 26 ... nozzle, 27 ... liquid injection head, 30 ... ink cartridge, 31 ... supply mechanism, 32 ... Mounting part, 33 ... Supply path, 34 ... Supply pump, 35 ... Filter unit, 36 ... Static mixer, 37 ... Liquid storage chamber, 38 ... Pressure adjustment unit, 39 ... Control unit, 40 ... Diaphragm pump, 41 ... Suction valve, 42 ... Discharge valve, 43 ... Maintenance mechanism, 44 ... Liquid receiving part, 45 ... Flushing unit, 46 ... Wiper unit as an example of cleaning device, 47 ... Cap part, 48 ... Cap unit, 49 ... Capping motor, 50 ... Suction Pump, 51 ... cloth sheet as an example of absorbing member, 52 ... wiper cassette, 52a ... opening, 53 ... wiper holder, 54 ... rail part, 55 ... head unit, 55a ... supply pipe part, 56 ... bracket part, 57 ... Flow path forming portion, 57a ... Ink flow path, 58 ... Head body, 59 ... Nozzle row, 60 ... Cover member, 60a ... Through hole, 61 ... Nozzle opening surface, 62 ... Nozzle area, 63 ... Nozzle surface, 64 ... Protruding surface as an example of non-nozzle region, 65 ... step, 66 ... liquid repellent film, 67 ... recording head, 68 ... guide part, 69 ... electric motor, 70 ... power transmission mechanism, 71 ... rack and pinion mechanism, 71a ... rack gear part, 71b ... pinion gear part, 72 ... feeding shaft, 73 ... winding shaft, 74 ... pressing roller as an example of pressing part, 74A ... small pressing roller as an example of pressing part, 75 ... supporting shaft, 76 ... Large diameter portion as an example of a convex portion, 76A ... Small large diameter portion as an example of a convex portion, 77 ... Small diameter portion, 78 ... Spring, 80 ... Rubber roller, 80a ... Recessed portion, 80b ... Convex portion, A ... Supply direction, HP ... home position, L ... dimension, M ... dimension, P1 ... pressure, P2 ... pressure, P3 ... pressure, PA ... transport area, Pa to Pd ... position, X ... scanning direction, Y ... transport direction, Z … Vertical direction.

Claims (10)

A liquid injection head that injects liquid from a nozzle arranged on the nozzle surface,
The absorbing member is pressed against the absorbing member capable of absorbing the liquid that comes into contact with the nozzle surface and adheres to the nozzle surface, and the absorbing member from the side opposite to the side of the absorbing member that comes into contact with the nozzle surface. A wiper unit having a pressing portion that comes into contact with the nozzle surface,
With
The pressing portion can rotate with the direction intersecting the direction in which the absorbing member moves with respect to the liquid injection head in the direction along the nozzle surface as the axial direction.
When the portion of the pressing portion that can press the absorbing member is a convex portion, a plurality of the convex portions formed at intervals in the axial direction and concave portions formed between the convex portions are formed. The peripheral surface has a concavo-convex region having the concavo-convex region and a flat region having no concave portion and capable of pressing the absorbing member.
The first contact operation of bringing the absorbing member pressed by the convex portion into contact with the nozzle region including the nozzle opening region of the nozzle surface.
By rotating the pressing portion, it is possible to perform a second contact operation of bringing the absorbing member pressed by the flat region into contact with a non-nozzle region which is a region other than the nozzle region of the nozzle surface. A liquid injection device characterized in that it is possible. Before SL recess liquid ejecting apparatus according to claim 1, characterized in that does not contact the absorbent member. The liquid injection device according to claim 1 or 2, wherein the uneven region is narrower than the flat region in the rotation direction of the pressing portion. A transport unit that transports the medium in the transport direction along the direction in which the absorption member moves, and
A carriage to which a plurality of the liquid injection heads are attached and reciprocating in the axial direction,
With more
The nozzle surfaces of the plurality of liquid injection heads are arranged so as to be separated from each other at a predetermined distance in the axial direction and displaced in the transport direction.
The width of the absorbing member in the axial direction is wider than the width of the nozzle surface in the axial direction and narrower than the distance obtained by adding the predetermined distance to the width of the nozzle surface in the axial direction. The liquid injection device according to any one of claims 1 to 3. 4. The fourth aspect of the present invention is characterized in that, in a state where the absorbing member is in contact with the nozzle surface, the wiper unit moves toward the downstream side in the transport direction to perform a wiping operation for wiping the nozzle surface. The liquid injection device according to the description. The liquid injection device according to claim 5, wherein after the wiping operation is performed, the wiper unit moves the pressing portion to a retracted position located upstream of the nozzle surface in the transport direction. An absorbing member capable of absorbing the liquid adhering to the nozzle surface in contact with the nozzle surface on which the liquid injection head ejects the liquid is arranged.
A pressing portion that presses the absorbing member from a side of the absorbing member opposite to the side that contacts the nozzle surface to bring the absorbing member into contact with the nozzle surface.
With
The pressing portion can rotate with the direction intersecting the direction in which the absorbing member moves with respect to the liquid injection head in the direction along the nozzle surface as the axial direction.
When the portion of the pressing portion that can press the absorbing member is a convex portion, a plurality of the convex portions formed at intervals in the axial direction and concave portions formed between the convex portions are formed. The peripheral surface has a concavo-convex region having the concavo-convex region and a flat region having no concave portion and capable of pressing the absorbing member.
The first contact operation of bringing the absorbing member pressed by the convex portion into contact with the nozzle region including the nozzle opening region of the nozzle surface.
By rotating the pressing portion, a second contact operation of bringing the absorbing member pressed by the flat region into contact with a non-nozzle region other than the nozzle region of the nozzle surface can be performed. A featured cleaning device. Before SL recesses cleaning device according to claim 7, characterized in that it does not contact the absorbent member. The cleaning device according to claim 7 or 8, wherein the uneven region is narrower than the flat region in the rotation direction of the pressing portion. 7. The width of the absorbing member in the axial direction is wider than the width of the nozzle surface in the axial direction and narrower than twice the width of the nozzle surface in the axial direction. 9. The cleaning device according to any one of 9.

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