Patent Application
20240168427
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-186483 filed Nov. 22, 2022.
The present disclosure relates to a transport device and an image forming apparatus.
Japanese Unexamined Patent Application Publication No. 2014-151520 describes a sheet drying device that dries a sheet while transporting the sheet along a transport path. The sheet drying device includes a leading end gripping member attached to an endless chain, traveling along the transport path by rotating the chain, and holding a leading end of the sheet, a suction plate disposed along the transport path at a fixed distance from the chain to suck the back surface of the sheet, a leading end guide inclined toward the suction plate from the leading end of the sheet to come into contact with the back surface of the sheet until being sucked by the suction plate, and a drying member that dries the sheet transported along the transport path from the top surface of the sheet. Japanese Unexamined Patent Application Publication No. 2014-151520 also describes an inkjet recording device. The inkjet recording device includes an image recording portion including an inkjet head that ejects a water-based ultraviolet curable ink on the sheet, the sheet drying device that dries the sheet on which an image is recorded by the image recording portion while transporting the sheet along a predetermined transport path, an UV irradiation processing portion that performs a fixing operation on the sheet dried by the sheet drying device, and a sheet discharging portion that discharges the sheet that has undergone the fixing operation performed by the UV irradiation processing portion.
Japanese Unexamined Patent Application Publication No. 2009-292631 describes a sheet transport device that includes a first roller formed from an elastic member, a second roller formed from a solid member to form a nip between itself and the first roller, a tension roller disposed upstream from the second roller in a sheet transport direction, an endless belt disposed between the second roller and the tension roller under a predetermined tension, having multiple holes, and forming the nip together with the second roller, and a suction member that sucks air on the sheet transport side through the holes in the endless belt. The sheet transport device transports the sheet to the nip portion while causing the suction member to attract the sheet to the endless belt to curl the transported sheet while the sheet is passing through the nip portion. Japanese Unexamined Patent Application Publication No. 2009-292631 also describes an image forming apparatus that includes the sheet transport device.
Japanese Unexamined Patent Application Publication No. 2000-247493 describes an image forming apparatus that transports a recording medium and forms an image on the recording medium. The image forming apparatus includes a transportation force providing member that provides a transport force to the recording medium to transport the recording medium, a guide member that guides a leading end portion of the recording medium to which the transport force is provided by the transportation force providing member, and a moving member that moves the guide member at substantially the same speed as the speed at which the recording medium to which the transport force is provided is transported.
Aspects of non-limiting embodiments of the present disclosure relate to a structure including a circulating holding member that holds the leading end portion of a recording medium while being spaced apart from each other in a width direction to reduce deflection of the recording medium held by the holding member in the width direction compared to the case where the holding member holds the leading end portion of the recording medium in a flat position.
Aspects of certain non-limiting embodiments of the present disclosure overcome the above disadvantages and/or other disadvantages not described above. However, aspects of the non-limiting embodiments are not required to overcome the disadvantages described above, and aspects of the non-limiting embodiments of the present disclosure may not overcome any of the disadvantages described above.
According to an aspect of the present disclosure, there is provided a transport device including multiple rotation members that rotate, a cycle member that has a loop shape, and that is wound around the multiple rotation members to cycle together with rotation of the rotation members, at least one holding member that is attached to the cycle member, that cycles together with the cycle member, and that holds a leading end portion of a recording medium while being spaced apart from each other in a width direction when the leading end portion arrives at a holding position, and a deformation member that deforms the leading end portion in a thickness direction throughout the width direction by time when the leading end portion arrives at the holding position.
Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein:
Examples of a transport device and an image forming apparatus according to an exemplary embodiment of the present disclosure are described.
Throughout the drawings, an arrow UP denotes the upper side of the apparatus in the vertical direction. Throughout the drawings, an arrow RH points the right side of the apparatus in the horizontal direction when the apparatus is viewed from the front. As illustrated in
The vertical direction specified in the following description without any particular note refers to the upward and downward directions of the apparatus in
Components denoted with the same reference signs throughout the drawings indicate the same or equivalent components. Redundant description or reference signs may be eliminated in the exemplary embodiments described below. All the drawings described below are schematic, and the dimensional relationships between the components or the ratios of the components illustrated in the drawings may differ from the actual ones. The dimensional relationships between the components or the ratios of the components between the drawings may differ from each other.
An image forming apparatus according to an exemplary embodiment of the present disclosure is described with reference to
First, a structure of an image forming apparatus 10 is described.
As illustrated in
As illustrated in
The image forming portion 11 has a function of forming an image on a sheet P of a recording medium at an image forming position in a cycle path D of the chains 49, described below. More specifically, the image forming portion 11 has a function of forming an image on the sheet P by forming an image on a top surface (outer circumferential surface) of a transfer belt 22, described below, and transferring the formed image on the sheet P at a second transfer position T serving as the image forming position. This image forming portion 11 has, for example, four image forming units 12. The four image forming units 12 form, for example, toner images of different colors such as yellow (Y), magenta (M), cyan (C), and black (K).
Each image forming unit 12 includes a photoconductor drum 20. The photoconductor drum 20 is an example of an image carrier, and rotates while carrying the toner image to be transferred to the recording medium on its outer circumferential surface. Each image forming unit 12 has functions of forming a toner image on the photoconductor drum 20 of the corresponding color, and transferring the toner image to the transfer belt 22 at a first transfer position between the photoconductor drum 20 and a first transfer roller 26.
Each image forming unit 12 includes a charging device 23 that electrically charges the photoconductor drum 20, an exposure device 24 that forms a latent image on the electrically charged photoconductor drum 20, and a development device 25 that develops a latent image with toner.
The transfer portion 30 has a function of transferring the image (toner image) formed on the top surface of the transfer belt 22 to the sheet P. More specifically, the transfer portion 30 includes the transfer belt 22 serving as an example of a transfer body, the first transfer rollers 26, multiple rollers 32, a second transfer roller 33, the transfer drum 36 serving as an example of a drum, and a cleaner 15.
The transfer belt 22 is endless, and is wound and stretched around the multiple rollers 32 and the second transfer roller 33 to be in an inverted triangular position in a front view (when viewed from the front in the apparatus depth direction). The transfer belt 22 cycles in the direction of arrow X when at least one of the multiple rollers 32 actuates rotation. The image forming units 12 and the cleaner 15 for each color are disposed at the outer periphery of the transfer belt 22.
The multiple first transfer rollers 26 are disposed on the inner side of the transfer belt 22. Each first transfer roller corresponds to the corresponding color of the image. Specifically, in the present exemplary embodiment, the four first transfer rollers 26 correspond to the respective colors. Each first transfer roller 26 is disposed opposite to the photoconductor drum 20 of the corresponding color with the transfer belt 22 interposed therebetween.
The second transfer roller 33 is disposed on the inner side of the transfer belt 22.
The transfer drum 36 is disposed opposite to the second transfer roller 33 with the transfer belt 22 interposed therebetween. As illustrated in
As illustrated in
The chains 49 are wound around the sprockets 35 on the transfer drum 36. Thus, the transfer drum 36 is driven to rotate with the cycle of the chains 49.
The roller portion 36B of the transfer drum 36 has recesses (not illustrated) to accommodate the grippers 42. The recesses each have a shape of a gutter extending from one end to the other end of the roller portion 36B in the axial direction (the same as the apparatus depth direction).
The transfer drum 36 forms a nip area between itself and the second transfer roller 33 that pushes the transfer belt 22 against the transfer drum 36. In other words, the nip area is formed between the transfer drum 36 and the transfer belt 22. The transfer drum 36 that is driven to rotate with the cycle of the chains 49 carries the transfer belt 22 at the nip area. While holding the sheet P transported by the chains 49 and the grippers 42 at the nip area between its outer circumferential portion and the transfer belt 22, and carrying the transfer belt 22, the transfer drum 36 transfers the toner image formed on the transfer belt 22 to the sheet P. The nip area formed between the transfer drum 36 and the transfer belt 22 serves as the second transfer position T serving as an example of the image forming position. Specifically, the image forming apparatus 10 according to the present exemplary embodiment transfers the toner image formed on the top surface of the transfer belt 22 by the image forming portion 11 at the second transfer position T to the top surface of the sheet P wound around the transfer drum 36.
The cleaner 15 is disposed downstream from the second transfer position T in the cycle direction of the transfer belt 22. The cleaner 15 includes a blade that is in contact with the outer circumferential surface of the transfer belt 22. This cleaner 15 removes, with the blade, toner and other residue (for example, paper dust when the sheet P is a paper sheet) that is left at a portion of the transfer belt 22 beyond the second transfer position T (nip area) in accordance with the cycle of the transfer belt 22.
As illustrated in
The sheet transport path A diverges at a position downstream from a receiving position D2, described below, toward a direction-change path B to change the sheet transport direction. The direction-change path B merges with the sheet transport path A at a position further downstream in the transport direction. A path in the sheet transport path A between the direction-change path B and the cycle path D is a merging path where the transport path for the top surface of the sheet P and the transport path for the back surface merge with each other. The cycle path D is described below. These transport paths include multiple sheet transport rollers not illustrated. These rollers transport the sheet P along the transport paths.
The image forming apparatus 10 includes a fixing portion 40 downstream from the second transfer position T in the transport direction of the sheet P. This fixing portion 40 has a function of fixing the toner image transferred to the sheet P by the transfer portion 30 to the sheet P. More specifically, the fixing portion 40 includes a heating roller 43 serving as a heater that heats the transported sheet P while coming into contact with the sheet P, and a transport drum 31 serving as a pressing portion that presses the sheet P against the heating roller 43 while holding the sheet P between itself and the heating roller 43. The transport drum 31 and the heating roller 43 oppose each other with the sheet transport path A interposed therebetween. Specifically, the sheet P subjected to a fixing operation is transported to pass between the transport drum 31 and the heating roller 43.
The transport drum 31 has a function of pressing the sheet P while holding the sheet P between itself and the heating roller 43. More specifically, the transport drum 31 includes a shaft portion (not illustrated) extending in the apparatus depth direction, a roller portion (not illustrated) serving as a cylindrical portion disposed at an intermediate portion of the shaft portion in the axial direction, and recesses (not illustrated) formed in the outer surface of the roller portion. Sprockets, not illustrated, around which the chains 49 are wound are attached to both ends of the shaft portion of the transport drum 31 in the axial direction. In other words, the roller portion of the transport drum 31 is disposed between the pair of sprockets.
The chains 49 are wound around the sprockets of the transport drum 31. Thus, the transport drum 31 is driven to rotate in accordance with the cycle of the chains 49.
The roller portion of the transport drum 31 has recesses (not illustrated) that accommodate the grippers 42. The recesses each have a shape of the gutter extending from one end to the other end of the roller portion of the transport drum 31 in the axial direction (the same as the apparatus depth direction).
The heating roller 43 has a function of heating the sheet P. More specifically, the transport drum 31 includes a shaft portion, not illustrated, extending in the apparatus depth direction, and a roller portion, not illustrated, serving as a cylindrical portion disposed at an intermediate portion of the shaft portion in the axial direction.
The heating roller 43 forms a nip area to hold the sheet P between itself and the transport drum 31 by bringing the outer circumferential surface of its roller portion into contact with the outer circumferential surface of the roller portion of the transport drum 31. The nip area formed between the transport drum 31 and the heating roller 43 serves as a receiving position D2 serving as an example of an image receiving position.
Subsequently, a basic operation of the image forming apparatus 10 to form an image on the sheet P is schematically described.
Various operations of the image forming apparatus 10 are performed by the controller 16 included in the apparatus. When receiving an image forming instruction from the outside, the controller 16 operates the image forming portion 11. The controller 16 transmits image data subjected to image processing by an image signal processing portion (not illustrated) to the image forming portion 11. The image forming portion 11 first-transfers the toner image to the top surface of the transfer belt 22. Then, the image forming portion 11 second-transfers the toner image to the sheet P from the transfer belt 22 at the second transfer position T to form an image on the sheet P.
During double-sided printing, the transport direction of the sheet P that has passed the receiving position D2 described below is changed in the direction-change path B included in the transport path. The sheet P is then transported along the transport path C including multiple rollers (not illustrated), and then transported again to the sheet transport path A.
The chains 49 are wound around the sprockets of the transport drum 31, the sprockets 35 on the transfer drum 36, and the sprockets 37 in the feed drum 60. The chains 49 are under a preset tension when being wound around these sprockets. As illustrated in
The chains 49 have a function of transporting the sheet P held by the grippers 42 attached to the chains 49 in the cycle direction of the chains 49 (in the direction indicated with arrow D in the drawing) with the grippers 42. More specifically, the chains 49 have a loop shape, and wound and stretched around the sprockets of the transport drum 31, the sprockets 35, and the sprockets 37. More specifically, one of the chains 49 is wound around the sprocket of the transport drum 31, the sprocket 35, and the sprocket 37 disposed at the near side in the depth direction, and the other one of the chains 49 is wound around the sprocket of the transport drum 31, the sprocket 35, and the sprocket 37 disposed at the far side in the depth direction.
In the simple description below, the chains 49 indicate a pair of chains 49 disposed at the near side and far side in the depth direction. The chains 49 cycle in accordance with the driving rotation of any of the sprockets of the transport drum 31, the sprockets 35, and the sprockets 37. Any of the sprockets of the transport drum 31, the sprockets 35, and the sprockets 37 may actuate rotation, and the sprockets that do not actuate rotation are driven to rotate in accordance with the cycle of the chains 49.
As illustrated in
As illustrated in
Each gripper 42 includes clips 44, a rectangular casing 46 covering the clip 44, and a shaft 48 extending in the depth direction.
The clips 44 are fixed to the shaft 48 to rotate together with the shaft 48. The clips 44 are arranged on the shaft 48 while being spaced apart from each other in the axial direction (the same as the apparatus depth direction) of the shaft 48 (refer to
The casing 46 has a length in the apparatus depth direction, and is held by the shaft 48. This casing 46 rotates independently from the rotation of the clips 44. The casing 46 covers the clips 44 on the upstream and downstream sides in the sheet transport direction and the back surface of the sheet. Herein, “the back surface” refers to the surface of the sheet P on which no image is formed. In such a structure, leading end portions 45 of the clips 44 and a fixed hook 47 of the casing 46 at the rear end hold the leading end portion P1 of the sheet P in the transport direction. As illustrated in
The shaft 48 is held by the pair of chains 49 at both ends in the depth direction. When these chains 49 cycle, the shaft 48 fixed to the pair of chains 49 also cycles. Thus, the grippers 42 cycle along the preset cycle path D (refer to
As illustrated in
The grippers 42 hold the leading end portion P1 of the sheet P while having the leading end portions 45 in the clips 44 and the fixed hook 47 of the casing 46 approaching each other at the point where the sheet transport path A and the cycle path D start overlapping each other. The holding position in the cycle path D where the grippers 42 hold the sheet P is a delivery position D1 where the sheet P is fed from the sheet transport path A to the grippers 42.
At an end point where the cycle path D and the sheet transport path A finish overlapping each other, the leading end portions 45 of the clips 44 and the fixed hook 47 of the casing 46 are spaced apart from each other, and the leading end portion P1 of the sheet P is released. The release position in the cycle path D where the grippers 42 release the sheet P is a receiving position D2 where the sheet P is handed over from the grippers 42 to the sheet transport path A.
In the present exemplary embodiment, the cycle speed of the grippers 42 is the same as the rotation speed of each sprocket.
The feeder portion 50 has a function of feeding the sheet P to the delivery position D1 serving as the holding position where the grippers 42 hold the sheet P. More specifically, as illustrated in
As illustrated in
As illustrated in
The surface of the sheet P facing the second transfer roller 33 when passing the second transfer position T serves as an image receiving surface, or a top surface. In other words, at the feeder portion 50 and the delivery position D1, the sheet P is transported while having the back surface or a no-image receiving surface facing upward.
The sheet P that has passed the second transfer position T is handed over from the cycle path D to the sheet transport path A. A diverging point between the cycle path D and the sheet transport path A serves as the receiving position D2. At the receiving position D2, the grippers 42 holding the leading end portion P1 of the sheet P are released, and the sheet P is handed over from the cycle path D to the sheet transport path A.
Subsequently, the structure of the relevant portion according to the present exemplary embodiment is described.
The transport device 70 according to the present exemplary embodiment is a device that transports the sheet P, and has a function of transporting the sheet P from the delivery position D1 to the receiving position D2, as described above. The transport device 70 includes the sprockets in the transport drum 31, the sprockets 35, the sprockets 37, the chains 49, the grippers 42, and the sheet deforming portion 80.
The sheet deforming portion 80 has a function of deforming the leading end portion P1 of the sheet P in the thickness direction throughout the width direction of the sheet P by the time when the leading end portion P1 arrives at the holding position where the leading end portion P1 is held by the grippers 42. Here, deforming the leading end portion P1 of the sheet P in the thickness direction refers to deforming the leading end portion P1 in the thickness direction with respect to the portion of the sheet P other than the leading end portion P1, that is, with respect to the intermediate portion and the rear end portion of the sheet P in the transport direction. Although the leading end portion P1 of the sheet P may be deformed either upward (one side of the thickness direction of the sheet P) or downward (the other side of the thickness direction of the sheet P), the leading end portion P1 of the sheet P is deformed upward in the present exemplary embodiment.
As illustrated in
As illustrated in
As illustrated in
The operations of the present exemplary embodiment are described now.
As illustrated in
In the transport device 70, the contact member 82 comes into contact with the sheet P to deform the leading end portion P1 to curve while supporting the sheet P. Thus, the transport device 70 may further reduce variation of the deformation amount of the leading end portion P1 than, for example, a structure that deforms the leading end portion P1 without being in contact with the sheet P.
In the transport device 70, the contact member 82 includes the guide portion 84 having a function of deforming the leading end portion P1 of the sheet P to curve while guiding the leading end portion P1. Thus, the transport device 70 may further save the space than, for example, a structure that separately performs deformation of the leading end portion P1 of the sheet P and guiding of the leading end portion P1 to the holding position.
In the transport device 70, the contact member 82 includes a support portion 86 that supports the sheet P fed from the feeder portion 50, and the guide portion 84 connected to the end portion of the support portion 86 in the direction in which the sheet P is transported. Thus, the transport device 70 may further reduce the number of components than, for example, a structure separately including the support portion 86 and the guide portion 84.
In the transport device 70, the leading end portion 84B of the guide portion 84 has the cutouts 88 through which the clips 44 pass. Thus, the leading end portion 84B of the guide portion may be brought closer to the holding position. Thus, the transport device 70 may further reduce deflection, in the width direction, of the sheet P held by the clips 44 of the grippers 42 than a structure where the guide portion 84 does not have the cutouts 88 at the leading end portion 84B, that is, a structure where the leading end portion 84B is spaced apart from the cycle path of the clips 44.
The image forming apparatus 10 according to the present exemplary embodiment includes the transport device 70. Thus, the image forming apparatus 10 further reduces deflection of the sheet P in the width direction than, for example, a structure where the grippers 42 hold the leading end portion P1 of the sheet P in a flat state. In this state, the sheet P arrives at the fixing portion 40, and the fixing portion 40 fixes the toner image on the sheet P. At this time, the image forming apparatus 10 reduces deflection of the sheet P in the width direction, and thus reduces creases formed in the sheet P during the fixing operation.
Although the leading end portion 84B of the guide portion 84 has the cutouts 88 in the above exemplary embodiment, the present disclosure is not limited to this structure. For example, as in a contact member 92 illustrated in
In the image forming apparatus 10 according to the above exemplary embodiment, the support portion 86 and the guide portion 84 included in the contact member 82 are integrated, but the present disclosure is not limited to this structure. For example, as in a contact member 102 illustrated in
Although the image forming apparatus 10 according to the above exemplary embodiment includes the sheet deforming portion 80 as an example of a deformation member that deforms the leading end portion P1 of the sheet P in the thickness direction, the present disclosure is not limited to this structure. Instead, the image forming apparatus 10 may include, for example, a sheet deforming portion 110 illustrated in
As described above, when multiple contact members 112 are included, one of the contact members 112 may actuate rotation. As illustrated in
Although the image forming apparatus 10 according to the above exemplary embodiment includes the sheet deforming portion 80 as an example of a deformation member that deforms the leading end portion P1 of the sheet P in the thickness direction, the present disclosure is not limited to this structure. Instead, the image forming apparatus 10 may include, for example, a sheet deforming portion 120 illustrated in
In the image forming apparatus 10 according to the above exemplary embodiment, the leading end portion P1 of the sheet P is deformed to curve by a blow of the gas from the blower 122, but the present disclosure is not limited to this structure. For example, the image forming apparatus 10 may include a suction portion to deform the leading end portion P1 of the sheet P to curve with suction from the suction portion.
The image forming apparatus 10 according to the present exemplary embodiment includes the chains as examples of cycle members, and the sprockets as examples of rotation members. However, the present disclosure is not limited to this structure. For example, the image forming apparatus 10 may include a timing belt having protrusions and recesses on the inner periphery as an example of the cycle member, or a timing pulley (a pulley having protrusions and recesses on the outer periphery) as an example of the rotation member. Instead, the image forming apparatus 10 may include a belt as an example of the cycle member, and a pulley that cycles the belt with friction as an example of the rotation member. In this structure, the belt cycles while the pulley rotates in contact with the belt instead of being engaged with the belt.
The image forming apparatus 10 according to the present exemplary embodiment includes a photoelectric image forming portion that forms an image on a recording medium with toner as the image forming portion 11, but the present disclosure is not limited to this. For example, the image forming apparatus 10 may include an inkjet image forming portion that forms an image on a recording medium with ink as the image forming portion.
The present disclosure is not limited to the above exemplary embodiments, and may be modified, changed, or improved in various manners within the scope not departing from the gist of the disclosure. For example, any two or more of the modification examples described above may be combined as appropriate.
The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.
(((1)))
A transport device, comprising:
The transport device according to (((1))), wherein the deformation member includes a contact member that deforms the leading end portion by coming into contact with the recording medium.
(((3)))
The transport device according to (((2))), wherein the contact member includes at least one guide portion that deforms the leading end portion of the recording medium while guiding the leading end portion to the holding position.
(((4)))
The transport device according to (((3))),
The transport device according to (((3))) or (((4))),
The transport device according to (((3))) or (((4))),
The transport device according to (((3))),
The transport device according to (((7))),
The transport device according to (((7))) or (((8))),
The transport device according to any one of (((7))) to (((9))),
The transport device according to (((1))),
An image forming apparatus, comprising:
The image forming apparatus according to (((12))), comprising:
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-186483 | Nov 2022 | JP | national |
