JP6350320B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus.

  Inkjet recording apparatuses are widely used in printers, copiers, multifunction machines, and the like. An ink jet recording apparatus records an image on a sheet such as paper by ejecting ink droplets from nozzle holes of a recording head.

  The ink jet recording apparatus cannot eject ink droplets when foreign matters such as paper dust adhere to the nozzle holes. As a result, an image defect occurs. Therefore, various techniques for suppressing the adhesion of foreign matters to the nozzle holes have been proposed.

  For example, an ink jet recording apparatus described in Patent Document 1 includes a housing provided upstream of the recording head in the sheet conveyance direction, and an air supply unit provided in the housing. With such a configuration, air is supplied from the air supply unit to the sheet conveyed into the housing, and foreign matter is removed from the sheet. As a result, the sheet from which the foreign matter has been removed is conveyed below the recording head. Therefore, the adhesion of foreign matter to the nozzle hole is suppressed.

JP 2011-183746 A

  However, the ink jet recording apparatus described in Patent Document 1 includes a dedicated air supply unit and a space where the air supply unit is disposed (internal space of the housing) in order to remove foreign matters such as paper dust. Need. For this reason, there exists a problem of causing the enlargement of an apparatus. There is also a problem that the configuration becomes complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ink jet recording apparatus that can suppress adhesion of foreign matter to nozzle holes with a simple configuration.

  The ink jet recording apparatus of the present invention records an image on a sheet by ejecting ink droplets. The ink jet recording apparatus includes a conveyance belt, a recording head, and a suction unit. The conveyance belt conveys the sheet in the first direction. The recording head discharges the ink droplets toward the sheet being conveyed by the conveyance belt. The suction part has a first pressure chamber and a second pressure chamber. The suction unit sucks the sheet toward the transport belt by generating a negative pressure in at least the first pressure chamber. The second pressure chamber is formed at least outside both ends of the first pressure chamber facing each other in a second direction orthogonal to the first direction. The suction unit generates a first negative pressure in the first pressure chamber and generates a first negative pressure in the second pressure chamber when generating a negative pressure in the first pressure chamber and the second pressure chamber. A second negative pressure greater than the pressure is generated.

  According to the present invention, adhesion of foreign matter to the nozzle hole can be suppressed with a simple configuration.

1 is a diagram illustrating a configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is the top view which looked at the line head shown in FIG. 1 from upper direction. It is the top view which looked at the conveyance belt shown in FIG. 1 from upper direction. It is the top view which looked at the conveyance board shown in FIG. 1 from upper direction. (A) It is a top view of the groove | channel and through-hole which are shown in FIG. (B) It is sectional drawing of the groove | channel and through-hole along the AA line shown to Fig.5 (a). It is a figure which shows the structure of the recording part shown in FIG. It is the top view which looked at the suction part shown in FIG. 6 from upper direction. It is the top view which looked at the suction part which concerns on other embodiment of this invention from upper direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in the figures, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated. In order to facilitate understanding, the drawings schematically show each component as a main component. In addition, numerical values, shapes, and the like shown in the following embodiments are examples and are not particularly limited.

  First, the configuration of the ink jet recording apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing the configuration of the inkjet recording apparatus 1. The ink jet recording apparatus 1 ejects ink droplets and records an image on paper P (an example of a sheet).

  The ink jet recording apparatus 1 includes an apparatus casing 100, a sheet feeding unit 2 disposed below the inside of the apparatus casing 100, a recording unit 3 disposed above the sheet feeding unit 2, and one of the recording units 3. A sheet conveying unit 4 disposed on the side (right side in FIG. 1) and a sheet discharging unit 5 disposed on the other side (left side in FIG. 1) of the recording unit 3 are provided.

  The paper feed unit 2 feeds the paper P to the paper transport unit 4. The paper feed unit 2 includes a paper feed cassette 21 detachably attached to the apparatus housing 100, a paper feed roller 22, and a guide plate 23. The paper feed roller 22 is disposed above one end side (right end in FIG. 1) of the paper feed cassette 21. The guide plate 23 is disposed between the paper feed roller 22 and the paper transport unit 4.

  The paper feed cassette 21 can store a plurality of sheets of paper P. The paper feed roller 22 (pickup roller) takes out the paper P one by one from the paper feed cassette 21 and feeds it toward the guide plate 23. The guide plate 23 guides the paper P taken out by the paper feed roller 22 to the paper transport unit 4.

  The paper transport unit 4 transports the paper P to the recording unit 3. The paper transport unit 4 includes a substantially C-shaped paper transport path 41, a first transport roller pair 42 provided on the entrance side of the paper transport path 41, and a second transport roller pair provided in the middle of the paper transport path 41. 43 and a registration roller pair 44 provided on the exit side of the sheet conveyance path 41.

  The paper transport path 41 is constituted by a guide plate. The first transport roller pair 42 sends out the paper P fed from the paper feed unit 2 into the paper transport path 41. The second transport roller pair 43 feeds the paper P sent by the first transport roller pair 42 toward the registration roller pair 44 with the paper P sandwiched therebetween.

  The registration roller pair 44 performs skew correction of the paper P sent out by the second transport roller pair 43. In addition, the registration roller pair 44 temporarily stops the paper P and synchronizes the recording timing of the image onto the paper P with the conveyance timing of the paper P to the recording unit 3. The data is sent to the recording unit 3 in accordance with the recording timing. More specifically, the sheet P comes into contact with the registration roller pair 44 and stops. The skew correction of the paper P is performed by this contact. Thereafter, the registration roller pair 44 sends the paper P to the recording unit 3 in accordance with the image recording timing.

  The recording unit 3 records an image on the paper P while conveying the paper P. The recording unit 3 includes a transport unit 31, a transport plate 32 (an example of a guide member), a transport guide 33, and a suction unit 34. The recording unit 3 further includes line heads 35Bk, 35C, 35M, and 35Y.

  The transport unit 31 transports the paper P sent from the registration roller pair 44. The conveyance unit 31 includes a conveyance belt 310 (an example of an endless belt). The conveyance unit 31 rotates the conveyance belt 310 in a predetermined rotation direction (counterclockwise direction in FIG. 1). The paper P sent out by the registration roller pair 44 is guided onto the transport belt 310. As the conveyance belt 310 rotates, the paper P is conveyed.

  The conveyance plate 32 supports the conveyance belt 310 and supports the paper P via the conveyance belt 310. The conveyance plate 32 guides the paper P conveyed by the conveyance unit 31 (conveyance belt 310) in the direction indicated by the arrow X1 (sub-scanning direction). Hereinafter, the direction in which the paper P is transported by the transport unit 31 (the transport belt 310) is referred to as a paper transport direction X1 (an example of the first direction).

  The conveyance guide 33 is disposed downstream of the conveyance plate 32 (left side in FIG. 1) with respect to the sheet conveyance direction X1. Therefore, the transport plate 32 guides the paper P to the transport guide 33. That is, the transport unit 31 sends the paper P to the transport guide 33. The transport guide 33 guides the paper P sent out by the transport unit 31 to the paper discharge unit 5.

  The suction unit 34 is disposed below the conveyance plate 32. The suction unit 34 sucks the paper P toward the transport belt 310 via the transport plate 32 and the transport belt 310. As a result, the paper P is attracted to the transport belt 310.

  The line head 35Bk ejects black ink droplets. The line head 35C discharges cyan ink droplets. The line head 35M ejects magenta ink droplets. The line head 35Y discharges yellow ink droplets. Since the line heads 35Bk, 35C, 35M, and 35Y have substantially the same configuration, they may be collectively referred to as the line head 35.

  The line head 35 is disposed above the transport unit 31 and faces the transport plate 32 via the transport belt 310. The line head 35 includes a plurality of nozzle holes (not shown) arranged in a direction orthogonal to the paper transport direction X1 (in FIG. 1, a direction orthogonal to the paper surface). The line head 35 records an image on the paper P while the transport unit 31 (the transport belt 310) transports the paper P. Specifically, the line head 35 ejects ink droplets from the nozzle holes toward the paper P passing through a position facing the line head 35. As a result, images such as characters and figures are recorded on the paper P.

  The paper discharge unit 5 discharges the paper P to the outside of the apparatus housing 100. The paper discharge unit 5 includes a discharge roller pair 51 and a discharge tray 52. The discharge tray 52 is fixed to the apparatus casing 100 so as to protrude outward from the discharge port 11 formed in the apparatus casing 100. The discharge port 11 is formed on one side surface (left side surface in FIG. 1) of the apparatus housing 100.

  The discharge roller pair 51 sends the paper P that has passed through the conveyance guide 33 in the direction of the discharge port 11. The paper P delivered by the discharge roller pair 51 is guided by the discharge tray 52, discharged to the outside of the apparatus housing 100 through the discharge port 11, and placed on the discharge tray 52. When images are continuously recorded on a plurality of sheets P, the plurality of sheets P are stacked on the discharge tray 52.

  There is a possibility that a foreign substance such as paper dust adheres to the paper P sent from the registration roller pair 44 to the recording unit 3. Paper dust may be generated when the paper P is transported in the inkjet recording apparatus 1. In particular, when the paper P is rubbed against the paper feed roller 22, fibers and fillers may be peeled off from the paper P, and may become paper dust and adhere to the paper P. The paper feed roller 22 is disposed to face the central portion of the paper P in a direction orthogonal to the direction in which the paper P is fed (in FIG. 1, a direction perpendicular to the paper surface). For this reason, the paper P sent to the recording unit 3 may have paper dust attached to the center thereof. In the present embodiment, the central portion of the paper P sent to the recording unit 3 indicates the central portion of the paper P in the direction orthogonal to the paper transport direction X1.

  In addition, various air flows are generated inside the apparatus housing 100 of the inkjet recording apparatus 1. For example, air flows from above the conveyor belt 310 into the suction unit 34. Further, as the paper P is transported, an air flow in the paper transport direction X1 occurs. Accordingly, the sheet P passes under the line head 35 while being hit by the wind. Further, since the space between the line head 35 and the conveyor belt 310 is narrow, a relatively strong wind is likely to be generated between the line head 35 and the conveyor belt 310. Accordingly, the environment below the line head 35 is an environment in which foreign matters such as paper dust are likely to be blown off from the paper P by the wind. Therefore, there is a possibility that the foreign matter blown off from the paper P adheres to the nozzle holes of the line head 35.

  Next, the configuration of the line head 35 will be described with reference to FIG. FIG. 2 is a plan view of the line heads 35Bk, 35C, 35M, and 35Y shown in FIG. 1 as viewed from above. As shown in FIG. 2, the line heads 35Bk, 35C, 35M, and 35Y are arranged in parallel from the upstream side to the downstream side in the paper transport direction X1 (leftward in FIG. 2).

  Each of the line heads 35Bk, 35C, 35M, and 35Y includes a first recording head 36a, a second recording head 36b, and a third recording head 36c. The first recording head 36a, the second recording head 36b, and the third recording head 36c are arranged in a staggered manner along a direction X2 orthogonal to the paper transport direction X1. Each of the first recording head 36a, the second recording head 36b, and the third recording head 36c includes a plurality of nozzle holes (not shown) arranged in a direction X2 orthogonal to the paper transport direction X1. Hereinafter, the direction X2 orthogonal to the paper transport direction X1 is referred to as a width direction X2 (an example of the second direction). Further, the first recording head 36a, the second recording head 36b, and the third recording head 36c have substantially the same configuration, and may be collectively referred to as the recording head 36.

  The recording head 36 ejects ink droplets from the nozzle holes corresponding to the printing position onto the paper P transported by the transport belt 310. As a result, images such as characters and figures are recorded on the paper P.

  Next, the conveyance belt 310 will be described with reference to FIG. FIG. 3 is a plan view of the conveyor belt 310 shown in FIG. 1 as viewed from above. As shown in FIG. 3, a plurality of suction holes 311 are drilled in the conveyor belt 310. The plurality of suction holes 311 are arranged along the paper transport direction X1 and the width direction X2. The plurality of suction holes 311 can be arranged in a staggered manner as shown in FIG.

  Subsequently, the conveyance plate 32 will be described with reference to FIGS. 4 and 5. FIG. 4 is a plan view of the conveying plate 32 shown in FIG. 1 as viewed from above. Specifically, FIG. 4 shows a part of the surface 320 of the conveying plate 32 on the line head 35 side. Hereinafter, the surface 320 on the line head 35 side of the transport plate 32 is referred to as a support surface 320. The conveyance plate 32 supports the conveyance belt 310 by the support surface 320 and also supports the paper P via the conveyance belt 310.

  As shown in FIG. 4, a plurality of grooves 321 are formed on the support surface 320. Each groove 321 is a long groove whose surface on the line head 35 side opens. Specifically, each groove 321 has an oval shape extending in the paper transport direction X1.

  The plurality of grooves 321 are arranged along the paper transport direction X1 and the width direction X2. The plurality of grooves 321 may be arranged in a staggered manner as shown in FIG. Specifically, the plurality of grooves 321 are arranged at positions that can face the suction holes 311 (see FIG. 3) of the conveyance belt 310. That is, the plurality of grooves 321 are arranged at a position where they can communicate with the suction hole 311. With this arrangement, the suction holes 311 facing the grooves 321 are replaced one by one as the conveyance belt 310 advances (rotates). Each groove 321 is formed so as to face at least two suction holes 311.

  The transport plate 32 further has a plurality of through holes 322. The plurality of through holes 322 are provided corresponding to the plurality of grooves 321. In the present embodiment, one through hole 322 is located in each groove 321. Each through hole 322 communicates with a corresponding groove 321. The cross section of each through hole 322 may be circular. As shown in FIG. 4, the plurality of through holes 322 can be arranged in a staggered manner.

  5A is a plan view of the groove 321 and the through hole 322 shown in FIG. 4, and FIG. 5B is a plan view of the groove 321 and the through hole 322 along the line AA shown in FIG. FIG. As shown in FIG. 5B, the through hole 322 penetrates the transport plate 32 in the thickness direction. That is, one end face (end face on the line head 35 side) of the through hole 322 opens to the inner face (bottom face) of the corresponding groove 321. Therefore, the through hole 322 communicates with the suction hole 311 (see FIG. 3) of the conveyor belt 310 via the corresponding groove 321. In addition, the other end surface (end surface on the suction part 34 side) of the through hole 322 is open to the lower surface of the transport plate 32.

  Next, the recording unit 3 will be described with reference to FIGS. FIG. 6 is a diagram showing the configuration of the recording unit 3 shown in FIG. FIG. 6 shows a partial cross section of the transport unit 31 for easy understanding.

  The conveyance unit 31 faces the line head 35 in the apparatus housing 100 (see FIG. 1). The conveyance unit 31 includes a drive roller 312, a belt speed detection roller 313, a tension roller 314, and a pair of guide rollers 315 arranged on the inner peripheral side of the conveyance belt 310. The transport unit 31 further includes a suction roller 316 disposed on the outer peripheral side of the transport belt 310.

  The conveyance belt 310 is stretched around a driving roller 312, a belt speed detection roller 313, a tension roller 314, and a pair of guide rollers 315. On the inner peripheral side of the stretched transport belt 310, the transport plate 32 and the suction unit 34 are arranged. The conveyance plate 32 faces the line head 35 via the conveyance belt 310. The suction unit 34 is disposed below the transport plate 32 on the inner peripheral side of the transport belt 310.

  The drive roller 312 is disposed on the downstream side (left side in FIG. 6) of the transport plate 32 with respect to the paper transport direction X1. The driving roller 312 is rotationally driven by a motor (not shown), and rotates the conveyance belt 310 in a predetermined rotation direction (counterclockwise direction in FIG. 6). As the transport belt 310 rotates, the paper P is transported in the paper transport direction X1.

  The belt speed detection roller 313 is disposed on the upstream side (the right side in FIG. 6) of the conveyance plate 32 with respect to the paper conveyance direction X1, and rotates due to friction generated between the belt and the conveyance belt 310. Preferably, the belt speed detection roller 313 is arranged so as to maintain the flatness of the conveyance belt 310 at a location facing the line head 35 together with the driving roller 312.

  The belt speed detection roller 313 includes a pulse plate (not shown), and the pulse plate rotates integrally with the belt speed detection roller 313. By measuring the rotational speed of the pulse plate, the rotational speed of the conveyor belt 310 is detected.

  The tension roller 314 applies tension to the conveyance belt 310 so that the conveyance belt 310 does not bend. The pair of guide rollers 315 guides the conveyor belt 310 so that the conveyor belt 310 passes below the suction unit 34.

  The suction roller 316 is a driven roller. The suction roller 316 is opposed to the upstream end of the transport plate 32 in the paper transport direction X1 through the transport belt 310. The suction roller 316 guides the paper P sent from the registration roller pair 44 (see FIG. 1) onto the transport belt 310 and causes the transport belt 310 to suck the paper P.

  The suction unit 34 sucks air from the space above the transport belt 310 through the grooves 321 and the through holes 322 of the transport plate 32 and the suction holes 311 (see FIG. 3) of the transport belt 310. By this suction, wind is generated from the space above the transport plate 32 toward the inside of the suction portion 34. When the paper P is guided onto the transport belt 310 and covers a part of the transport belt 310, a suction force acts on the paper P and the paper P is attracted to the transport belt 310.

  The suction part 34 includes a box-shaped member 341 whose upper surface is open, and a plurality of suction devices 342. The conveyance plate 32 is disposed so as to cover the upper surface opening of the box-shaped member 341. A pressure chamber 343 is defined by the transport plate 32 and the box-shaped member 341. The pressure chamber 343 communicates with the suction hole 311 of the transport belt 310 through the through hole 322 and the groove 321 of the transport plate 32.

  The suction device 342 is fixed to the lower surface of the box-shaped member 341. Specifically, an opening 344 is formed in the bottom wall of the box-shaped member 341. The suction device 342 is disposed corresponding to the opening 344. The suction device 342 is a fan.

  When the suction device 342 is driven, a negative pressure (gauge pressure) is generated in the pressure chamber 343. Due to this negative pressure, a suction force is generated in the groove 321 through the through hole 322, and a suction force is generated in the suction hole 311 of the transport belt 310 through the groove 321. As a result, air is sucked into the pressure chamber 343 through the suction holes 311 of the transport belt 310 and the grooves 321 and the through holes 322 of the transport plate 32. Further, when the paper P is guided onto the conveyance belt 310 and a part of the suction hole 311 is closed, a suction force (negative pressure) is applied to the paper P from the suction hole 311 closed by the paper P. The paper P is attracted to the transport belt 310.

  The line head 35 can be supported at such a height that a predetermined distance (1 mm in the present embodiment) is formed between the line head 35 and the conveyor belt 310. Note that the inkjet recording apparatus 1 may include a mechanism for moving the line head 35 up and down according to the thickness of the paper P conveyed by the conveyance belt 310. With such a configuration, it is possible to support the line head 35 at such a height that a predetermined interval (1 mm in the present embodiment) is formed between the line head 35 and the paper P.

  Next, the suction unit 34 will be described with reference to FIG. FIG. 7 is a plan view of the suction portion 34 shown in FIG. 6 as viewed from above. For easy understanding, the projected image of the line head 35 (recording head 36) and the projected image of the suction device 342 are indicated by broken lines.

  The pressure chamber 343 of the suction unit 34 includes one first pressure chamber 343a and two second pressure chambers 343b. The first pressure chamber 343a is formed (partitioned) at the center of the pressure chamber 343 in the width direction X2. Specifically, the first pressure chamber 343a is formed (partitioned) so that the central portion of the paper P passes above the first pressure chamber 343a. The two second pressure chambers 343b are formed (partitioned) outside both ends in the width direction X2 of the first pressure chamber 343a.

  In the present embodiment, the suction part 34 includes two partition plates 345 provided in the box-shaped member 341. The two partition plates 345 are provided at an interval in the width direction X2. Each of the two partition plates 345 is provided from one end to the other end of the box-shaped member 341 in the paper transport direction X1. With such a configuration, the pressure chamber 343 is divided (divided) into one first pressure chamber 343a and two second pressure chambers 343b.

  The suction unit 34 includes one first suction device 342a and two second suction devices 342b as a plurality of suction devices 342. The first suction device 342a is provided for the first pressure chamber 343a. The two second suction devices 342b are provided for the two second pressure chambers 343b, respectively. Therefore, the magnitude of the negative pressure (gauge pressure) generated in the first pressure chamber 343a can be controlled by the first suction device 342a. Similarly, the magnitude of the negative pressure (gauge pressure) generated in each of the two second pressure chambers 343b can be controlled by the corresponding second suction device 342b.

  When the width in the width direction X2 of the paper P delivered from the registration roller pair 44 described with reference to FIG. 1 is wider than the width in the width direction X2 of the first pressure chamber 343a, the suction unit 34 performs the first suction. The device 342a and the second suction device 342b are driven. That is, the suction unit 34 generates negative pressure in the first pressure chamber 343a and the second pressure chamber 343b. At this time, the first suction device 342a and the first suction device 342a are configured so that the negative pressure (first negative pressure) generated in the first pressure chamber 343a is smaller than the negative pressure (second negative pressure) generated in the second pressure chamber 343b. The operation of the two suction device 342b is controlled. In the present embodiment, the suction unit 34 generates a negative pressure (gauge pressure) of 300 Pa in the first pressure chamber 343a and generates a negative pressure (gauge pressure) of 500 Pa in the second pressure chamber 343b. Hereinafter, the width of the first pressure chamber 343a in the width direction X2 is described as the width of the first pressure chamber 343a, and the width of the paper P in the width direction X2 is described as the width of the paper P. When the paper P has a long side and a short side, the width of the paper P is different between a case where the long side is orthogonal to the paper conveyance direction X1 and a case where the short side is orthogonal to the paper conveyance direction X1.

  When the width of the paper P is narrower than the width of the first pressure chamber 343a, the suction unit 34 drives only the first suction device 342a and generates a negative pressure only in the first pressure chamber 343a. At this time, the suction unit 34 generates a negative pressure larger than the negative pressure (first negative pressure) generated in the first pressure chamber 343a when the width of the paper P is wider than the width of the first pressure chamber 343a. In the present embodiment, the suction unit 34 generates a negative pressure of 500 Pa in the first pressure chamber 343a.

  As described above, according to the present embodiment, the central portion of the paper P to which paper dust may adhere passes above the first pressure chamber 343a. Further, when the width of the sheet P is wider than the width of the first pressure chamber 343a, the negative pressure (first negative pressure) generated in the first pressure chamber 343a is the negative pressure (second pressure) generated in the second pressure chamber 343b. Less than negative pressure). Therefore, it is possible to suppress the wind speed of the wind blown in the area where the central portion of the paper P passes in the area below the line head 35, and to suppress the rise of the foreign matter such as paper dust. Therefore, according to the present embodiment, adhesion of foreign matter to the nozzle holes can be suppressed with a simple configuration in which the pressure chamber 343 is divided into a plurality of pressure chambers.

  Further, according to the present embodiment, when the width of the paper P is wider than the width of the first pressure chamber 343a, that is, when the four corners of the paper P pass above the second pressure chamber 343b, the second pressure chamber 343b. Is made larger than the negative pressure generated in the first pressure chamber 343a. Therefore, even if the four corners of the paper P sent out from the registration roller pair 44 described with reference to FIG. 1 are curled, the floating of the four corners of the paper P from the conveyance belt 310 can be suppressed.

  Further, according to the present embodiment, when the width of the paper P is narrower than the width of the first pressure chamber 343a, when the width of the paper P is wider than the width of the first pressure chamber 343a, the first pressure chamber 343a is emitted. A negative pressure larger than the negative pressure (first negative pressure) is generated in the first pressure chamber 343a. Therefore, even when the width of the paper P is narrower than the width of the first pressure chamber 343a, the lifting of the paper P from the conveyance belt 310 at the four corners can be suppressed.

  Furthermore, according to this embodiment, when the width of the paper P is narrower than the width of the first pressure chamber 343a, only the first suction device 342a is driven, and the two second suction devices 342b are not driven. Therefore, according to this embodiment, power consumption can be suppressed.

  In addition, as shown in FIG. 7, the first pressure chamber 343a in the present embodiment includes a region A in which the recording heads 36 adjacent in the width direction X2 partially overlap in the paper transport direction X1. In the area A, the distance between the adjacent recording heads 36 in the paper transport direction X1 is short. For this reason, in the area A, the ratio of the area where the space above the transport belt 310 is narrow is larger than that in the other areas. As a result, the speed of the wind blown in the area A is likely to increase, and in the area A, foreign matters such as paper dust are likely to rise. In this embodiment, since the first pressure chamber 343a includes the area A in this embodiment, the wind speed of the wind blown in the area A can be suppressed. Therefore, the adhesion of foreign matter to the nozzle hole can be efficiently suppressed.

  Furthermore, the partition plate 345 in the present embodiment is provided in the vicinity of the region A so that the first pressure chamber 343a includes the region A. Thereby, the kind of paper P which passes only above the 1st pressure chamber 343a can be decreased, and the adhesion of the foreign material to a nozzle hole can be suppressed efficiently.

  It is preferable that the type of the paper P that passes only above the first pressure chamber 343a does not include the type of the paper P that is predicted to be used frequently. For example, when it is predicted that the usage frequency of the A4 size paper P is increased, when the A4 size paper P is transported so that the short side thereof is orthogonal to the paper transport direction X1, the width direction X2 The width of the first pressure chamber 343a is set so that each end of the sheet P passes above each second pressure chamber 343b. Thereby, the adhesion of foreign matter to the nozzle hole can be efficiently suppressed.

  In the present embodiment, the first pressure chamber 343a is partitioned (formed) from one end to the other end of the pressure chamber 343 along the paper transport direction X1, but the first pressure chamber 343a is formed in the paper transport direction X1. The line heads 35Bk, 35C, 35M, and 35Y may be opposed to each other. For example, as shown in FIG. 8, the second pressure chamber 343b may be formed (partitioned) so as to surround the first pressure chamber 343a. FIG. 8 is a plan view of the suction unit 34 according to another embodiment as viewed from above. However, in this case, a groove 321 extending from the first pressure chamber 343a to the second pressure chamber 343b is provided so that the sheet P is reliably adsorbed to the transport belt 310 when a negative pressure is generated only in the first pressure chamber 343a. Form. Further, the through hole 322 of the transport plate 32 communicating with the groove 321 is formed at a position communicating with the first pressure chamber 343a.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, in the embodiment of the present invention, the line head 35 including the three recording heads 36 has been described as an example, but the present invention is not limited to this. The line head 35 can be constituted by one, two, or four or more recording heads.

  In the embodiment of the present invention, the suction part 34 has three suction devices 342. However, the present invention is not limited to this. The suction unit 34 may include at least one first suction device 342a provided for the first pressure chamber 343a and at least one second suction device 342b provided for the second pressure chamber 343b. . For example, in the configuration shown in FIG. 8, one second suction device 342 may be provided for the second pressure chamber 343b.

  In the embodiments of the present invention, the case where the present invention is applied to an inkjet recording apparatus capable of recording an image in full color has been described. However, the present invention can also be applied to an inkjet recording apparatus that records an image in monochrome. .

  Note that the items described in the embodiment of the present invention can be combined as appropriate.

  The present invention can be used in an electronic apparatus capable of recording an image on a sheet by discharging ink droplets.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 34 Suction part 35 Line head 36 Recording head 310 Conveying belt 342 Suction device 342a First suction device 342b Second suction device 343 Pressure chamber 343a First pressure chamber 343b Second pressure chamber P Paper X1 Paper transport direction X2 Width direction

Claims (6)

An inkjet recording apparatus that discharges ink droplets and records an image on a sheet,
A transport belt for transporting the sheet in a first direction;
A line head having a plurality of recording heads arranged in a zigzag pattern along a second direction orthogonal to the first direction and ejecting the ink droplets toward the sheet being conveyed by the conveying belt;
A suction section that has a first pressure chamber and a second pressure chamber, and sucks the sheet toward the transport belt by generating a negative pressure in at least the first pressure chamber ;
A conveying plate that supports the conveying belt and guides the sheet in the first direction;
An adsorption roller that faces the upstream end of the conveyance plate in the first direction via the conveyance belt and adsorbs the sheet to the conveyance belt ;
The suction part is
A box-shaped member whose upper surface is open and in which the opening is covered by the transport plate;
A plurality of suction devices for generating negative pressure in the first pressure chamber and the second pressure chamber;
A partition plate provided in the box-shaped member, and partitioning an internal space of the box-shaped member into the first pressure chamber and the second pressure chamber;
Have
The partition plate, the second pressure chamber is formed on the outside of both ends of the first pressure chamber facing in the second direction,
The partition plate is formed so that the area A where the recording heads adjacent in the second direction overlap each other in the first direction is located at the inner side of each of the both ends of the first pressure chamber. Provided in the vicinity of each,
The plurality of suction devices generate a first negative pressure in the first pressure chamber and a second pressure chamber in the first pressure chamber when generating a negative pressure in the first pressure chamber and the second pressure chamber. An ink jet recording apparatus that generates a second negative pressure greater than one negative pressure. The plurality of suction devices are
When the image is recorded on the sheet having a width in the second direction wider than the width in the second direction of the first pressure chamber, negative pressure is applied to the first pressure chamber and the second pressure chamber. Is generated,
The negative pressure is generated only in the first pressure chamber when the image is recorded on the sheet whose width in the second direction is narrower than the width of the first pressure chamber in the second direction. Item 10. The ink jet recording apparatus according to Item 1. When the image is recorded on the sheet, the plurality of suction devices has a width in the second direction narrower than a width in the second direction of the first pressure chamber. The ink jet recording apparatus according to claim 2, wherein a negative pressure larger than the first negative pressure is generated. A plurality of the line heads arranged along the first direction;
A plurality of the regions A are arranged along the first direction,
Wherein the first pressure chamber is opposed to the plurality of regions A, an ink jet recording apparatus according to any one of claims 1 to 3. 5. The inkjet recording apparatus according to claim 1, wherein the partition plate is provided from one end to the other end of the box-shaped member in the first direction. The plurality of suction devices are
A first suction device provided for the first pressure chamber;
The inkjet recording device according to claim 1, further comprising: a second suction device provided for the second pressure chamber.

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