JP2010037077A - Carrying object material carrying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrying object material carrying device and an image forming device superior in capability of changing the planarity of a carrying object material, while saving space. <P>SOLUTION: A decurler is provided for correcting curling of the carrying object material, in carrying by sandwiching and carrying recording paper P in and to a recessed nip part 230 formed when a hard roller 220 bites into a soft roller 210, by making the soft roller 210 and the hard roller 220 abut against parallel to the axial direction. Both rollers 210 and 220 have a driving means for respectively rotatingly driving both rollers 210 and 220. The respective driving means rotatingly drive a surface speed of the hard roller 220 so as to become larger than the surface speed of the soft roller 210. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a transported material transport apparatus and an image forming apparatus, in which two rotating bodies having different hardnesses are brought into contact with each other in parallel in the axial direction, and a high hardness rotating body bites into a low hardness rotating body. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transported material transport apparatus that transports a transported material between sandwiched nip portions and changes the flatness of the transported material during transport, and an image forming apparatus including the transported material transport apparatus.

  In an image forming apparatus using an electrophotographic process such as a copying machine, a printer, or a facsimile machine, the toner image transferred from the photosensitive member onto the recording paper is fixed on the recording paper by pressurizing and heating with a fixing device. I am letting. However, when the fixing is performed by the fixing device that nips the recording paper between the heat roller and the pressure roller, the recording paper is curled. This curl has a large possibility of adversely affecting the transportability of the recording paper in the subsequent process. In view of this, an apparatus and a decurler intended to remove curl immediately after the fixing device are arranged to remove the curl and improve transportability.

  FIG. 10 is a front view showing a configuration of a conventional decurler. The decurler 1100 presses the soft roller 1110 having a relatively low hardness with the hard roller 1120 having a high hardness facing each other, and the deformation direction of the soft roller 1110 is changed in the nip portion 1130 where the hard roller 1120 bites into the soft roller 1110. By curling the curled paper in the reverse direction, the curl is corrected.

  In Patent Document 1, in a decurling apparatus in which an elastic roller and a hollow cooling pipe roller are nipped on each other's outer peripheral surface and the recording paper is passed through the nip portion, the cooling pipe roller is heated from the surface of the recording paper. A decurling device for an image forming apparatus is described, which has an endothermic action for removing heat.

  Further, Patent Document 2 discloses a high-hardness roller made of a rigid body and a pressure contact with the high-hardness roller so as to maintain a stable conveyance force of the curl correction roller without being affected by a difference in transfer image or fixing temperature. A curl correction roller comprising an elastic roller having an elastic layer and a drive source for applying a rotational driving force to the high-hardness roller, and a conveyance path for discharging the printed paper in the electrophotographic process step In the curl straightening device that is disposed downstream of the fixing unit and corrects the curl of the paper, a gear that meshes with the high-hardness roller and the elastic roller is disposed, and a rotational driving force of the elastic roller is provided from the high-hardness roller. What is obtained is described.

  Further, in Patent Document 3, in order to make the curl correction by heating and fixing appropriate for not only plain paper but also thick recording paper, fixing is performed using a heating roller and a pressure roller. In a fixing device that discharges paper using a paper discharge roller and a pressure roller, the pressing force of the pressure roller against the paper discharge roller acts on a pressure lever that supports a shaft on which the pressure roller is fixed. It is described that the power is changed by changing the thickness of the recording paper, and the tension of the recording paper P to be discharged after heating and fixing is changed to change the curl correcting force.

  In Patent Document 4, even when a new type of paper is used, the curl correction amount suitable for the paper is stored in the storage means so that it can be set more easily and appropriately. The rewriting operation means for rewriting the curl control information being stored is newly displayed while referring to the display means for displaying the existing control information stored in the storage means in a predetermined format and the control information displayed on the display means. And input means for inputting various information. When a new type of paper is used, information on the new type of paper is additionally input to the existing control information by the input unit and rewritten. Further, there is described a method for newly creating control information related to the curl correction amount of the new type of paper.

  Patent Document 4 discloses a humidity sensor, a curl detection sensor for detecting a curl of a recording material, and a recording material in order to prevent the curling of the recording material caused by fixing and to prevent the occurrence of a jam and uneven discharge. There is described a curl correcting means for correcting curl and operating the curl correcting means in accordance with the output of these sensors.

  Contrary to such decurlers, there are some which curl uncurled paper. That is, in the ink jet recording apparatus, when at least the front end (front end side in the transport direction) of the sheet to be recorded is curled so as to protrude upward from the center portion, the front end of the recording paper P passes through the spur roller. In some cases, the ink-jet head may hit the ink-jet head, and when the sheet hits in this way, unnecessary ink adheres to the leading edge of the sheet and the sheet becomes dirty. In order to prevent such a situation, Patent Document 6 discloses that a curling unit that curls a sheet in a predetermined direction is provided on the upstream side of the recording unit.

No. 2525796 gazette JP 2007-031025 A Japanese Patent Laid-Open No. 06-087558 JP 2001-337564 A JP-A-11-268856 JP 2002-249259 A

  When correcting the curl of the paper in this way, it is desired that the ability to bend in the reverse direction with respect to the curl of the paper is desired. In this case, in particular, the deformation in the direction opposite to the curl at the nip portion is increased. It is effective. Conversely, in order to curl a sheet that has not been curled in a predetermined direction, it is effective to increase the deformation of the sheet in the direction in which it is desired to curl at the nip portion. Therefore, when the outer diameter of the soft roller is constant, it is effective to increase the biting amount of the hard roller or reduce the diameter of the hard roller to increase the curvature.

  Here, if the soft roller is greatly deformed or the diameter of the hard roller is reduced, it becomes difficult for the soft roller to follow the hard roller, and it is easy to cause a delay. It will be limited to the diameter.

  SUMMARY An advantage of some aspects of the invention is that it provides a transported material transport apparatus and an image forming apparatus that are excellent in ability to change the flatness of the transported material while saving space.

  According to the first aspect of the present invention, a material to be conveyed is formed in a concave nip portion formed by causing two rotating bodies having different hardnesses to abut in parallel in the axial direction and the high hardness rotating body bites into the low hardness rotating body. Is a transported material transport device that changes the degree of flatness of the transported material during transport, and both rotating bodies are provided with driving means for rotating both rotating bodies, and each driving means Each of the rotating bodies is driven such that the surface speed of the rotating body with high hardness is larger than the surface speed of the rotating body with low hardness.

  According to a second aspect of the present invention, in the transported material conveying apparatus according to the first aspect, at least one of the rotating bodies is a roller member.

  According to a third aspect of the present invention, in the transported material conveying device according to the first aspect, at least one of the rotating bodies includes an endless belt member.

  According to a fourth aspect of the present invention, in the conveyed material conveying apparatus according to any one of the first to third aspects, the curl of the conveyed material is corrected.

  According to a fifth aspect of the present invention, in the transported material transport apparatus according to any one of the first to third aspects, the transported material that is not curled is curled.

  A sixth aspect of the present invention is the conveyed material conveying apparatus according to any one of the first to fifth aspects, wherein an outer diameter of the high-hardness rotating body is smaller than an outer diameter of the low-hardness rotating body. It is characterized by.

  A seventh aspect of the present invention is the transported material conveying apparatus according to any one of the first to sixth aspects, wherein the outer diameter D2 (2 * R2, R2: radius) of the high-hardness rotating body and the outer surface of the low-hardness rotating body. When the diameter D1 (2 * R1, R1: radius)) and the amount of biting (a) when the high-hardness rotating body is pressed against the low-hardness rotating body, the rotational speed of the low-hardness rotating body is The ratio of the rotational speed of the high-hardness rotating body is defined as θ ′ / θ using θ and θ ′ defined by the following equation.

  The invention of claim 8 is the material transport apparatus according to claim 7, wherein the biting amount changing means for changing the value of the biting amount (a) of the high hardness rotating body into the low hardness rotating body; Rotational speed ratio changing means for changing the ratio (θ ′ / θ) of the rotational speed of the high-hardness rotating body to the rotational speed of the low-hardness rotating body corresponding to the set amount of biting. Features.

  The ninth aspect of the present invention is the transported material conveying apparatus according to the seventh aspect, wherein the high-hardness rotating body and the low-hardness rotating body include an outer diameter D2 of the high-hardness rotating body and the low-hardness rotating body. It is characterized in that the outer diameter D1 of the rotating body of hardness is connected to the rotating connection means that rotates in conjunction with the rotation speed ratio (θ ′ / θ) set by the amount of biting (a). To do.

  According to a tenth aspect of the present invention, in the transported material conveying apparatus according to the ninth aspect, the rotation connecting means is constituted by a gear mechanism or a winding mechanism disposed in each rotating body.

  According to an eleventh aspect of the present invention, in the transported material conveying apparatus according to the seventh aspect, the high-hardness rotating body and the low-hardness rotating body are rotationally variable and are rotationally driven by individually arranged driving means. It is characterized by that.

  According to a twelfth aspect of the present invention, in the transported material transport apparatus according to any one of the first to 11th aspects, the transported material is roll paper.

  According to a thirteenth aspect of the present invention, there is provided an electrophotographic image forming apparatus characterized in that the conveyed material conveying device according to any one of the first to eleventh aspects is provided on the downstream side of the thermal fixing device.

  A fourteenth aspect of the present invention is an image forming apparatus comprising the transported material transport device according to the twelfth aspect.

  According to the transported material transport apparatus and the image forming apparatus according to the present invention, each of the high-hardness rotating body and the low-hardness rotating body includes a driving unit, and each driving unit has a rotational speed of the high-hardness rotating body. Since each rotating body is driven to be larger than the rotational speed of the low-hardness rotating body, the diameter of the high-hardness rotating body is reduced, or the high-hardness rotating body is strongly bitten into the low-hardness rotating body. However, in addition to being able to drive both rotating bodies well, it is possible to set optimal conditions for changing the flatness of the transported material, and to change the flatness of the transported material while saving space It can be excellent in ability.

  Embodiments as the best mode for carrying out the present invention will be described below with reference to the drawings.

  Hereinafter, an image forming apparatus according to an embodiment will be described with reference to the drawings. FIG. 1 is a sectional view conceptually showing the image forming apparatus according to the embodiment. The image forming apparatus according to the present exemplary embodiment includes an image reading unit 111 that reads a document, an image forming unit 112 that forms an image, an automatic document conveying device 113, a document discharge tray 114 that stacks documents sent from the automatic document conveying device 113, A paper feed unit 119 including paper feed cassettes 115 to 118 and a paper discharge unit (discharge tray 120) for stacking recording sheets are provided.

Then, when the document D is set on the document table 121 of the ADF 113 and an operation unit (not shown) is operated, for example, a press of a print key is performed, the uppermost document D is sent out in the direction of the arrow B 1 by the rotation of the pickup roller 122. Then, the paper is fed onto the contact glass 124 fixed to the image reading unit 111 by the rotation of the document conveying belt 123 and stops there. The image of the document D placed on the contact glass 124 is read by the reading device 125 positioned between the image forming unit 112 and the contact glass 124. The reading device 125 includes a light source 126 that illuminates the document D on the contact glass 124, an optical system 127 that forms an image of the document, a photoelectric conversion element 128 that includes a CCD that forms an image of the document, and the like. After the image reading is completed, the document D is transported in the direction of arrow B2 by the rotation of the document transport belt 123 and discharged onto the document discharge tray 114. In this way, the document D is fed one by one onto the contact glass 124 and the document image is read by the image reading unit 111.

On the other hand, inside the image forming unit 112, a photoreceptor 130 as an image carrier is disposed. The photoconductor 130 is driven to rotate clockwise in the drawing, and the charging device 131 charges the surface to a predetermined potential. Further, the writing unit 132 emits a laser beam L that is light-modulated in accordance with image information read by the reading device 125, and the surface of the charged photoreceptor 130 is exposed with the laser beam L. An electrostatic latent image is formed on the surface of the body 130. When the electrostatic latent image passes through the developing device 133, the electrostatic latent image is transferred to the recording paper P fed between the photosensitive member 130 and the transfer device 134 by the opposing transfer device 134. The surface of the photoreceptor 130 after the toner image transfer is cleaned by a cleaning device 135.

A plurality of paper feed cassettes 115 to 118 arranged at the lower part of the image forming unit 12 contain recording paper P as a recording medium. The toner image formed on the surface of the photoreceptor 130 as described above is transferred onto the surface of the recording paper P. Next, the recording paper P is passed through the fixing device 136 in the image forming unit 112 as indicated by an arrow B4, and the toner image transferred onto the surface of the recording paper P by the action of heat and pressure is fixed. The recording paper P that has passed through the fixing device 136 passes through a decurler 300 that is a transported material transport device to remove the curl, and is transported by the discharge roller pair 137, and is discharged to the discharge tray 120 and stacked as indicated by an arrow B5. .

  Next, a decurler that is a transported material transport device according to the embodiment will be described. First, the operating conditions of the decurler will be described. FIG. 2 is a schematic diagram showing the configuration of the decurler. In this example, the decurler 200 includes a synthetic resin soft roller 210 having a radius R 1 and a metal hard roller 220 having a radius R 2. The hard roller 220 bites into the soft roller 210 with a biting amount a, and the nip portion 230. Is forming. Here, the radius R1 of the hard roller 220 is smaller than the radius R1 of the soft roller 210 (R1> R2). The rotational speeds of the soft roller 210 and the hard roller 220 when both the soft roller 210 and the hard roller 220 are rotationally driven in this state will be examined. Here, the angle of the soft roller 210 facing the nip portion 230 is 2θ ′, and the angle of the hard roller 220 facing the nip portion 230 is 2θ. Since the radius R1 of the soft roller 210 is larger than the radius of the hard roller 220, the angle θ is larger than the angle θ ′.

  Here, in order to convey the material to be conveyed in the nip portion 230 without any trouble, the rollers 210 and 220 are rotated so that the conveyance speed (linear velocity) in the nip portion 230 is substantially equal in each roller 210 and 220. In this example, when the time for passing through the nip portion 230 is Δt, the peripheral speed of the hard roller 220 is 2R2 · 2θ / Δt, and the peripheral speed of the roller 210 is 2R1 · 2θ ′ / Δt.

Here, from the relation of θ> θ ′, the peripheral speed of the hard roller 220 needs to be larger than the peripheral speed of the roller 210.

  Next, the rotational speeds of the soft roller 210 and the hard roller 220 will be examined. First, since the hard roller 220 is made of metal and hardly deformed and can be ignored, the sheet feeding speed at the nip 230 of the hard roller 220 is the same as the surface speed of the hard roller 220 (L = 2R2 · θ). .

  On the other hand, on the soft roller 210 side, since the soft roller 210 is deformed at the nip portion 230, in the soft roller 210, while the soft roller 210 rotates by 2θ ′, the nip portion 230 has a dimension L. It will be transported. Here, the linear velocity at the nip portion 230 of the soft roller 210 is larger than the peripheral velocity of the soft roller 210 other than the nip portion 230 (L> 2R1 · θ ′).

  Since the time for which each of the rollers 210 and 220 rotates by an angle (2θ, 2θ ′) is the same (Δt), the rotation speed of the soft roller 210 is θ ′ / Δt (radians / second), and the rotation speed of the hard roller 220 is θ / Δt (radians / second), and the ratio between the rotational speed of the soft roller 210 and the rotational speed of the hard roller 220 is θ ′ / θ (formula 1). Thereby, the conveyance speed (linear velocity) of both the rollers 210 and 220 in the nip part 230 becomes equal. Here, when θ and θ ′ are obtained using the dimensions R1, R2, and a, the following equation 2 is obtained from the sine theorem.

... Formula 2

  Next, a specific configuration of the decurler will be described. FIG. 3 is a perspective view showing the decurler according to the embodiment. The decurler 300 according to this example is disposed on the downstream side of the fixing device 136 of the image forming apparatus.

  The decurler 300 includes a soft roller 310 made of synthetic resin and having a radius R1, and a hard roller 320 made of metal and having a radius R2, and the hard roller 320 is disposed by biting the soft roller 310 by a predetermined amount (a). . In the decurler 300, the soft roller 310 and the hard roller 320 are driven to rotate at variable rotational speeds by independent drive devices.

  That is, the hard roller 320 is rotationally driven by the driving device 330. The drive device 330 of the drive device 330 includes a drive gear 331 that is rotationally driven by a zero drive force from a motor having a variable rotation speed (not shown), a driven gear 332 that meshes with the drive gear 331, and a coaxial with the driven gear 332. The drive-side toothed pulley 333 disposed on the rotation side, the driven-side toothed pulley 334 disposed on the rotation shaft 321 of the hard roller 320, the drive-side toothed pulley 333, and the driven-side toothed pulley 334. And a toothed belt 335. In addition, a driving device similar to the driving device 330 is disposed on the rotation shaft 311 of the soft roller 310.

  In this example, the rotational speeds of the motors of the driving devices for both rollers 210 and 220 are adjusted so that the peripheral speed of the hard roller 320 is larger than the peripheral speed of the soft roller 310, specifically, the rotation of the soft roller 210. The ratio of the speed and the rotational speed of the hard roller 220 is rotationally driven to satisfy θ ′ / θ (Expression 1) using θ ′ and θ determined by the above Expression 2.

  Therefore, according to this example, in order to make the peripheral speed of the hard roller 320 larger than the peripheral speed of the soft roller 310, specifically, the ratio of the rotational speed of the soft roller 210 and the rotational speed of the hard roller 220 is expressed by the above formula. Since θ ′ and θ determined by 1 are used to rotate to θ ′ / θ, the surface speeds at the nip portions of the rollers 310 and 320 at the nip portion are substantially equal, that is, the material to be conveyed Since the peripheral speeds of both rollers 310 and 320 on the front and back sides can be made equal, the transportability of the transported material can be improved, the image of the transported material can be prevented from rubbing, the surface of the transported material can be prevented from being damaged, etc. Therefore, it is possible to prevent problems caused by rubbing and reduce slippage between rotating bodies.

  Further, in this example, since the peripheral speeds of both rollers 310 and 320 at the nip portion can be made substantially equal, the amount of biting in both rollers 310 and 320 and the degree of freedom in selecting the outer diameter of the hard roller 320 can be increased. . That is, the biting amount of the hard roller 320 can be increased, the diameter of the hard roller 320 can be reduced, and the effect of changing the degree of flatness of the conveyed material can be improved.

  Further, the size of the apparatus can be reduced without increasing the amount of biting of the hard roller 320 or reducing the diameter of the hard roller 320 and reducing the flatness even if the diameter of the hard roller 320 is reduced. Space saving can be achieved.

  Next, the decurler 400 according to the second embodiment will be described. FIG. 4 is a side view schematically showing a decurler according to the second embodiment. The decurler 400 according to the present example is configured such that a predetermined amount of the hard roller 420 is bitten into the soft roller 410 to form the nip portion 430. In this example, the driving device of the soft roller 410 and the hard roller 420 and the rotation speed of each of the rollers 410 and 420 are the same as the decurler shown in the first example.

  In this example, a hard roller moving device 440 that moves the rotation shaft 421 of the hard roller 420 and changes the amount of biting of the hard roller 420 into the soft roller 410 is disposed. According to this example, the amount of biting of the hard roller can be set according to the curl amount of the recording paper P that is the conveyed material, and the curl correction ability can be improved. Further, the curl correction capability can be improved by automatically measuring the curl amount of the recording paper P and manually or automatically feeding back the amount of biting into the soft roller 410 of the hard roller 420.

)
Next, a decurler 500 according to a third embodiment will be described. FIG. 5 is a plan view schematically showing a decurler according to a third embodiment. The decurler 500 according to the present example includes a soft roller 510 and a hard roller 520, and is arranged on the bases 551 and 552 so that a predetermined amount of the hard roller 520 is bitten into the soft roller 510 to form the nip portion 430. .

  In this example, the hard roller 520 is rotationally driven by a driven gear 541 that is driven by a drive gear (not shown). A gear 542 is coaxially disposed on the hard roller 520, and meshes with a 543 coaxially disposed on the soft roller 510. The number of teeth of both the gears 542 and 543 is set so as to satisfy the rotation condition of the both rollers. According to this example, both rollers 510 and 520 can be rotated with a single drive device, and curl correction performance can be achieved while reducing costs and saving space with a simple configuration. Can do.

  Next, a decurler 600 according to a fourth embodiment will be described. FIG. 6 shows a schematic configuration of a decurler according to a fourth embodiment, wherein (a) is a side view and (b) is a perspective view. The decurler 600 according to this example includes a soft roller 610 and a hard roller 620, and the hard roller 620 is bitten into the soft roller 610 to form a nip portion 630. In this example, a driven gear 642 that meshes with a drive gear 641 that is driven by a motor that is a drive source (not shown) is coaxially disposed on the soft roller 610 and is driven to rotate. A winding type rotation transmission mechanism is disposed between the soft roller 610 and the hard roller 620. That is, a driving toothed pulley 643 is coaxially disposed on the soft roller 610, and a driven toothed pulley 644 is coaxially disposed on the hard roller 620. The driving toothed pulley 643 and the driven toothed pulley A toothed belt 655 is wound around 644. Here, the diameters of the driving toothed pulley 643 and the driven toothed pulley 644 are set so that the rotation ratio between the soft roller 510 and the hard roller 520 is (θ ′ / θ).

  In the decurler 600 according to this example, the driven gear 642 and the driving toothed pulley 643 are arranged on the soft roller 610, so that the driving gear 641, the driven gear 642, and the driving toothed pulley 643 are driven. By changing the number of teeth of the toothed pulley 644, the gear ratio can be finely changed, and the rotation speed ratio between the soft roller 610 and the hard roller 620 can be adjusted with high accuracy. In addition, the number of components can be relatively small, and cost and space can be saved.

  In the above description, the decurler has been described with respect to the arrangement example downstream of the fixing device in the image forming apparatus. However, the transported material transport apparatus according to the present invention can be used in other places. FIG. 7 is a cross-sectional view showing a schematic configuration of the image forming apparatus. The image forming apparatus according to this example is a facsimile apparatus 700 that uses thermal roll paper 710. The facsimile apparatus 700 includes a print head 720 that heat-prints the thermal roll paper 710, a printing unit 740 that includes a platen roller 730 that presses the thermal roll paper 710 against the print head 720, a CCD line sensor 750 that reads an original, and a CCD line sensor 750. A reading unit 790 including a pressing roller 760 for pressing the document, a pickup roller 770 for feeding the document, and a pickup plate 780 is provided. The facsimile apparatus 700 includes a decurler 800 downstream of the printing unit 740. The decurler 800 includes a soft roller 810 and a hard roller 820, and corrects the curled thermal paper. As the decurler 800, any of the decurlers shown in the first to fourth embodiments can be used. According to this example, it is possible to effectively suppress the rounding of the discharged paper due to the roll of the heat-sensitive roll paper.

  In addition, the present invention can be applied to an image forming apparatus that uses large-size roll paper as a means for correcting curl of roll paper. FIG. 9 is a cross-sectional view showing a schematic configuration of an image forming apparatus using large roll paper. The image forming apparatus 900 according to this example performs image formation by pulling out three types of large roll papers 911, 912, and 913. In this example, the decurler 940 corrects the curl of the roll paper that is transported from the transport roller 920 and cut by the cutter 930. The decurler 940 includes a soft roller 950 and a hard roller 960 disposed so as to bite into the soft roller 950, and any of the decurlers shown as the first to fourth embodiments can be used.

  The roll paper with the curl corrected is discharged from the conveying roller 970 through the image forming unit 980 and the fixing device 990.

  In addition, in the ink jet recording apparatus, when at least the front end (front end side in the transport direction) of the recorded recording paper is curled so as to protrude upward from the central portion, the ink jet is detected when the front end of the recording paper passes through the spur roller. May hit the head. When the recording paper hits the ink jet head in this way, unnecessary ink adheres to the leading end of the recording paper and the recording paper becomes dirty. In order to prevent such a situation, a curler for curling the sheet in a predetermined direction is provided on the upstream side of the recording unit.

  FIG. 9 is a cross-sectional view showing a schematic configuration of the ink jet recording apparatus. The ink jet recording apparatus 1000 according to the present application performs printing by transporting the recording paper P by the transport mechanism 1010 and ejecting ink of each color onto the recording paper P by the ink jet head 1030 of the six color ink jet head unit 1020. In this example, a curler 1020 for curling paper is provided on the upstream side of the inkjet head unit 1020. The curler 1040 includes a soft roller 1050 and a hard roller 1060, and any of the decurlers shown as the first to fourth embodiments can be used.

  According to the ink jet recording apparatus 1000 according to this example, the curler 1020 can reliably change the flatness of the recording paper P, and can set optimum conditions for changing the flatness of the recording paper. It can be made excellent in the ability to change the flatness of the conveyed material while saving space.

1 is a cross-sectional view conceptually showing an image forming apparatus according to an embodiment. It is a schematic diagram which shows the structure of a decurler. It is a perspective view which shows the decurler which concerns on an Example. It is a side view which shows typically the decurler concerning a 2nd Example. It is a top view which shows typically the decurler concerning a 3rd Example. The schematic structure of the decurler based on a 4th Example is shown, (a) is a side view, (b) is a perspective view. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus that uses large roll paper. It is sectional drawing which shows schematic structure of an inkjet recording device. It is a front view which shows the structure of the conventional decurler.

Explanation of symbols

2 Expression 12 Image forming unit 111 Image reading unit 112 Image forming unit 113 Automatic document feeder 114 Document discharge trays 115 to 118 Paper feed cassette 119 Paper feed unit 120 Paper discharge tray 121 Document stand 122 Pickup roller 123 Document transport belt 124 Contact glass 125 Reading device 126 Light source 127 Optical system 128 Photoelectric conversion device 130 Photoconductor 131 Charging device 132 Writing device 133 Developing device 134 Transfer device 135 Cleaning device 136 Fixing device 137 Discharge roller pair 200 Decaler (conveyed material conveying device)
210 Soft roller (low hardness rotating body)
220 Hard roller (high hardness rotating body)
230 Nip part 300 decurler (conveying material conveying device)
310 Soft Roller (Low hardness rotating body)
311 Rotating shaft 320 Hard roller (High hardness rotating body)
321 Rotating shaft 330 Drive device 331 Drive gear 332 Driven gear 333 Drive side toothed pulley 334 Driven side toothed pulley 335 Toothed belt 400 Decaler (conveyed material transport device)
410 Soft roller (low hardness rotating body)
420 Hard roller (Rotating body with high hardness)
421 Rotating shaft 430 Nip part 440 Hard roller moving device 500 Decaler (conveyed material conveying device)
510 Soft Roller (Low hardness rotating body)
520 Hard roller (high hardness rotating body)
541 Driven gear 542 Gear 543 Gears 551 and 552 Pedestal 600 decurler (conveyed material conveying device)
610 Soft Roller (Low hardness rotating body)
620 Hard roller (high hardness rotating body)
630 Nip part 641 Drive gear 642 Driven gear 643 Driven toothed pulley 644 Driven toothed pulley 655 Toothed belt 700 Facsimile device 710 Thermal roll paper 720 Print head 730 Platen roller 740 Print part 750 CCD line sensor 760 Pressing roller 770 Pickup Roller 780 Pickup plate 790 Reading unit 800 Decaler (conveyed material conveying device)
810 Soft Roller (Low hardness rotating body)
820 Hard roller (Rotating body with high hardness)
900 Image Forming Apparatus 911 Large Roll Paper 920 Conveying Roller 930 Cutter 940 Decaler (Conveyed Material Conveying Device)
950 soft roller (low hardness rotating body)
960 Hard roller (high hardness rotating body)
970 Conveying roller 980 Image forming unit 990 Fixing device 1000 Inkjet recording device 1010 Conveying mechanism 1020 Inkjet head unit 1030 Inkjet head 1040 Curler (conveyed material conveying device)
1050 Soft roller (low hardness rotating body)
1060 Hard roller (Rotating body with high hardness)

Claims (14)

Two rotators with different hardnesses are brought into contact in parallel in the axial direction, and a high hardness rotator bites into a low hardness rotator and is conveyed with a material to be conveyed sandwiched in a concave nip, A transported material transport device that changes the degree of flatness of the transported material during transport,
Both rotating bodies are provided with driving means for rotating and driving both rotating bodies,
Each drive means drives each rotating body so that the surface speed of the rotating body with high hardness is larger than the surface speed of the rotating body with low hardness.   The transported material transport apparatus according to claim 1, wherein at least one of the rotating bodies is a roller member.   The transported material transport apparatus according to claim 1, wherein at least one of the rotating bodies includes an endless belt member.   4. The transported material transport apparatus according to claim 1, wherein curling of the transported material is corrected.   4. The transported material transport apparatus according to claim 1, wherein the transported material that is not curled is curled.   6. The transported material transport apparatus according to claim 1, wherein an outer diameter of the high-hardness rotating body is smaller than an outer diameter of the low-hardness rotating body. The outer diameter D2 (2 * R2, R2: radius) of the rotating body with high hardness, the outer diameter D1 (2 * R1, R1: radius) of the rotating body with low hardness, and the rotating body with the low hardness. When the amount of biting (a) is pressed against the rotating body, the ratio of the rotational speed of the low-hardness rotating body to the rotational speed of the high-hardness rotating body is determined using θ and θ ′ defined by the following equations: , Θ ′ / θ, The transported material transport device according to claim 1.
  The biting amount changing means for changing the biting amount (a) of the high hardness rotating body into the low hardness rotating body, and the rotation of the low hardness rotating body in accordance with the set biting amount. The transported material transport apparatus according to claim 7, further comprising a rotational speed ratio changing unit that changes a ratio (θ ′ / θ) of a rotational speed of the rotating body having high hardness to a speed.   The high hardness rotating body and the low hardness rotating body are set by the outer diameter D2 of the high hardness rotating body, the outer diameter D1 of the low hardness rotating body, and the biting amount (a). The transported material transport device according to claim 7, wherein the transported material transport device is coupled by a rotational coupling means that rotates in conjunction with the ratio (θ ′ / θ) of the rotational speeds.   The transported material transport apparatus according to claim 9, wherein the rotation connecting unit is configured by a gear mechanism or a winding mechanism disposed in each rotating body.   8. The transported material transport apparatus according to claim 7, wherein the high-hardness rotating body and the low-hardness rotating body are rotationally variable and are driven to rotate by individually arranged driving means.   The transported material transport apparatus according to claim 1, wherein the transported material is roll paper.   12. An electrophotographic image forming apparatus, wherein the transported material transport device according to claim 1 is provided on a downstream side of a heat fixing device. An image forming apparatus comprising the transported material transport device according to claim 12.