JP5919770B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a liquid ejection apparatus having a liquid ejection head that ejects liquid.

  In Patent Document 1, a suction force generation source (fan) is provided between the heads, and the mist is sucked up by the suction force generated by the suction force generation source to prevent the mist from adhering to the head.

JP 2002-154196 A

  For the purpose of adjusting the distance between the ejection surface of the head and the recording medium, the present inventor has studied a configuration in which a moving mechanism for moving a head holding portion that holds the head is provided. As a result, the following problems were discovered. For example, when the suction force generation source is attached to the head holding unit, the load applied to the moving mechanism may be excessive. In addition, vibration generated from the suction force generation source is directly transmitted to the head holding unit, and the head may vibrate, which may adversely affect liquid ejection.

  An object of the present invention is to provide a liquid ejection apparatus in which vibration generated in a suction force generation source hardly causes adverse effects on liquid ejection.

In order to achieve the above object, a liquid ejection apparatus according to an aspect of the present invention includes a plurality of liquid ejection heads each having an ejection surface that ejects liquid, and a medium support member that supports a recording medium at a position facing the ejection surface. A suction pipe formed with a first opening disposed between two adjacent liquid ejection heads among the plurality of liquid ejection heads; and a suction force generation source coupled to the suction pipe; A head holding unit that holds the plurality of liquid discharge heads, and a moving mechanism that moves the head holding unit relative to at least the suction force generation source. The moving mechanism is coupled to the head holding portion via an elastic member.

According to the liquid ejection apparatus of the present invention, the head holding unit is moved relative to the suction force generation source. Therefore, a load is not easily applied to the moving mechanism that moves the head holding unit, and vibration from the suction force generation source is difficult to be transmitted to the head, so that liquid ejection is hardly affected. In addition, the elastic member can suppress the vibration of the suction force generation source from the moving mechanism to the head holding portion.

  In the present invention, the suction tube includes a first tube and a second tube, and the first tube is formed on the medium support member side in an orthogonal direction orthogonal to the discharge surface. 1 opening, the 2nd opening formed in the said orthogonal direction on the opposite side to the said medium support member side, and the communication space which connects the said 1st opening and 2nd openings, The said 2nd pipe | tube is The front end portion connected to the suction force generation source and having a third opening formed therein, and the front end portion is inserted into the communication space from the second opening, and the head holding portion is The first tube is held, and the moving mechanism preferably moves the first tube relative to the second tube.

  If the positional relationship between the ejection surface, which is a mist generation source, and the first opening, which is a suction port, changes, the ability to suck mist may change. Therefore, it is preferable that the suction tube is supported by the head holding portion in order not to change the positional relationship between the ejection surface and the first opening even when the position of the head is moved by the moving mechanism. However, when the suction tube having the first opening is held by the head holding portion, there is a problem that vibration of the suction force generation source connected to the suction tube is easily transmitted to the head. According to the configuration of the present invention, the suction tube has a first tube and a second tube. Then, mist is drawn from the first opening formed in the first pipe to the communication space. Further, the mist is drawn into the third opening formed at the tip of the second pipe disposed in the communication space. And the 1st pipe | tube is hold | maintained at the head holding | maintenance part, and is moved with respect to a 2nd pipe | tube by a moving mechanism. Thereby, even when the position of the head is moved by the moving mechanism, the positional relationship between the ejection surface and the first opening does not change, so that the ability to suck mist by the suction mechanism is unlikely to change. Further, the head and the first tube are held by the head holding portion, and are moved relative to the suction force generation source and the second tube by the moving mechanism. Thereby, the vibration of the suction force generation source is not easily transmitted to the head. Therefore, it is possible to suppress a decrease in image quality.

  Further, in the present invention, the first pipe includes a pair of side walls sandwiching the communication space between each other with respect to a direction connecting the two liquid discharge heads, and one end of the side wall on the medium support member side. A pair of side walls, the bottom wall, and the ceiling wall; and a bottom wall formed with the first opening and a ceiling wall that connects the other ends of the side walls and formed with the second opening. It is preferable that the communication space is defined by. According to this, the communication space is defined by the pair of side walls, the bottom wall, and the ceiling wall. Then, mist is drawn into the communication space. Therefore, it is difficult for mist to remain outside the first tube, and it is possible to suppress the mist from adhering to the configuration outside the first tube such as the head.

  The present invention further includes a transport mechanism that transports a recording medium from one of the two liquid discharge heads to the other, and the surface of the bottom wall on the medium support member side in the orthogonal direction is the transport Preferably, the guide surface guides the recording medium conveyed by the mechanism. According to this, the 1st pipe | tube has a guide surface which guides a recording medium. Since the first tube is supported by the head holding portion, the positional relationship between the ejection surface and the guide surface does not change even when the moving mechanism moves the head holding portion. If the positional relationship between the ejection surface and the guide surface changes, the guide surface may not be able to properly guide the recording medium conveyed from the ejection surface. However, according to the present invention, the positional relationship does not change, so the head holding Even if the part moves, the guide surface can guide the recording medium appropriately. Therefore, the conveyance accuracy is unlikely to decrease.

  In the present invention, the first pipe has a fourth opening formed in the bottom wall and a rotating member pivotally supported in the communication space, and a part of the rotating member is the It is preferable to protrude from the fourth opening to the outside of the inter-head member. According to this, the floating of the recording medium due to the suction force of the suction force generation source can be suppressed by the rotating member. However, mist may enter the gap around the rotating member. In the present invention, the rotating member is pivotally supported in the communication space, and a part of the rotating member protrudes from the fourth opening formed in the bottom wall to the outside of the first pipe. Therefore, the mist entering from the gap between the rotating member and the fourth opening reaches the communication space. The mist that has reached the communication space is sucked from the third opening. Therefore, the suction means can reliably suck the mist entering the gap around the rotating member.

  In the present invention, an introduction part for introducing an air flow from the first opening toward the second opening is formed in the first pipe, and the tip part is located in the vicinity of the second opening. It is preferable. According to this, since the front-end | tip part of a 2nd pipe | tube is located in the 2nd opening side, attraction | suction of the mist from a communicating space is hard to be prevented by the introduction part.

  Further, in the present invention, based on the setting value storing means for storing the setting value relating to the thickness of the recording medium, the sensor for detecting the thickness of the recording medium, and the setting value stored in the setting value storing means, A movement mechanism control means for controlling the movement mechanism so as to adjust a separation distance between the ejection surface and the medium support means; a thickness detected by the sensor; and a setting value stored in the setting value storage means. It is preferable to further include suction force adjusting means for controlling the suction force generation source so as to adjust the suction force based on the difference.

  When the liquid ejection head ejects liquid onto the recording medium and records an image on the recording medium, the separation distance between the ejection surface and the recording medium affects the image quality. Therefore, high image quality can be maintained by adjusting the separation distance between the ejection surface and the medium support member according to the thickness of the recording medium. However, the thickness of the recording medium actually used may be different from the set value. If the thickness of the recording medium is smaller than the set value, the actual separation distance between the ejection surface and the surface of the recording medium is larger than the set value. When the separation distance between the ejection surface and the surface of the recording medium is large, the flight distance of the liquid ejected from the ejection surface becomes long. If the flight distance of the liquid is long, the distance that the discharged liquid receives resistance from the air increases, so that a phenomenon that the amount of mist generated increases is observed. That is, when the thickness of the recording medium that is actually used is different from the set value, the distance between the surface of the recording medium and the ejection surface is different from when the thickness of the recording medium is equal to the set value. Therefore, the amount of mist generated is also different. According to the present invention, since the suction force is adjusted based on the difference between the detected value and the set value, it is possible to appropriately suck the mist according to the difference in the generation amount.

  In the present invention, the head holding portion has a box shape having an opening on the side away from the medium support member in a direction orthogonal to the ejection surface, and the moving mechanism is parallel to the ejection surface. The suction pipe is connected to the head holding part at a side of the head holding part in a certain direction, and the suction pipe is located between the two liquid ejection heads from the side opposite to the medium support member side in the orthogonal direction. The tip may extend.

  In the present invention, the moving mechanism may include a rack supported by the head holding portion and a pinion that meshes with the rack.

The head holding unit is moved with respect to the suction force generation source. Therefore, a load is not easily applied to the moving mechanism that moves the head holding unit, and vibration from the suction force generation source is difficult to be transmitted to the head, so that liquid ejection is hardly affected. In addition, the elastic member can suppress the vibration of the suction force generation source from the moving mechanism to the head holding portion.

It is a front view which shows notionally the internal structure of the inkjet printer which concerns on one Embodiment of this invention. FIG. 2 is an exploded perspective view conceptually showing a configuration of a sub-carriage 100 that holds an inkjet head and a configuration of a main carriage 120 that supports the sub-carriage 100 in the inkjet printer of FIG. 1. 2 is a side view specifically showing the configuration of a sub-carriage 100. FIG. FIG. 4 is a cross-sectional view specifically showing the configuration of the main carriage 120 and the sub-carriage 100 and corresponding to a cross section taken along line IV-IV in FIG. 2. It is a front view. It is a front view which shows notionally the structure of the thickness sensor provided in the middle of the paper conveyance path | route. FIG. 6A is a cross-sectional view specifically showing the configuration around the inkjet head, and is a vertical cross-sectional view corresponding to the cross section taken along the line VI-VI of FIG. FIG. 6B is a cross-sectional view specifically showing the configuration around the suction mechanism, and is a vertical cross-sectional view along the main scanning direction. It is a disassembled perspective view which shows concretely the structure of the relay part which comprises some suction pipes of a suction mechanism. It is a perspective view of the viewpoint from diagonally downward which shows the structure of the lower member which comprises the lower part of a relay part. It is a functional block diagram which shows the structure of a control part. It is a flowchart which shows a series of flows of control by a control part.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. With reference to FIGS. 1-8, the structure of the inkjet printer 1 which is one Embodiment which concerns on this invention is demonstrated.

  The printer 1 has a rectangular parallelepiped housing 1a as shown in FIG. A paper discharge unit 35 is provided on the top plate of the housing 1a. In the housing 1a, a paper transport path for transporting the paper P, which is a recording medium, is formed along the thick arrow shown in FIG. . A direction in which the paper P is transported along the transport path is a transport direction. In the housing 1a, a precoat head 10 and an inkjet head 11 (a plurality of liquid ejection heads), a transport unit 30 (transport mechanism) that transports the paper P, a platen 40 (medium support member) that supports the paper P, and the head 10 are provided. And a cartridge (not shown) for storing a liquid to be supplied to 11, a sub carriage 100 (head holding unit) for holding the heads 10 and 11, a main carriage 120 for supporting the sub carriage 100, and operations of each unit of the printer 1 The control part 1p etc. which control are accommodated.

  As shown in FIG. 2, the precoat head 10 is a line head having a substantially rectangular parallelepiped shape that is long in the main scanning direction. An image quality improving liquid is supplied to the precoat head 10 from a liquid tank (not shown). On the discharge surface 10a which is the lower surface of the precoat head 10, a number of discharge ports for discharging the image quality improving liquid are opened. As the image quality improving liquid, a colorless and transparent liquid that agglomerates ink pigments is used. As this liquid, a liquid containing a polyvalent metal salt such as a cationic polymer or a magnesium salt is appropriately selected. When the ink adheres to the area of the paper P to which the image quality improving liquid has been previously attached, the polyvalent metal salt or the like acts on the dye or pigment in the ink. When the image quality improving liquid and the ink come into contact with each other, an insoluble or hardly soluble metal complex or the like aggregates or precipitates. The image quality improving liquid may have a function of improving the color density of the ink. The prerecord head 10 discharges the image quality improving liquid from the discharge port under the control of the control unit 1p.

  As shown in FIG. 2, the inkjet head 11 is a line head having the same shape as the precoat head 10. The inkjet head 11 is arranged alongside the precoat head 10 on the downstream side of the precoat head 10 in the transport direction. The ink jet head 11 is disposed at the same position as the precoat head 10 in the main scanning direction described later. Black ink is supplied to the inkjet head 11 from an ink tank (not shown). On the ejection surface 11a, which is the lower surface of the inkjet head 11, a number of ejection ports for ejecting black ink are opened. The ink jet head 11 ejects ink from the ejection port under the control of the control unit 1p. Hereinafter, when it is not necessary to distinguish between the precoat head 10 and the inkjet head 11, these may be referred to as “head 10” and “head 11”.

  In the following description, the sub-scanning direction is a direction from the left to the right in FIG. 1, and corresponds to the transport direction of the paper P at a position facing the ejection surface 10a and the ejection surface 11a. The main scanning direction is a direction parallel to the horizontal plane and orthogonal to the sub-scanning direction.

  As shown in FIG. 2, the sub-carriage 100 has side walls 101 to 104 and a bottom wall 105. The side walls 101 to 104 and the bottom wall 105 generally constitute a rectangular parallelepiped box-like shape opened upward (on the side away from the platen 40 in the vertical direction). A through hole 105 a is formed in the bottom wall 105. The heads 10 and 11 are arranged with a predetermined interval between each other in the sub scanning direction, and are fixed to the bottom wall 105 of the sub carriage 100. That is, the heads 10 and 11 are held by the sub carriage 100. The lower ends of the heads 10 and 11 protrude downward from the through hole 105a. As shown in FIGS. 3 and 4, rails 112 along the vertical direction are fixed to the outer surfaces of the side walls 101 and 102. In the side walls 101 and 102, a recess 112a is formed at the lower end of the rail 112 as shown in FIG. A spring 113 is installed in the recess 112a so that the expansion / contraction direction is along the vertical direction.

  As shown in FIG. 2, the main carriage 120 has side walls 121 to 124 and ceiling walls 125 and 126. The side walls 121 to 124 and the ceiling walls 125 and 126 constitute a substantially rectangular parallelepiped box shape that opens upward and downward, respectively. As shown in FIG. 4, a support portion 116 that supports a pinion 115 described later and a pinion motor 51 </ b> M (see FIG. 9) that drives the pinion 115 are provided on the inner surfaces of the side walls 121 and 122. The main carriage 120 is fixed to the housing 1a.

  Between the main carriage 120 and the sub-carriage 100, a moving mechanism 110 that moves the sub-carriage 100 in the vertical direction with respect to the main carriage 120 is provided. As shown in FIGS. 1 and 4, the moving mechanism 110 is connected to both sides of the sub-carriage 100 in the sub-scanning direction. The moving mechanism 110 includes a rack 111 supported by the sub-carriage 100 and a pinion 115 supported by the main carriage 120. Two racks 111 are arranged on the side walls 101 and 102 of the sub-carriage 100 with a predetermined interval in the main scanning direction. A hook-shaped locking portion 111 a is formed at the lower end of the rack 111. The upper end portion of the spring 113 is wound around the locking portion 111a. The rack 111 has a plurality of teeth arranged in a straight line, and is attached to the rail 112 so that these teeth are arranged in the vertical direction. The rail 112 restricts the movement of the rack 111 so as not to move in the horizontal direction but to move only in the vertical direction.

  The pinion 115 is provided at a position facing each of the racks 111 in the sub-scanning direction. Each pinion 115 is supported by the support portion 116 so as to be rotatable in the direction C in FIG. 4 while being engaged with the opposite rack 111. In FIG. 2, the main carriage 120 and the sub-carriage 100 are illustrated as being separated from each other. However, in a state where these are combined with each other, the rack 111 and the rack 111 and the corresponding relationship indicated by arrows C1 to C4 are illustrated. The pinions 115 mesh with each other. The pinion 115 is connected to the drive shaft of the pinion motor 51M, and rotates in the direction C in FIG. 4 when the control unit 1p controls the pinion motor 51M. When the pinion 115 rotates, the rack 111 moves along the vertical direction with respect to the pinion 115. Since the pinion 115 is supported by the main carriage 120, when the rack 111 moves with respect to the pinion 115, the sub-carriage 100 connected to the rack 111 via the spring 113 extends along the vertical direction with respect to the main carriage 120. Move. Thus, the moving mechanism 110 (the rack 111 and the pinion 115) is connected to the sub-carriage 100 via the spring 113. Therefore, the vibration of the main carriage 120 is absorbed by the spring 113. Therefore, vibration is not easily transmitted from the main carriage 120 to the sub carriage 100.

  As shown in FIG. 1, the transport unit 30 includes a paper feed unit 1 c, guides 26 a to 26 c, 27 and 28 a to 28 c, feed roller pairs 29 and 34, a registration roller pair 31, and an inter-head roller pair 32. The control unit 1p controls the driving of the transport unit 30 to transport the paper P from the paper feed unit 1c to the paper discharge unit 35 along the paper transport path.

  The paper feed unit 1 c includes a paper feed tray 23 and a paper feed roller 24. Of these, the paper feed tray 23 can be attached to and detached from the housing 1a in the sub-scanning direction. The paper feed tray 23 is a box that opens upward, and can accommodate paper P. The paper feed roller 24 rotates by the control unit 1p controlling the paper feed motor 55M (see FIG. 9), and feeds the paper P at the uppermost position of the paper feed tray 23. The paper P sent out by the paper feed roller 24 is guided by the guide 26 a and sent to the feed roller pair 29. The feed roller pair 29 is rotated by the control unit 1p controlling the feed motor 52M (see FIG. 9), and feeds the paper P to the registration roller pair 31. The guides 26 b and 26 c guide the paper P to the registration roller pair 31.

  The registration roller pair 31 rotates when the control unit 1p controls the registration motor 53M (see FIG. 9). The registration roller pair 31 feeds the paper P to the inter-head roller pair 32 while correcting the inclination of the paper P. The inter-head roller pair 32 is rotated by the control unit 1p controlling the feed motor 52M. The inter-head roller pair 32 is disposed between the head 10 and the head 11 in the sub-scanning direction, and includes two rollers, a first roller 81 and a second roller 82. The second roller 82 is a roller driven by the feed motor 52M, and the first roller 81 is a roller that rotates following the paper P while the paper P is sandwiched between the second roller 82 and the second roller 82. The configuration around the first roller 81 will be described later. The head-to-head roller pair 32 feeds the paper P fed from the registration roller pair 31 to the feed roller pair 34. At this time, the paper P passes through a position facing the ejection surfaces 10a and 11a while being supported by a platen 40 described later.

  The feed roller pair 34 is rotated by the control unit 1p controlling the feed motor 52M. The pair of feed rollers 34 transports the paper P along the guides 28a to 28c, and feeds the paper P to the paper discharge unit 35 through the opening 38 formed in the upper portion of the housing 1a.

  A thickness sensor 60 for detecting the thickness of the paper is provided between the feed roller pair 29 and the registration roller pair 31 on the most downstream side. As shown in FIG. 5, the thickness sensor 60 includes a contact bar 61 that contacts the surface of the paper P, a rotation shaft 61 a that is supported by the housing 1 a so as to be rotatable in the direction B of FIG. 5, and a contact bar 61. And a stopper 63 for restricting the movement of the contact bar 61, and an encoder (not shown) for detecting the position of the rotating shaft 61a in the B direction.

  The urging member 62 urges the contact bar 61 leftward in FIG. Thereby, the contact bar 61 is held in a state of contacting the stopper 63 from the right side in FIG. The lower end of the contact bar 61 is disposed at a position where the lower end of the contact bar 61 contacts the sheet P when the sheet P passes below the thickness sensor 60. When the sheet P reaches the lower side of the thickness sensor 60, the sheet P abuts against the lower end portion of the abutting bar 61, and the lower end portion of the abutting bar 61 is opposed to the urging force of the urging member 62 in FIG. Push it out. As a result, the contact bar 61 moves from the position indicated by the solid line in FIG. 5 to the position indicated by the broken line. At this time, the encoder detects the amount of displacement of the rotating shaft 61a. The thickness sensor 60 outputs a signal indicating the detection result of the encoder to the control unit 1p. This signal indicates the thickness of the paper P. This is because the contact bar 61 rotates more as the thickness of the paper P is larger, and thus the amount of displacement of the rotation shaft 61a becomes a size corresponding to the thickness of the paper P. When the entire sheet P passes through the thickness sensor 60, the contact bar 61 returns to the position indicated by the solid line in FIG.

  The two platens 40 are provided at a position facing the discharge surface 10a and a position facing the discharge surface 11a, respectively. Each platen 40 includes two door members 41 and 42. Each of the door members 41 and 42 is supported by a pair of rotating shafts 40a sandwiching the corresponding ejection surface 10a or 11a and extending in the main scanning direction in parallel with the ejection surface 10a or 11a in a plan view. Each platen 40 rotates about the rotation shaft 40a as the control unit 1p controls the platen motor 54M (see FIG. 9). As a result, the platen 40 selectively takes a facing position (a solid line position in FIG. 1) and a non-facing position (a broken line position in FIG. 1). The facing position is a position where the door members 41 and 42 are positioned horizontally and face the corresponding ejection surface 10a or 11a. Further, the non-facing position is a position where each door member 41 and 42 hangs down without facing the corresponding discharge surface 10a or 11a.

  When the platen 40 is at the opposing position, slight gaps are formed between the upper surface of the platen 40 on the left side of FIG. 1 and the discharge surface 10a and between the upper surface of the platen 40 on the right side of FIG. 1 and the discharge surface 11a. Is done. These gaps become a sheet conveyance path. When the paper P is supported on the left platen 40, the image quality improving liquid is ejected from the head 10 so that the image quality improving liquid adheres to the paper P. Further, when the paper P is supported by the right platen 40, the ink is attached to the paper P by discharging the image quality improving liquid from the head 11.

  A facing member 8 is disposed below the platen 40 at the facing position. For example, there is a case where a process of discharging liquid from the heads 10 and 11 is executed in order to recover the discharge performance. In this case, the platen 40 is moved to the non-facing position and the liquid is discharged toward the facing member 8, so that the platen 40 supporting the paper P does not need to be stained.

  By the way, when the image quality improving liquid and ink are ejected from the head 10 and the head 11, some of the ejected liquids that have not adhered to the paper P become minute droplets and mist in the air. May float. A mist is such a mist-like microdroplet. The amount of mist generated varies according to the separation distance between the ejection surfaces 10a and 11a of the head 10 and the surface of the paper P. For example, when the separation distance between the ejection surfaces 10a and 11a of the head 10 and the surface of the paper P is large, the distance that the ejected liquid receives resistance from the air also increases, so that the amount of mist generated also increases.

  Here, when liquid is ejected from the heads 10 and 11 to the paper P and an image is recorded on the paper P, the paper P is located between the heads 10 and 11 and the platen 40 from the left in FIG. It is conveyed toward the right. Therefore, in the vicinity of the heads 10 and 11, an air flow from the left to the right in FIG. In other words, in the vicinity of the heads 10 and 11, an airflow is generated toward the downstream side in the transport direction. That is, of the liquid ejected from the heads 10 and 11, the mist that does not land on the paper P and floats in the air moves from the left to the right in FIG. . The mist of the image quality improving liquid generated from the head 10 may move to the head 11 by the air flow and adhere to the ejection surface 11a. When the mist generated from the head 10 adheres to the ejection surface 11a, the image quality improving liquid and the ink may come into contact with each other. Then, since the image quality improving liquid aggregates or deposits the ink, particularly when the mist of the image quality improving liquid adheres to the vicinity of the discharge port, the discharge port may be blocked, and there is a possibility of causing a discharge failure. Further, ink mist generated from the head 11 may flow downstream in the sheet conveyance direction, and may contaminate the inside of the printer 1 (for example, the guides 28a to 28c constituting the conveyance path or the feed roller pair 34).

  Therefore, the printer 1 is provided with suction mechanisms 130 and 150 for sucking the image quality improving liquid and ink mist generated in the printer 1. Hereinafter, the suction mechanisms 130 and 150 and the surrounding configuration will be described with reference to FIGS. 1, 2, and 6 to 8.

  The suction mechanism 130 includes a first duct (suction tube) and a suction unit 133 (suction force generation source). The first duct has a fixed duct 131 (second pipe) and a movable duct 132 (first pipe). As shown in FIG. 6B, the left end of the fixed side duct 131 is fixed to the ceiling wall 125 of the main carriage 120 via a fixing member 134. The right end of the fixed duct 131 is fixed to the ceiling wall 126 of the main carriage 120 via the suction unit 133. That is, the fixed duct 131 is held by the main carriage 120. As shown in FIG. 6A, the fixed duct 131 is disposed between the head 10 and the head 11 in the sub-scanning direction. The fixed duct 131 has a long cylindrical shape in the main scanning direction. The lower end (front end) of the fixed duct 131 is narrower in width in the sub-scanning direction than the upper end, and is a rectangular plane that is slightly smaller than an opening 132d (second opening) of the movable duct 132 described later. It has a shape. As shown in FIGS. 6A and 6B, the lower end portion of the fixed side duct 131 is inserted from the opening 132d of the movable side duct 132 into the internal space 132a (communication space) of the movable side duct 132. Yes. The lower end portion of the fixed-side duct 131 is disposed so as not to contact a ceiling wall 145 (described later) that defines the opening 132d. Further, the portion inserted into the opening 132d at the lower end portion of the fixed duct 131 is moved down to the maximum with respect to the main carriage 120 when the position of the sub carriage 100 in the vertical direction is adjusted (described later). Even in this case, the lower end portion of the fixed duct 131 has a sufficient length so that it does not completely come out of the opening 132d. Further, the fixed duct 131 is configured so that the lower end portion of the fixed duct 131 does not contact the movable duct 132 even when the sub carriage 100 is raised to the maximum with respect to the main carriage.

  The outer wall of the fixed duct 131 is a thin plate as shown in FIG. A hollow internal space 131 a is formed in the fixed duct 131. At the upper end of the fixed duct 131, an air flow outlet 131b is formed at the right end of FIG. At the lower end portion of the fixed duct 131, an airflow inlet 131c is formed that extends substantially the full width of the fixed duct 131 in the main scanning direction.

  Guide portions 131d to 131f for guiding the airflow generated by the suction unit 133 are formed in the internal space 131a. As shown in FIG. 6B, each of the guide portions 131d to 131f includes a curved portion and a flat plate portion. The curved portion rises from the inlet 131c toward the ceiling wall of the fixed-side duct 131 and curves to the right. The flat plate portion extends linearly from the right end of the curved portion to the right. The guide portions 131d to 131f are formed in the order of a guide portion 131d, a guide portion 131e, and a guide portion 131f from the left side to the right side of FIG. 6B, and the flat plate portion is arranged below the right side. Has been. As a result, the guide portions 131d to 131f divide the internal space 131a into four air flow paths R1 to R4 as shown in FIG. 6B. The path R1 connects the left end of the inflow port 131c and the outflow port 131b. The route R2 connects the portion slightly on the left side of the middle at the inflow port 131c and the outflow port 131b. The path R3 connects the portion slightly on the right side of the middle of the inflow port 131c and the outflow port 131b. The path R4 connects the right end portion of the inflow port 131c and the outflow port 131b. By forming these paths, air smoothly flows from the entire inlet 131c to the outlet 131b.

  As shown in FIGS. 2, 6A and 6B, the movable duct 132 is disposed between the heads 10 and 11 in the sub-scanning direction, and the bottom wall of the sub-carriage 100 is secured by a screw 105b. 105 is fixed. That is, the movable duct 132 is held by the subcarriage 100. As shown in FIGS. 6A and 7, the movable duct 132 has an outer wall including side walls 141 to 144, a ceiling wall 145, and a bottom wall 146, and is a rectangular parallelepiped that is long in the main scanning direction as a whole. It has the following general shape. The outer wall of the movable duct 132 defines a hollow inner space 132a. The side walls 141 and 142 sandwich the internal space 132a between each other in the direction connecting the heads 10 and 11 (sub-scanning direction). The side walls 143 and 144 sandwich the internal space 132a between each other in the main scanning direction. The bottom wall 146 connects one end of the side walls 141 and 142 (the end on the side close to the platen 40). The ceiling wall 145 connects the other ends (ends far from the platen 40) of the side walls 141 and 142.

  In the internal space 132a, four first rollers 81 (rotating members) and spur rollers 33 (rotating members) arranged in the main scanning direction are accommodated. In the internal space 132a, the region where the first roller 81 is disposed and the region where the spur roller 33 is disposed communicate with each other. Each first roller 81 has a cylindrical roller portion 81a and a rotation shaft 81b. The spur roller 33 has eight roller portions 33a and a rotation shaft 33b. The eight roller portions 33a are arranged with a predetermined interval in the main scanning direction. The roller portion 33a has a substantially cylindrical shape, and a plurality of protrusions that protrude with the same length in the radial direction are arranged in the circumferential direction on the outer periphery thereof.

  The movable duct 132 has an upper member 132b and a lower member 132c as shown in FIG. The upper member 132b and the lower member 132c are fixed to each other with a screw 147. The upper member 132b is a flat plate member having a substantially rectangular shape that is long in the main scanning direction in plan view. The upper member 132b includes a ceiling wall 145 of the movable duct 132, a part of the side wall 141, and a part of the side wall 142. It is composed. An opening 132d having a rectangular planar shape elongated in the main scanning direction is formed on the upper surface of the upper member 132b. The opening 132d communicates with the internal space 132a.

  The lower member 132c has a box-like schematic shape opened upward. The lower member 132 c constitutes a part of the side wall 141 and a part of the side wall 142 of the movable duct 132, the side walls 143 and 144, and the bottom wall 146. As shown in FIG. 8, on the bottom wall 146 of the lower member 132c, an opening 132e (fourth opening) is arranged at a position where the roller portion 81a of the first roller 81 is arranged, and a roller portion 33a of the spur roller 33 is arranged. Openings 132f (fourth openings) are respectively formed at the positions. In the bottom wall 146 of the lower member 132c, an opening 132g (first opening) extending in the main scanning direction is formed at the center in the sub-scanning direction. The length of the opening 132g in the main scanning direction is longer than the length of the ejection region in the main scanning direction. Here, the discharge region is a region that connects two discharge ports arranged on the outermost side in the main scanning direction among the plurality of discharge ports formed on the discharge surface 10a. In other words, this is a region connecting two discharge ports arranged on both outer sides. A plurality of openings 132g are arranged in the main scanning direction with a later-described rib 149 interposed therebetween. The opening 132g communicates with the internal space 132a. The internal space 132a is an example of a communication space of the present invention that allows the opening 132d and the opening 132g to communicate with each other.

  On the upper surface of the bottom wall 146, as shown in FIG. 6A, FIG. 7 and FIG. 8, a protruding portion 148 that protrudes vertically upward from the opening 132g is formed. The protruding portion 148 is formed along the opening 132 g, and the upper end portion thereof is disposed below the lower end portion of the fixed side duct 131. That is, the lower end portion of the fixed side duct 131 is disposed closer to the opening 132 d than the upper end portion of the protruding portion 148.

  Here, the movable duct 132 is held by the sub-carriage 100. On the other hand, the fixed duct 131 is held by the main carriage 120. The sub-carriage 100 is moved in the vertical direction with respect to the main carriage 120 by the moving mechanism 110. That is, when the sub-carriage 100 is moved with respect to the main carriage 120 by the moving mechanism 110, the movable duct 132 is moved with respect to the fixed duct 131. That is, when the sub-carriage 100 moves upward, the movable duct 132 moves so as to approach the fixed duct 131. On the other hand, when the sub-carriage 100 moves downward, the movable duct 132 moves away from the fixed duct 131.

  The portion inserted into the opening 132d at the lower end of the fixed duct 131 is fixed even when the sub carriage 100 is lowered to the maximum with respect to the main carriage 120 when the sub carriage 100 is moved in the vertical direction. The lower end portion of the side duct 131 has a sufficient length so as not to completely come out of the opening 132d. Further, the fixed duct 131 is configured so that the lower end portion of the fixed duct 131 does not contact the movable duct 132 even when the sub carriage 100 is raised to the maximum with respect to the main carriage. That is, the lower end portion of the fixed duct 131 and the upper end portion of the protruding portion 148 are arranged with a predetermined distance therebetween. This predetermined distance is a distance at which the fixed duct 131 and the protruding portion 148 do not interfere with each other even when the sub carriage 100 is raised to the maximum with respect to the main carriage. The protruding portion 148 functions as an introduction portion that introduces an airflow vertically upward from the opening 132g to the internal space 132a. A plurality of ribs 149 are formed on the lower surface (surface on the platen 40 side) of the lower member 132c. Each rib 149 extends across the opening 132g along the sub-scanning direction, and the lower surface is formed at the same height. The lower surface of each rib 149 functions as a guide surface for guiding the paper P from below the head 10 to below the head 11.

  As described above, in the present embodiment, the first duct is configured by the fixed duct 131 and the movable duct 132, the fixed duct 131 is held by the main carriage 120, and the movable duct 132 is attached to the sub-carriage 100. It is held. The distal end portion of the fixed side duct 131 is inserted into the opening 132 d of the movable side duct 132. Further, the movable duct 132 and the fixed duct 132 are configured not to interfere with each other even when the sub-carriage 100 moves. Thus, when the sub-carriage 100 moves, the fixed duct 131 and the movable duct 132 move relative to each other, so that the first duct as the suction pipe is expanded and contracted. That is, even if the sub-carriage 100 moves, the relative position between the ejection surfaces 10a and 11a and the opening 132g of the movable duct 132 does not change.

  On the upper surface of the lower member 132c (the surface opposite to the platen 40), as shown in FIGS. 7 and 8, the support portion 135 that supports the rotation shaft 81b of the first roller 81 and the rotation shaft of the spur roller 33 are provided. The support part 136 which supports 33b is formed. Concave portions 135a and 136a are formed in the support portions 135 and 136, respectively. A support portion 138 that supports a spring 137 described later is provided between the support portions 135. The support portion 138 is a cylindrical portion that protrudes upward, and has a recess 138a.

  The first roller 81 is supported by the support portion 135 when the rotation shaft 81b is inserted into the recess 135a. When the first roller 81 is supported by the support portion 135, the lower end portion of the roller portion 81a protrudes out of the movable duct 132 through the opening 132e while leaving a gap with the opening 132e. In other words, the lower end portion of the roller portion 81a protrudes downward (on the platen 40 side) through the opening 132e. On the other hand, the spur roller 33 is supported by the support part 136 by inserting the rotating shaft 33b into the recess 136a. When the spur roller 33 is supported by the support portion 136, the lower end portion of the roller portion 33a protrudes out of the movable duct 132 through the opening 132f while leaving a gap with the opening 132f. In other words, the lower end portion of the roller portion 33a protrudes downward (platen 40 side) through the opening 132f. Thereby, both the 1st roller 81 and the spur roller 33 are supported by the support parts 135 and 136 in the state which can be rotated without contacting each opening.

  The distal end portion of the rotation shaft 81 b of the first roller 81 is inserted into the recess 138 a of the support portion 138. A spring 137 is further inserted into the recess 138a from above the rotating shaft 81b. The spring 137 biases the rotating shaft 81b downward. The first roller 81 faces the recording surface of the paper P (the surface of the paper P that faces the ejection surfaces 10a and 11a). Since the first roller 81 is biased toward the second roller 82, the first roller 81 and the second roller 82 can pinch the paper P reliably.

  The spur roller 33 faces the recording surface of the paper P (the surface of the paper P facing the ejection surfaces 10a and 11a), and the lowest point of the protrusion formed on the roller portion 33a is substantially the paper P in the vertical direction. It is arrange | positioned so that it may become the same position as this conveyance path | route. When the paper P is about to rise, the projection of the spur roller 33 comes into contact with the recording surface of the paper P. The spur roller 33 rotates as the paper P moves. Since each protrusion is in point contact with the recording surface of the paper P, it is possible to prevent the image quality improving liquid discharged on the paper P from being disturbed.

  As shown in FIG. 6, the suction unit 133 is fixed to the ceiling wall 126 of the main carriage 120, and is connected to the fixed duct 131 in the vicinity of the outlet 131b. The suction unit 133 has a through hole, a suction fan, and a filter. The through hole is connected to the outlet 131b. When the control unit 1p controls the fan, the fan rotates to generate an air flow that sucks air through the through hole. As a result, air near the opening 132g of the movable duct 132 is sucked into the movable duct 132 through the opening 132g. Then, the air is sucked into the suction unit 133 through the internal space 132a, the inlet 131c (third opening) of the fixed duct 131, the inner space 131a, and the outlet 131b. Thus, the fixed side duct 131 and the movable side duct 132 function as the suction pipe of the present invention. The air sucked by the suction unit 133 is separated from the mist by the filter and discharged to the outside of the suction unit 133. The suction force by the suction mechanism 130 is set to be a suction force suitable for collecting the mist generated from the head 10. Specifically, the suction force is determined by the rotational speed of the fan, the shape of the first duct, and the shape of the opening 132g.

  The suction mechanism 150 includes a second duct 151 (suction pipe) and a suction unit 153. As shown in FIGS. 2 and 6A, one end of the second duct 151 is fixed to the ceiling wall 125 of the main carriage 120 via a fixing member 154. The other end of the second duct 151 is fixed to the ceiling wall 126 of the main carriage 120 via a fixing member. As shown in FIG. 6A, the second duct 151 is disposed in the vicinity of the side surface of the head 11 opposite to the fixed side duct 131. That is, the second duct 151 is arranged on the downstream side in the transport direction of the head 11. The second duct 151 has a substantially rectangular parallelepiped shape that is narrow in the sub-scanning direction, and has a hollow internal space 151a. An airflow outlet is formed at the upper end of the second duct 151, and an airflow inlet 151 b is formed at the lower end of the second duct 151. The outflow port and the inflow port 151b communicate with the internal space 151a. The second duct 151 is connected to the suction unit 153 at the outlet. The suction unit 153 has the same configuration as the suction unit 133, and sucks air including mist below the second duct 151 from the inflow port 151b. The suction force by the suction mechanism 150 is set to be a suction force suitable for collecting the mist generated from the head 11. Specifically, the suction force is determined by the rotational speed of the fan, the shape of the second duct, and the shape of the inflow port 151b.

  Hereinafter, control of image recording by the control unit 1p will be described. As shown in FIG. 9, the control unit 1p includes a print control unit 161, a setting value storage unit 162 (setting value storage unit), a head movement control unit 163 (movement mechanism control unit), and a suction control unit 164 (suction force adjustment unit). )have. In image recording, as the paper P, a plurality of types of paper having different thicknesses are used. The user designates paper used for image recording in an external device such as a PC. The external device transmits print data including data indicating the paper type designated by the user to the inkjet printer 1. Alternatively, the user may specify the type of paper P via the interface of the inkjet printer 1.

  At this time, assuming that the positions of the heads 10 and 11 with respect to the platen 40 are always the same, when the paper P having a different thickness is used, the separation distance between the recording surface of the paper P and the ejection surfaces 10a and 11a is the printing distance. The distance may be different from the distance suitable for Therefore, the set value storage unit 162 stores thickness data indicating the thicknesses related to these plural types of sheets. The head movement control unit 163 acquires the thickness data corresponding to the paper type designated by the user from the stored contents of the setting value storage unit 162. Then, the head movement control unit 163 controls the pinion motor 51M based on the acquired thickness data to place the sub carriage 100 at a predetermined position in the vertical direction with respect to the main carriage 120. The predetermined position at this time corresponds to a position where the recording surface of the paper P supported by the platen 40 and the ejection surfaces 10a and 11a are separated by a predetermined distance suitable for printing. Thus, the position of the sub-carriage 100 is adjusted so that the recording surface of the paper P and the ejection surfaces 10a and 11a are separated from each other by an appropriate distance according to the type of paper specified by the user. An example of a predetermined distance suitable for printing will be described. For example, when the type of paper designated by the user is plain paper, the position of the sub-carriage 100 is adjusted so that the separation distance between the ejection surfaces 10a and 11a and the platen 40 is 1 mm. In addition, when the type of paper designated by the user is thick paper, the position of the sub-carriage 100 is adjusted so that the separation distance between the ejection surfaces 10a and 11a and the platen 40 is 2 mm. This is because the thickness of the cardboard is normally considered to be 1 mm. By adjusting the position of the sub-carriage 100 in this way, the separation distance between the recording surface of the paper P supported by the platen 40 and the ejection surfaces 10a and 11a becomes a predetermined distance suitable for printing.

  When the print data is transferred from the external device, the print control unit 161 controls the platen 40, the transport unit 30, and the heads 10 and 11 as follows based on the print data. First, the head movement control unit 163 of the print control unit 161 arranges the sub-carriage 100 at an appropriate position as described above. Then, the print control unit 161 controls the platen motor 54M so that the platen 40 takes the facing position. Next, the print control unit 161 controls the feed motor 52M, the registration motor 53M, and the paper feed motor 55M to convey the paper P from the paper feed tray 23 to the paper discharge unit 35. At this time, when the paper P conveyed from the paper feed tray 23 reaches the thickness sensor 60, the thickness sensor 60 outputs a detection signal indicating that the contact bar 61 has been displaced. The print controller 161 causes the head 10 and the head 11 to eject image quality improving liquid or ink a predetermined time after the thickness sensor 60 starts outputting the detection signal. Here, for each of the heads 10 and 11, the predetermined time is along the transport path from the leading edge of the sheet P when the thickness sensor 60 starts outputting the detection signal to the discharge port located upstream. This is the time obtained by dividing the distance by the conveyance speed of the paper P. The print control unit 161 records a desired image based on the print data on the paper P by ejecting liquid from the heads 10 and 11.

  The suction control unit 164 controls the fans of the suction units 133 and 153 to suck the mist generated from the heads 10 and 11 during the image recording period. Here, the amount of mist generated from the heads 10 and 11 depends on the separation distance between the ejection surfaces 10a and 11a and the surface of the paper P as described above. On the other hand, as described above, the head movement control unit 163 moves the sub-carriage 100 according to the type of paper designated by the user, and adjusts the separation distance to a predetermined distance suitable for printing. For this reason, when the type of paper designated by the user matches the type of paper actually used, the separation distance is always maintained at a predetermined distance, so that the amount of mist generated does not change. However, when the type of paper specified by the user is different from the type of paper actually used, the separation distance fluctuates, so that the amount of mist generated may also fluctuate.

  Therefore, the suction control unit 164 adjusts the suction force of the suction units 133 and 153 based on the detection result of the thickness sensor 60. Specifically, the suction controller 164 controls the number of rotations of the fan as shown in FIG. First, the suction controller 164 compares the thickness of the paper P detected by the thickness sensor 60 (hereinafter referred to as detected thickness) with the thickness corresponding to the type of paper specified by the user (hereinafter referred to as specified thickness). . The specified thickness is acquired from the thickness data corresponding to the sheet specified by the user based on the stored contents of the set value storage unit 162. If it is determined that the detected thickness and the specified thickness match each other (step S1, Yes), the suction control unit 164 controls the fans of the suction units 133 and 153 so as to rotate at a predetermined rotation number (step S3). ).

  On the other hand, if the detected thickness and the specified thickness do not match each other (step S1, No), and it is determined that the detected thickness is greater than the specified thickness (step S2, Yes), the suction control unit 164 determines whether the detected thickness and the specified thickness are The fan is controlled to rotate at a rotational speed smaller than the predetermined rotational speed by a magnitude corresponding to the absolute value of the difference (step S4). As a result, the suction force by the fan is smaller than when the detected thickness and the specified thickness match each other. When the detected thickness is greater than the specified thickness, the amount of mist generated is expected to be smaller than when the detected thickness matches. That is, the position of the sub-carriage 100 is set such that the distance between the recording surface of the sheet P having the specified thickness and the ejection surfaces 10a and 11a is a distance suitable for printing. In this case, when the detected thickness is larger than the specified thickness, the distance between the recording surface of the paper P and the ejection surfaces 10a and 11a is shorter than when the detected thickness is equal to the specified thickness. When the distance between the recording surface and the ejection surfaces 10a and 11a is shortened, the flying distance of the ejected droplets is shortened, so that mist is hardly generated. Therefore, by reducing the suction force, appropriate control according to the amount of mist generated is achieved. Energy saving can be achieved as compared with the case where the suction force by the fan is not adjusted.

  When the detected thickness and the specified thickness do not match each other (step S1, No) and it is determined that the detected thickness is smaller than the specified thickness (step S2, No), the suction control unit 164 determines whether the detected thickness and the specified thickness are The fan is controlled to rotate at a rotational speed larger than the predetermined rotational speed by a magnitude corresponding to the absolute value of the difference between the two (step S5). As a result, the suction force by the fan is greater than when the detected thickness and the specified thickness match each other. When the detected thickness is smaller than the specified thickness, it is expected that the amount of mist generated will be larger than when the detected thickness matches. That is, the position of the sub-carriage 100 is set such that the distance between the recording surface of the sheet P having the specified thickness and the ejection surfaces 10a and 11a is a distance suitable for printing. In this case, when the detected thickness is smaller than the specified thickness, the distance between the recording surface of the paper P and the ejection surfaces 10a and 11a becomes longer than when the detected thickness is equal to the specified thickness. When the distance between the recording surface and the ejection surfaces 10a and 11a is increased, the flying distance of the ejected liquid droplets is increased, so that mist is easily generated. Therefore, by increasing the suction force, it is possible to perform appropriate control according to the amount of mist generated. If the suction force is large, the paper P is likely to float, but the spur roller 33 and the first roller 81 come into contact with the recording surface of the paper P. Therefore, the spur roller 33 and the first roller 81 cause the paper P to float. I can hold it down.

According to the present embodiment described above, the opening 132g of the first duct is arranged between the head 10 and the head 11. Therefore, even if a mist of the image quality improving liquid is generated in the head 10 and flows toward the head 11 while riding on the airflow in the transport direction, the mist is sucked into the suction mechanism 130 together with the air. As a result, the mist of the image quality improving liquid does not easily reach the head 11 side, so that the image quality improving liquid is less likely to adhere to the ejection surface 11a, and ejection failure is less likely to occur.

  Further, the suction units 133 and 153 of this embodiment are held by the main carriage 120. The moving mechanism 110 is configured to move the sub-carriage 100 holding the heads 10 and 11 with respect to the main carriage 120. Therefore, compared to the configuration in which the suction units 133 and 153 are provided on the subcarriage 100, a load is not easily applied to the moving mechanism 110 that moves the subcarriage 100. Therefore, an increase in size of the moving mechanism 110 can be suppressed. Further, vibration from the suction units 133 and 153 is not easily transmitted to the sub-carriage 100. As a result, vibration from the suction units 133 and 153 is not easily transmitted to the heads 10 and 11. This suppresses the vibration generated in the suction units 133 and 153 from affecting the liquid ejection of the heads 10 and 11. Therefore, it is possible to suppress a decrease in image quality. Further, in the moving mechanism 110, a rack 111 provided on the subcarriage 100 side is supported by a spring 113. Therefore, the vibration generated in the suction units 133 and 153 held by the main carriage 120 is absorbed by the spring 113. Therefore, vibrations are not easily transmitted from the main carriage 120 to the sub-carriage 100 via the moving mechanism 110, and the adverse effect on liquid ejection is further suppressed.

  In the present embodiment, the movable side duct 132 that is a part of the suction pipe of the suction mechanism 130 is held by the sub-carriage 100. Therefore, when the moving mechanism 110 moves the sub-carriage 100, the movable duct 132 also moves in the same manner as the heads 10 and 11. For this reason, the positional relationship between the opening 132g of the movable duct 132 and the ejection surfaces 10a and 11a does not change. If these positional relationships change, the relationship between the mist generation position and the suction position in the suction mechanism 130 changes, and the ability to suck mist from the opening 132g may vary. On the other hand, as described above, since the positional relationship between the opening 132g of the movable duct 132 and the ejection surfaces 10a and 11a does not change, the suction capability of the suction mechanism 130 hardly changes.

  Further, a fixed duct 131 that is a part of the suction pipe of the suction mechanism 130 is held by the main carriage 120. The fixed duct 131 and the movable duct 132 are configured not to contact each other. Therefore, it is possible to suppress the vibration of the suction unit 133 connected to the fixed duct 131 from being transmitted to the head 10 or the head 11 via the sub-carriage 100. If the suction pipe is composed of only the fixed duct 131, the relative position between the inlet 131c of the fixed duct 131 and the discharge surfaces 10a and 11a changes when the sub-carriage 100 moves. There is a possibility that the suction force by the suction mechanism 130 may fluctuate. On the other hand, when the fixed-side duct 131 is configured to be held by the sub-carriage 100, the weight of the sub-carriage 100 increases, and the moving mechanism 110 becomes large. Further, the vibration of the suction unit 133 connected to the fixed duct 131 is transmitted to the subcarriage 100. That is, the vibration of the suction unit 133 is transmitted to the heads 10 and 11, and the image quality can be degraded.

  In the present embodiment, the sucked mist is once taken into the internal space 132 a of the movable duct 132. The internal space 132 a is defined by the side walls 141 to 144, the ceiling wall 145, and the bottom wall 146, and is surrounded by these outer walls, so that it is difficult for mist to escape outside the movable duct 132. Therefore, it is possible to prevent mist from adhering to the configuration outside the movable duct 132 such as the head 11.

  In the present embodiment, a guide surface for the paper P is formed on the rib 149 of the movable duct 132. Since the movable duct 132 is supported by the sub-carriage 100, even if the moving mechanism 110 moves the sub-carriage 100, the positional relationship between the ejection surfaces 10a and 11a and the guide surface does not change. If the positional relationship between the discharge surfaces 10a and 11a and the guide surface changes, the guide surface may not be able to properly guide the paper P conveyed from the discharge surfaces 10a and 11a side. Since the relationship does not change, the guide surface can guide the paper P appropriately even if the sub-carriage 100 moves. Therefore, the conveyance accuracy is unlikely to decrease.

  Here, in the present embodiment, the suction mechanism 130 is provided between the heads 10 and 11, and an air flow from the opening 132g toward the internal space 132a is generated. For this reason, the paper P may float upward due to the suction force of the suction mechanism 130. If the paper P floats, there is a risk of jamming. Therefore, in the present embodiment, a spur roller 33 and a first roller 81 that are in contact with the recording surface of the paper P and suppress the floating of the paper P are disposed between the heads 10 and 11. When the spur roller 33 and the first roller 81 are attached to a support member different from the movable duct 131, a gap is generated between the spur roller 33 and the first roller 81 and the support member. May get in. If mist enters the gap, the mist adheres to the spur roller 33 and the first roller 81 and may be transferred from the spur roller 33 and the first roller 81 onto the paper P. In the present embodiment, the roller portion 81 a of the first roller 81 protrudes through the opening 132 e of the movable duct 131. Further, the roller portion 33 a of the spur roller 33 protrudes through the opening 132 f of the movable duct 131. Therefore, the mist that has entered the gap between the first roller 81 and the opening 132 e and the gap between the spur roller 33 and the opening 132 f reaches the internal space 132 a of the movable duct 132. The mist entering from the gap between the first roller 81 and the opening 132e and the gap between the spur roller 33 and the opening 132f reaches the inlet 131c of the fixed duct 131 through the internal space, and from this inlet 131c. Suction into the fixed duct 131. Therefore, the suction mechanism 130 can reliably suck the mist that enters the gap around the spur roller 33.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

  For example, in the above-described embodiment, two heads, the precoat head 10 and the inkjet head 11, are provided. However, the present invention may be applied when three or more heads are provided. In this case, the suction mechanism 130 is disposed between any two heads adjacent to each other. The precoat head 10 is not limited to ejecting the image quality improving liquid, but may be an ink jet head that ejects ink. Although the spur roller 33 and the first roller 81 are attached to the movable duct 132, only one of them may be installed, or both may be attached. The guide surface may not be formed on the movable duct 132. The structure which does not have the movable side duct 132 may be sufficient. The suction mechanism 150 may have the same configuration as the suction mechanism 130.

  In the above-described embodiment, the main carriage 120 supports the sub-carriage 100 and holds the fixed-side duct 131 and the suction unit 133. However, the fixed duct 131 and the suction unit 133 may be held other than the main carriage 120. For example, the fixed duct 131 and the suction unit 133 may be directly held by the housing 1a. Even in such a case, if the moving mechanism 110 has a configuration for moving the sub-carriage 100 with respect to the fixed-side duct 131 and the suction unit 133, vibration is generated from the fixed-side duct 131 and the suction unit 133 to the sub-carriage 100. It is hard to become the composition that is transmitted directly. For this reason, the vibrations of the fixed duct 131 and the suction unit 133 are not easily transmitted to the heads 10 and 11, and the liquid ejection is hardly affected.

  In the above-described embodiment, the suction mechanisms 130 and 150 having fans are provided as the suction force generation sources. However, a suction unit that generates a suction force may be provided by a configuration other than the fan. For example, a suction unit that employs a pump-type suction method may be provided.

  In the above-described embodiment, the suction control unit 164 determines the magnitude relationship between the detected thickness and the specified thickness, and controls the rotational speed of the fan based on the determination result. However, the suction control unit 164 has a function or table that associates the difference between the detected thickness and the specified thickness with the rotational speed, and the fan may be rotated at the rotational speed derived based on the function or table. .

  The present invention is not limited to a printer, and can be applied to various liquid ejecting apparatuses such as a facsimile machine and a copier. The head may eject liquid other than ink or image quality improving liquid.

1 Inkjet printer (printer)
1p control unit 10 precoat head (head)
11 Inkjet head (head)
11a Discharge surface 30 Transport unit 60 Thickness sensor 100 Subcarriage 110 Moving mechanism 120 Main carriage 130 Suction unit 131 Duct 132 Relay unit 133 Suction unit 162 Setting value storage unit 163 Head movement control unit 164 Suction control unit

Claims (9)

A plurality of liquid discharge heads each having a discharge surface for discharging liquid;
A medium support member that supports the recording medium at a position facing the ejection surface;
A suction tube having a first opening formed between two liquid discharge heads arranged adjacent to each other among the plurality of liquid discharge heads;
A suction force source connected to the suction tube;
A head holding unit for holding the plurality of liquid ejection heads;
A moving mechanism for moving the head holding unit at least with respect to the suction force generation source ,
The liquid ejecting apparatus , wherein the moving mechanism is coupled to the head holding portion via an elastic member . The suction tube has a first tube and a second tube,
The first pipe has a first opening formed on the medium support member side in an orthogonal direction orthogonal to the ejection surface, and a second opening formed on the opposite side of the medium support member side in the orthogonal direction. And a communication space for communicating the first opening and the second opening,
The second tube is connected to the suction force generation source and has a tip portion formed with a third opening, and the tip portion is inserted into the communication space from the second opening,
The head holding part holds the first tube,
The liquid ejecting apparatus according to claim 1, wherein the moving mechanism moves the first tube relative to the second tube.   The first pipe connects a pair of side walls sandwiching the communication space between each other in a direction connecting the two liquid discharge heads, and one end of the side wall on the medium support member side, and the first opening is A bottom wall that is formed and a ceiling wall that connects the other ends of the side walls and is formed with the second opening, and the communication space is defined by the pair of side walls, the bottom wall, and the ceiling wall. The liquid ejecting apparatus according to claim 2, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. A transport mechanism for transporting a recording medium from one of the two liquid discharge heads toward the other;
The liquid ejection apparatus according to claim 3, wherein a surface of the bottom wall on the medium support member side with respect to the orthogonal direction is a guide surface that guides a recording medium conveyed by the conveyance mechanism. The first pipe has a fourth opening formed in the bottom wall and a rotating member pivotally supported in the communication space;
5. The liquid ejection apparatus according to claim 2, wherein a part of the rotating member protrudes from the fourth opening to the outside of the first pipe. In the first pipe, an introduction part for introducing an airflow from the first opening toward the second opening is formed,
6. The liquid ejection apparatus according to claim 2, wherein the distal end portion is positioned in the vicinity of the second opening. Setting value storage means for storing a setting value relating to the thickness of the recording medium;
A sensor for detecting the thickness of the recording medium;
A moving mechanism control means for controlling the moving mechanism so as to adjust a separation distance between the ejection surface and the medium support means based on a setting value stored in the setting value storage means;
And a suction force adjusting means for controlling the suction force generation source so as to adjust the suction force based on a difference between the thickness detected by the sensor and the set value stored in the set value storage means. The liquid ejection device according to claim 1, wherein the liquid ejection device is a liquid ejection device. The head holding part has a box shape with an opening on the side separated from the medium support member in an orthogonal direction orthogonal to the ejection surface;
The moving mechanism is connected to the head holding part at a side of the head holding part in a direction parallel to the ejection surface;
The suction pipe, any one of claims 1-7 wherein in the perpendicular direction to the medium support member side, wherein the distal end portion toward the opposite side between the two liquid ejection heads extend The liquid ejection device according to item. The moving mechanism comprises a rack which is supported by the head holding portion, a liquid ejecting apparatus according to any one of claims 1 to 8, characterized in that it has a pinion which meshes with the rack.