JP5590207B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an inkjet recording apparatus that conveys a recording medium by adsorbing the recording medium to a conveying member.

  Japanese Patent Application Laid-Open No. H10-228707 discloses a recording medium that is attracted to an endless belt and conveyed to a recording head. In this document, there is provided an adsorbing means for adsorbing the recording medium to the endless belt by forming a charging circuit for discharging the charging roller to the endless belt to charge the recording medium.

JP 2007-230035 A

  In order to prevent an excessive current from flowing through the charging circuit when the resistance of the recording medium is low or when there is no recording medium, a material having a certain large resistance value is required in the charging circuit. For this purpose, the resistance value of the charging roller is generally adjusted to some extent. However, this restricts the material used for the charging roller, which may cause inconvenience.

  For example, in order to adjust the resistance value of the charging roller, a material in which a conductive material is contained in a base material made of urethane or rubber may be used. On the other hand, if the ink adhering to the endless belt adheres to the charging roller, the recording medium may be soiled. In order to prevent this, for example, the surface of the charging roller may be subjected to water repellent treatment such as coating with a fluororesin. However, since coating with a fluororesin requires firing at a high temperature of about 200 ° C., it is difficult to apply to a charging roller made of urethane, rubber, or the like. As described above, there are cases where it is difficult to ensure water repellency by limiting the material used for the charging roller.

  An object of the present invention is to provide an ink jet recording apparatus in which the material used for the electrode on the mounting surface side in the charging circuit is not easily limited.

An ink jet recording apparatus according to the present invention includes a conveying unit that conveys a recording medium placed on the placement surface by circulating an endless belt having a placement surface on which the recording medium is placed along a predetermined path. A recording head that discharges ink disposed to face the endless belt, and a first head that is disposed at a position facing the mounting surface and upstream of the recording head in the conveyance direction of the recording medium. An electrode and a second electrode disposed at a position that sandwiches the endless belt between the electrode and the inner surface on the opposite side of the mounting surface, and the first electrode, First suction means for applying a predetermined voltage between the second electrode and discharging the recording medium on the placement surface and the first electrode to attract the recording medium to the placement surface. When the first conductive in the conveyance direction of the recording medium And a third electrode disposed at a position downstream of the second electrode and facing the inner surface, and a voltage is applied between the second electrode and the third electrode, A second adsorbing means for adsorbing the recording medium on the surface to the mounting surface, and a surface of the second electrode facing the inner surface of the endless belt contains an ion conductive resistivity control material. And a surface layer material made of a resin material having a volume resistivity of 10 ¹⁰ to 10 ¹⁴ Ω · cm (ohm centimeter) when the predetermined voltage is applied in an environment where the temperature is 22.5 ° C. and the relative humidity is 50%. Are stacked, and the first adsorbing means and the second adsorbing means generate a potential difference between the first electrode and the second electrode and between the second electrode and the third electrode. As described above, between the first electrode and the second electrode Respectively a predetermined voltage is applied between the third electrode and the second electrode.

According to the inkjet recording apparatus of the present invention, the surface of the second electrode facing the inner surface of the endless belt contains an ion conductive resistivity control material whose resistance value is unlikely to change according to the applied voltage, and has a volume resistivity. A relatively high surface layer material made of a resin material having 10 ¹⁰ to 10 ¹⁴ Ω · cm (ohm centimeter) is laminated. This prevents an excessive current from being generated in the charging circuit formed in the first adsorption unit. For this reason, it is not necessary to limit the material of the first electrode for the purpose of preventing an excessive current from being generated in the charging circuit, so that the degree of freedom of the material used for the first electrode can be increased. For example, a material suitable for water repellent treatment can be selected as the first electrode.
Further, since the electrode of the first suction means and the electrode of the second suction means can be shared, the number of parts can be reduced.

  In the present invention, the second electrode is a position upstream of the recording head with respect to the conveyance direction of the recording medium and extending in a direction along the mounting surface, and the connection part is described above. It is preferable that the first electrode has a comb-tooth portion extending in a comb-tooth shape in a direction along the placement surface, and the first electrode is disposed to face the connection portion. Since there are many cases where the recording medium cannot be stably adsorbed around the connecting portion, the recording head cannot be disposed in the vicinity thereof, and a dead space is likely to occur. Since the first electrode is arranged in such a dead space, the width of the apparatus in the transport direction can be suppressed.

In the second electrode, the surface facing the inner surface of the endless belt contains an ion conductive resistivity control material whose resistance value is unlikely to change according to the applied voltage, and has a relatively high volume resistivity of 10 ¹⁰ to 10 ^14. A surface material made of a resin material of Ω · cm (ohm centimeter) is laminated. This prevents an excessive current from being generated in the charging circuit formed in the first adsorption unit. For this reason, it is not necessary to limit the material of the first electrode for the purpose of preventing an excessive current from being generated in the charging circuit, so that the degree of freedom of the material used for the first electrode can be increased. For example, a material suitable for water repellent treatment can be selected as the first electrode. Further, since the electrode of the first suction means and the electrode of the second suction means can be shared, the number of parts can be reduced.

1 is a schematic diagram schematically showing an internal configuration of an ink jet printer according to an embodiment of the present invention. FIG. 2 is a plan view of the periphery of the transport mechanism in FIG. 1, in which a part of the transport belt and the upper part of the suction platen are not illustrated, and the lower part of the suction platen is illustrated. It is the elements on larger scale of the III-III sectional view of FIG. FIG. 5 is an enlarged view around a charging roller in a cross-sectional view taken along line VV in FIG. 2. It is an electric circuit diagram formed between a recording medium, an adsorption platen, and a transport mechanism.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the ink jet printer 1 according to the first embodiment includes a rectangular parallelepiped housing 1 a, and a paper discharge unit 15 is provided at an upper portion. The inside of the housing 1a is divided into two spaces S1 and S2 in order from the top. In the space S1, four inkjet heads 2 (recording heads) that discharge magenta, cyan, yellow, and black ink, respectively, and a transport mechanism 50 that transports the paper P in the transport direction A are sequentially arranged from above. A paper feeding device 10 is disposed in the space S2. Furthermore, the inkjet printer 1 includes a control unit 100 that controls these operations. In the present embodiment, the direction parallel to the transport direction A when the paper P is transported by the transport mechanism 50 is a sub-scanning direction, and the direction perpendicular to the sub-scanning direction and along the horizontal plane is the main scanning. The direction.

  Inside the inkjet printer 1, a paper transport path is formed through which the paper P is transported along the thick arrow shown in FIG. The paper feeding device 10 rotates a paper feeding roller 12 controlled by the control unit 100, a paper feeding cassette 11 that can store a plurality of stacked paper P, a paper feeding roller 12 that feeds the paper P from the paper feeding cassette 11. A sheet feeding motor (not shown).

  The paper feed roller 12 sends out a plurality of sheets P stored in the paper feed cassette 11 one by one in order from the top. A conveyance guide 17 that extends while being curved upward from the paper feed cassette 11 is provided upstream of the conveyance mechanism 50. A peeling plate 9 for peeling the paper P from the transport mechanism 50 is provided downstream of the transport mechanism 50. Further, downstream of the peeling plate 9, feed rollers 21 a and 21 b that guide the paper P to the paper discharge unit 15, a conveyance guide 18, and feed rollers 22 a and 22 b are provided.

  In this configuration, the paper feed roller 12 sends out the paper P under the control of the control unit 100. The paper P is sent to the transport mechanism 50 through the transport guide 17. The transport mechanism 50 transports the paper P to a region below the inkjet head 2 and facing the ink ejection surface 2a. The ink-jet head 2 ejects ink onto the paper P transported by the transport mechanism 50. As a result, an image is formed on the paper P. The paper P on which the image is formed is peeled off by the peeling plate 9 at the right end of the transport mechanism 50 and discharged to the upper paper discharge unit 15 by the feed rollers 21a and 21b, the transport guide 18 and the feed rollers 22a and 22b. .

  Hereinafter, the transport mechanism 50 will be described in more detail. As shown in FIGS. 1 and 2, the transport mechanism 50 is disposed at a position facing the four inkjet heads 2, and is bridged between the two belt rollers 51 and 52 and the two rollers 51 and 52. And an endless transport belt 53 wound around the belt, and a transport motor (not shown) that is controlled by the control unit 100 and rotates the belt roller 52. These members constitute the conveying means of the present invention. The two belt rollers 51 and 52 are juxtaposed along the transport direction A and are rotatably supported by the housing 1a. The conveyance belt 53 is made of a flexible material, and includes a placement surface 54 that is a surface on which the paper P is placed, and an inner surface 55 that is a surface opposite to the placement surface 54. Yes.

  Further, the transport mechanism 50 has an adsorption platen 60 (second adsorption means) that faces the four inkjet heads 2. 2 and 3, the suction platen 60 includes a plate-like base member 61 made of an insulating material, electrodes 62 and 63 (third electrode and second electrode) bonded to the upper surface 61a thereof, and And faces the inner surface 55 of the conveyor belt 53. The electrodes 62 and 63 have connecting portions 62b and 63b extending along the main scanning direction, and a plurality of comb tooth portions 62a and 63a extending along the sub-scanning direction. The connecting portion 62b is disposed downstream of the inkjet head 2 in the transport direction of the paper P, and the connecting portion 63b is disposed upstream of the ink jet head 2 in the transport direction of the paper P. The comb tooth portion 62a extends from the connecting portion 62b toward the connecting portion 63b, and the comb tooth portion 63a extends from the connecting portion 63b toward the connecting portion 62b. The comb teeth 62a and the comb teeth 63a are alternately arranged in the main scanning direction. Thus, the electrodes 62 and 63 are each formed in a comb-like shape as a whole, and are arranged so that the comb-tooth portions are alternately adjacent to each other.

  The region where the electrodes 62 and 63 are formed has substantially the same width as the paper P in the main scanning direction, and straddles the region where the inkjet head 2 is disposed in the sub-scanning direction. The upper surfaces of the electrodes 62 and 63 are formed horizontally and are arranged at the same height. The electrode 62 is connected to a power source 69 provided in the housing 1a, and the electrode 63 is grounded. The power source 69 is controlled by the control unit 100. The electrodes 62 and 63 are made of a material such as conductive metal.

  A surface layer material 64 is laminated on the upper surfaces of the electrodes 62 and 63 by adhesion. The surface layer material 64 is formed so as to straddle the electrodes 62 and 63, and covers the entire upper surfaces of the electrodes 62 and 63. As a result, the surfaces of the electrodes 62 and 63 are protected from wear and the like due to contact with the transport belt 53. FIG. 2 shows a state where the surface layer material 64 is removed from the adsorption platen 60.

  As shown in FIGS. 2 and 4, a charging roller 70 (first electrode) is disposed at a position at the upstream end of the suction platen 60 and facing the connecting portion 63 b of the electrode 63. The charging roller 70 faces the placement surface 54 of the conveyor belt 53. The charging roller 70 has a substantially cylindrical shape whose axial direction is along the main scanning direction, and extends substantially from one end of the conveying belt 53 to the other end in the main scanning direction. As shown in FIG. 4, the charging roller 70 includes a rotating shaft 71 and a roller body 72 fixed to the outer periphery thereof. The rotating shaft 71 is connected to a power source 79 controlled by the control unit 100 and is rotatably supported by a bearing provided in the housing 1a.

  In this configuration, under the control of the control unit 100, the belt roller 52 rotates clockwise in FIG. On the other hand, the paper P sent out from the paper feeding device 10 is sandwiched between the placement surface 54 of the transport belt 53 and the charging roller 70. The charging roller 70 rotates counterclockwise in FIG. 4 as the paper P moves while the paper P is sandwiched between the charging roller 70 and the transport belt 53. Here, when a voltage of a predetermined magnitude is supplied to the rotating shaft 71 of the charging roller 70, a discharge is generated from the charging roller 70 toward the paper P, and the surface of the paper P is positively charged. Due to this charging, the surface of the paper P facing the transport belt 53 is negatively polarized, and the surface of the transport belt 53 facing the paper P is positively polarized. Accordingly, the paper P is electrostatically attracted to the placement surface 54 of the transport belt 53. As described above, the charging roller 70 and the electrode 63 form a charging circuit that charges the paper P by discharging, thereby constituting an adsorbing unit (first adsorbing unit) that adsorbs the paper P to the transport belt 53. Yes.

  The sheet P adsorbed on the placement surface 54 by the charging roller 70 is conveyed to a position facing the comb teeth portions 62a and 63a. On the other hand, a positive potential is applied to the electrode 62 and a ground potential is applied to the electrode 63 under the control of the control unit 100. When a voltage is applied between the electrodes 62 and 63 with the paper P facing the comb teeth 62a and 63a, a current flows between the electrodes 62 and 63 via the transport belt 53 and the paper P. FIG. 5 shows an electric circuit formed when a predetermined voltage V is applied between the electrodes 62 and 63. In the present embodiment, the magnitude of the voltage V is set to 3 kV (kilovolts), but may be other magnitudes. Note that the electric circuit shown in FIG. 5 is only one model assumed when the present embodiment is idealized as an electrical configuration.

  This electric circuit includes a path of electrode 62 → conveying belt 53 → paper P → conveying belt 53 → electrode 63. Rk, Rgb, Rb, Rgp, and Rp in FIG. 5 represent the electrical resistance of each part along this path. Specifically, Rk corresponds to the electrical resistance of the surface material 64. Rgb corresponds to the contact resistance between the surface layer material 64 and the conveyor belt 53. Rb corresponds to the electric resistance of the conveyor belt 53. Rgp corresponds to the contact resistance between the conveyance belt 53 and the paper P. Rp corresponds to the electrical resistance of the paper P.

  Further, this electric circuit includes detour paths connected in parallel to the above-described paths, and Rkm and Rbm indicate the electric resistances of these detour paths. Specifically, Rkm indicates an electrical resistance of a detour path that directly connects the electrodes 62 and 63 via only the surface layer material 64. Rbm indicates the electrical resistance of a detour path that connects the electrode 62 side and the electrode 63 side via the conveyance belt 53 without using the paper P.

  In this electric circuit, as shown in FIG. 5, a capacitor connected in parallel to each electric resistance is formed. Minute concavities and convexities are formed on the opposing surfaces of the paper P and the transport belt 53, and when a voltage is applied between the electrodes 62 and 63, the paper P and the transport belt 53 are in contact with each other. A small current flows in the gap between the belt and the conveyor belt 53, and a potential difference is generated in the gap. Where the paper P and the conveyance belt 53 are not in contact with each other, charges having different polarities are stored, and an adsorption force which is a Coulomb force acts between the two. This attracting force is called a Johnsen-Rahbek force, whereby the sheet P on the transport belt 53 is electrostatically attracted to the placement surface 54.

  As described above, in the present embodiment, there are provided two suction means, that is, the suction means by the charging roller 70 and the electrode 63 and the suction means by the electrodes 62 and 63 disposed downstream in the conveyance direction of the paper P. Yes. Accordingly, the sheet P is attracted to the conveyance belt 53 by the charging roller 70 and the electrode 63 upstream in the conveyance direction, and is conveyed toward the electrodes 62 and 63 disposed downstream. Then, while being more reliably adsorbed by the conveyance belt 53 by the electrodes 62 and 63, it passes under the inkjet head 2 along with the movement of the conveyance belt 53 and moves toward the peeling plate 9.

By the way, when the resistance of the sheet P is low or when the sheet P is not on the placement surface 54, an excessive current is prevented from being generated in the charging circuit formed by the charging roller 70 and the electrode 63. Therefore, it is necessary to interpose a member having a certain large resistance value in this charging circuit. Generally, for this purpose, the material of the charging roller 70 itself is made a material having a certain resistance value. For example, the charging roller 70 having a resistance value of about 10 ⁸ Ω may be formed of a material in which a suitable conductive material is contained in a base material made of a resin material such as urethane or rubber.

  However, if the material of the charging roller 70 is limited in order to adjust the resistance value, there is a risk of inconvenience. For example, since the charging roller 70 is located at a position facing the placement surface 54 of the conveyor belt 53, the charging roller 70 may be contaminated by ink adhering to the placement surface 54. Further, since it is close to the ink jet head 2, it may be directly contaminated by the ink ejected from the ink jet head 2. When the charging roller 70 is contaminated with ink, the ink attached to the charging roller 70 may further contaminate the paper P. In order to prevent this, it is conceivable that the surface of the charging roller 70 is subjected to water repellent treatment such as coating with a fluororesin so that the charging roller 70 is not easily contaminated with ink. However, coating with a fluororesin requires firing at a high temperature of about 200 ° C. Therefore, when the charging roller 70 is formed of urethane, rubber, or the like as described above, it is difficult to perform water-repellent treatment that requires high-temperature baking such as coating with a fluororesin. As described above, if the material used for the charging roller 70 is limited for the purpose of adjusting the resistance value, there may be a disadvantage that water repellency cannot be secured.

  Therefore, in this embodiment, the material used for the charging roller 70 is not limited. Therefore, the charging roller 70 is disposed at a position facing the electrode 63, and the charging circuit is formed by the charging roller 70 and the electrode 63. As a result, the charging circuit includes the surface layer material 64 which is a protective layer for protecting the surface of the electrode 63, and the resistance value of the entire charging circuit can be adjusted by adjusting the resistance value of the surface layer material 64. become able to.

Specifically, as the material of the surface layer material 64, a material whose resistance value is adjusted to be relatively large by using a resistivity control material in the resin material is used. At this time, the present inventor has found that it is preferable to use an ion conductive resistivity control material for the surface layer material 64. This is because the ion resistivity-based resistivity control material has a small volume resistivity variation with respect to the applied voltage. According to a certain measurement result, the volume resistivity of the sample when a voltage of 100 V (volt) is applied to a sample made of a resin material containing an ion conductivity-based resistivity control material is about 10 ¹³ Ω · cm, and 500 V The volume resistivity of the sample when this voltage was applied was about 10 ¹² to 10 ¹³ Ω · cm. On the other hand, for example, the volume resistivity of the sample when a voltage of 100 V is applied to a sample made of a resin material containing an electron conductive resistivity control material such as carbon black is about 10 ¹² Ω · cm. The volume resistivity of the sample when a voltage of 500 V was applied was about 10 ⁸ Ω · cm.

  The above resistance value is measured under the following measurement conditions. [Measurement Conditions] Measuring instrument: “Hiresta UP” manufactured by Mitsubishi Chemical Corporation (“Hiresta” is a registered trademark). Probe used: UR100. Measurement time: 60 seconds. Measurement environment: normal temperature and normal humidity (temperature 22.5 ° C. and relative humidity 50%). The environment where the temperature is 22.5 ° C. and the relative humidity is 50% corresponds to the main use environment assumed in the inkjet printer 1.

  As the ion conductive resistivity control material, for example, an ionic surfactant, an alkali metal salt, an alkaline earth metal, an organic ion electrolyte, or the like is used alone, or a plurality of them are used in combination. In particular, an alkyl quaternary ammonium salt is preferably used. For example, when an alkyl quaternary ammonium salt is used for the surface layer material 64 as an ion conductive resistivity control material, fluctuations in the volume resistivity of the resistivity control material with respect to environmental fluctuations are suppressed.

  Examples of alkyl quaternary ammonium salts include lauryl trimethyl ammonium, stearyl trimethyl ammonium, octadecyl trimethyl ammonium, dodecyl trimethyl ammonium, hexadecyl trimethyl ammonium perchlorate, chlorate, borofluoride, sulfate, etho Examples thereof include sulfate salts, benzyl halide salts (benzyl bromide salts, benzyl chloride salts, and the like).

As described above, in the present embodiment, a resin material containing an ion conductive resistivity control material is used for the surface layer material 64. The resin material has a volume resistivity of 10 ¹⁰ to 10 ¹⁴ Ω · cm when a predetermined voltage V is applied between the electrodes 62 and 63 in an environment where the temperature is 22.5 ° C. and the relative humidity is 50%. Thus, an ion conductive resistivity control material is contained. The surface of the charging roller 70 is covered with a material having water repellency by coating with a fluororesin or the like.

The volume resistivity of the resin material is adjusted to 10 ¹⁰ to 10 ¹⁴ Ω · cm for the following reason. The volume resistivity of the paper P varies depending on the type and moisture absorption, and is in the range of 10 ⁷ to 10 ¹⁴ Ω · cm. The upper limit of the volume resistivity of the resin material is 10 ¹⁴ Ω · cm because the maximum value of the volume resistivity of the paper P is 10 ¹⁴ Ω · cm, and thus an excessive current is generated in the charging circuit. In order to suppress the surface resistivity, the volume resistivity of the surface layer material 64 may be about 10 ¹⁴ Ω · cm. On the other hand, if the volume resistivity of the surface layer material 64 exceeds 10 ¹⁴ Ω · cm, the resistance value of the entire charging circuit This is because an excessively large value prevents the suction force between the paper P and the conveyance belt 53 from being obtained. In addition, the volume resistivity of the resin material is in the range of 10 ¹⁰ to 10 ¹⁴ Ω · cm, and the volume resistivity is adjusted by adding an ion conductive resistivity control material to the resin material. This is because, normally, a manufacturing variation of about 10 ^{± 2} times at the maximum with respect to the target value of the volume resistivity must be generated. Therefore, a width of 4 digits with the volume resistivity being 10 ¹⁴ Ω · cm as the upper limit is assumed as a suitable range of the resin material used for the surface layer material 64.

Thus, the volume resistivity of the surface layer material 64 is relatively large and is in the range of 10 ¹⁰ to 10 ¹⁴ Ω · cm, so that the surface layer material 64 is included in the charging circuit constituted by the charging roller 70 and the electrode 63. The resistance value is added, and the resistance value of the entire charging circuit becomes relatively large. This prevents an excessive current from being generated in the charging circuit, so that it is not necessary to limit the material of the charging roller 70 with a resistance value. Therefore, for example, the rotating shaft 71 and the roller body 72 constituting the charging roller 70 can be made of a conductive metal material or a semiconductive material having a certain degree of conductivity. In addition, a material that can be subjected to water repellent treatment by coating with a fluororesin accompanied by high-temperature firing can be selected.

  In this embodiment, in addition to the suction means by the charging roller 70 and the electrode 63, suction means by the electrodes 62 and 63 are provided, and the electrode 63 is shared by these two suction means. For this reason, the number of parts is reduced compared with the case where parts are not shared.

  In the present embodiment, the charging roller 70 is disposed at a position of the electrode 63 that faces the connecting portion 63b. The periphery of the connecting portion 63b corresponds to a region where the suction force by the electrodes 62 and 63 cannot be stably generated. Accordingly, the periphery of the connecting portion 63b is a place where the paper P is not reliably adsorbed to the transport belt 53, and the ink jet head 2 is not disposed, and thus a dead space is likely to occur. However, since the charging roller 70 is arranged in such a place as in the present embodiment, the charging roller 70 is arranged using the dead space effectively. Each part is arranged compactly.

<Modification>
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the means for solving the problem. It is possible.

  In the above-described embodiment, both the suction means using the charging roller 70 and the electrode 63 and the suction means using the electrodes 62 and 63 are provided, but only the suction means using the charging roller 70 and the electrode 63 may be provided. . Further, instead of the charging roller 70, a fixed electrode or the like having no roller shape may be used.

  In the above-described embodiment, the power source 69 for applying a positive voltage to the electrode 62 is provided. However, any configuration may be used as long as a potential difference of a predetermined magnitude is generated between the electrodes 62 and 63. Good. For example, a negative potential may be applied to the electrode 62, a ground potential may be applied to the electrode 62, and a potential different from the ground potential may be applied to the electrode 63.

  In the above-described embodiment, the surface layer material 64 is formed over the entire surface of the adsorption platen 60 so as to straddle the electrodes 62 and 63, but the surface layer material 64 partially covers the upper surface of the adsorption platen 60. It may be formed.

  Moreover, although the above-mentioned embodiment is an example which applied this invention to the inkjet head which discharges an ink from a nozzle, the object which can apply this invention is not restricted to such an inkjet head. For example, a conductive paste is discharged to form a fine wiring pattern on the substrate, an organic light emitter is discharged to the substrate to form a high-definition display, or an optical resin is discharged to the substrate. The present invention can be applied to a droplet discharge head for forming a microelectronic device such as an optical waveguide. Furthermore, the present invention may be applied to a recording head that prints by other methods such as a thermal method.

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Inkjet head 50 Conveying mechanism 51, 52 Belt roller 53 Conveying belt 54 Placement surface 60 Adsorption platen 62, 63 Electrode 64 Surface material 70 Charging roller

Claims (2)

Conveying means for conveying the recording medium placed on the placement surface by circulating an endless belt having a placement surface on which the recording medium is placed along a predetermined path;
A recording head that ejects ink disposed to face the endless belt;
The position where the endless belt is sandwiched between the first electrode and the first electrode disposed at a position facing the mounting surface and upstream of the recording head in the recording medium conveyance direction. A second electrode disposed at a position opposite to the inner surface on the opposite side of the mounting surface, and applying a predetermined voltage between the first electrode and the second electrode. A first suction means for discharging between the recording medium on the surface and the first electrode to attract the recording medium to the mounting surface ;
A third electrode disposed at a position downstream of the first electrode and the second electrode with respect to the conveyance direction of the recording medium and facing the inner surface, and the second electrode and the third electrode A second suction means for applying a voltage between the recording medium and the recording medium on the mounting surface to suck the recording medium on the mounting surface ;
The surface of the second electrode facing the inner surface of the endless belt contains an ion conductive resistivity control material, and the predetermined voltage is applied in an environment where the temperature is 22.5 ° C. and the relative humidity is 50%. A surface layer material made of a resin material having a volume resistivity of 10 ¹⁰ to 10 ¹⁴ Ω · cm (ohm centimeter) is laminated ,
The first adsorbing means and the second adsorbing means may be configured such that a potential difference is generated between the first electrode and the second electrode and between the second electrode and the third electrode. A predetermined voltage is applied between the electrode and the second electrode and between the second electrode and the third electrode, respectively . The second electrode is a position upstream of the recording head in the conveyance direction of the recording medium and extends in a direction along the placement surface, and a direction from the connection portion along the placement surface. A comb tooth portion extending like a comb tooth,
The inkjet recording apparatus according to claim 1 , wherein the first electrode is disposed so as to face the connecting portion.