JP2008201564A - Belt rotation device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt rotation device capable of evenly and stably exhibiting suppression effect relative to wrinkle generated on a belt laid across in a tensioned state by a plurality of tension rollers over a width direction and rotation direction of the belt. <P>SOLUTION: A pair of elastic ribs 42 are arranged at both ends in a width direction of an inner peripheral surface of the conveying belt 18 laid across in a tensioned state by a drive roller 20 and driven rollers 22, 23. Further, a pair of rib guides 44 extending along the ribs are arranged between the pair of ribs 42 so as to be spaced in a belt width direction in the state that the distance is larger than a distance between the pair of ribs 42. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt rotating device and an image forming apparatus including the belt rotating device.

  In a belt rotating device that functions as a conveying device, an intermediate transfer device, or the like in an ink jet image forming apparatus or the like, the belt is stretched by a plurality of stretching rollers, so that the belt is wrinkled, and the paper on the belt or the belt There is a case where the image quality formed in itself deteriorates. For this reason, the structure aiming at suppressing the wrinkle which generate | occur | produces in the belt stretched by the several tension roller is devised (for example, refer patent document 1 thru | or patent document 3).

  The configuration described in Patent Document 1 is such that the platen is disposed (higher) on the head side than the tension roller. In this configuration, the effect of suppressing wrinkles that occur in the outer portion of the belt in the width direction is exhibited, but there is a problem that the effect of suppressing the wrinkles that occur in the central portion in the width direction of the belt is not sufficiently exhibited. is there.

  The configuration described in Patent Document 2 is provided with a roller for urging the belt outward in the width direction. In this configuration, the urging force can be applied to the belt only in a discrete manner, so that the effect of suppressing wrinkles generated in the vicinity of the roller is exhibited, but against wrinkles generated at a position away from the roller. Has a problem that a sufficient suppression effect is not exhibited.

The configuration described in Patent Document 3 is to adsorb the belt and the platen by electric force. In this configuration, since the adsorption force between the belt and the platen is unstable with respect to environmental fluctuations, there is a problem in that the effect of suppressing wrinkles generated in the belt is not stably exhibited.
JP 2004-175494 A JP-A-11-65302 JP 2002-145474 A

  The present invention has been made in consideration of the above-described facts, and the effect of suppressing wrinkles generated in a belt stretched by a plurality of stretch rollers is uniform and stable in the belt width direction and the belt rotation direction. It is an object of the present invention to provide a belt rotating device that can be applied to the above.

  The belt rotating device according to claim 1 is an endless belt, a plurality of stretching rollers that stretch and rotate the belt, and both ends of the inner peripheral surface of the belt in the width direction along the belt rotating direction. A pair of ribs that are arranged in parallel and partially or entirely made of an elastic member, and a pair of ribs that are arranged in parallel along the rib between the pair of ribs, and whose separation distance is larger than the separation distance of the pair of ribs. And a guide means.

  In the belt rotating device according to the first aspect, the endless belt is stretched and rotated by a plurality of stretching rollers. A pair of ribs are juxtaposed along the belt rotation direction on both ends in the width direction of the inner peripheral surface of the endless belt, and a pair of guide means are juxtaposed along the ribs between the pair of ribs. .

  Here, the pair of ribs is entirely or partly constituted by an elastic member, and the distance between the pair of guide means is larger than the distance between the pair of ribs. Therefore, the pair of ribs are elastically deformed in whole or in part and fit into the pair of guide means.

  Thereby, the tension | tensile_strength to the belt width direction outer side is continuously given to a belt rotation direction with respect to a belt from a pair of rib. Therefore, the effect of suppressing wrinkles generated in a belt stretched by a plurality of stretch rollers can be exhibited evenly and stably over the belt width direction and the belt rotation direction.

  A belt rotation device according to a second aspect of the present invention is the belt rotation device according to the first aspect, further comprising movement restriction means for restricting movement of the rib toward the belt outer peripheral side.

  In the belt rotating device according to the second aspect, the movement of the ribs from the guide means is prevented by restricting the movement of the ribs toward the belt outer peripheral side by the movement restricting means. Therefore, the effect of suppressing wrinkles generated in the belt stretched by a plurality of stretching rollers can be reliably exhibited.

  The belt rotating device according to claim 3 is the belt rotating device according to claim 2, wherein the movement restricting means is formed on the inner side in the belt width direction of the rib, and extends from the belt outer peripheral side to the inner peripheral side. It is a taper part which inclines from the outside in the belt width direction to the inside.

  In the belt rotating device according to claim 3, a taper portion is formed on the inner side in the belt width direction of the rib so as to incline from the outer side of the belt to the inner peripheral side. The movement of the rib to the belt outer peripheral side is restricted.

  In addition, tension is applied to the belt from the taper portion to the belt from the inner side to the outer side in the belt width direction, so that the belt is biased toward the inner peripheral side of the belt. In addition, it is possible to more effectively exert the effect of suppressing the lifting of the belt to the belt outer peripheral side.

  The belt rotation device according to claim 4 is the belt rotation device according to any one of claims 1 to 3, wherein a joint portion between the rib and the belt is formed of an elastic member. Features.

  In the belt rotating device according to the fourth aspect, the joint portion between the rib and the belt is formed by an elastic member, and the pair of ribs are fitted into the pair of guide means by elastically deforming the joint portion. Thereby, it is possible to make the contact portion of the rib with the guide means a rigid body, and therefore, wear of the rib can be suppressed.

  An image forming apparatus according to a fifth aspect includes the belt rotating device according to any one of the first to fourth aspects, wherein the belt includes a pair of guide means between the pair of ribs. A conveying belt that holds and conveys a recording medium by a string portion provided therein, and has an image forming unit that forms an image on the recording medium conveyed by the conveying belt.

  In the image forming apparatus according to the fifth aspect, the chord portion having the conveying belt receives tension toward the outside in the belt width direction from the pair of ribs fitted to the pair of rib guides. The string portion holds and conveys the recording medium, and the image forming unit forms an image on the recording medium conveyed by the string portion. Here, the chord portion that conveys the recording medium of the conveyance belt receives a tension from the rib to the outside in the belt width direction, thereby suppressing the generation of wrinkles.

  Therefore, it is possible to improve the flatness of the recording medium during image formation and the positional accuracy (clearance accuracy) between the recording medium and the image forming means, thereby improving the quality of the image formed on the recording medium by the image forming means. Can be improved.

  An image forming apparatus according to a sixth aspect includes the belt rotating device according to any one of the first to fourth aspects, wherein the pair of guide means of the belt is provided between the pair of ribs. An image forming unit that forms an image on the string portion, and a transfer unit that transfers the image formed on the belt by the image forming unit to a recording medium.

  According to another aspect of the image forming apparatus of the present invention, the chord portion having the belt receives tension toward the outside in the belt width direction from the pair of ribs fitted to the pair of rib guides. The string portion is image-formed by image forming means. Here, the string portion where the image of the belt is formed receives the tension from the rib to the outside in the belt width direction, thereby suppressing the generation of wrinkles.

  Therefore, the flatness of the belt and the positional accuracy (clearance accuracy) between the belt and the image forming unit can be improved, and thus the quality of the image formed on the belt by the image forming unit can be improved.

  As described above, according to the present invention, the effect of suppressing wrinkles generated in a belt stretched by a plurality of stretching rollers can be exerted evenly and stably over the belt width direction and the belt rotation direction. A simple belt rotating device can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the belt rotation direction (hereinafter referred to as belt rotation direction) is indicated by an arrow X in the drawing, and the direction orthogonal to the belt rotation direction (hereinafter referred to as belt width direction) is indicated by an arrow Y in the drawing.

  FIG. 1 shows an ink jet recording apparatus 12 as an image forming apparatus including a conveying device 10 according to a first embodiment of a belt rotating device of the present invention. The ink jet recording apparatus 12 is provided with a paper feed tray (not shown), and the paper P stacked in the paper feed tray is taken out one by one and a plurality of transport roller pairs constituting a predetermined transport path. (Only one is shown).

  A transport device 10 is disposed on the downstream side of the transport roller pair 16 in the transport direction. The transport device 10 includes a transport belt 18 as an endless belt, and a driving roller 20 and driven rollers 22 and 23 as stretch rollers that stretch the transport belt 18 in a triangular shape.

  The driving roller 20 and the driven roller 22 are disposed substantially horizontally, and the driven roller 23 is disposed below the upper chord portion (upper stretched portion) 18A of the conveyor belt 18. The driving roller 20 is disposed downstream of the driven roller 22 in the conveying direction, is driven by a motor (not shown), and rotates the conveying belt 18 by frictional force. The driven rollers 22 and 23 are rotated by the conveyance belt 18 rotated by the driving roller 20.

  A recording head array 30 serving as an image forming unit is disposed above the conveyor belt 18 and faces the upper chord portion 18A of the conveyor belt 18. This opposed area is an ejection area SE where ink droplets are ejected from the recording head array 30. The paper P is held by the conveyance belt 18 and reaches the discharge area SE, and ink droplets corresponding to image information are attached from the recording head array 30 in a state of facing the recording head array 30.

  In this embodiment, the recording head array 30 has a long shape in which the effective recording area is equal to or larger than the width of the paper P (the length in the direction orthogonal to the transport direction), and is yellow (Y) and magenta (M). , Four ink jet recording heads (hereinafter referred to as recording heads) 32 corresponding to the four colors of Sian (C) and Black (K) are arranged along the transport direction, and a full color image can be recorded. ing.

  Each recording head 32 is driven by a head drive circuit (not shown). The head drive circuit has a configuration in which, for example, the ejection timing of ink droplets and the ink ejection port (nozzle) to be used are determined according to image information and a drive signal is sent to the recording head 32.

  A charging roller 36 connected to a power source 38 is disposed upstream of the recording head array 30 in the transport direction. The charging roller 36 is driven by the driven roller 22 in a state where the conveyance belt 18 and the paper P are sandwiched together with the driven roller 22, and presses the paper P against the conveyance belt 18. At this time, a predetermined potential difference is generated between the grounded driven roller 22 and the charging roller 36, so that the sheet P is electrostatically attracted to the transport belt 18 by being charged.

  Further, a peeling plate 40 is disposed on the downstream side of the recording head array 30 in the transport direction, and the paper P is peeled from the transport belt 18. The peeled paper P is transported by a plurality of discharge roller pairs (not shown) on the downstream side in the transport direction of the peeling plate 40 and discharged outside the apparatus.

  Here, the configuration of the transport apparatus 10 will be described.

  As shown in FIGS. 1 to 3, the transport apparatus 10 includes a platen 24. The upper surface 24A of the platen 24 is in contact with the inner peripheral surface of the upper chord portion 18A of the transport belt 18, and is disposed to face the recording head 32 with the upper chord portion 18A interposed therebetween. Further, the upper surface 24A of the platen 24 is subjected to a process for reducing the coefficient of friction with the transport belt 18, such as an overcoat process of a fluororesin.

  A pair of ribs 42 having a rectangular cross section are disposed at both ends in the width direction of the transport belt 18 along the belt rotation direction. The rib 42 is formed in an endless shape, or is formed in an annular shape by joining one end and the other end in the longitudinal direction, and makes one round in the belt rotation direction.

  In addition, a pair of stepped portions 24B that are recessed to the opposite side of the upper chord portion 18A are formed at both ends of the platen 24 in the belt width direction, and the pair of end surfaces at both ends of the upper surface 24A in the belt width direction are guide means. The pair of rib guides 44 is disposed between the pair of ribs 42.

  Here, the conveyance belt 18 is made of a highly elastic material (for example, polyimide, elastic modulus E = 70 MPa), and the rib 42 is made of a low elastic material (for example, rubber-based material, elastic modulus E = 0.2 MPa). . Further, the rib guide 44 (platen 24) is configured by a rigid body (for example, aluminum, elastic modulus E = 70 GPa).

  The elastic modulus Eb of the conveying belt 18, the elastic modulus Er of the rib 42, and the elastic modulus Eg of the rib guide 44 must satisfy the following expressions (1) and (2).

Eb> Er (1)
Eg> Er (2)

  As shown in FIG. 3B, the separation distance (distance in the belt width direction) Lb of the pair of ribs 42 is shorter than the separation distance (distance in the belt width direction) Lg of the pair of rib guides 44. The pair of ribs 42 are elastically deformed and fit into the pair of rib guides 44 (at both ends of the upper surface 24A in the belt width direction).

  The separation distance Lb between the pair of ribs 42 is longer than the shaft length (length in the belt width direction) Lr of the roller portion of the drive roller 20 and the driven rollers 22 and 23, and the drive roller 20 and the driven roller 22, 23 is not in contact with the pair of ribs 42.

  Incidentally, as shown in FIG. 4, in the belt rotating device 1 that does not include the pair of ribs 42 and the pair of rib guides 44, the upper chord 18 </ b> A of the conveyor belt 18 receives the tension P from the driving roller 20 and the driven roller 22. As a result, wrinkles extending in the belt width direction are generated.

  Next, the operation in this embodiment will be described.

  As shown in FIG. 3A, the pair of ribs 42 formed of an elastic member (low elastic material) is elastically deformed and fitted into the pair of rib guides 44. A tension F outward in the belt width direction is continuously applied to both ends of the belt in the belt rotation direction.

  Therefore, the effect of suppressing wrinkles generated on the conveying belt 18 stretched by the driving roller 20 and the driven rollers 22 and 23 can be exhibited evenly in the belt width direction and the belt rotation direction. In addition, stability against environmental fluctuations can be improved as compared with the case where the conveying belt 18 and the platen 24 are attracted (electrostatically attracted) by electric force.

  Accordingly, the flatness of the paper P during image formation and the positional accuracy (clearance accuracy) between the paper P and the recording head 32 can be improved, and thus the quality of the image formed on the paper P by the recording head 32 can be improved. Can be improved.

  Further, since the pair of ribs 42 abut against the pair of rib guides 44, the movement of the conveying belt 18 in the width direction (so-called walk) is suppressed, so that the quality of the image formed on the paper P by the recording head 32 is improved. It can be further improved.

  Further, since the driving roller 20 and the driven rollers 22 and 23 are not in contact with the pair of ribs 42, various problems caused by the contact between the driving roller 20 and the driven rollers 22 and 23 and the rib 42, for example, The ribs 42 are elastically deformed by the drive roller 20 and the driven rollers 22 and 23, and the ribs 42 are not in contact with the rib guides 44, so that it is possible to prevent problems such as the effect of suppressing wrinkles from being exhibited.

  For example, Lb = 300 mm, Lg = 302 mm, Er = 0.2 MPa, Eb = 70 MPa, Eg = 70 GPa, the contact width A = 2 mm × 300 mm = 600 between the rib 42 and the rib guide 44, and the width 42 of the rib 42 Sr = 5 mm In this case, the shrinkage amount λ (mm) of the rib 42 and the tension F (N) due to the compressive stress generated when the rib 42 is shrunk are as follows.

λ = (Lg−Lb) / 2 = (302−300) / 2 = 1 (mm)
F = (ErλA) / Sr = ErA (Lg−Lb) / 2Sr
= (0.2 × 10 ⁶ × 1 × 10 ⁻³ × 6 × 10 ⁻⁴ ) / 5 × 10 ⁻³ = 120 (N)
≒ 12.2 (kgf)

  In this setting, the tension P in the belt rotation direction at the moment when the conveyance belt 18 buckles and wrinkles is generated, and can be allowed up to about 12 kgf.

  Next, a second embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  5A and 5B show a transport apparatus 50 according to the second embodiment of the present invention. As shown in this figure, the conveyance device 50 includes a rib 52 instead of the rib 42 in the first embodiment, and includes a platen 54 instead of the platen 24 in the first embodiment.

  The rib 52 includes a main body 52A having a rectangular cross section joined to both ends in the width direction of the transport belt 18, and a thin cross section engaging in the belt width direction from the belt inner peripheral end of the main body 52A. And a piece 52B.

  In addition, a pair of end surfaces at both end portions in the belt width direction of the upper surface 54 </ b> A of the platen 54 serve as a pair of rib guides 44. The pair of ribs 52 are fitted into the pair of rib guides 44 by elastically deforming the main body 52A.

  Here, an engaging recess 54B that is recessed inward in the belt width direction is formed on the side of the rib guide 44 opposite to the upper chord 18A. The engaging recess 54B and the engaging piece 52B can be engaged with the upper chord 18A and the upper surface 54A in contact with each other. It is configured.

  Next, the operation in this embodiment will be described.

  The pair of ribs 52 elastically deforms the main body 52A and fits into the pair of rib guides 44, whereby the tension F outward in the belt width direction from the pair of ribs 52 to both ends in the width direction of the conveyance belt 18 is obtained. Is given.

  Further, the engagement recess 54B and the above-described engagement piece 52B engage with the upper chord 18A and the upper surface 54A in contact with each other, thereby restricting (blocking) the movement of the rib 52 to the belt outer peripheral side. The rib 52 is prevented from being detached from the rib guide 54.

  Therefore, the effect of suppressing wrinkles generated on the conveying belt 18 stretched by the driving roller 20 and the driven rollers 22 and 23 can be reliably exhibited.

  Next, a third embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st and 2nd embodiment, and description is abbreviate | omitted.

  6A and 6B show a transport device 60 according to a third embodiment of the present invention. As shown in this figure, the conveying device 60 includes a rib 62 instead of the rib 42 in the first embodiment, and includes a platen 64 instead of the platen 24 in the first embodiment.

  The rib 62 has a trapezoidal cross section, and includes a taper portion 62 </ b> A inclined from the outer side in the belt width direction to the inner side from the outer periphery side to the inner periphery side on the inner side in the belt width direction.

  Further, a pair of end surfaces at both ends in the belt width direction of the upper surface 64A of the platen 64 is used as a rib guide 66 as a pair of guide means. The pair of rib guides 66 are inclined from the inner side to the outer side in the belt width direction from the inner peripheral side to the outer peripheral side of the belt.

The minimum separation distance Lb _MIN of the pair of ribs 62 is shorter than the minimum separation distance Lg _{MIN of} the pair of rib guides 66, and the maximum separation distance Lb _MAX of the pair of ribs 62 is the maximum separation distance Lg of the pair of rib guides 66. _The pair of ribs 62 are fitted into the pair of rib guides 66 by being elastically deformed as a whole.

Further, as shown in FIG. 6B, in the state where the pair of ribs 62 are fitted to the pair of rib guides 66, the maximum separation distance Lg _MAX of the pair of rib guides 66 is smaller than the minimum separation distance Lb _MIN of the pair of ribs 62. Has also been shortened.

  The pair of ribs 62 and the pair of rib guides 66 can be contacted (engaged) in a state where the upper chord portion 18A and the upper surface 64A are in contact with each other, and as a result, a movement restricting portion 68 as movement restricting means. Is configured.

  Next, the operation in this embodiment will be described.

  Since the pair of ribs 62 are elastically deformed and fitted into the pair of rib guides 66, a tension F outward in the belt width direction is applied from the pair of ribs 62 to both ends in the width direction of the conveyance belt 18.

Further, as shown in FIG. 6B, in the state where the pair of ribs 62 are fitted to the pair of rib guides 66, the maximum separation distance Lg _MAX of the pair of rib guides 66 is smaller than the minimum separation distance Lb _MIN of the pair of ribs 62. The length of the rib 62 is limited (blocked) to the belt outer peripheral side, and the rib 62 is prevented from being detached from the rib guide 64.

  Also, the rib guide 66 is configured to be tapered from the belt inner circumferential side to the outer circumferential side, and is inclined from the inner side to the outer side in the belt width direction. Since the tapered portion 62A is inclined from the outer side in the belt width direction toward the inner side toward the circumferential side, a force inclined toward the inner circumferential side of the belt from the rib guide 66 toward the outer side in the belt width direction acts on the rib 62. To do. As a result, a force inclined toward the belt inner circumferential side from the rib 62 toward both ends of the upper chord portion 18A in the belt width direction acts on the outer side in the belt width direction, and the upper chord portion 18A acts on the upper surface 64A of the platen 64. Be energized. Therefore, it is possible to suppress the upper string portion 18A from floating from the platen 64.

In the present embodiment, the maximum separation distance Lg _MAX of the pair of rib guides 66 is longer than the minimum separation distance Lb _MIN of the pair of ribs 62 fitted to the pair of rib guides 66. distance between part of the part and the other rib guide 66, only to be longer than the minimum distance Lb _MIN pair of ribs 62 which fit into a pair of rib guide 66. For example, a configuration in which the pair of rib guides 66 are parallel to the belt thickness direction, and the distance between the pair of rib guides 66 is shorter than the minimum distance Lr _MIN between the pair of ribs 62 fitted with the pair of rib guides 66 is also possible. The same effect as the embodiment can be obtained.

  Next, a fourth embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 3rd embodiment, and description is abbreviate | omitted.

  FIG. 7 shows a transfer apparatus 70 according to the third embodiment of the present invention. As shown in this figure, the conveyance device 70 includes a pair of rib pressing rollers 72 as movement restricting means. The pair of rib pressing rollers 72 are disposed at both ends in the width direction of the outer peripheral surface of the upper chord portion 18A so as to face both ends of the rib 42 and the upper surface 24A in the belt width direction with the upper chord portion 18A interposed therebetween. It rotates following the upper chord 18A.

  Here, a circular hole is formed in the rotation center of the rib pressing roller 72, and a tension coil spring 74 extending in the belt width direction is inserted into the circular hole. The rib pressing roller 72 is rotatable around the tension coil spring 74 and is pressed against the rib 42 and both ends of the upper surface 24A in the belt width direction by both ends of the upper chord 18A in the belt width direction. Yes.

  Next, the operation in this embodiment will be described.

  The rib pressing roller 72 is pressed against the rib 42 via both ends of the upper chord 18A in the belt width direction by the tension coil spring 74, so that the rib 42 is prevented from being detached from the rib guide 44. As a result, the effect of suppressing wrinkles generated on the conveyor belt 18 can be reliably exhibited.

  Next, a fifth embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 4th embodiment, and description is abbreviate | omitted.

  8A to 8C show a transport apparatus 80 according to a fifth embodiment of the present invention. As shown in this figure, the conveying device 80 includes a rib 82 instead of the rib 42 in the first embodiment. The pair of ribs 82 are configured to have a rectangular cross section, and are bonded to both ends in the width direction of the transport belt 18 by an adhesive layer 84 as a joint.

  Here, the conveying belt 18 and the rib 82 are both made of a highly elastic material (for example, polyimide, elastic modulus E = 70 MPa), and the adhesive layer 84 is a low elastic adhesive (for example, rubber adhesive, elastic modulus E = 0.2 MPa). Further, the rib guide 44 is configured by a rigid body (for example, aluminum, elastic modulus E = 70 GPa).

  In such a case, the elastic modulus Eb of the conveying belt 18, the elastic modulus Er of the rib 82, the elastic modulus Eg of the rib guide 44, and the elastic modulus Ea of the adhesive layer 84 are expressed by the following equations (3) to (5). Need to be satisfied.

Eb> Ea (3)
Eg> Ea (4)
Er> Ea (5)

  The separation distance Lr between the pair of ribs 82 is the same as that of the first embodiment, and the pair of ribs 82 is fitted into the pair of rib guides 44 by elastically deforming the elastic layer 84.

  Next, the operation in this embodiment will be described.

  By the pair of ribs 82 elastically deforming the elastic layer 84 and fitting into the pair of rib guides 44, the tension F outward in the belt width direction from the pair of ribs 82 to both ends in the width direction of the transport belt 18. Given. Thereby, the suppression effect with respect to the wrinkle which generate | occur | produces in the conveyance belt 18 can be exhibited uniformly over a belt width direction and a belt rotation direction.

  Further, since the pair of ribs 82 is made of a highly elastic material, wear of the ribs 82 can be reduced.

  Next, a sixth embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 5th embodiment, and description is abbreviate | omitted.

  FIG. 9 shows a transport apparatus 90 according to the sixth embodiment of the present invention. As shown in this figure, the transport apparatus 90 includes a platen 92 instead of the platen 24 in the first embodiment. On the upper surface 92A of the platen 92, a pair of grooves 92B having a rectangular cross section extending along the belt rotation direction facing the ribs 42 are formed, and the inner wall surfaces of the grooves 92B in the belt width direction serve as rib guides 44. A pair of rib guides 44 are disposed between the pair of ribs 42. As in the first embodiment, the pair of ribs 42 are elastically deformed and fitted into the pair of rib guides 44, and the same operation and effect as in the first embodiment can be obtained also in the transport device 90 according to the present embodiment. Is possible.

  Next, an intermediate transfer device 100 according to a seventh embodiment of the belt rotating device of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 6th embodiment, and description is abbreviate | omitted.

  FIG. 10 shows an inkjet recording apparatus 200 as an image forming apparatus including the intermediate transfer apparatus 100 according to the present embodiment. In the ink jet recording apparatus 200, an intermediate transfer apparatus 100 is provided below the recording head array 30.

  The intermediate transfer device 100 includes an intermediate transfer belt 116 as an endless belt, drive rollers 20 and driven rollers 22 and 23 as stretch rollers for stretching the intermediate transfer belt 116, and an inner periphery of the intermediate transfer belt 116. The platen 24 is disposed on the side of the intermediate transfer belt 116 and abuts against the upper chord portion (upper stretched portion) 116A of the intermediate transfer belt 116.

  The drive roller 20 is disposed downstream of the driven roller 22 in the belt rotation direction, and is driven by a motor (not shown) to rotate the intermediate transfer belt 116 by frictional force. The driven roller 23 is disposed below the driving roller 20 and the driven roller 22, and the intermediate transfer belt 116 is supported in a triangular shape by the driving roller 20 and the driven rollers 22 and 23.

  Further, a transfer roller 122 serving as a transfer unit is pressed against a portion of the intermediate transfer belt 116 that is wound around the driven roller 23. The transfer roller 122 rotates following the intermediate transfer belt 116. The driven roller 23 and the transfer roller 122 are disposed on both sides of the conveyance path of the paper P, and the paper P is transferred to the intermediate transfer belt 116 on the upstream side of the driven roller 23 and the transfer roller 122 in the conveyance direction. A pair of conveying rollers 124 that conveys between the rollers 23 is provided.

  The platen 24 is in contact with the inner peripheral surface of the upper chord portion 116A and faces the recording head 32 with the upper chord portion 116A interposed therebetween. The upper surface 24A of the platen 24 is subjected to a process for reducing the friction coefficient with the intermediate transfer belt 116, such as a fluororesin overcoat process.

  A pair of ribs 42 having a rectangular cross section are disposed along the belt rotation direction at both ends in the width direction of the intermediate transfer belt 116. The rib 42 is formed in an annular shape by joining one end portion and the other end portion in the longitudinal direction, and makes one round in the belt rotation direction. Further, a pair of rib guides 44 (see FIGS. 2 and 3) are formed at both ends of the platen 24 in the belt width direction, and the pair of rib guides 44 are disposed between the pair of ribs 42. .

  Here, the intermediate transfer belt 18 is made of a highly elastic material (for example, polyimide, elastic modulus E = 70 MPa), and as described above, the rib 42 is made of a low elastic material. Further, the rib guide 44 (platen 24) is also made of a rigid body as described above.

  The elastic modulus Eb of the intermediate transfer belt 18, the elastic modulus Er of the rib 42, and the elastic modulus Eg of the rib guide 44 must satisfy the above expressions (1) and (2).

  Similarly to the first embodiment, the separation distance Lb between the pair of ribs 42 is shorter than the separation distance Lg between the pair of rib guides 44, and the pair of ribs 42 is elastically deformed to form the pair of rib guides 44. It is fitted (on the upper surface 24A).

  The separation distance Lb between the pair of ribs 42 is longer than the shaft length (length in the belt width direction) Lr of the roller portion of the drive roller 20 and the driven rollers 22 and 23, and the drive roller 20 and the driven roller 22, 23 is not in contact with the pair of ribs 42.

  Next, the operation in this embodiment will be described.

  The pair of ribs 42 formed by the elastic members are elastically deformed and fitted into the pair of rib guides 44, so that the pair of ribs 42 outward from the pair of ribs 42 in the width direction of the intermediate transfer belt 116. Is continuously applied in the belt rotation direction.

  Therefore, the effect of suppressing wrinkles generated in the intermediate transfer belt 116 stretched by the driving roller 20 and the driven rollers 22 and 23 can be exhibited evenly in the belt width direction and the belt rotation direction. In addition, the stability against environmental fluctuations can be improved as compared with the case where the intermediate transfer belt 116 and the platen 24 are attracted (electrostatically attracted) by electric force.

  Accordingly, the flatness of the intermediate transfer belt 116 during image formation and the positional accuracy (clearance accuracy) between the intermediate transfer belt 116 and the recording head 32 can be improved, so that the recording head 32 forms on the intermediate transfer belt 116. The quality of the image to be improved can be improved.

  Further, since the pair of ribs 42 abut against the pair of rib guides 44, the walk of the intermediate transfer belt 116 is suppressed, so that the quality of the image formed on the intermediate transfer belt 116 by the recording head 32 can be further improved.

  Next, a modified example of the rib guide 44 will be described.

  FIG. 11 shows a rib guide 45 that is a first modification of the rib guide 44. The rib guide 45 has a wave shape in a plan view (when viewed in the thickness direction of the upper chord portion 18A (see FIGS. 1 to 3) of the conveyor belt 18), and swells outward in the belt width direction. The protruding protrusion 45A is brought into contact with the rib 42 to elastically deform the rib 42. Thereby, it is possible to obtain the same effect as the first to seventh embodiments.

  12A and 12B show a rib guide 47 which is a second modification of the rib guide 44. FIG. The rib guide 47 is constituted by a large number of spherical rollers 49 arranged along the belt rotation direction, and the rib 42 is elastically deformed by contacting the rib 42 on the outer side in the belt width direction. Thereby, the same effect as the first to seventh embodiments can be obtained.

  When the rib 42 is detached from the rib guide 47, it is only necessary to prevent the rib 42 from moving to the belt outer peripheral side by the rib pressing roller 72 described above, as shown in FIG.

  As mentioned above, although the belt rotating device of the present invention has been described in detail for a specific embodiment, the present invention is not limited to such an embodiment, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, the belt rotating device of the present invention can be applied to a transport device that is disposed downstream of the transport device or the intermediate transfer device in the transport direction and transports the printed paper. The image forming apparatus of the present invention is not limited to an ink jet recording apparatus, and may be an image forming apparatus using another image forming method such as an electrophotographic image forming device.

1 is a side view illustrating an outline of an ink jet recording apparatus including a transport device according to a first embodiment of a belt rotating device of the present invention. It is a perspective view which shows the conveying apparatus which concerns on 1st Embodiment of the belt rotating apparatus of this invention. (A) which shows the conveying apparatus which concerns on 1st Embodiment of the belt rotating apparatus of this invention is sectional drawing, (B) is an exploded sectional view. It is a perspective view which shows the state which the wrinkle generate | occur | produced on the conveyance belt. (A) which shows the conveying apparatus which concerns on 2nd Embodiment of the belt rotating apparatus of this invention is an exploded sectional view, (B) is sectional drawing. (A) which shows the conveying apparatus which concerns on 3rd Embodiment of the belt rotating apparatus of this invention is an exploded sectional view, (B) is sectional drawing. It is sectional drawing which shows the conveying apparatus which concerns on 4th Embodiment of the belt rotating apparatus of this invention. (A) which shows the conveyance apparatus which concerns on 5th Embodiment of the belt rotating apparatus of this invention is sectional drawing, (B) is the exploded sectional view which expanded a part, (C) is sectional drawing which expanded a part. . It is sectional drawing which shows the conveying apparatus which concerns on 6th Embodiment of the belt rotating apparatus of this invention. It is a side view which shows the outline of an inkjet recording device provided with the intermediate transfer apparatus which concerns on 7th Embodiment of the belt rotating apparatus of this invention. It is a top view which shows the 1st modification of the rib guide with which the conveying apparatus which concerns on 1st thru | or 6th embodiment of the belt rotation apparatus of this invention is provided. (A) is a top view and (B) is a sectional view showing the 2nd modification of the rib guide with which the conveyance device concerning the 1st thru / or the 6th embodiment of the belt rotation device of the present invention is provided.

Explanation of symbols

10 Conveying device (belt rotating device)
12 Inkjet recording device (image forming device)
18 Conveyor belt (belt)
20 Drive roller (stretching roller)
22 Followed roller (Tension roller)
23 Followed roller (Tension roller)
30 Recording head array (image forming means)
42 Rib 44 Rib guide (guide means)
45 Rib guide (guide means)
49 Rib guide (guide means)
50 Conveying device (belt rotating device)
52 Rib 56 Movement Restriction Unit (Movement Restriction Unit)
60 Conveying device (belt rotating device)
62 Rib 62A Tapered part (movement restricting means)
66 Rib guide (guide means)
68 Movement restriction part (movement restriction means)
70 Conveying device (belt rotating device)
72 Rib pressing roller (movement restricting means)
80 Conveying device (belt rotating device)
82 Rib 84 Adhesive layer (joint)
90 Conveying device (belt rotating device)
100 Intermediate transfer device (belt rotating device)
116 Intermediate transfer belt (belt)
122 Transfer roller (transfer means)
200 Inkjet recording apparatus (image forming apparatus)
P paper (recording medium)

Claims (6)

An endless belt,
A plurality of stretching rollers that stretch and rotate the belt;
A pair of ribs that are arranged in parallel in the belt rotation direction at both ends in the width direction of the inner peripheral surface of the belt, and the entirety or a part of which is constituted by an elastic member;
A pair of guide means arranged in parallel along the rib between the pair of ribs and having a separation distance larger than a separation distance between the pair of ribs;
A belt rotating device comprising:   The belt rotating device according to claim 1, further comprising movement restricting means for restricting movement of the rib toward the belt outer peripheral side.   The said movement control means is a taper part formed in the belt width direction inner side of the said rib, and inclined from the belt width direction outer side to an inner side from a belt outer peripheral side to an inner peripheral side. Belt rotating device.   The belt rotating device according to any one of claims 1 to 3, wherein a joint portion between the rib and the belt is formed of an elastic member. A belt rotating device according to any one of claims 1 to 4, comprising:
The belt is a transport belt that transports the recording medium by holding a pair of the guide means between the pair of ribs while holding the recording medium.
An image forming apparatus comprising image forming means for forming an image on a recording medium transported by the transport belt. A belt rotating device according to any one of claims 1 to 4, comprising:
An image forming means for forming an image on a string portion provided with a pair of guide means of the belt between the pair of ribs;
Transfer means for transferring an image formed on the belt by the image forming means to a recording medium;
An image forming apparatus comprising:

Images