JP6252467B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus.

  An ink jet recording apparatus, which is a type of image forming apparatus, forms an image by ejecting ink onto a recording medium such as paper. The ink jet recording apparatus includes a recording head in which nozzles for ejecting ink are formed. In an ink jet recording apparatus, when foreign matter such as paper dust adheres to a nozzle, nozzle clogging may occur and image quality may deteriorate. In order to solve this problem, a technique for suppressing the adhesion of foreign matter to the nozzle has been proposed.

  For example, Patent Document 1 discloses an ink jet recording apparatus including a paper dust removing device on the upstream side in the conveyance direction of a recording medium with respect to the recording head. Specifically, the paper dust removing device includes a static elimination brush and an air blower. The neutralizing brush neutralizes the recording medium. As a result, the paper dust is easily peeled off from the recording medium. The air blower blows air onto the recording medium that has been neutralized to remove paper dust from the recording medium.

JP 2011-183746 A

  However, the ink jet recording apparatus described in Patent Document 1 requires a static eliminating brush and an air blower in order to remove paper dust from the recording medium. This complicates the configuration of the ink jet recording apparatus.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ink jet recording apparatus capable of suppressing adhesion of paper dust to nozzles with a simple configuration.

  The ink jet recording apparatus of the present invention includes a recording head, a conveyance belt, a space forming unit, an insulating unit, and a negative pressure applying unit. The recording head ejects ink onto a recording medium. The conveyance belt conveys the recording medium to a position facing the recording head. The space forming unit forms a foreign substance collection space through which the recording medium passes between the recording head and the conveyance belt on the upstream side in the conveyance direction of the recording medium with respect to the recording head. The insulating part is disposed so as to come into contact with the transport belt. The negative pressure application unit applies a negative pressure to the foreign substance recovery space. The position of the material constituting the insulating portion in the triboelectric charging series is different from the position of the material constituting the conveying belt in the triboelectric charging series. The space forming portion includes a conductive facing surface facing the transport belt. The conveyor belt is charged by frictional charging between the conveyor belt and the insulating portion, and an electric field is formed between the conveyor belt and the facing surface.

  According to the ink jet recording apparatus of the present invention, it is possible to suppress the adhesion of paper dust to the nozzle surface 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. FIG. 2 is a diagram illustrating a configuration of an image forming unit illustrated in FIG. 1. (A) is sectional drawing of the guide member shown in FIG. 2, (b) is a top view of the guide member and insulation member shown in FIG. 2, (c) is A shown in FIG.3 (b). It is sectional drawing along the -A line. FIG. 3 is a cut perspective view illustrating configurations of a negative pressure application unit, an air circulation chamber, a guide member, and a conveyance belt illustrated in FIG. 2. It is a figure which shows the foreign material collection | recovery space shown in FIG. 2, and its vicinity. It is a figure which shows the electrification tendency of the conveyance belt and insulating member which concern on embodiment of this invention. It is a figure which shows the effect | action of the insulating member shown in FIG. It is a figure which shows the foreign material collection | recovery space shown in FIG. 2, and its vicinity. It is a figure which shows operation | movement of the paper dust which reached the downward direction of the recording head which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 9). In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

  First, an ink jet recording apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration of an inkjet recording apparatus 1 according to the present embodiment. 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, an image forming unit 3 disposed above the sheet feeding unit 2, and one side of the image forming unit 3. A sheet transport unit 4 disposed on the right side in FIG. 1 and a sheet discharge unit 5 disposed on the other side (left side in FIG. 1) of the image forming unit 3 are provided.

  The paper feed unit 2 includes a paper feed cassette 21, a paper feed roller 22, and a first guide plate 23. The paper feed cassette 21 is detachably attached to the apparatus housing 100. The paper feed cassette 21 accommodates a plurality of recording papers P. Hereinafter, “recording paper” is simply referred to as “paper” for convenience. The paper feed roller (pickup roller) 22 is disposed above one side end (right side end in FIG. 1) of the paper feed cassette 21. The paper feed roller 22 takes out the paper P stored in the paper feed cassette 21 one by one from the top. The first guide plate 23 is disposed between the paper feed roller 22 and the paper transport unit 4 and guides the paper P taken out by the paper feed roller 22 to the paper transport unit 4. The paper P corresponds to an example of “recording medium”.

  The paper transport unit 4 includes a second guide plate 41. The second guide plate 41 constitutes a substantially C-shaped paper conveyance path L. The paper transport unit 4 includes a first transport roller pair 42 provided on the entrance side of the paper transport path L, a second transport roller pair 43 provided in the middle of the paper transport path L, and an exit side of the paper transport path L. A registration roller pair 44 provided in

  The first transport roller pair 42 and the second transport roller pair 43 are feed roller pairs that feed the paper P along the paper transport path L. The first transport roller pair 42 feeds the paper P guided by the first guide plate 23 into the paper transport path L. The second transport roller pair 43 feeds the paper P sent by the first transport roller pair 42 toward the registration roller pair 44 across the paper P.

  The registration roller pair 44 corrects the skew 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 in order to synchronize the timing of image formation on the paper P and the conveyance timing of the paper P, and then sets the paper P to the image formation timing. Send to forming unit 3.

  The image forming unit 3 includes a conveyance belt 32, four types of recording heads 34a, 34b, 34c, and 34d, and a third guide plate 36. Since the four types of recording heads 34a, 34b, 34c, and 34d have substantially the same configuration, they may be collectively referred to as the recording head 34.

  The conveyance belt 32 is driven to convey the paper P sent from the registration roller pair 44 in a predetermined direction. In FIG. 1, the conveyor belt 32 is driven counterclockwise. As a result, the paper P is conveyed leftward in FIG. The transport belt 32 corresponds to an example of an “endless belt”. Hereinafter, the direction in which the paper P is transported by the transport belt 32 may be referred to as a transport direction D. The paper P is transported by the transport belt 32 and passes through a position facing the recording head 34. The recording head 34 discharges ink onto the paper P passing through a position facing the recording head 34, and forms an image on the paper P. The paper P on which an image is formed by the recording head 34 is conveyed toward the third guide plate 36 by the conveyance belt 32.

  The third guide plate 36 guides the paper P transported from the transport belt 32 to the paper discharge unit 5. 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 housing 100 so as to protrude from a discharge port 101 formed in the apparatus housing 100 to the outside.

  The discharge roller pair 51 sends the paper P guided by the third guide plate 36 toward the discharge port 101. The paper P sent out by the discharge roller pair 51 is discharged to the outside of the apparatus housing 100 through the discharge port 101. The sheet P discharged from the discharge port 101 is placed on the discharge tray 52.

  Next, the image forming unit 3 will be described with reference to FIGS. 1 and 2. FIG. 2 is a diagram showing the configuration of the image forming unit 3 shown in FIG.

  As shown in FIG. 2, in addition to the recording head 34, the image forming unit 3 includes a transport unit 31, a negative pressure applying unit 33, a plate member 11 that is an example of a space forming unit, and an insulating member that is an example of an insulating unit. 12 and a head base 37. The transport unit 31 includes a transport belt 32.

  The transport unit 31 is disposed to face the recording head 34. In addition to the conveyance belt 32, the conveyance unit 31 includes a belt speed detection roller 311, an adsorption roller 312, a drive roller 313, a tension roller 314, a pair of guide rollers 315, and a guide member 316.

  The belt speed detection roller 311, the driving roller 313, the tension roller 314, and the pair of guide rollers 315 stretch the conveyance belt 32.

  The belt speed detection roller 311 is arranged on the upstream side (right side in FIG. 2) in the transport direction D with respect to the guide member 316, and rotates due to a frictional force between the belt speed detection roller 311 and the transport belt 32. The belt speed detection roller 311 includes a pulse plate (not shown), and the pulse plate rotates integrally with the belt speed detection roller 311. By measuring the rotational speed of the pulse plate, the rotational speed of the conveyor belt 32 is detected.

  The suction roller 312 is a driven roller. The suction roller 312 faces the guide member 316 via the transport belt 32. The suction roller 312 guides the paper P sent from the registration roller pair 44 onto the transport belt 32. The paper P is preferably guided to the transport belt 32 so that the center of the paper P in the direction orthogonal to the transport direction D coincides with the center of the transport belt 32 in the direction orthogonal to the transport direction D. Hereinafter, the direction orthogonal to the conveyance direction D in the paper P may be referred to as the width direction of the paper P. In addition, the direction perpendicular to the conveyance direction D in the conveyance belt 32 may be described as the width direction of the conveyance belt 32.

  The drive roller 313 is disposed on the downstream side (left side in FIG. 2) in the transport direction D with respect to the guide member 316. Preferably, the driving roller 313 is arranged so as to maintain the flatness of the conveyance belt 32 at a position facing the recording head 34 together with the belt speed detection roller 311.

  The driving roller 313 is rotationally driven by a motor (not shown), and rotates the conveying belt 32 in the counterclockwise direction of FIG.

  The tension roller 314 applies tension to the conveyance belt 32 so that the conveyance belt 32 does not bend.

  The pair of guide rollers 315 are arranged so as to form a space below the negative pressure application unit 33. By arranging in this way, contact between the conveyance belt 32 and the negative pressure application unit 33 below the negative pressure application unit 33 can be prevented.

  The guide member 316 supports the paper P via the transport belt 32. Of the rotating conveyor belt 32, the portion supported by the guide member 316 may be described as the upper surface of the conveyor belt 32. The guide member 316 corresponds to an example of a “conveyance plate”. In the present embodiment, the guide member 316 is made of a metal material. Specifically, as the material of the guide member 316, an aluminum die cast, a pressed plate, or the like can be used. Alternatively, as the material of the guide member 316, a conductive resin excellent in slidability with the transport belt 32 can be selected. The guide member 316 is grounded.

  In the present embodiment, for convenience, the mode in which the transport unit 31 includes the guide member 316 is described. However, the negative pressure application unit 33 may include the guide member 316.

  The negative pressure application unit 33 is disposed below the guide member 316 so as to face the recording head 34 with the conveyance belt 32 interposed therebetween. The negative pressure application unit 33 applies the negative pressure to the paper P via the transport belt 32, thereby causing the paper P to be attracted to the transport belt 32. The negative pressure application unit 33 includes an air circulation chamber 331, a negative pressure generation unit 336, and a duct 337. The air circulation chamber 331, the negative pressure generator 336, and the duct 337 are arranged from the upper side to the lower side in this order.

  The air circulation chamber 331 is formed by a bottomed cylindrical box-shaped member whose upper surface is open. The upper surface of the air circulation chamber 331 is covered with a guide member 316. The upper surface of the side wall constituting the air circulation chamber 331 is fixed to the guide member 316. The negative pressure generator 336 is disposed below the air circulation chamber 331. Further, the negative pressure generator 336 is disposed below the recording head 34. When the negative pressure generator 336 is driven, a negative pressure is generated in the air circulation chamber 331, and air flows into the air circulation chamber 331 via the transport belt 32 and the guide member 316. As a result, the paper P is sucked toward the transport belt 32. In the present embodiment, the air circulation chamber 331 is in a negative pressure state that is lower by about 0.005 atm (≈about 500 Pa) than the atmospheric pressure by the negative pressure generator 336.

  The negative pressure generator 336 generates a negative pressure in the air circulation chamber 331, and is a fan in this embodiment. However, the negative pressure generator 336 is not limited to a fan, and may be a vacuum pump, for example.

  Duct 337 is connected to the lower surface of negative pressure generator 336. The air sucked by the negative pressure generating part 336 is discharged from the duct 337 to the outside.

  The four types of recording heads 34a, 34b, 34c, and 34d are arranged in parallel from the upstream side in the transport direction D to the downstream side. In the present embodiment, the recording head 34 is a line type. That is, the ink jet recording apparatus 1 is a line head type ink jet recording apparatus.

  The four types of recording heads 34a, 34b, 34c, and 34d each include a nozzle surface 341. Each nozzle surface 341 has a plurality of nozzles (not shown). Ink of each color is ejected from the nozzles of the recording heads 34a, 34b, 34c, and 34d onto the paper P that is passing through the positions facing the recording heads 34a, 34b, 34c, and 34d. As a result, images such as characters and figures are formed on the paper P. In the present embodiment, each nozzle surface 341 has a coat layer made of a fluororesin in order to improve water repellency. Each nozzle surface 341 is charged with a negative polarity when ink is ejected from the nozzle.

  The plate-like member 11 is disposed opposite the conveyance belt 32 on the upstream side in the conveyance direction D with respect to the recording head 34. The plate-like member 11 includes a conductive facing surface 11 f that faces the conveyor belt 32. The opposing surface 11f is grounded. By arranging the plate-like member 11 so as to face the conveyance belt 32, a foreign substance collection space 11 a is formed between the opposed surface 11 f of the plate-like member 11 and the upper surface of the conveyance belt 32. The plate-like member 11 is disposed such that the distance H between the facing surface 11f and the upper surface of the conveyor belt 32 is a predetermined distance. The distance H is the length in the vertical direction of the foreign substance collection space 11a, and is set to a predetermined threshold distance HS (3 mm in the present embodiment) or less. The threshold distance HS is set so that the velocity of the airflow flowing into the foreign matter collection space 11a from the space around the foreign matter collection space 11a is larger than that before flowing into the foreign matter collection space 11a and before entering the foreign matter collection space 11a. Is done. The threshold distance HS is preferably set so that the velocity (wind velocity) of the air flow flowing into the foreign substance collection space 11a is 6.0 m / second or more. In the present embodiment, the distance H is 2 mm.

  The insulating member 12 is provided on the guide member 316. The insulating member 12 is exposed from the upper surface of the guide member 316. The insulating member 12 supports the paper P via the transport belt 32. The insulating member 12 and the conveyor belt 32 come into contact with each other and are charged when the conveyor belt 32 is driven. In the present embodiment, the material of the conveyor belt 32 is polyimide, and the material of the insulating member 12 is a fluororesin. The fluororesin is located on the negative polarity side of the polyimide in the triboelectric charging series. For this reason, the insulating member 12 is charged with a negative polarity, and the transport belt 32 is charged with a positive polarity. The friction charging tendency of the insulating member 12 is the same as the charging tendency of the nozzle surface 341.

  The recording head 34 and the plate-like member 11 are fixed to the head base 37.

  Next, the guide member 316 and the insulating member 12 will be described in detail with reference to FIGS. 3 (a) to 3 (c). 3A is a sectional view of the guide member 316 shown in FIG. 2, FIG. 3B is a top view of the guide member 316 and the insulating member 12 shown in FIG. 2, and FIG. FIG. 4 is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 3A, the guide member 316 has a recess 316a. The guide member 316 is formed with a plurality of first grooves 334. Specifically, the upper surface side of the guide member 316 is open in each first groove 334. The depth d1 of the recess 316a is deeper than the depth d2 of the first groove 334. A first through hole 335 is formed below the first groove 334 and the recess 316a. Each first through-hole 335 penetrates the guide member 316 in the thickness direction of the guide member 316.

  As shown in FIG. 3B, the guide member 316 has a row formed by a plurality of first grooves 334 arranged along the transport direction D in the direction orthogonal to the transport direction D in the guide member 316. A plurality of lines are formed. Hereinafter, the direction orthogonal to the conveyance direction D in the guide member 316 may be described as the width direction of the guide member 316.

  Each first groove 334 has an oval shape extending in the transport direction D, and each first through hole 335 has a circular cross section. Each first through hole 335 is formed at a substantially central position in the transport direction D of each first groove 334.

  The insulating member 12 is provided from one end side to the other end side in the width direction of the guide member 316. That is, the recess 316a shown in FIG. 3A is formed from one end side in the width direction to the other end side of the guide member 316.

  As shown in FIGS. 3B and 3C, the insulating member 12 has a plurality of second grooves 121 formed therein. Specifically, a plurality of rows formed by the two second grooves 121 arranged along the transport direction D are formed in a direction perpendicular to the transport direction D in the insulating member 12. Each of the second grooves 121 has an opening on the upper surface side of the insulating member 12, and the shape thereof is an oval extending in the transport direction D. A second through hole 122 communicating with the first through hole 335 is formed at the bottom of the insulating member 12. Specifically, the second through hole 122 is formed at a substantially central position in the transport direction D of the second groove 121. The cross section of the second through hole 122 is circular. The diameter of the second through hole 122 is equal to the diameter of the first through hole 335. The upper surface of the insulating member 12 fitted in the recess 316a is the same height as the upper surface of the guide member 316.

  A two-dot chain line shown in FIG. 3B indicates the position of the plate member 11 projected onto the insulating member 12 and the guide member 316. As shown in FIG. 3B, a plurality of second grooves 121 formed in the insulating member 12 are formed at positions facing the plate-like member 11. Of the two second grooves 121 formed along the conveyance direction D, the second groove 121 formed on the upstream side in the conveyance direction D is in the conveyance direction D within the range of the projection image of the plate member 11. It extends further upstream in the transport direction D than the position of the upstream end. Further, the second through hole 122 communicating with the second groove 121 is formed within the range of the projection image of the plate-like member 11. Similarly, of the two second grooves 121, the second groove 121 formed on the downstream side in the transport direction D is from the position of the downstream end in the transport direction D within the range of the projection image of the plate-like member 11. Further, it extends further downstream in the transport direction D. The second through hole 122 communicating with the second groove 121 is also formed within the range of the projected image of the plate-like member 11.

  Next, with reference to FIG. 4, the structure of the negative pressure generation part 336, the air circulation chamber 331, the guide member 316, and the conveyance belt 32 is demonstrated. 4 is a cut perspective view showing configurations of the negative pressure generating unit 336, the air circulation chamber 331, the guide member 316, and the transport belt 32 shown in FIG.

  As shown in FIG. 4, the negative pressure generator 336, the air circulation chamber 331, the guide member 316, and the transport belt 32 are arranged in this order from the lower side to the upper side.

  A number of suction holes 321 are formed in the conveyance belt 32 at substantially equal intervals. Specifically, a plurality of rows formed of a large number of suction holes 321 arranged in the transport direction D are formed in the width direction of the transport belt 32. The plurality of rows are arranged so that the suction holes 321 are arranged in a staggered manner. In the present embodiment, the diameter of the suction holes 321 is 2 mm, and the interval between the adjacent suction holes 321 is 8 mm. The paper P transported from the paper transport unit 4 onto the transport belt 32 covers a part of the many suction holes 321. The rows of the plurality of suction holes 321 in the transport belt 32 are arranged corresponding to the rows of the plurality of first grooves 334, respectively. Each of the plurality of first grooves 334 faces at least two suction holes 321. As the transport belt 32 moves, the suction holes 321 facing each of the plurality of first grooves 334 are replaced one by one.

  The air circulation chamber 331 communicates with the suction hole 321 of the transport belt 32 through the first through hole 335 and the first groove 334 of the guide member 316. Similarly, the air circulation chamber 331 is connected to the suction hole of the conveyor belt 32 through the second through hole 122 and the second groove 121 of the insulating member 12 described with reference to FIGS. 3B and 3C. 321 communicates. As a result, an air flow passage for air flowing from the air circulation chamber 331 to the foreign substance collection space 11a is formed. The negative pressure generation unit 336 generates a negative pressure in the air circulation chamber 331 and adsorbs the paper P on the upper surface of the transport belt 32.

  Next, with reference to FIGS. 1-5, the effect | action of the airflow which flows in into the foreign material collection | recovery space 11a is demonstrated. FIG. 5 is a view showing the foreign substance recovery space 11a shown in FIG. 2 and the vicinity thereof.

  As shown in FIG. 5, when the air circulation chamber 331 is in a negative pressure state, air flows from the holes 371 and 372 formed in the head base 37 into the foreign substance collection space 11a along the arrows FD1 and FD2. The air that has flowed into the foreign matter collection space 11a flows into the air circulation chamber 331 along the air flow path.

  When the leading end portion of the paper P being transported by the transport belt 32 enters the foreign matter collection space 11a, the air flow flowing along the arrow FD1 flows above the leading end portion of the paper P. Similarly, when the rear end portion of the paper P moves out of the foreign matter collection space 11a, the air flow that flows along the arrow FD2 flows above the rear end portion of the paper P. As described above, the velocity (wind speed) of the airflow flowing into the foreign material recovery space 11a along the arrows FD1 and FD2 increases in the foreign material recovery space 11a. For this reason, the paper dust PD adhering to the front end portion and the rear end portion of the paper P is peeled off from the paper P and removed.

  Next, the operation of the insulating member 12 will be described with reference to FIGS. FIG. 6 is a diagram illustrating the charging tendency of the conveyor belt 32 and the insulating member 12. FIG. 7 is a diagram showing the operation of the insulating member 12 shown in FIG.

  As shown in FIG. 6, when the conveyor belt 32 is driven, a portion of the conveyor belt 32 that contacts the insulating member 12 is charged to a positive polarity by frictional charging with the insulating member 12. The insulating member 12 is charged with a negative polarity. As a result, an electric field is formed between the conveyance belt 32 and the opposing surface 11f of the plate-like member 11, that is, in the foreign matter collection space 11a. A portion of the conveyor belt 32 that is charged by sliding contact with the insulating member 12 is neutralized by the grounded guide member 316 when it passes through the upper surface of the insulating member 12 and contacts the guide member 316.

  As shown in FIG. 7, when the paper P enters the foreign matter collection space 11a, the paper powder PD charged to a positive polarity among the paper powder PD attached to the paper P adheres to the facing surface 11f. . Specifically, the transport belt 32 is charged to a positive polarity by frictional charging with the insulating member 12. For this reason, among the paper dust PD adhering to the paper P, the paper dust PD charged to a positive polarity moves in a direction away from the transport belt 32 due to the electric repulsive force. That is, the paper dust PD charged to a positive polarity moves from the conveying belt 32 side to the facing surface 11 f side and is peeled off from the paper P. The paper powder PD peeled from the paper P reaches the facing surface 11 f of the plate-like member 11. The opposing surface 11f has conductivity and is grounded. For this reason, the paper dust PD that has reached the plate-like member 11 adheres to the facing surface 11f due to a mirror image force.

  Next, the operation of the paper dust PD will be described with reference to FIGS. FIG. 8 is a diagram showing the foreign substance collection space 11a shown in FIG. 2 and the vicinity thereof. Specifically, the sheet P covers the second groove 121 formed in the insulating member 12. FIG. 9 is a diagram illustrating the operation of the paper dust PD that has reached the lower side of the recording head 34.

  As shown in FIG. 8, the paper P covers the second groove 121 formed in the insulating member 12 before entering the foreign material recovery space 11a and before leaving the foreign material recovery space 11a. When the second groove 121 is covered with the paper P, there is a possibility that the smooth flow of the air flow between the foreign material recovery space 11a and the air circulation chamber 331 may be hindered. If the smooth flow of the airflow is hindered, the speed of the airflow flowing into the foreign matter collection space 11a from the space around the foreign matter collection space 11a may be reduced. If the velocity of the air flow flowing into the foreign material recovery space 11a is reduced, the paper powder PD adhering to the paper P may not be separated from the paper P. However, according to the present embodiment, the paper powder PD charged to the same polarity (positive) as the charged polarity (positive) of the transport belt 32 is peeled off from the paper P by the action of the electric field formed in the foreign matter collection space 11a. To be removed.

  On the other hand, as shown in FIG. 9, the paper powder PD charged to a negative polarity may reach below the nozzle surface 341. In the present embodiment, the nozzle surface 341 is charged to a negative polarity by ejecting ink. Therefore, the charging polarity (negative) of the paper dust PD that has reached the lower side of the nozzle surface 341 is the same as the charging polarity (negative) of the nozzle surface 341. As a result, even if the paper dust PD is swollen from the paper P by the air flowing under the recording head 34, the paper dust PD does not adhere to the nozzle surface 341. Therefore, the adhesion of the paper powder PD to the nozzle surface 341 can be suppressed.

  In the present embodiment, the insulating member 12 has a bottom portion in which the second through hole 122 is formed, but the insulating member 12 does not have to have a bottom portion. In this case, both the upper surface (surface on the conveyor belt 32 side) and the lower surface (surface on the guide member 316 side) of the second groove 121 are open.

  In the present embodiment, the nozzle surface 341 has a coat layer made of a fluororesin, but a material other than the fluororesin may be used as a material for the coat layer of the nozzle surface 341. For example, a silicone resin can be used as a material for the coating layer of the nozzle surface 341.

  In this embodiment, the case where polyimide is used as the material of the conveyance belt 32 has been described. However, the material of the conveyance belt 32 is not limited to polyimide. For example, polyamide, polyamideimide, or polyvinylidene fluoride (PVDF) can be used as the material of the conveyor belt 32.

  Moreover, in this embodiment, although the fluororesin was used as a material of the insulating member 12, the material of the insulating member 12 is not limited to a fluororesin. The insulating member 12 may be made of a material whose charging tendency due to friction with the conveying belt 32 is the same as the charging tendency of the nozzle surface 341. For example, a silicone resin can be used as the material of the insulating member 12.

  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 ease of understanding, the drawings schematically show each component as a main component, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual for convenience of drawing. There is a case. Moreover, the shape, dimension, etc. of each component shown by said embodiment are an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the structure of this invention.

  For example, in the embodiment of the present invention, the case where the guide member 316 and the air circulation chamber 331 are separate members has been described. However, the guide member 316 and the air circulation chamber 331 may be integrally formed. In this case, a negative pressure leak from the air circulation chamber 331 can be prevented. Specifically, the inflow of air into the air circulation chamber 331 from the gap between the guide member 316 and the air circulation chamber 331 can be prevented.

  In the embodiment of the present invention, the case where one negative pressure generating unit 336 is used has been described. However, the number of negative pressure generating units 336 is not limited to one. For example, two or more negative pressure generators 336 may be used.

  The present invention is applicable to an ink jet recording apparatus.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 Image forming part 11 Plate-shaped member 11f Opposing surface 12 Insulating part 32 Conveying belt 316 Guide member 33 Negative pressure applying part 34 Recording head

Claims (7)

A recording head for ejecting ink onto a recording medium;
A transport belt for transporting the recording medium to a position facing the recording head;
A space forming portion that forms a foreign substance recovery space through which the recording medium passes between the recording head and the conveyance belt on the upstream side in the conveyance direction of the recording medium with respect to the recording head;
An insulating part disposed so as to come into contact with the conveyor belt;
A negative pressure application unit that applies a negative pressure to the foreign substance recovery space,
The position of the material constituting the insulating part in the triboelectric charging series is different from the position of the material constituting the conveying belt in the triboelectric charging series,
The space forming portion includes a conductive facing surface facing the conveyor belt,
The inkjet recording apparatus, wherein the conveyance belt is charged by frictional charging between the conveyance belt and the insulating portion, and an electric field is formed between the conveyance belt and the facing surface.
The recording head includes a nozzle surface on which nozzles for discharging the ink are formed,
The inkjet recording apparatus according to claim 1, wherein a charging tendency of the insulating part due to frictional charging between the transport belt and the insulating part is the same as a charging tendency of the nozzle surface.
The nozzle surface is charged to the first polarity when the ink is ejected,
The insulating portion is charged to the first polarity by frictional charging with the conveyor belt,
The inkjet recording apparatus according to claim 2, wherein the conveyance belt is charged to a second polarity that is opposite to the first polarity.
The inkjet recording apparatus according to claim 3, wherein the first polarity is a negative polarity.
The inkjet recording apparatus according to claim 2, wherein the insulating portion includes the same material as that of the nozzle surface.
Further comprising a transport plate that supports the transport belt and faces the recording head via the transport belt;
The inkjet recording apparatus according to claim 1, wherein the insulating plate is provided on the transport plate.
  The inkjet recording apparatus according to claim 1, wherein the insulating portion faces the facing surface.

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