Conveying device, fixing device, and image forming apparatus

Abstract

A conveyance device, a fixing device, and an image forming apparatus. The conveyance device includes a first conveyance body; a second conveyance body movable between a contact position with the first conveyance body sandwiching a conveyed material and a spaced position; and a conveyance section that conveys the conveyed material to a sandwiching region where the conveyed material is sandwiched by the first conveyance body and the second conveyance body in a state where the second conveyance body is located at the spaced position, the second conveyance body moving from the spaced position to the contact position to sandwich the conveyed material conveyed to the sandwiching region by the conveyance section by the first conveyance body and the second conveyance body, thereby conveying the conveyed material.

Description

Technical Field

[0001] This disclosure relates to a conveying device, a fixing device, and an image forming device. Background Technology

[0002] Japanese Patent Application Publication No. 2006-259223 discloses a fixing device for fixing an image drawn on a recording medium using particles containing at least resin onto the recording medium. The fixing device includes: a fixing roller pair comprising a first fixing roller and a second fixing roller arranged in pair with the first fixing roller, at least one of which is a heating roller, and the surface layer of at least one fixing roller is replaceable; an adhesion member comprising an adhesion member for adhering the recording medium; a charging member for charging at least one of the recording medium and the adhesion member; and a fixing member for physically fixing the front end of the recording medium in the transport direction to a predetermined position on the adhesion member via a gripping part. The charging member causes the adhesion member to electrostatically attract the recording medium on which the image is drawn, and the fixing member fixes the front end of the recording medium on which the image is drawn to the predetermined position on the adhesion member. The fixing roller pair, together with the adhesion member, clamps and transports the recording medium, thereby fixing the image onto the recording medium. Summary of the Invention

[0003] In a structure in which the material to be transported is sandwiched between a first conveying body (e.g., a conveying roller or a heating roller) and a second conveying body (e.g., a conveying roller or a pressure roller) and is transported to a state of contact with each other, wrinkles may sometimes occur in the material to be transported.

[0004] The purpose of this disclosure is to suppress the formation of wrinkles on the material being transported, compared to a structure in which the material being transported is sandwiched between a first conveyor and a second conveyor and transported to a state of contact with each other.

[0005] According to a first aspect of this disclosure, a conveying device is provided, comprising: a first conveying body; a second conveying body movable between a contact position and a spaced position relative to the first conveying body, wherein the second conveying body clamps a conveyed material with the first conveying body at the contact position; and a conveying section that, when the second conveying body is located at the spaced position, conveys the conveyed material to a clamping region where the conveyed material is clamped by the first conveying body and the second conveying body, wherein the second conveying body moves from the spaced position to the contact position to clamp the conveyed material conveyed by the conveying section to the clamping region with the first conveying body, thereby conveying the conveyed material.

[0006] According to a second aspect of this disclosure, the second conveying body is disposed on the upper side relative to the first conveying body.

[0007] According to a third aspect of this disclosure, the first moving speed of the second conveyor from the spaced position to the contact position is faster than the second moving speed from the contact position to the spaced position.

[0008] According to the fourth aspect of this disclosure, at least one of the first conveying body and the second conveying body is formed of an elastic body, which elastically deforms due to the load when the second conveying body and the first conveying body clamp the conveyed material.

[0009] According to the fifth aspect of this disclosure, from the moment the front end of the conveyed material enters the clamping area until it has passed through the clamping area, the second conveying body and the first conveying body clamp the conveyed material.

[0010] According to the sixth aspect of this disclosure, while the first conveying body and the second conveying body are rotating, the second conveying body moves from the spaced-out position to the contact position and clamps the conveyed material with the first conveying body.

[0011] According to the seventh aspect of this disclosure, the circumferential speeds of the first conveying body and the second conveying body in their rotating states are the same.

[0012] According to the eighth aspect of this disclosure, a fixing device is provided, which is a fixing device serving as the conveying device, wherein the first conveying body is one of a heating member and a pressurizing member, and the second conveying body is the other of the heating member and the pressurizing member.

[0013] According to the ninth aspect of this disclosure, when the material being transported is ordinary paper, the second transport body clamps the material being transported with the first transport body under a first load; when the material being transported is coated paper, the second transport body clamps the material being transported with the first transport body under a second load greater than the first load.

[0014] According to the tenth aspect of this disclosure, when the base weight of the conveyed material is less than a predetermined reference value, the second conveying body clamps the conveyed material with the first conveying body under a first load; when the base weight of the conveyed material is greater than or equal to the reference value, the second conveying body clamps the conveyed material with the first conveying body under a second load greater than the first load.

[0015] According to the eleventh aspect of this disclosure, an image forming apparatus is provided, including an image forming section that forms an image on a recording medium and a fixing device. The fixing device includes: a first conveying body, which is one of a heating member and a pressurizing member; a second conveying body, which is the other of the heating member and the pressurizing member, movable between a contact position and a spaced position relative to the first conveying body, and clamping the recording medium with the first conveying body at the contact position; and a conveying section that, when the second conveying body is located at the spaced position, conveys the recording medium to a clamping region where the recording medium is clamped by the first conveying body and the second conveying body, and the second conveying body moves from the spaced position to the contact position to clamp the recording medium conveyed by the conveying section to the clamping region with the first conveying body, fixing the image formed on the recording medium by the image forming section to the recording medium, and the second conveying body clamping the recording medium with the first conveying body after the rear end of the recording medium is disengaged from the image forming section.

[0016] (Effect)

[0017] According to the first scheme, compared with the structure in which the material to be transported is sandwiched between the first and second conveying bodies and transported to a state of contact with each other, the generation of wrinkles on the material to be transported is suppressed.

[0018] According to the second scheme, compared with the structure in which the conveyor body located on the lower side moves to the contact position and the separation position, the generation of wrinkles on the conveyed material is suppressed.

[0019] According to the third scheme, compared with the structure where the first moving speed is slower than the second moving speed, the generation of wrinkles on the conveyed material is suppressed.

[0020] According to the fourth scheme, compared with the structure of the first and second conveying bodies, which are rigid bodies that are inelastically deformable, the impact when the second and first conveying bodies clamp the conveyed material is absorbed.

[0021] According to the fifth scheme, the conveying of the conveyed material can begin from a state in which the front end of the conveyed material is sandwiched between the second conveyor and the first conveyor.

[0022] According to the sixth embodiment, compared to a structure in which the second conveyor and the first conveyor clamp the conveyed material when at least one of the first and second conveyors is stopped, the generation of wrinkles on the conveyed material is suppressed.

[0023] According to the seventh scheme, compared with structures where the circumferential velocities of the first and second conveying bodies in a rotating state are different, the generation of wrinkles on the conveyed material is suppressed.

[0024] According to the eighth scheme, compared with the structure in which the material to be transported is sandwiched between the first and second transport bodies and transported by means of the first and second transport bodies, the generation of wrinkles on the material to be transported is suppressed.

[0025] According to the ninth embodiment, compared with the structure in which the second conveyor body clamps the conveyed material with the first conveyor body under a first load when the conveyed material is coated paper, the gloss of the conveyed material is improved.

[0026] According to the tenth embodiment, compared with the structure in which the second conveyor body clamps the conveyed material with the first conveyor body under the first load when the base weight of the conveyed material is above the reference value, the poor fixing of the conveyed material is suppressed.

[0027] According to the eleventh embodiment, compared to a structure in which the recording medium is transported between a first conveyor and a second conveyor that are in contact with each other by being sandwiched between the first and second conveyors, wrinkles are generated on the recording medium. Attached Figure Description

[0028] Figure 1 This is a schematic diagram showing the structure of the image forming apparatus according to the first embodiment.

[0029] Figure 2 This is a schematic diagram showing the structure of the fixing device according to the first embodiment.

[0030] Figure 3 It means in Figure 2 The diagram shows a schematic of the structure in which the heating roller is positioned at a distance from the pressure roller.

[0031] Figure 4 It means in Figure 3 The diagram shows a schematic representation of the structure in which the conveyor belt transports the recording medium to the clamping area.

[0032] Figure 5 It means in Figure 3 The diagram shows a schematic representation of the conveyor belt transporting the recording medium to the clamping area.

[0033] Figure 6 It means in Figure 5 The diagram shows a schematic representation of the state in which the recording medium, to be transported to the clamping area, is clamped by heating rollers and pressure rollers.

[0034] Figure 7 It means in Figure 6 The diagram shows a schematic representation of the state in which the recording medium sandwiched between the heating roller and the pressure roller is conveyed.

[0035] Figure 8 This is a schematic diagram (comparative example) showing the structure (comparative example) in which the recording medium is conveyed between the heating roller and the pressure roller when the heating roller and the pressure roller are in contact.

[0036] Figure 9 It means to utilize Figure 8 The diagram shows a schematic representation of the state in which wrinkles are formed on the recording medium being transported due to the structure shown.

[0037] Figure 10 This is a schematic diagram showing a modified example of using a heating belt instead of a heating roller.

[0038] Figure 11 This is a schematic diagram showing the structure of the image forming apparatus according to the second embodiment. Detailed Implementation

[0039] Hereinafter, an example of an embodiment of the present disclosure will be described based on the accompanying drawings.

[0040] <First Implementation>

[0041] (Image forming apparatus 10)

[0042] First, the structure of the image forming apparatus 10 of the first embodiment will be explained. Figure 1 This is a schematic diagram showing the structure of the image forming apparatus 10 according to this embodiment. In addition, arrow H in each figure indicates the vertical direction and the up-down direction of the apparatus, arrow W indicates the horizontal direction and the width direction of the apparatus, and arrow D indicates the front-back direction of the apparatus (the depth direction of the apparatus). The dimensional ratios of the various parts shown in each figure in the H, W, and D directions may sometimes differ from the actual dimensional ratios.

[0043] Figure 1 The image forming apparatus 10 shown is an example of an image forming apparatus that forms an image on a recording medium. Specifically, the image forming apparatus 10 is an inkjet-type image forming apparatus that forms an ink image on a recording medium P. The recording medium P is an example of a conveyed material, and the ink image is an example of an image.

[0044] More specifically, the image forming apparatus 10 includes an image forming unit 14 and a fixing device 60. Hereinafter, each part of the image forming apparatus 10 (the image forming unit 14 and the fixing device 60) will be described.

[0045] (Image forming unit 14)

[0046] The image forming unit 14 has the function of forming an ink image on the recording medium P. Specifically, the image forming unit 14 includes a transfer belt 31 as an intermediate transfer body, multiple rollers 32, opposing rollers 34, an adhesive layer forming device 24, a particle supply device 18, a printhead 20, a transfer roller 36, and a cleaner 28.

[0047] like Figure 1 As shown, the transfer belt 31 is seamless and is wound around a plurality of rollers 32 and opposing rollers 34 in an inverted triangular shape when viewed from the front (i.e., viewed along the depth of the device). The transfer belt 31 is driven to rotate by at least one of the plurality of rollers 32, thereby rotating in the direction of arrow A.

[0048] The adhesive layer forming device 24, the particle supply device 18, the nozzle 20, the transfer roller 36, and the cleaner 28 are arranged in this order along the rotation direction of the transfer belt 31 (hereinafter referred to as the "belt rotation direction") on the outer periphery of the transfer belt 31.

[0049] Specifically, the adhesive layer forming apparatus 24 is positioned at the end of the horizontal portion of the inverted triangular-shaped transfer belt 31, on one side (left side in the figure) in the width direction. The adhesive layer forming apparatus 24 contains an adhesive inside, and by applying the adhesive to the outer peripheral surface of the rotating transfer belt 31, an adhesive layer (not shown) is formed. For example, paste, organic solvents, etc., can be used as the adhesive.

[0050] The particle supply device 18 is positioned on the downstream side (right side in the figure) of the horizontal portion of the transfer belt 31 relative to the belt rotation direction of the adhesive layer forming device 24. The particle supply device 18 contains ink-accepting particles 16 capable of accommodating ink droplets on its inner side and supplies the ink-accepting particles 16 to the transfer belt 31 on which the adhesive layer is formed. As a result, the ink-accepting particles 16 supplied to the transfer belt 31 by the particle supply device 18 adhere to the adhesive layer using the adhesive force of the adhesive layer, forming an ink-accepting particle layer 16A on the transfer belt 31.

[0051] The printhead 20 is positioned on the downstream side (right side in the figure) of the horizontal portion of the transfer belt 31 relative to the belt rotation direction of the particle supply device 18. Multiple printheads 20 are provided to form ink images corresponding to each color. In this embodiment, printheads 20 for four colors—yellow (Y), magenta (M), cyan (C), and black (K)—are provided. Figure 1 The (Y), (M), (C), and (K) shown represent the corresponding colors of the constituent parts.

[0052] In each of the various colored printheads 20, ink droplets are ejected from the nozzle (not shown) into the ink-accepting particle layer 16A using existing methods such as thermal or piezoelectric methods, forming an ink image based on image data. The ink droplets ejected from the various colored printheads 20 are contained in the ink-accepting particle layer 16A to form an ink image.

[0053] The transfer roller 36 is arranged facing the transfer belt 31 on the lower side relative to the transfer belt 31. Specifically, the transfer roller 36 and the opposing roller 34 form a clamping area 36T that clamps the transfer belt 31.

[0054] In this embodiment, the ink image formed on the ink-accommodating particle layer 16A is transported to the clamping region 36T by the rotation of the transfer belt 31, and the recording medium P is transported to the clamping region 36T by the transport mechanism (not shown). In addition, in each figure, the transport path of the recording medium P is represented by a two-point chain line, and the transport direction of the recording medium P is represented by an arrow X.

[0055] Furthermore, the transfer roller 36 and the transfer belt 31 clamp and pressurize the recording medium P and the ink image being transported to the clamping area 36T, thereby transferring the ink image to the recording medium P.

[0056] In addition, when pressure is applied to the recording medium P and the ink image by clamping the transfer belt 31 in the clamping area 36T, the recording medium P and the ink image can also be heated by the transfer roller 36.

[0057] The cleaner 28 is positioned downstream of the clamping region 36T in the direction of rotation and upstream of the adhesive layer forming apparatus 24 in the direction of rotation. The cleaner 28 includes a scraper 28a that contacts the outer peripheral surface of the transfer belt 31. As the transfer belt 31 rotates, the cleaner 28 uses the scraper 28a to remove residual adhesive layer, ink-containing particles 16, ink, and other foreign matter (e.g., paper dust if the recording medium P is paper) from the portion of the transfer belt 31 passing through the clamping region 36T.

[0058] (Fixing device 60)

[0059] Figure 1 The fixing device 60 shown is a device for fixing an ink image transferred to a recording medium P onto the recording medium P, and is an example of a conveying device. Specifically, as Figure 2 As shown, the fixing device 60 includes a conveyor belt 65, a pressure roller 61, and a heating roller 62. The conveyor belt 65 is an example of a conveying section. The pressure roller 61 is an example of a first conveying body and an example of a pressure member. The heating roller 62 is an example of a second conveying body and an example of a heating member.

[0060] The pressure roller 61 and the heating roller 62 are arranged vertically. Specifically, the heating roller 62 is positioned above the pressure roller 61. The heating roller 62 has a heating source 62A, such as a halogen lamp, inside its interior.

[0061] In this embodiment, for example, one of the pressure roller 61 and the heating roller 62 is driven to rotate, while the other of the pressure roller 61 and the heating roller 62 rotates passively. Alternatively, the structure may be such that both the pressure roller 61 and the heating roller 62 are driven to rotate.

[0062] The heating roller 62 can be in contact with the pressure roller 61 at a position ( Figure 2 The position shown) and the separated position ( Figure 3 The heating roller 62 moves between the positions shown. Specifically, the heating roller 62 moves between the contact positions (shown) using a moving mechanism (hereinafter referred to as moving mechanism A) such as a cam. Figure 2 The position shown) and the separated position ( Figure 3 The heating roller 62 moves between the positions shown. That is, the heating roller 62 is pressed or stretched toward the contact position by the elastic force of the elastic member (e.g., a spring) of the moving mechanism A, and moves to the spaced position by the cam of the moving mechanism A against the elastic force.

[0063] like Figure 6 As shown, the heating roller 62 clamps the recording medium P with the pressure roller 61 at the contact position. Furthermore, in each figure, the symbol NP represents the clamping area where the pressure roller 61 and the heating roller 62 clamp the recording medium P. The clamping area NP is a region with width in the transport direction X. Moreover, as described later, the recording medium P transported to the clamping area NP is clamped by the pressure roller 61 and the heating roller 62 in the clamping area NP; therefore, the clamping area NP can also be described as the location where the pressure roller 61 and the heating roller 62 are intended to clamp the medium.

[0064] The conveyor belt 65 is a transport section that transports the recording medium P by contacting the non-transfer surface but not the transfer surface. Specifically, the conveyor belt 65 includes an annular belt wound around a pair of rollers 65A. The conveyor belt 65 uses suction force, for example, by negative pressure or electrostatic force, to draw the recording medium P onto the belt and transport it. Furthermore, the transfer surface of the recording medium P refers to the surface where the image is transferred, and the non-transfer surface refers to the surface opposite to the transfer surface. Moreover, guide sections (i.e., guides) (not shown) are provided between the clamping region 36T and the conveyor belt 65, and between the conveyor belt 65 and the clamping region NP, to guide the recording medium P.

[0065] In this embodiment, such as Figure 4 as well as Figure 5As shown, with the heating roller 62 in the separated position, the conveyor belt 65 conveys the recording medium P to the clamping area NP. Specifically, as... Figure 4 as well as Figure 5 As shown, the conveyor belt 65 transports the leading edge of the recording medium P along the pressure roller 61 to the clamping region NP. That is, the conveyor belt 65 transports the recording medium P to the clamping region NP via the outer periphery of the pressure roller 61. The conveyor belt 65 stops, for example, when transporting the recording medium P to the clamping region NP. Specifically, the conveyor belt 65 stops the recording medium P from the moment the leading edge of the recording medium P enters the clamping region NP until it has completely passed through the clamping region NP. In other words, the conveyor belt 65 stops the recording medium P while the leading edge of the recording medium P is in the clamping region NP. When the leading edge of the recording medium P enters the clamping region NP, for example, the heating roller 62 and the pressure roller 61 are set to a non-rotating, stopped state.

[0066] In addition, the recording medium P is transported to the clamping region NP, for example, by detecting the time starting from the detection of the front end of the recording medium P by the detection unit (specifically, the sensor) on the upstream side of the transport direction of the clamping region NP.

[0067] The heating roller 62 moves from the spaced-out position to the contact position, and as Figure 6 As shown, the pressure roller 61 clamps the recording medium P, which is conveyed to the clamping region NP by the conveyor belt 65. Specifically, the heating roller 62 clamps the recording medium P together with the pressure roller 61 from the moment the front end of the recording medium P enters the clamping region NP until it has completely passed through the clamping region NP. In other words, the heating roller 62 clamps the recording medium P together with the pressure roller 61 while the front end of the recording medium P is located in the clamping region NP. Furthermore, the pressure roller 61 and the heating roller 62... Figure 7 As shown, the recording medium P is rotated and transported while being sandwiched between the recording medium P.

[0068] In the fixing device 60, the heating roller 62 and the pressure roller 61 are used to transport the recording medium P while it is being sandwiched, and at the same time the recording medium P is being heated and pressurized, thereby fixing the ink image transferred to the recording medium P to the recording medium P.

[0069] After conveying the recording medium P, the heating roller 62 moves from the contact position ( Figure 2 Move the position shown to the next available position. Figure 3 (as shown in the image). Specifically, the heating roller 62 moves from the contact position to the separation position after the transport of the recording medium P is completed (in other words, after the image is fixed to the recording medium P) and before the front end of the recording medium P, which is then transported to the clamping region NP, enters the clamping region NP.

[0070] As described above, in this embodiment, the heating roller 62 moves from a separated position to a contact position when it clamps the recording medium P with the pressure roller 61, and moves from the contact position to a separated position when the transport of the recording medium P ends. Furthermore, the first moving speed of the heating roller 62 from the separated position to the contact position is faster than the second moving speed of the heating roller 62 from the contact position to the separated position. That is, the heating roller 62 moves from the separated position to the contact position at a first moving speed, which is faster than the second moving speed, via the moving mechanism A. In other words, the movement time of the heating roller 62 from the separated position to the contact position is shorter than the movement time from the contact position to the separated position.

[0071] Here, the moving mechanism A includes: a cam follower (not shown), a support body (not shown) or heating roller 62 provided on the support roller 62; and a cam (not shown) having a minor diameter portion and a major diameter portion whose length along the radial direction, measured from the center of rotation, is longer than the minor diameter portion. In the moving mechanism A, for example, by rotating the cam in a predetermined direction of rotation, a range (hereinafter referred to as range X) on the outer peripheral surface of the cam, extending from the minor diameter portion to the major diameter portion, contacts the cam follower, thereby moving the heating roller 62 from the contact position to the spaced position. Furthermore, in the moving mechanism A, for example, by rotating the cam in the same direction of rotation, a range (hereinafter referred to as range Y) on the outer peripheral surface of the cam, extending from the major diameter portion to the minor diameter portion, contacts the cam follower, thereby moving the heating roller 62 from the spaced position to the contact position. In this structure, for example, range X is formed on the outer peripheral surface of the cam that is longer than range Y, and the change in radial length from the short diameter portion to the long diameter portion within range X is gentler than the change in radial length from the long diameter portion to the short diameter portion within range Y. As a result, the heating roller 62 moves from the spaced-out position to the contact position at a first moving speed that is faster than the second moving speed.

[0072] Alternatively, the structure can be as follows: on the outer circumferential surface of the cam, range X and range Y are set to have the same length, and the change in radial length from the minor diameter portion to the major diameter portion within range X is set to be the same as the change in radial length from the major diameter portion to the minor diameter portion within range Y. In this structure, for example, the rotational speed of the cam when range Y contacts the cam follower is faster than the rotational speed of the cam when range X contacts the cam follower, thereby causing the heating roller 62 to move from the separated position to the contact position at a first moving speed that is faster than the second moving speed.

[0073] Furthermore, in this embodiment, when the recording medium P is ordinary paper (i.e., not coated paper), the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load; when the recording medium P is coated paper, it clamps the recording medium P with the pressure roller 61 under a second load greater than the first load. Additionally, in this embodiment, when the recording medium P is coated paper, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a second load, regardless of the basis weight of the recording medium P. Ordinary paper is paper without a coating layer.

[0074] In this embodiment, the presence or absence of a coating layer on the recording medium P is detected, for example, by input from the user of the fixing device 60 or by a detection unit such as a light sensor, thereby determining whether the recording medium P is coated paper. Furthermore, in this embodiment, based on the determination, a first load or a second load is selected as the load on the heating roller 62.

[0075] Furthermore, in this embodiment, when the recording medium P is ordinary paper, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load when the basis weight of the recording medium P is less than a predetermined reference value, and clamps the recording medium P with the pressure roller 61 under a second load when the basis weight of the recording medium P is greater than or equal to the reference value.

[0076] In this embodiment, the basis weight of the recording medium P is detected, for example, by input from the user of the fixing device 60 or by a detection unit such as an ultrasonic sensor, to determine whether the basis weight of the recording medium P is above a reference value. Furthermore, in this embodiment, based on the determination, a first load or a second load is selected as the load on the heating roller 62.

[0077] In this embodiment, the moving mechanism A adjusts the load on the heating roller 62 by changing the contact position of the short-diameter portion of the cam with the cam follower through the rotation angle of the cam. Specifically, in the moving mechanism A, the shortest-diameter position of the short-diameter portion of the cam contacts the cam follower, thereby generating a second load as the load on the heating roller 62. Furthermore, in the moving mechanism A, the cam follower contacts at a position where the radial length of the short-diameter portion of the cam is longer than the shortest-diameter position, thereby generating a first load as the load on the heating roller 62.

[0078] Furthermore, in this embodiment, the load on the heating roller 62 is not changed according to the size of the recording medium P. Therefore, when the recording medium P is coated paper, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a second load, regardless of the size of the recording medium P. Moreover, when the recording medium P is plain paper, if the basis weight of the recording medium P is greater than or equal to the aforementioned reference value, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a second load, regardless of the size of the recording medium P. Furthermore, when the recording medium P is plain paper, if the basis weight of the recording medium P is less than a predetermined reference value, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load, regardless of the size of the recording medium P.

[0079] At least one of the pressure roller 61 and the heating roller 62 is formed of an elastomer, which elastically deforms under the load when the heating roller 62 and the pressure roller 61 sandwich the recording medium P. In this embodiment, both the pressure roller 61 and the heating roller 62 are formed, for example, of a rubber roller (an example of an elastomer) having a rubber layer on the outer periphery of the roller.

[0080] (The function of this implementation method)

[0081] In the image forming apparatus 10, such as Figure 1 As shown, the adhesive layer forming apparatus 24 applies an adhesive to the outer peripheral surface of the rotating transfer belt 31, thereby forming an adhesive layer (not shown). Next, the particle supply apparatus 18 supplies ink-accepting particles 16 to the transfer belt 31, forming an ink-accepting particle layer 16A on the adhesive layer of the transfer belt 31.

[0082] Next, the printhead 20 ejects ink droplets into the ink-accepting particle layer 16A to form an ink image. The ink image formed in the ink-accepting particle layer 16A is transported to the clamping area 36T by the rotation of the transfer belt 31, and the recording medium P is transported to the clamping area 36T by the transport mechanism (not shown).

[0083] The transfer roller 36 and the transfer belt 31 clamp and pressurize the recording medium P and the ink image that are being transported to the clamping area 36T, thereby transferring the ink image to the recording medium P.

[0084] Recording medium P with transferred ink image Figure 4 as well as Figure 5 As shown, with the heating roller 62 in the spaced-out position, it is conveyed to the clamping area NP by the conveyor belt 65. In this embodiment, as... Figure 4 As shown, the recording medium P is conveyed to the clamping area NP along the pressure roller 61 after the front end just touches the pressure roller 61.

[0085] Next, as Figure 6As shown, the heating roller 62 moves from the spaced-out position to the contact position, where it, together with the pressure roller 61, clamps the recording medium P conveyed by the conveyor belt 65 to the clamping area NP. Furthermore, as... Figure 7 As shown, the pressure roller 61 and the heating roller 62 begin to rotate while the recording medium P is sandwiched between them, in order to transport the recording medium P.

[0086] The heating roller 62 and the pressure roller 61 convey the recording medium P while it is sandwiched between them, and heat and pressurize the recording medium P, thereby fixing the ink image transferred to the recording medium P onto the recording medium P.

[0087] Here, as Figure 8 As shown, in the structure (hereinafter referred to as the "first structure") in which the recording medium P is conveyed by clamping the pressure roller 61 and the heating roller 62 between them in a state of contact, the orientation of the recording medium P is restricted to the position when the front end of the recording medium P enters between the pressure roller 61 and the heating roller 62. For example, if the recording medium P enters between the pressure roller 61 and the heating roller 62 in a wrinkled state or in a state tilted relative to the conveying direction X, it will remain in this state and be clamped by the pressure roller 61 and the heating roller 62, thus... Figure 9 As shown, wrinkles can sometimes form on the recording medium P. Wrinkles are particularly prone to occur when the recording medium P is thin paper.

[0088] In contrast, in this embodiment, such as Figure 4 as well as Figure 5 As shown, with the heating roller 62 in the spaced-out position, the conveyor belt 65 conveys the recording medium P to the clamping area NP. The heating roller 62 moves from the spaced-out position to the contact position, thereby... Figure 6 As shown, the pressure roller 61 clamps the recording medium P, which is conveyed to the clamping area NP by the conveyor belt 65. Furthermore, as... Figure 7 As shown, the pressure roller 61 and the heating roller 62 transport the recording medium P while it is sandwiched between them.

[0089] In this way, the recording medium P is conveyed to the clamping region NP with the heating roller 62 in the spaced-out position, and therefore is not restricted to the posture when the front end of the recording medium P enters between the pressure roller 61 and the heating roller 62. Therefore, for example, if the recording medium P is wrinkled or tilted relative to the conveying direction X, such a state can be eliminated. Therefore, according to the structure of this embodiment, the generation of wrinkles on the recording medium P is suppressed compared to the first structure.

[0090] Furthermore, in this embodiment, the heating roller 62, which is positioned above the pressure roller 61, moves between a contact position and a spaced-out position. Here, in the structure where the pressure roller 61, positioned below, moves between a contact position and a spaced-out position (hereinafter referred to as the "second structure"), when the pressure roller 61 moves from the spaced-out position to the contact position to clamp the recording medium P, the recording medium P placed on the pressure roller 61 moves, thereby changing the posture of the recording medium P while being clamped, which may sometimes cause wrinkles to form on the recording medium P.

[0091] In contrast, in this embodiment, as described above, the heating roller 62, positioned above the pressure roller 61, moves between a contact position and a spaced-out position. Therefore, compared to the second structure, the recording medium P placed on the pressure roller 61 is less likely to move, and the orientation of the recording medium P is less likely to change while being clamped. Consequently, the generation of wrinkles on the recording medium P is suppressed compared to the second structure.

[0092] Furthermore, in this embodiment, the heating roller 62 enters the clamping region NP from the front end of the recording medium P and continues until it has completely passed through the clamping region NP, clamping the recording medium P together with the pressure roller 61. Thus, the transport of the recording medium P begins from the state where the front end of the recording medium P is clamped by the heating roller 62 and the pressure roller 61. As a result, an image can be fixed onto the recording medium P starting from the front end of the recording medium P.

[0093] Furthermore, in this embodiment, the first moving speed of the heating roller 62 from the spaced-out position to the contact position is faster than the second moving speed of the heating roller 62 from the contact position to the spaced-out position. Therefore, even if, for example, the heating roller 62 is tilted relative to the pressure roller 61, and there is a deviation in the contact timing between one end of the heating roller 62 and the other end in the axial direction contacting the recording medium P, such deviation is smaller than in a structure where the first and second moving speeds are the same. As a result, the time during which the load is biased towards one side of the recording medium P is reduced, and the formation of wrinkles on the recording medium P is suppressed.

[0094] Furthermore, in this embodiment, since the second moving speed is slower than the first moving speed, the change in radial length from the short diameter portion to the long diameter portion in the range X of the outer circumferential surface of the cam is more gradual than the change in radial length from the short diameter portion to the long diameter portion in the range Y of the outer circumferential surface of the cam. Therefore, when the heating roller 62 is moved from the contact position to the separation position, the noise caused by the contact between the cam and the cam follower is suppressed.

[0095] Furthermore, in this embodiment, both the pressure roller 61 and the heating roller 62 are formed, for example, of rubber rollers (an example of an elastomer) having a rubber layer on their outer periphery. Therefore, compared to the structure of the pressure roller 61 and the heating roller 62 being rigid bodies that do not elastically deform, the impact when the heating roller 62 and the pressure roller 61 clamp the recording medium P is absorbed.

[0096] Furthermore, in this embodiment, when the recording medium P is ordinary paper, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load; when the recording medium P is coated paper, the heating roller 62 clamps the recording medium P with the pressure roller 61 under a second load greater than the first load. Therefore, compared to the structure where the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load when the recording medium P is coated paper, the heat imparted to the recording medium P is increased, and the gloss of the recording medium P is improved.

[0097] Furthermore, in this embodiment, when the recording medium P is ordinary paper, the heating roller 62 clamps the conveyed material with the pressure roller 61 under a first load when the basis weight of the recording medium P is less than a predetermined reference value, and clamps the recording medium P with the pressure roller 61 under a second load when the basis weight of the recording medium P is greater than or equal to the reference value. Therefore, compared to the structure where the heating roller 62 clamps the recording medium P with the pressure roller 61 under a first load when the basis weight of the recording medium P is greater than or equal to the reference value, the heat imparted to the recording medium P is increased, and the fixing defects of the recording medium P are suppressed.

[0098] (Modification of the conveying device)

[0099] In this embodiment, a fixing device 60 having both a conveying function and a fixing function is used as an example of a conveying device, but it is not limited to this. As an example of a conveying device, there may also be a device with functions other than conveying and fixing (such as a transfer function), or a conveying device with only a conveying function.

[0100] (Modifications of the first transport body and the second transport body)

[0101] In this embodiment, a pressure roller 61 is used as the first conveying body, but it is not limited to this. As an example of the first conveying body, a pressure belt wound on multiple rollers may also be used.

[0102] In this embodiment, a heating roller 62 is used as an example of a second conveyor, but it is not limited to this. For example, a heating roller 62 can also be used as a second conveyor. Figure 10 The heating belt 162 is wound around the heating roller 62 and the roller 161 as shown.

[0103] Furthermore, the structure can also be as follows: as an example of the first conveying body, heating components such as heating rollers and heating belts are used; as an example of the second conveying body, pressure components such as pressure rollers and pressure belts are used.

[0104] In the case of using a device with both conveying and transfer functions as a conveying device, as an example of the first conveying body and the second conveying body, a transfer component such as a transfer roller or transfer belt, and a counter-contact component such as a counter-contact roller or counter-contact belt facing the transfer component may also be used.

[0105] In the case of using a conveying device that only has a conveying function as an example of a conveying device, as an example of a first conveying body and a second conveying body, a first conveying member such as a conveying roller or a conveying belt and a second conveying member such as a conveying roller or a conveying belt facing the conveying member may also be used.

[0106] Furthermore, in this embodiment, the pressure roller 61, which is an example of a first conveying body, and the heating roller 62, which is an example of a second conveying body, are both formed of rubber rollers (an example of an elastomer) having a rubber layer on their outer periphery, but this is not a limitation. It is also possible that only one of the pressure roller 61 and the heating roller 62 is formed of an elastomer such as a rubber roller, as long as at least one of the pressure roller 61 and the heating roller 62 is formed of an elastomer.

[0107] Furthermore, in this embodiment, one of the pressure roller 61 and the heating roller 62 is driven to rotate while the other rotates passively, but this is not a limitation. As mentioned above, it is also possible for both the pressure roller 61 and the heating roller 62 to be driven to rotate. In this structure, for example, when the heating roller 62 is in a spaced-out position, the pressure roller 61 and the heating roller 62 rotate independently, and in this rotating state, the conveyor belt 65 conveys the recording medium P to the clamping region NP. Thus, the recording medium P is given a conveying force from the pressure roller 61.

[0108] Furthermore, while both the heating roller 62 and the pressure roller 61 are rotating, the heating roller 62 moves from a separated position to a contact position to clamp the recording medium P with the pressure roller 61. Therefore, in this embodiment, the recording medium P is conveyed by the pressure roller 61 while the recording medium P is clamped by the heating roller 62 and the pressure roller 61. In addition, at this time, the conveyor belt 65 can also convey the recording medium P in addition to the pressure roller 61. The heating roller 62 and the pressure roller 61 are configured, for example, such that the driving force is transmitted to their own rotational shaft via a transmission member such as a gear, thereby being driven to rotate. Alternatively, at least one of the heating roller 62 and the pressure roller 61 may contact a drive roller different from the heating roller 62 and the pressure roller 61 to perform driven rotation, thereby allowing the heating roller 62 and the pressure roller 61 to rotate independently. At this time, the following structure may also be adopted: the heating roller 62 replaces the heating source 62A or, in addition to the heating source 62A, the heat is transferred from the drive roller that contacts the heating roller 62.

[0109] Furthermore, the circumferential speeds of the rotating pressure roller 61 and heating roller 62 are the same. However, the circumferential speeds of the pressure roller 61 and heating roller 62 do not need to be completely identical; a difference in circumferential speed between the pressure roller 61 and heating roller 62 is permissible within a range that prevents wrinkling of the recording medium P.

[0110] Here, in the structure (hereinafter referred to as the first structure) in which the heating roller 62 and the pressure roller 61 clamp the recording medium P with only one of the heating roller 62 and the pressure roller 61 rotating, a conveying force is applied to one side of the recording medium P, while a braking force is applied to the other side, thus easily causing wrinkles on the recording medium P.

[0111] In contrast, in the modified example, with both the heating roller 62 and the pressure roller 61 rotating, the heating roller 62 and the pressure roller 61 clamp the recording medium P, thus suppressing the generation of wrinkles on the recording medium P compared to the first structure.

[0112] Furthermore, in this modified example, the circumferential speeds of the rotating pressure roller 61 and heating roller 62 are the same. Therefore, the conveying force acting on one side of the recording medium P is the same as that on the other side. As a result, compared to the structure where the circumferential speeds of the rotating pressure roller 61 and heating roller 62 are different (hereinafter referred to as the second structure), the generation of wrinkles on the recording medium P is suppressed. Additionally, the second structure is one where the circumferential speeds of the rotating pressure roller 61 and heating roller 62 are different to the extent that wrinkles would be generated on the recording medium P.

[0113] (A variation of the transport department)

[0114] In this embodiment, a conveyor belt 65 is used as an example of a conveying unit, but it is not limited to this. As an example of a conveying unit, a conveying member such as a conveying drum that conveys the recording medium P without contacting the transfer surface of the recording medium P but in contact with the non-transfer surface may also be used.

[0115] Furthermore, as an example of a conveying section, it may be a conveying section with a release layer, such as a conveying roller or conveying belt, and a contact member that contacts the transfer surface within a range that does not affect the image transferred to the recording medium P.

[0116] Furthermore, as an image forming apparatus, it can also be structured so that there is no transport member for transporting the recording medium P between the clamping region 36T and the fixing device 60. In this case, the transfer belt 31 and the transfer roller 36 function as an example of a transport unit.

[0117] In cases where a device with both conveying and transfer functions or a conveying device with only conveying function is used as an example of a conveying device, and without considering the influence of the image on the recording medium P, a conveying member such as a conveying roller that contacts both sides of the recording medium P may also be used as an example of a conveying unit.

[0118] <Second Implementation>

[0119] (Image forming apparatus 200)

[0120] In the first embodiment, the image forming apparatus 10 is an inkjet image forming apparatus that forms an image on a recording medium P using ink, but it is not limited to this. For example, an electrophotographic image forming apparatus could also be used, as long as it is an image forming apparatus. In the second embodiment, an electrophotographic image forming apparatus 200 will be described. Figure 11 This is a schematic diagram showing the structure of the image forming apparatus 200 according to this embodiment. Furthermore, parts having the same function as in the first embodiment are labeled with the same symbols, and descriptions are omitted as appropriate.

[0121] (Image forming unit 214)

[0122] The image forming apparatus 200 replaces the image forming unit 14 with an image forming unit 214. The image forming unit 214 is an example of an image forming unit that forms an image on a recording medium. Specifically, the image forming unit 214 has the function of forming a toner image (an example of an image) on the recording medium P by electrophotography. More specifically, as... Figure 11 As shown, the image forming unit 214 includes: a toner image forming unit 222 for forming a toner image; and a transfer device 217 for transferring the toner image formed by the toner image forming unit 222 to the recording medium P.

[0123] (Toner image forming part 222)

[0124] Figure 11 The toner image forming unit 222 shown is provided in a plurality of configurations, each forming a toner image corresponding to a different color. In this embodiment, four toner image forming units 222 are provided for yellow (Y), magenta (M), cyan (C), and black (K). Figure 11 The (Y), (M), (C), and (K) shown represent the corresponding colors of the constituent parts.

[0125] Furthermore, the toner image forming sections 222 of each color are constructed identically, except for the toner used. Therefore, the toner image forming sections 222 representing each color are... Figure 11 The various parts of the toner image forming section 222(K) are marked with symbols.

[0126] Specifically, the toner image forming section 222 of each color has a unidirectional (e.g., Figure 11 The photosensitive element 224 rotates counterclockwise. Furthermore, the toner image forming unit 222 of each color includes a battery 223, an exposure device 240, and a developing device 238.

[0127] In the toner image forming section 222, the charge carrier 223 charges the photoreceptor 224. Then, the exposure apparatus 240 exposes the charged photoreceptor 224 to form an electrostatic latent image on the photoreceptor 224. Furthermore, the developing apparatus 238 develops the electrostatic latent image formed on the photoreceptor 224 by the exposure apparatus 240 to form a toner image.

[0128] (Transfer device 217)

[0129] Figure 11 The transfer apparatus 217 shown is a device for transferring a toner image formed by the toner image forming unit 222 to a recording medium P. Specifically, the transfer apparatus 217 transfers toner images of each color photoreceptor 224 overlappingly onto a transfer belt 213, which serves as an intermediate transfer body, in one pass, and then transfers the overlapping toner images to the recording medium P. Specifically, as... Figure 11 As shown, the transfer device 217 includes a transfer belt 213, a primary transfer roller 226, and a secondary transfer roller 236.

[0130] The primary transfer roller 226 is a roller that transfers the toner image of each color photoreceptor 224 from the photoreceptor 224 to the transfer belt 213 at the primary transfer position T1 between the photoreceptor 224 and the primary transfer roller 226. In this embodiment, by applying a primary transfer electric field between the primary transfer roller 226 and the photoreceptor 224, the toner image formed on the photoreceptor 224 is transferred to the transfer belt 213 at the primary transfer position T1.

[0131] The transfer belt 213 transfers the toner image from the photoreceptors 224 of various colors to the outer peripheral surface. For example... Figure 11 As shown, the transfer belt 213 is seamless and is wound around a plurality of rollers 232 and opposing rollers 234 in an inverted triangular shape when viewed from the front (viewed along the depth of the device). The transfer belt 213 is rotated in the direction of arrow A by at least one of the plurality of rollers 232.

[0132] The secondary transfer roller 236 is a roller that transfers the toner image transferred to the transfer belt 213 to the recording medium P at the secondary transfer position T2 between the opposing roller 234 and the secondary transfer roller 236. In this embodiment, by applying a secondary transfer electric field between the opposing roller 234 and the secondary transfer roller 236, the toner image transferred to the transfer belt 213 is transferred to the recording medium P at the secondary transfer position T2.

[0133] (Fixing device 60)

[0134] In this embodiment, the fixing device 60 functions as a device for fixing the toner image transferred to the recording medium P by the secondary transfer roller 236 to the recording medium P.

[0135] In the fixing apparatus 60, the recording medium P is heated and pressurized while being conveyed by the heating roller 62 and the pressure roller 61 while being sandwiched, thereby fixing the toner image transferred to the recording medium P onto the recording medium P. The fixing apparatus 60 is configured in the same way as in the first embodiment, except that it fixes the toner image transferred to the recording medium P onto the recording medium P.

[0136] (The function of this implementation method)

[0137] In the image forming apparatus 200, toner image forming units 222 of each color form toner images. The toner images formed by the toner image forming units 222 of each color are transferred once overlappingly to the transfer belt 213 at their respective first transfer positions T1, and the overlapping toner images are transferred a second time to the recording medium P at the second transfer position T2.

[0138] like Figure 4 as well as Figure 5 As shown, the recording medium P, with the toner image transferred onto it, is conveyed to the clamping area NP by the conveyor belt 65 while the heating roller 62 is in the separated position. In this embodiment, as... Figure 4 As shown, the recording medium P is conveyed along the pressure roller 61 to the clamping area NP after the front end just touches the pressure roller 61.

[0139] Next, as Figure 6As shown, the heating roller 62 moves from the spaced-out position to the contact position, where it, together with the pressure roller 61, clamps the recording medium P conveyed by the conveyor belt 65 to the clamping area NP. Furthermore, as... Figure 7 As shown, the pressure roller 61 and the heating roller 62 transport the recording medium P while sandwiching it.

[0140] The heating roller 62 and the pressure roller 61 convey the recording medium P while sandwiching it, and heat and pressurize the recording medium P, thereby fixing the toner image transferred to the recording medium P onto the recording medium P.

[0141] In this way, the recording medium P is conveyed to the clamping region NP with the heating roller 62 in a spaced-out position, thus not being restricted to the posture of the front end of the recording medium P when it enters between the pressure roller 61 and the heating roller 62. Therefore, for example, if the recording medium P is in a wrinkled state or tilted relative to the conveying direction X, such state of the recording medium P can be eliminated. Therefore, according to the structure of this embodiment, the generation of wrinkles on the recording medium P is suppressed compared to the first structure.

[0142] In this embodiment, as described above, the heating roller 62, positioned above the pressure roller 61, moves between a contact position and a spaced-out position. Therefore, compared to the second structure, the recording medium P placed on the pressure roller 61 is less likely to move, and the orientation of the recording medium P is less likely to change while being clamped. Consequently, the generation of wrinkles on the recording medium P is suppressed compared to the second structure.

[0143] This disclosure is not limited to the described embodiments, and various modifications, alterations, and improvements can be made without departing from its spirit. For example, the modified examples shown above can also be appropriately combined in multiple ways. Moreover, in addition to being individual components, the components in the embodiments can also be integrated with surrounding components.

Claims

1. A conveying device, comprising: a first conveying member; a second conveying member, which is movable between a contact position and a separated position relative to the first conveying member, and nips a conveyed material together with the first conveying member at the contact position; and a conveying unit, configured to convey the conveyed material to a nip region where the conveyed material is nipped by the first conveying member and the second conveying member, and convey the conveyed material along the outer periphery of the first conveying member to the nip region in a state where the second conveying member is located at the separated position, the second conveying member moves from the separated position to the contact position to nip the conveyed material that has been conveyed to the nip region together with the first conveying member, in a state where the leading end of the conveyed material conveyed by the conveying unit enters the nip region and is held in contact with the first conveying member, so as to convey the conveyed material.

2. The conveying device according to claim 1, wherein the second conveying member is disposed on an upper side relative to the first conveying member.

3. The conveying device according to claim 1 or 2, wherein a first moving speed at which the second conveying member moves from the separated position to the contact position is higher than a second moving speed at which the second conveying member moves from the contact position to the separated position.

4. The conveying device according to claim 1 or 2, wherein at least one of the first conveying member and the second conveying member is formed of an elastic body, and the elastic body is elastically deformed by a load generated when the second conveying member and the first conveying member nip the conveyed material.

5. The conveying device according to claim 1 or 2, wherein from when the leading end of the conveyed material enters the nip region until the conveyed material completely passes through the nip region, the second conveying member and the first conveying member nip the conveyed material.

6. The conveying device according to claim 1 or 2, wherein in a state where both the first conveying member and the second conveying member rotate, the second conveying member moves from the separated position to the contact position to nip the conveyed material together with the first conveying member.

7. The conveying device according to claim 6, wherein the peripheral speeds of the first conveying member and the second conveying member in the rotating state are identical.

8. A fixing device, which is the fixing device serving as the conveying device according to any one of claims 1 to 7, wherein the first conveying member is one of a heating member and a pressure member, the second conveying member is the other one of the heating member and the pressure member.

9. The fixing device according to claim 8, wherein when the conveyed material is plain paper, the second conveying member nips the conveyed material together with the first conveying member at a first load, when the conveyed material is coated paper, the second conveying member nips the conveyed material together with the first conveying member at a second load that is larger than the first load.

10. The fixing device according to claim 8, wherein If the base weight of the material being transported is less than a predetermined reference value, the second transport body clamps the material being transported with the first transport body under a first load. When the base weight of the material being transported is above the reference value, the second transport body clamps the material being transported with the first transport body under a second load greater than the first load.

11. An image forming apparatus, comprising an image forming unit that forms an image on a recording medium and a fixing device. The fixing device includes: The first conveying body is either a heating component or a pressurizing component; A second conveyor, which is the other of the heating member and the pressurizing member, is movable between a contact position and a spaced position relative to the first conveyor, and at the contact position encloses the recording medium with the first conveyor; and A conveying unit is used to convey the recording medium to an enclosure region where the recording medium is sandwiched between the first conveying body and the second conveying body, and with the second conveying body in the separated position, the recording medium is conveyed along the outer periphery of the first conveying body to the enclosure region. When the front end of the recording medium being transported by the transport unit enters the clamping region and is in contact with and held by the first transport unit, the second transport body moves from the separated position to the contact position to clamp the recording medium transported to the clamping region with the first transport body, thereby fixing the image formed on the recording medium by the image forming unit onto the recording medium. After the second conveyor body detaches from the image forming unit at the rear end of the recording medium, it joins the first conveyor body to enclose the recording medium.

Images