Medium transport device and medium processing device using the same

Abstract

A medium conveying device and a medium processing device using the same, which take into account both the parallelism of the image transferred to the medium and the oblique adjustment of the medium. The medium conveying device includes: a conveying belt; a first tensioning roller, which clamps the medium between the image holding element and the conveying belt and conveys it, and transfers the image held by the image holding element to the medium; a second tensioning roller, which is tensioned from a tensioning position based on the first tensioning roller to a position located on the downstream side of the conveying direction of the medium; a contact adjustment element, which uses one end of the axial direction of the first tensioning roller as a fulcrum to swing the other end to adjust the contact state of the contact area between the image holding element and the conveying belt along the long side direction; and a posture adjustment element, which keeps the distance between the axes of the first tensioning roller and the second tensioning roller constant, and uses one end of the axial direction of the second tensioning roller as a fulcrum to swing the other end to adjust the posture of the second tensioning roller relative to the first tensioning roller.

Description

Technical Field

[0001] The present invention relates to a medium conveying device and a medium processing device using the same. Background Art

[0002] Conventionally, as this type of medium transport device, devices described in Patent Documents 1 to 3 are known.

[0003] Patent Document 1 discloses an image forming apparatus in which an elastic secondary transfer belt is stretched over a pair of rollers, and an adjustment element is used to adjust the inclination angle of one roller relative to the other roller to adjust the paper conveyance direction, thereby adjusting the image parallelism.

[0004] Patent document 2 discloses an image forming device including an image parallelism adjustment mechanism, which adjusts the parallelism of the image in a width direction orthogonal to the conveying direction of the recording material by causing the elastic transfer roller to twist by making the amount of bite of the elastic transfer roller at both ends of the axial direction different.

[0005] Patent document 3 discloses an image forming device in which, when a secondary transfer conveyor belt experiences belt walk, the outer end of a peeling roller is shaken about the rotation axis of a driving roller, thereby applying a force caused by twisting to the secondary transfer conveyor belt, thereby causing the secondary transfer conveyor belt to shake in a direction opposite to the belt walk.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Laid-Open No. 2006-267704 (Best Mode for Implementing the Invention, Figure 3 )

[0009] [Patent Document 2] Japanese Patent Laid-Open No. 2006-276294 (Best Mode for Implementing the Invention, Figure 1 )

[0010] [Patent Document 3] Japanese Patent Laid-Open No. 2007-11107 (Best Mode for Implementing the Invention, Figure 2 ) Summary of the invention

[0011] [Problems to be solved by the invention]

[0012] The technical problem to be solved by the present invention is to achieve both parallelism adjustment of the image transferred onto the medium and skew adjustment of the medium in a mode in which the medium to which the image is transferred is conveyed by a conveyor belt.

[0013] [Technical means to solve the problem]

[0014] The invention described in technical solution 1 is a medium conveying device, comprising: a conveying belt, which is arranged opposite to an image holding element holding an image, and conveys the medium, and the conveying belt can move in a circular motion; a first tensioning roller, which tensions and mounts a portion of the conveying belt and is arranged opposite to the image holding element, and sandwiches and conveys the medium between the image holding element and the conveying belt, and transfers the image held by the image holding element to the medium; a second tensioning roller, which tensions and mounts the conveying belt from the tensioning mounting portion based on the first tensioning mounting roller to the portion located on the medium a contact adjustment element, which uses one axial end of the first tensioning roller as a fulcrum to swing the other end, thereby adjusting the contact state of the image holding element and the conveying belt in the long side direction of the contact area between the image holding element and the conveying belt; and a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one axial end of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller.

[0015] The invention described in claim 2 is the medium conveying device according to claim 1, wherein the contact adjustment element includes a displacement mechanism that causes the other axial end of the first tension roller to swing toward the image holding element side facing it.

[0016] The invention described in claim 3 is the medium transport device described in claim 2, wherein the displacement mechanism linearly advances and retreats a holding member via an eccentric rotating member, and the holding member rotatably holds the other axial end of the first tension roller.

[0017] The invention described in Technical Solution 4 is a medium conveying device according to Technical Solution 1, and the posture adjustment element includes: a position constraint mechanism, which is arranged at the two ends of the first tensioning roller and the second tensioning roller, allowing the rotation of the two and keeping the axial distance between the two constant; and a displacement mechanism, which uses the other axial end of the first tensioning roller as a fulcrum to shake the other axial end of the second tensioning roller.

[0018] The invention described in Technical Solution 5 is a medium conveying device according to Technical Solution 4, wherein the position restraining mechanism includes: limiting rollers, which are arranged at both ends of the first tensioning roller and both ends of the second tensioning roller, and each of the limiting rollers is coaxially arranged with the first tensioning roller and the second tensioning roller; spacing adjustment rollers, which are interposed between the limiting rollers and are configured in contact; and retaining frames, each of the retaining frames retains the two limiting rollers and one spacing adjustment roller so that each axis can rotate, and retains the axes of the limiting roller and the spacing adjustment roller so as to be parallel in a straight line.

[0019] The invention described in claim 6 is a medium transport device according to claim 4, wherein the displacement mechanism causes the other axial end of the second tension roller to move forward and backward in a direction substantially orthogonal to a reference line connecting the axial centers of the first tension roller and the second tension roller.

[0020] The invention described in claim 7 is a medium transport device according to any one of claims 1 to 6,

[0021] A static eliminating element for eliminating static electricity from the medium is provided on the downstream side of the conveying belt in the conveying direction of the medium, and the static eliminating element moves following the swing of the second tension roller.

[0022] The invention described in Technical Solution 8 is a medium conveying device according to any one of Technical Solutions 1 to 6, comprising a guiding element for guiding the medium on the downstream side of the conveying direction of the medium relative to the conveying belt, and the guiding element moves following the shaking of the second tensioning installation roller.

[0023] The invention described in claim 9 is the medium transport device according to any one of claims 1 to 6, wherein the second tension roller is grounded via a high resistor, and the connection portion to the high resistor moves following the swing of the second tension roller.

[0024] The invention described in technical solution 10 is a medium conveying device according to any one of technical solutions 7 to 9, wherein the conveying belt, the first tensioning roller and the second tensioning roller are mounted on a shaking frame that can be shaken relative to a fixed frame, and the destaticizing element, the guiding element or the connecting portion for the high resistor is provided on the shaking frame.

[0025] The invention described in Technical Solution 11 is a medium conveying device according to Technical Solution 1, including a cleaning element, which cleans the conveying belt at the portion of the conveying belt that is tensioned and mounted by the first tensioning and mounting roller, and the cleaning element moves following the shaking of the first tensioning and mounting roller.

[0026] The invention described in claim 12 is the medium transport device described in claim 11, wherein the cleaning frame of the cleaning element moves around a predetermined fulcrum to follow the swing of the first tension roller.

[0027] The invention described in Technical Solution 13 is a medium processing device, comprising: an image holding element that holds an image; and a medium conveying device according to any one of Technical Solutions 1 to 12, which is arranged opposite to the image holding element and transfers and conveys the image held by the image holding element.

[0028] The invention described in claim 14 is the medium processing device according to claim 13, further comprising a contact and separation element that causes the medium conveying device to contact and separate from the image holding element.

[0029] The invention described in Technical Solution 15 is a medium processing device according to Technical Solution 13, characterized in that the image holding element has a second contact adjustment element, which adjusts the contact state between the image holding element and the conveying belt in the contact area with an adjustment amount coarser than the adjustment amount of the contact adjustment element through the medium conveying device.

[0030] The invention described in claim 16 is the medium processing device according to claim 15, wherein the medium transport device is arranged below the image holding element and is provided to be pullable relative to the medium processing device frame.

[0031] The invention described in claim 17 is the medium processing device described in claim 15, wherein the opposing constituent member on the medium conveying device side that faces each other across the contact region has a lower hardness than the opposing constituent member on the image holding element side.

[0032] [Effects of the Invention]

[0033] According to the invention described in claim 1, in a mode in which a medium with an image transferred thereto is conveyed by a conveyor belt, it is possible to adjust the parallelism of the image transferred to the medium and adjust the skew of the medium at the same time.

[0034] According to the invention described in technical solution 2, the contact adjustment element can be easily realized.

[0035] According to the invention described in claim 3, the contact state between the image holding member and the conveyor belt can be finely adjusted in stages.

[0036] According to the invention described in claim 4, the posture adjustment element can be easily realized.

[0037] According to the invention described in claim 5, when constructing the position restraining mechanism as one element of the posture adjusting means, it is easy to achieve both a constant interaxial distance between the first tensioning roller and the second tensioning roller and the rotational operability of both.

[0038] According to the invention described in claim 6, when the displacement mechanism is constructed as an element of the posture adjustment means, the distance between the axes of the tension rollers can be maintained and the posture of the second tension roller can be easily adjusted.

[0039] According to the invention described in claim 7, even if the second tension roller is shaken, the relative positional relationship between the conveyor belt and the static eliminating element can be maintained.

[0040] According to the invention described in claim 8, even if the second tension roller is shaken, the relative positional relationship between the conveyor belt and the guide element can be maintained.

[0041] According to the invention described in claim 9, even if the second tension roller is shaken, the relative positional relationship between the second tension roller and the connection portion to the high resistor can be maintained.

[0042] According to the invention described in claim 10, it is easy to provide a structure in which the relative positional relationship between the neutralizing element, the guide element, or the connection portion to the high resistor and the second tension roller is maintained even if the second tension roller is shaken.

[0043] According to the invention described in claim 11, even if the first tension roller shakes, the relative positional relationship between the conveyor belt and the cleaning element can be maintained.

[0044] According to the invention described in claim 12, it is possible to easily provide a structure in which the relative positional relationship between the conveying belt and the cleaning element is maintained even when the first tension roller is shaken.

[0045] According to the invention described in technical solution 13, a medium processing device including a medium conveying device can be constructed, and the medium conveying device can take into account both the parallelism adjustment of the image transferred to the medium and the skew adjustment of the medium in the form of conveying the medium with the image transferred thereon using a conveyor belt.

[0046] According to the invention described in claim 14, the image holding element can be brought into contact with or separated from the medium conveying device as needed.

[0047] According to the invention described in claim 15, compared with a form without the second contact adjustment element, when using different types of media, the contact state of the contact area between the image holding element and the medium conveying device can be greatly switched.

[0048] According to the invention described in technical solution 16, when adjusting the contact state of the contact area between the medium conveying device and the image holding element, by pulling out the medium conveying device located below the image holding element, detailed adjustment work based on the contact adjustment element can be easily implemented.

[0049] According to the invention described in claim 17, when adjusting the contact state of the contact area between the medium conveying device and the image holding element, a detailed adjustment operation using the contact adjusting element can be performed for the medium conveying device having a lower hardness condition than the image holding element. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 (a) is an explanatory diagram showing an overview of an embodiment of a medium processing device including a medium transport device to which the present invention is applied, Figure 1 (b) means Figure 1 (a) is an explanatory diagram of the main parts of the medium transport device shown in FIG. Figure 1 (c) is an explanatory diagram showing an example of setting a contact adjustment element and a posture adjustment element.

[0051] Figure 2 This is an explanatory diagram showing the overall configuration of an image forming apparatus as an example of a medium processing apparatus according to an embodiment.

[0052] Figure 3 It is an explanatory diagram schematically showing the components around the secondary transfer device according to the embodiment.

[0053] Figure 4 It is an explanatory diagram showing the structure of the secondary transfer device and its surroundings according to the embodiment.

[0054] Figure 5 It is an explanatory diagram showing the details of the clamping pressure switching mechanism used in the embodiment.

[0055] Figure 6 It is a perspective explanatory diagram showing a configuration example of a belt transfer module of a secondary transfer device used in the embodiment.

[0056] Figure 7 Yes means Figure 6 A three-dimensional illustration of the swing parts of the transfer module shown.

[0057] Figure 8 Yes means Figure 6 A three-dimensional illustration of the fixing components of the transfer module shown.

[0058] Fig. 9 Yes means Figure 7 A perspective view illustrating the relationship between the transfer belt unit and the cleaning unit in the swing member shown.

[0059] Fig.10 Yes means Figure 7 1 is an explanatory diagram of a structural example of a transfer belt unit in the swing member shown.

[0060] Fig.11 (a) is an explanatory diagram showing an example of a position restraining mechanism of a transfer belt unit, Fig.11 (b) is an explanatory diagram schematically showing a restraining state of a position restraining mechanism based on a transfer belt unit, Fig.11 (c) is an explanatory diagram showing the behavior of the peeling roller as the second tensioning roller of the transfer belt unit.

[0061] Fig.12 This is an explanatory diagram showing an operation example (1) of a retracting mechanism used in the embodiment.

[0062] Fig.13 This is an explanatory diagram showing an operation example (2) of the retracting mechanism.

[0063] Fig.14 This is an explanatory diagram showing an operation example (1) of the clamping pressure adjustment mechanism and the posture adjustment mechanism used in the embodiment.

[0064] Fig.15 This is an explanatory diagram showing an operation example (2) of the clamping pressure adjustment mechanism and the posture adjustment mechanism.

[0065] Fig.16 It is an explanatory diagram showing the relative positional relationship between the transfer belt unit and peripheral parts when the secondary transfer device according to the embodiment is located at the installation position.

[0066] Fig.17 It is an explanatory diagram showing the relative positional relationship between the transfer belt unit and peripheral parts when the secondary transfer device is retracted to the retracted position.

[0067] Fig.18 It is an explanatory diagram showing the behavior of peripheral parts of the transfer belt unit when the secondary transfer device is located at the installation position.

[0068] Fig.19 It is an explanatory diagram showing the behavior of peripheral parts of the transfer belt unit when the secondary transfer device retreats to the retracted position.

[0069] Fig. 20 (a) is an explanatory diagram showing the selected state of the clamping pressure in the secondary transfer area under the condition that the medium is a special medium such as embossed paper, Fig. 20 (b) is an explanatory diagram showing the switching state of the nip pressure in the secondary transfer area under the condition that the medium is a normal medium.

[0070] Fig.21 (a) is an explanatory diagram schematically showing an operation example of the clamping pressure adjustment mechanism. Fig.21 (b) is an explanatory diagram showing a method of adjusting the clamping pressure using the clamping pressure adjustment mechanism.

[0071] Fig. 22 (a) is an explanatory diagram schematically showing a structural example of a transfer belt unit, Fig. 22 (b) is an explanatory diagram showing the behavior during posture adjustment based on the posture adjustment mechanism, Fig. 22 (c) is an explanatory diagram showing the behavior of the transfer belt unit used in the secondary transfer device of Comparative Method 1 when the posture is adjusted. Fig. 22 (d) is an explanatory diagram showing a tensioned state of the transfer belt during posture adjustment by the posture adjustment mechanism of Comparative Example 1.

[0072] Fig.23 It is an explanatory diagram showing a configuration example of a nip pressure adjustment mechanism in a secondary transfer region of Comparative Example 2.

[0073] [Explanation of Symbols]

[0074] 1: Media transport device

[0075] 2: Conveyor belt

[0076] 3: The first tensioning roller

[0077] 4: Second tensioning roller

[0078] 5: Contact adjustment element

[0079] 5a: Displacement mechanism

[0080] 6: Posture adjustment element

[0081] 6a: Position constraint mechanism

[0082] 6b: Displacement mechanism

[0083] 10: Image retention element

[0084] 11: Static elimination element

[0085] 12: Guide element

[0086] 13: High resistance

[0087] 14: Cleaning components

[0088] 14a: Clean the frame

[0089] S: Medium

[0090] G: Image

[0091] CN: contact area

[0092] L o : Distance between axes DETAILED DESCRIPTION

[0093] Summary of Implementation Methods

[0094] Figure 1 (a) is an explanatory diagram showing an overview of an embodiment of a medium processing device to which the present invention is applied.

[0095] In the figure, the medium processing device includes: an image holding element 10 that holds an image G; and a medium conveying device 1 that is arranged opposite to the image holding element 10 and transfers the image G held by the image holding element 10 to a medium S and conveys the medium S.

[0096] Here, if Figure 1 (a)~ Figure 1 As shown in (c), the medium conveying device 1 includes: a conveying belt 2, which is arranged opposite to the image holding element 10 holding the image G, and conveys the medium S, and the conveying belt 2 has elasticity and can be circulated; a first tensioning roller 3, which is a part of the tensioning conveying belt 2 and is arranged opposite to the image holding element 10, and sandwiches the medium S between the image holding element 10 and the conveying belt 2 and conveys it, and transfers the image held by the image holding element 10 to the medium S; a second tensioning roller 4, which is a tensioning conveying belt 2 from a tensioning portion based on the first tensioning roller 3 to a portion located on the downstream side of the conveying direction of the medium S; a contact adjustment element 5, which uses one end of the axial direction of the first tensioning roller 3 as a fulcrum to swing the other end, thereby adjusting the contact state of the contact area CN between the image holding element 10 and the conveying belt 2 along the long side direction; and a posture adjustment element 6, which adjusts the axial distance L between the first tensioning roller 3 and the second tensioning roller 4. o The posture of the second tension roller 4 relative to the first tension roller 3 is adjusted by keeping the second tension roller 4 constant and swinging one end of the second tension roller 4 in the axial direction as a fulcrum and the other end.

[0097] In such technical means, the medium transport device 1 broadly includes a device that transfers the image G held by the image holding element 10 onto the medium S and transports the medium S.

[0098] The transfer method of the image G is not limited to electrostatic transfer but includes a wide range of methods of transfer by contact with a medium. The image holding element 10 includes a wide range of elements that hold an image before transfer to the medium S, not limited to a photoreceptor, a dielectric, or an intermediate transfer element.

[0099] Furthermore, in terms of deformation following the shaking of the tensioning rollers 3 and 4 caused by the contact adjustment element 5 or the posture adjustment element 6, the conveyor belt 2 is preferably mainly an elastic belt member, but also includes the following form: the conveyor belt 2 is not elastic but the first tensioning roller 3 and the second tensioning roller 4 are elastic.

[0100] Furthermore, the conveyor belt 2 is not limited to the embodiment in which the conveyor belt 2 is tensioned and stretched only by the first tensioning roller 3 and the second tensioning roller 4, and may also be tensioned and stretched using other tensioning rollers.

[0101] In addition, the first tension roller 3 is often used as a normal driving roller, but the present invention is not limited to this, and another tension roller may be used as a driving roller.

[0102] In addition, the first tension roller 3 needs to have a function of transferring the image G held by the image holding element 10 (for example, an electrode function for forming a transfer electric field) in addition to conveying the medium S by sandwiching it with the image holding element 10 .

[0103] Furthermore, from the viewpoint of easily peeling the medium S from the conveyor belt 2 , it is preferable to use a roller having a smaller diameter than the first tension roller 3 as the second tension roller 4 .

[0104] The contact adjusting element 5 adjusts the contact state of the contact area CN between the image holding element 10 and the conveying belt 2 along the longitudinal direction, specifically, the amount of the conveying belt 2 biting into the contact area CN. For example, the contact pressure in the contact area CN can be adjusted substantially uniformly without deviation.

[0105] Furthermore, the posture adjusting device 6 can adjust the inclination of the conveyor belt while effectively utilizing the adjustment by the contact adjusting device 5 .

[0106] Next, a typical form or a preferred form of the medium transport device according to the present embodiment will be described.

[0107] First, as a representative form of the contact adjustment element 5, the following forms can be cited: Figure 1 As shown in (b), a displacement mechanism 5a is included to swing the other axial end of the first tension roller 3 toward the image holding element 10 side facing it.

[0108] In this example, as a preferred form of the contact adjustment element 5, the following form can be cited: the displacement mechanism 5a linearly advances and retreats the holding member via the eccentric rotating member, and the holding member rotatably holds the other axial end of the first tensioning roller 3. This example is a form using an eccentric rotating member (cam member) as the displacement mechanism 5a, and the position of the other axial end of the first tensioning roller 3 can be continuously or stepwise displaced by continuously or stepwise changing the eccentricity of the eccentric rotating member.

[0109] In addition, as a representative form of the posture adjustment element 6, the following form can be cited: it includes a position restraining mechanism 6a and a displacement mechanism 6b, wherein the position restraining mechanism 6a is provided at both ends of the first tensioning and stretching roller 3 and the second tensioning and stretching roller 4, allowing the rotation of the two and setting the distance L between the axes of the two. o The displacement mechanism 6 b swings the other axial end of the second tension roller 4 with the other axial end of the first tension roller 3 as a fulcrum while maintaining the other axial end of the second tension roller 4 constant.

[0110] Here, as preferred forms of the posture adjustment element 6, the following forms can be listed: each position restraining mechanism 6a has two limiting rollers, and a total of four limiting rollers are arranged at both ends of the first tensioning installation roller 3 and both ends of the second tensioning installation roller 4, and are arranged coaxially with these tensioning installation rollers; there are a total of two interval adjustment rollers, and each interval adjustment roller is interposed between the two limiting rollers and is configured in contact; and there are a total of two retaining frames, each retaining frame retains the two limiting rollers and one interval adjustment roller so that each axis can rotate, and at this time, the axes of the three rollers are maintained in parallel on a straight line; or the displacement mechanism 6b makes the other axial end of the second tensioning installation roller 4 move forward and backward in a direction approximately orthogonal to the reference line connecting the axial centers of the first tensioning installation roller 3 and the second tensioning installation roller 4.

[0111] Furthermore, when the medium transport device 1 includes peripheral components, it is preferable to maintain the relative positional relationship with the peripheral components.

[0112] For example, as a preferred form when the static elimination element 11 is included, it can be set as follows: the static elimination element 11 for removing static electricity from the medium S is included on the downstream side of the conveying direction of the medium S relative to the conveyor belt 2, and the static elimination element 11 moves following the swing of the second tensioning roller 4. This example is a form in which the static elimination element 11 moves following the swing of the second tensioning roller 4.

[0113] In addition, as a preferred embodiment when the guide element 12 is included, the guide element 12 for guiding the medium S may be included on the downstream side of the conveying direction of the medium S relative to the conveyor belt 2, and the guide element 12 may move following the swing of the second tensioning roller 4. In this example, the guide element 12 may move following the swing of the second tensioning roller 4.

[0114] Furthermore, as a preferred form when the high resistor grounding method is adopted, it can be set as follows: the second tensioning roller 4 is grounded via the high resistor 13, and the connection portion to the high resistor 13 moves following the swing of the second tensioning roller 4. This example is a form in which the connection portion to the high resistor 13 moves following the swing of the second tensioning roller 4.

[0115] Here, as a structural example when using the static elimination element 11, the guide element 12 and the high resistor grounding method, the following form can be listed: the conveyor belt 2, the first tensioning roller 3 and the second tensioning roller 4 are mounted on an unillustrated shaking frame that can be shaken relative to the unillustrated fixed frame, and the static elimination element 11, the guide element 12 or the connection part for the high resistor 13 are provided on the shaking frame.

[0116] In addition, as a preferred form when the cleaning element 14 is included, it can be set as follows: the cleaning element 14 is included in the portion of the conveyor belt 2 that is stretched and tensioned by the first tensioning roller 3 to clean the conveyor belt 2, and the cleaning element 14 moves following the swing of the first tensioning roller 3. In this example, the following form can be cited: the cleaning frame 14a of the cleaning element 14 moves following the swing of the first tensioning roller 3 with a predetermined fulcrum as the center.

[0117] Furthermore, as a preferred embodiment of the medium processing device, a device including a contact and separation element ( Figure 1 (a)~ Figure 1 The contact and separation element can separate the image holding element 10 and the medium conveying device 1 from each other to deal with the blockage when the medium is blocked (jammed) between the image holding element 10 and the medium conveying device 1, for example.

[0118] In addition, as another preferred embodiment of the medium processing device, the following embodiment can be cited: the image holding element 10 has a second contact adjustment element ( Figure 1 (a)~ Figure 1 (c) (not shown), the second contact adjustment element adjusts the contact state of the contact area by an adjustment amount greater than an adjustment amount of the contact adjustment element 5 based on the medium transport device 1.

[0119] In this example, when adjusting the contact state (eg, clamping pressure) of the contact area CN between the image holding element 10 and the medium conveying device 1 , rough adjustment can be performed using the second contact adjustment element on the image holding element 10 side, and fine adjustment can be performed on the medium conveying device 1 side.

[0120] In this embodiment, the following embodiment is particularly preferred: the medium conveying device 1 is arranged below the image holding element 10 and is provided so as to be pulled out relative to the medium processing device frame (not shown). In this example, by pulling out the medium conveying device 1, the operator can easily operate the contact adjustment element 5 provided on the side of the medium conveying device 1, thereby being able to finely adjust the contact state of the contact area CN.

[0121] Furthermore, in this embodiment, it is preferable that the opposing constituent member on the medium conveying device 1 side facing each other across the contact area CN has a lower hardness than the opposing constituent member on the image holding element 10 side. Here, the opposing constituent member on the medium conveying device 1 side refers to a combination of the conveying belt 2 and the first tensioning roller 3. In addition, as an opposing constituent member on the image holding element 10 side, for example, if the image holding element 10 of the intermediate transfer method is taken as an example, it refers to a combination of a belt-shaped intermediate transfer body and an opposing roller. In addition, the hardness of each opposing constituent member depends on the hardness of each member, but when the hardness of the two members is different, it refers to the hardness when the combination of the two members is regarded as a whole. In this case, it is estimated that the hardness of the member with low hardness is the hardness that makes the main contribution.

[0122] In this example, the hardness of the opposing component on the medium conveying device 1 side is lower than that on the image holding element 10 side, so the contact state in the contact area CN between the medium conveying device 1 and the image holding element 10 tends to be easily abnormal on the medium conveying device 1 side. Therefore, the contact adjustment element 5 on the medium conveying device 1 side can finely adjust the contact state of the contact area CN by a fine adjustment amount.

[0123] Furthermore, even in the opposing components of the medium transport device 1 having low hardness, hardness varies due to changes over time or tolerances during molding. Therefore, fine adjustment using the contact adjustment element 5 is also effective in these cases.

[0124] Hereinafter, the present invention will be described in more detail based on the embodiments shown in the accompanying drawings.

[0125] Implementation

[0126] Figure 2 The overall configuration of an image forming apparatus as an example of a medium processing apparatus according to the embodiment is shown.

[0127] -Overall structure of image forming apparatus-

[0128] In the figure, the image forming device 20 includes: an image forming unit 22 (specifically 22a~22d), which forms multiple color component (yellow, magenta, cyan, and black in this embodiment) images in the device frame 21; an intermediate transfer body 30, which sequentially transfers (primary transfer) and maintains the color component images formed by each image forming unit 22, and the intermediate transfer body 30 is belt-shaped; a secondary transfer device (unified transfer device) 50, which secondary transfers (unified transfer) the color component images transferred to the intermediate transfer body 30 to a medium (for example, paper); a fixing device 70, which fixes the secondary transferred image on the medium; and a medium conveying system 80, which conveys the medium to the secondary transfer area.

[0129] -Image Forming Section-

[0130] In the present embodiment, each image forming unit 22 (22a~22d) has a drum-shaped photosensitive body 23, and a charging device 24 such as a corotron or a transfer roller for charging the photosensitive body 23 is arranged around each photosensitive body 23, a latent image writing device 25 such as a light emitting diode (LED) writing head for writing an electrostatic latent image on the charged photosensitive body 23, a developing device 26 for developing the electrostatic latent image written on the photosensitive body 23 using toner of each color component, a primary transfer device 27 such as a transfer roller for transferring the toner image on the photosensitive body 23 to the intermediate transfer body 30, and a photosensitive body cleaning device 28 for removing residual toner on the photosensitive body 23.

[0131] -Intermediate transfer body-

[0132] In addition, the intermediate transfer body 30 is mounted on a plurality of (three in this embodiment) tension rollers 31 to 33. For example, the tension roller 31 is used as a driving roller driven by a driving source (not shown) and is circulated by the driving roller. Furthermore, an intermediate transfer body cleaning device 35 is provided between the tension rollers 31 and 33 to remove residual toner on the intermediate transfer body 30 after secondary transfer.

[0133] In this example, the intermediate transfer member 30 may be appropriately selected, for example, a belt made of a synthetic resin such as polyimide or polyamide-imide, and the tension rollers 31 to 33 may be made of an elastic material such as urethane rubber.

[0134] Furthermore, if Figure 2 As shown, the intermediate transfer body 30 and the tension rollers 31 to 33 are held by the intermediate transfer frame and integrated as an intermediate transfer module.

[0135] -Secondary transfer device (unified transfer device)-

[0136] Furthermore, the secondary transfer device (unified transfer device) 50 also functions as a medium transport device. Figure 2 and Figure 3 As shown in FIG. 1 , the transfer belt unit 51 having a transfer conveyor belt 54 stretched and tensioned on a plurality of (e.g., two) tension rollers 52 and 53 is arranged so as to contact the surface of the intermediate transfer body 30. In particular, in this example, the transfer belt unit 51 is retracted by a retracting mechanism 110 (see FIG. 1 ) described later. Figure 6 , Figure 7 ) is supported so as to be able to retract and to be able to contact / separate from the intermediate transfer body 30.

[0137] Here, the transfer conveyor belt 54 is a semi-conductive elastic belt with a volume resistivity of 8.5logΩ to 10.0logΩ made of an elastic material such as urethane rubber, and the first tensioning roller 52 is constructed as a transfer roller 55. The transfer roller 55 is crimped to the intermediate transfer body 30 in the secondary transfer area (unified transfer area) TR via the transfer conveyor belt 54, and the tensioning roller 33 of the intermediate transfer body 30 is used as an opposing roller 56 constituting an opposing electrode of the transfer roller, forming a conveying path for the medium S from the position of the first tensioning roller 52 toward the position of the second tensioning roller 53, and the second tensioning roller 53 is made to function as a peeling roller.

[0138] In this example, the first tension roller 52 (used as the transfer roller 55) is a structure in which an elastic layer is coated around a metal shaft, and the elastic layer is formed by mixing carbon black or the like in a foaming material such as foamed urethane rubber, while the second tension roller 53 is, for example, a metal roller. In this example, the first tension roller 52 of the transfer belt unit 51 is directly grounded, and the second tension roller 53 is grounded via a high resistor 58 (for example, about 500 MΩ), thereby preventing the transfer conveyor belt 54 from being charged.

[0139] In particular, in this example, as the opposing constituent members sandwiching the secondary transfer region TR, the transfer conveyor belt 54 is selected to have a lower hardness than the intermediate transfer body 30, and the first tension roller 52 (transfer roller 55) is selected to have a lower hardness than the opposing roller 56 (tension roller 33). Therefore, in this example, the opposing constituent members on the transfer belt unit 51 side sandwiching the secondary transfer region TR (the transfer conveyor belt 54 + the first tension roller 52 in this example) are lower in hardness than the opposing constituent members on the intermediate transfer module side (the intermediate transfer body 30 + the opposing roller 56 in this example).

[0140] Furthermore, in this example, the first tensioning roller 52 and the second tensioning roller 53 use rollers of the same diameter. If the peeling property of the medium S at the downstream end of the transfer conveyor belt 54 is taken into consideration, the second tensioning roller 53 can be set to function as a peeling roller with a diameter smaller than that of the first tensioning roller 52.

[0141] Furthermore, a transfer voltage V is applied from a transfer power source 60 via a conductive power supply roller 57 to the facing roller 56 (which also serves as the tension roller 33 in this example). TR , thereby forming a predetermined transfer electric field between the transfer roller 55 and the facing roller 56 .

[0142] -Fixing device-

[0143] like Figure 2 As shown, the fixing device 70 includes: a heating fixing roller 71, which is arranged in contact with the image holding surface side of the medium and can be driven to rotate; and a pressure fixing roller 72, which is arranged in pressure contact with the heating fixing roller 71 and rotates following the heating fixing roller 71, and allows the image held on the medium S to pass through the transfer area between the two fixing rollers 71 and 72, so as to heat and pressurize the image.

[0144] -Media transport system-

[0145] Furthermore, if Figure 2 and Figure 3 As shown, the medium transport system 80 has multi-stage (two-stage in this example) medium supply containers 81, 82, so that the medium S supplied from either of the medium supply containers 81, 82 is transmitted from a vertical transport path 83 extending in a substantially vertical direction to a horizontal transport path 84 extending in a substantially horizontal direction to reach the secondary transfer area TR, and then the medium S holding the transferred image is transmitted via a conveying belt 85 to a fixing position based on the fixing device 70, and is discharged to a medium discharge receiving portion 86 arranged on the side of the device frame 21.

[0146] In addition, the medium conveying system 80 has a reversible branch conveying path 87 that branches downward from a portion of the horizontal conveying path 84 located on the downstream side of the medium conveying direction of the fixing device 70, so that the medium S reversed through the branch conveying path 87 returns, passes through the conveying path 88 and returns again from the vertical conveying path 83 to the horizontal conveying path 84, transfers the image to the back side of the medium S in the secondary transfer area TR, and is discharged to the medium discharge receiving portion 86 through the fixing device 70.

[0147] In addition to the positioning rollers 90 that align the position of the medium S and supply it to the secondary transfer region TR, the medium transport system 80 also includes a suitable number of transport rollers 91 in each of the transport paths 83 , 84 , 87 , and 88 .

[0148] Furthermore, a manual medium supply device 95 capable of supplying manual medium toward the horizontal conveyance path 84 is provided on the side of the device housing 21 opposite to the medium discharge receiving portion 86 .

[0149] - Example of the structure around the transfer belt unit -

[0150] <With transfer module>

[0151] In this example, in the transfer belt unit 51, as shown in FIG. Figure 6 , Figure 7 and Fig. 9 As shown in FIG. 1 , a cleaning unit 170 is provided at a position of the transfer conveyor belt 54 corresponding to the first tension roller 52 (transfer roller 55 ).

[0152] In this example, the transfer belt unit 51 and the cleaning unit 170 function as an oscillating member 201 that can oscillate relative to a fixed member 202 , and both the oscillating member 201 and the fixed member 202 are referred to as a belt transfer module 200 .

[0153] Furthermore, in this example, the tape transfer module 200 is mounted so as to be pulled out from the front side relative to the device housing 21 , and for example, is pulled out from the device housing 21 for maintenance.

[0154] Here, Figure 6 The overall structure of the belt transfer module 200 is shown in FIG. Figure 7 The shaking part 201 is shown in FIG. Figure 8 The appearance of the fixing member 202 is shown in FIG.

[0155] <Swing parts>

[0156] In this example, if Figure 7 , Fig. 9 and Fig.10 As shown, the transfer belt unit 51 as the swing member 201 includes a belt unit frame 510 that integrally holds the transfer conveyor belt 54 and other components, and the belt unit frame 510 is supported to be swingable relative to the fixed member 202 .

[0157] Specifically, the first tension roller 52 is used as a driving roller, and the second tension roller 53 is used as a driven roller. The second tension roller 53 is supported so as to be able to swing with the rotation shaft 52a of the first tension roller 52 as a swing fulcrum.

[0158] In addition, if Figure 7 , Fig. 9 and Fig.10 as well as Figures 16 to 19As shown, the cleaning unit 170 as the shaking component 201 has a cleaning unit frame 171 for accommodating residues on the transfer conveyor belt 54, and a cleaning scraper 173 is provided in the cleaning unit frame 171 with a support bracket 172 interposed therebetween, and the front end portion of the cleaning scraper 173 is arranged in contact with the width direction of the direction intersecting the moving direction of the transfer conveyor belt 54.

[0159] Here, Fig.16 , Fig.17 FIG. 2 shows a cross section of the cleaning unit 170 cut at the front side in the width direction of the belt transfer module 200. Fig.16 In the case of retraction by the retraction mechanism 110, in addition, Fig.17 Indicates when the retraction is released (when in contact) by the retraction mechanism 110. Fig.18 , Fig.19 2 shows a cross section of the tape transfer module 200 cut at a substantially central portion in the width direction. Fig.18 In the case of retraction by the retraction mechanism 110, in addition, Fig.19 This indicates when the retraction mechanism 110 is released (when in contact).

[0160] Furthermore, the cleaning unit frame 171 is supported so as to be able to rock relative to the fixed frame 210 of the fixed component 202 with the fixed shaft 175 as a rocking fulcrum, and the fixed shaft 175 is fixed in a manner extending parallel to the axial direction of the first tensioning roller 52 of the transfer belt unit 51. In addition, a part of the cleaning unit frame 171 is maintained so as to be able to rotate relative to both ends of the rotating shaft 52a of the first tensioning roller 52 of the transfer belt unit 51.

[0161] Furthermore, an urging spring 176 is provided between the support bracket 172 of the cleaning unit frame 171 and the fixed frame 210 of the fixing member 202 , and the cleaning blade 173 is kept in contact with the transfer conveyor belt 54 by the urging force of the urging spring 176 .

[0162] In addition, reference numeral 177 is a support fixture which is provided at the substantially center of the longitudinal direction of the cleaning unit frame 171 and has a through hole through which the fixing shaft 175 passes and supports the fixing shaft 175. Fig. 9 As shown, the cleaning unit frame 171 is constrained at three points: both ends of the rotating shaft 52 a of the first tension roller 52 of the transfer belt unit 51 , and the contact portion between the support fixture 177 and the fixed shaft 175 .

[0163] In addition, as peripheral parts mounted on the swing member 201, there are the following parts.

[0164] Regarding the shaking component 201, as Figure 6 and Figure 7As shown, a de-static component (e.g., a de-static needle) 180 as a de-static element or a plate-shaped guide groove 185 as a guide element for guiding the medium to be transported is provided on the downstream side of the transfer conveyor belt 54 of the transfer belt unit 51 in the conveying direction. The de-static element 180 and the guide groove 185 are integrally mounted on the belt unit frame 510 of the transfer belt unit 51 (see Fig.10 ).

[0165] In addition, in this example, Figure 6 and Fig.14 As shown, the second tensioning roller 53 is supported to be rotatable relative to the belt unit frame 510. Since a grounding method via a high resistor 58 is adopted, a contact 190 including a metal plate is provided on the belt unit frame 510 as a connecting portion with the high resistor 58, and a rotating shaft 53a of the second tensioning roller 53 is arranged in contact with the contact 190.

[0166] <Fixed parts>

[0167] In addition, if Figure 6 and Figure 8 As shown, the fixed component 202 has a fixed frame 210, and the fixed frame 210 ensures a receiving portion 211 that can carry the shaking component 201. Furthermore, in order to enable the cleaning unit 170 to shake around a predetermined shaking fulcrum, a fixed shaft 175 is provided in the area where the cleaning unit 170 is mounted in a manner of bridging the two side walls of the fixed frame 210.

[0168] In addition, a plurality of positioning pins 214 are provided on upper portions of both side walls of the fixing frame 210 , and are inserted into positioning holes (not shown) of the intermediate transfer frame 34 to position the intermediate transfer frame 34 .

[0169] - Various mechanisms installed around the secondary transfer device -

[0170] In this embodiment, if Figure 3 As shown, arranged around the secondary transfer device 50 are: a retracting mechanism 110 for retracting the secondary transfer device 50 from the secondary transfer area TR; a clamping pressure switching mechanism 120 for switching the clamping pressure (contact pressure) Np of the secondary transfer area TR according to the type of the medium S; a clamping pressure adjustment mechanism 130 for fine-tuning the clamping pressure Np of the secondary transfer area TR; and a posture adjustment mechanism 150 for adjusting the posture of the transfer belt unit 51.

[0171] In addition, symbol 101 is a medium discriminator for discriminating the type of medium S, and there is a discriminator that discriminates the type of medium S in a manner of discriminating the medium specified by the user, or uses a detector not shown to detect the medium contained in the medium supply container 81, 82 or the medium in transport, and discriminates the type of medium S based on the obtained detection signal.

[0172] Furthermore, the control device 100 receives the discrimination signal from the medium discriminator 101 and sends a control signal to, for example, the clamping pressure switching mechanism 120 .

[0173] In addition, when the control device 100 detects a medium jam (blockage) at the secondary transfer region TR, the control device 100 sends a control signal so that the retracting mechanism 110 can perform a retracting operation.

[0174] In this example, the clamping pressure adjustment mechanism 130 and the posture adjustment mechanism 150 are adjusted manually or by using a jig by the user as described later, and therefore control by the control device 100 is not performed.

[0175] - Retraction mechanism -

[0176] In this example, if Figures 6 to 8 As shown, the retracting mechanism 110 is respectively disposed on the outer sides of the two side walls of the fixing frame 210 of the fixing component 202 of the belt transfer module 200 .

[0177] In this example, the retraction mechanism 110 supports a link arm 111 having arm portions 112 to 114 extending in three directions so that it can be swung with the fixed axis 175 of the cleaning unit 170 as the swung fulcrum Oa, and applies force to the link arm 111 in the counterclockwise direction (or clockwise direction) by hooking a force spring 115 on the first arm portion 112 extending downward when viewed from the outside of the fixed frame 210 among the three arm portions 112 to 114 of the link arm 111. Moreover, a cam follower 117 including, for example, a rotating roller is provided on the second arm portion 113 extending in a direction opposite to the direction of the force applied by the force spring 115, and a cam surface 116a of a retraction cam 116 as a rotating eccentric member is pressed against the lower side of the cam follower 117. Furthermore, in the third arm portion 114 of the link arm 111 extending to the side opposite to the retraction cam 116 separated by the rocking fulcrum Oa, the rotating shaft 52a of the first tensioning roller 52 (transfer roller 55) of the transfer belt unit 51 is supported so as to be rotatable.

[0178] Furthermore, in this example, the cam shaft 116b of the retracting cam 116 extends to the rear side of the belt transfer module 200, and a rear retracting cam 116 is provided on the rear side of the cam shaft 116b, and a retracting gear 118 (see FIG. 1 ) as an example of a drive transmission mechanism is provided. Fig.12 ), the driving force from a driving source (not shown) is transmitted to the retracting gear 118.

[0179] As described above, in this example, the retracting mechanism 110 supports both ends of the rotating shaft 52 a of the first tension roller 52 of the transfer belt unit 51 so as to be retractable.

[0180] -Clamping pressure switching mechanism-

[0181] In this embodiment, if Figure 4 and Figure 5 As shown, the nip pressure switching mechanism 120 displaces the position of the rotation shaft 56 a of the facing roller 56 (corresponding to the tension roller 33 ) of the secondary transfer device 50 .

[0182] In particular, in this example, the nip pressure switching mechanism 120 functions as a second nip pressure adjustment mechanism (equivalent to a second contact adjustment element) that more roughly adjusts the nip pressure (contact pressure) Np of the secondary transfer region TR than the nip pressure adjustment mechanism 130 described later.

[0183] In this example, a roller holder 560 is provided to cover both ends and the upper part of the facing roller 56 in the axial direction, and both ends of the rotating shaft 56a of the facing roller 56 are rotatably supported by both axial side walls of the roller holder 560 via bearing members 561, and the bearing members 561 are held by the roller holder 560 so as to be contactable and separable with respect to the transfer belt unit 51. Furthermore, a biasing spring 562 is provided between the roller holder 560 and the bearing member 561, and the biasing spring 562 biases the facing roller 56 toward the transfer belt unit 51 side.

[0184] In this example, the clamping pressure switching mechanism 120 supports the switching cams 121 as eccentric rotating members at positions coaxial with both ends of the rotating shaft 56a of the facing roller 56, and each switching cam 121 has a cam surface 122 formed so that the outer diameter of the switching cam 121 changes along the circumferential direction of the switching cam 121. In this example, the cam surface 122 has a small diameter portion 122a and a large diameter portion 122b formed at a position offset 180 degrees from the small diameter portion 122a in the circumferential direction of the switching cam 121, and the small diameter portion 122a and the large diameter portion 122b are smoothly connected.

[0185] Furthermore, a driving force from a driving source (not shown) is transmitted to each switching cam 121 via a driving transmission mechanism 124 , and each switching cam 121 rotates synchronously by a predetermined amount.

[0186] In this example, a driving source (not shown) is provided on the rear side (inner side) of the device housing 21, and a driving transmission mechanism 124 is provided in such a manner that a transmission shaft 125 extending from the rear side (inner side) toward the front side (near front side) is rotatably supported on both side walls of the roller holder 560, a driven gear 126 is fixed on the rear side (inner side) of the transmission shaft 125, and a switching cam 121 on the front side (near front side) is rotationally driven via a transmission gear train 127 (in this example, three transmission gears are used) on the front side (near front side) of the transmission shaft 125. The transmission gear train 127 described here includes a transmission gear 127a provided coaxially with the transmission shaft 125, a final stage transmission gear 127c provided coaxially with the switching cam 121, and an intermediate transmission gear 127b interposed between the transmission gears 127a and 127c. Furthermore, the drive transmission mechanism 124 may be configured to transmit the driving force from the driven gear 126 to the switching cam 121 provided on the rear side (back side) via a transmission gear train (not shown).

[0187] -Clamping pressure adjustment mechanism-

[0188] In this example, if Figures 4 to 6 as well as Fig.14 , Fig.15 As shown, the clamping pressure adjustment mechanism 130 is respectively disposed at two locations, the front side and the rear side of the tape transfer module 200 .

[0189] Here, the clamping pressure adjustment mechanism 130 provided on the front side of the tape transfer module 200 will be described, and the clamping pressure adjustment mechanism 130 on the rear side is the same as the clamping pressure adjustment mechanism on the front side, so the description thereof will be omitted.

[0190] In this example, regarding the clamping pressure adjustment mechanism 130, as shown in FIG. Figure 4 , Figure 6 , Figure 7 , Fig.14 and Fig.15 As shown, a fine adjustment cam 131 is coaxially provided with the front end of the rotation shaft 52a of the first tensioning roller 52 (transfer roller 55) of the transfer belt unit 51, and in this example, is configured to be exposed on the outer side surface of the link arm 111 of the retracting mechanism 110.

[0191] Furthermore, Fig.14 and Fig.15 FIG. 1 shows a state in which the swing member 201 of the belt transfer module 200 is arranged at a position retracted from the intermediate transfer body 30 by the retracting mechanism 110 .

[0192] In this example, the fine adjustment cam 131 has a cam surface 132 whose outer diameter gradually changes from the minimum diameter portion to the maximum diameter portion along the circumferential direction of the fine adjustment cam 131 . The cam surface 132 is arranged to contact the cam surface 122 of the switching cam 121 of the clamping pressure switching mechanism 120 .

[0193] In addition, position limiting rings 133 for limiting the angle position are provided on the near front side of the front fine adjustment cam 131 and the inner side of the rear fine adjustment cam 131. In this example, the position limiting ring 133 is formed with a plurality of recesses 135 at predetermined intervals along the circumference of the annular ring body 134. Here, the number of recesses 135 can be appropriately selected. For example, if there are 12 recesses 135, the recesses 135 can be formed at an angle interval of 30°. In addition, the amount of change in the outer diameter of each fine adjustment cam 131 can be appropriately selected, and the outer diameter can be set to increase by an outer diameter change amount Δd (for example, 50μm to 100μm) as a unit as one recess 135 advances in the circumferential direction.

[0194] In addition, in this example, a stopper rod 136 as a stopper element is provided below the position limiting ring 133 on the outer side surface of the link arm 111 of the retracting mechanism 110. The stopper rod 136 has a hemispherical convex portion 136a at the front end portion, and is pressed by a pressing spring 137 in a manner that the convex portion 136a is pressed toward the concave portion 135 of the position limiting ring 133. In this example, the hemispherical convex portion 136a is pressed in a manner that blocks the entrance portion of the concave portion 135, and when the user rotates the position limiting ring 133 appropriately manually or using a jig, for example, the stopper rod 136 repeatedly moves in and out while being pressed by the pressing spring 137 as the concave portion 135 of the position limiting ring 133 moves, so that the position limiting ring 133 can be rotated with a click feeling at intervals of the concave portion 135.

[0195] That is, by moving the position regulating ring 133 by a predetermined angle, in other words, by a predetermined number n of recesses 135 , it is possible to finely adjust the outer diameter change amount n×Δd of the cam surface 132 as the fine adjustment cam 131 .

[0196] Furthermore, the clamping pressure adjustment mechanism 130 provided on the rear side is also configured in substantially the same manner as the clamping pressure adjustment mechanism on the front side.

[0197] -Posture adjustment mechanism-

[0198] In this example, if Figures 4 to 6 , Fig.10 , Fig.11 (a)~ Fig.11 (c) and Fig.14 , Fig.15As shown, the posture adjustment mechanism 150 is provided to be adjustable at the front side of the tape transfer module 200 .

[0199] That is, the posture adjustment mechanism 150 includes: a position restraining mechanism 151, which is arranged at the two ends of the first tensioning roller 52 and the second tensioning roller 53 of the transfer belt unit 51, allowing the rotation of the two and keeping the axial distance between the two constant; and a displacement mechanism 160, which uses the other axial end of the first tensioning roller 52 (the front end of the rotating shaft 52a in this case) as a fulcrum to shake the other axial end of the second tensioning roller 53 (the front rotating shaft 53a).

[0200] Here, if Figures 9 to 11 As shown in (a), the position restraining mechanism 151 includes: limiting rollers 152, 153, which are coaxially arranged at both ends of the first tensioning roller 52 and the second tensioning roller 53; an interval adjustment roller 154, which is interposed between the limiting rollers 152, 153 and is configured in contact with them; and a retaining frame 155, which retains the limiting rollers 152, 153 and the interval adjustment roller 154 in a manner that allows them to rotate in a linear configuration with their respective axes.

[0201] At this time, if Fig.11 (a) Fig.11 As shown in (b), the distance between the axes of the first tension roller 52 and the second tension roller 53 is a constant dimension Lc at both the front side (near front side) and the rear side (inner side).

[0202] In addition, if Figure 6 , Figure 8 , Fig.14 and Fig.15 As shown, the displacement mechanism 160 is provided on the front side (near front side) of the second tension roller 53 in the rotation axis direction.

[0203] In this example, the displacement mechanism 160 is arranged on the outer side of the near-front side wall of the fixed frame 210 of the fixed component 202 with the transfer module 200, and is configured to enable the other axial end of the second tensioning roller 53 to move forward and backward in a direction w that is approximately orthogonal to a reference line s connecting the axial centers of the first tensioning roller 52 and the second tensioning roller 53.

[0204] Specifically, if Fig.14As shown, the displacement mechanism 160 has a long displacement adjustment plate 161 extending in a direction w that is substantially orthogonal to the reference line s. The rotation axis 53a of the second tensioning roller 53 is supported to be rotatable on the displacement adjustment plate 161, and substantially U-shaped or inverted U-shaped guide grooves 162 and 163 are formed at the upper and lower ends of the displacement adjustment plate 161. On the other hand, on the outer side of the side wall of the fixed frame 210, guide protrusions 164 and 165 are formed to protrude corresponding to the guide grooves 162 and 163, and are configured to be able to slide along the guide grooves 162 and 163.

[0205] In addition, a plurality of (two in this example) fixing holes 166 are formed in the long side direction of the displacement adjustment plate 161. The fixing holes 166 are formed in the shape of long holes along the moving direction of the displacement adjustment plate 161, and fixing members 167 such as screws are inserted into the fixing holes 166 to fix the displacement adjustment plate 161 to the fixed frame 210. Therefore, if the fixing member 167 is tightened, the head of the fixing member 167 contacts the displacement adjustment plate 161, and the displacement adjustment plate 161 is fixed in an immovable state. If the fixing member 167 is loosened, the displacement adjustment plate 161 becomes movable along the guide grooves 162 and 163.

[0206] Furthermore, a cam follower hole 168 is formed above the guide groove 163 on the lower side of the displacement adjustment plate 161. The cam follower hole 168 is formed in the shape of a long hole extending in the short side direction intersecting the long side direction of the displacement adjustment plate 161. A displacement adjustment cam 169 is accommodated in the cam follower hole 168. The displacement adjustment cam 169 is configured as an eccentric cam having a substantially elliptical outer shape with respect to the rotation shaft 169a. The displacement adjustment cam 169 is rotated by the user manually or by using a jig to rotate the rotation shaft 169a when the fixed state by the fixing member 167 is released, so that the cam follower hole 168 moves upward or downward.

[0207] Therefore, in this example, the displacement adjustment plate 161 is appropriately moved in the w direction, so that Fig.11 As shown in (c), the position of the front side rotation shaft 53a of the second tension roller 53 held by the displacement adjustment plate 161 is displaced upward (U) or downward (D) in the w direction.

[0208] Furthermore, Fig.15 The displacement adjustment plate 161 is shown in Fig.14 The reference position shown is in a state where it has moved downward as indicated by an arrow.

[0209] Next, the operation of the image forming apparatus according to this embodiment will be described.

[0210] -Retraction action based on retraction mechanism-

[0211] In this embodiment, the retracting mechanism 110 is disposed on both sides of the belt transfer module 200 and operates synchronously. Fig.12 and Fig.13 As shown, the retracting cam 116 can be rotated in a predetermined direction. When the retracting cam 116 rotates in a direction in which the outer diameter of the cam surface increases and reaches the maximum outer diameter corresponding to the retracted position, the second arm portion 113 of the link arm 111 is pressed upward, and the third arm portion 114 moves downward, and the position of the bearing portion of the first tensioning roller 52 (transfer roller 55) of the transfer belt unit 51 is retracted from the secondary transfer area TR to reach the predetermined retracted position (see FIG. Fig.12 ).

[0212] In addition, when the retracting action based on the retracting mechanism 110 is released, when the outer diameter of the cam surface 116a of the retracting cam 116 is rotated to the minimum position, the link arm 111 is urged by the urging force of the urging spring 115, and the second arm portion 113 moves downward. In conjunction with this, the position of the bearing portion of the first tensioning roller 52 (transfer roller 55) of the transfer belt unit 51 reaches a contact position (contact position) in contact with the secondary transfer area TR (see Fig.13 ).

[0213] -Switching of clamping pressure by clamping pressure switching mechanism-

[0214] In this embodiment, there are many types of media S used. For example, when using a medium Sa having a rough surface such as embossed paper, Fig. 20 As shown in (a), when the same secondary transfer conditions (nip pressure) as those for medium Sb such as plain paper are used, there is a concern that the image portion may be difficult to transfer to the recessed portions 300 on the surface of the medium Sa.

[0215] Therefore, in this embodiment, when a medium Sa having a rough surface such as embossed paper is used, the control device 100 identifies the medium Sa based on the identification signal from the medium identifier 101 and sends a predetermined control signal to the clamping pressure switching mechanism 120 .

[0216] In this way, the clamping pressure switching mechanism 120 can appropriately rotate the switching cam 121 so that, for example, the small diameter portion 122 a of the cam surface 122 of the switching cam 121 contacts the cam surface 132 of the fine adjustment cam 131 of the clamping pressure adjustment mechanism 130 .

[0217] In this state, the nip pressure Np1 between the first tension roller 52 (transfer roller 55) and the facing roller 56 of the transfer belt unit 51 becomes high, and a secondary transfer condition suitable for the medium Sa is obtained. As a result, the image is also secondary transferred to the concave portion 300 of the medium Sa, and the image quality can be kept good.

[0218] On the other hand, in the case of using a medium Sb such as ordinary paper, Fig. 20 As shown in (b) of FIG. 1 , the control device 100 may be configured to cause the large diameter portion 122 b of the cam surface 122 as the switching cam 121 to contact the cam surface 132 of the fine adjustment cam 131 of the clamping pressure adjustment mechanism 130 .

[0219] In this state, the nip pressure Np2 between the first tension roller 52 (transfer roller 55) and the facing roller 56 of the transfer belt unit 51 is set low, and a secondary transfer condition suitable for the medium Sb is obtained.

[0220] - Fine adjustment based on clamping pressure adjustment mechanism -

[0221] Next, the fine adjustment of the clamping pressure by the clamping pressure adjustment mechanism 130 will be described.

[0222] In this example, if Fig.21 As shown in (a) of FIG. 5 , the nip pressure adjustment mechanism 130 located on the front side can finely adjust the position of the front side of the rotation shaft 52 a of the first tension roller 52 of the transfer belt unit 51 .

[0223] At this time, the first tension roller 52 is caused to swing with the rear end of the rotation shaft 52a as a fulcrum, so that Fig.21 As shown in (b), for example, when the clamping pressure at the secondary transfer area TR becomes too high on the front side compared to the rear side as shown by the dotted line, or becomes lower on the front side compared to the rear side as shown by the two-dash line, the clamping pressure of the secondary transfer area TR can be adjusted to be approximately uniform as shown by the solid line by appropriately displacing the front end of the rotating shaft 52a of the first tensioning roller 52.

[0224] Furthermore, the clamping pressure adjustment mechanism 130 located on the rear side functions in substantially the same manner as the front side. With respect to the first tensioning roller 52, the rear end of the rotating shaft 52a can be shaken using the front end of the rotating shaft 52a as a fulcrum, thereby finely adjusting the rear position of the rotating shaft 52a of the first tensioning roller 52 of the transfer belt unit 51.

[0225] In particular, in this embodiment, not only the first tension roller 52 (functioning as the transfer roller 55) of the transfer belt unit 51 is made of an elastic material, but also the transfer conveyor belt 54 is made of an elastic material, and thus has a lower hardness than the intermediate transfer body 30 and the facing roller 56. Accordingly, the amount of deformation of the transfer belt unit 51 facing the intermediate transfer body 30 and the facing roller 56 in the secondary transfer region TR relative to the nip pressure Np becomes larger. Therefore, in this example, the nip pressure Np is finely adjusted by adding a nip pressure adjustment mechanism 130 on the transfer belt unit 51 side.

[0226] - Posture adjustment based on posture adjustment mechanism -

[0227] In this embodiment, regarding the posture adjustment mechanism 150, as shown in FIG. Fig. 22 (a) Fig. 22 As shown in (b), the axial distance between the first tensioning roller 52 and the second tensioning roller 53 of the transfer belt unit 51 maintains a certain dimension Lc at both ends of the axial direction. In the above state, the position of the rotating shaft 53a on the front side of the second tensioning roller 53 is displaced to adjust the posture of the second tensioning roller 53.

[0228] At this time, the speed of both ends of the transfer conveyor belt 54 in the width direction is constant, and the travel of the transfer conveyor belt 54 can be adjusted by adjusting the posture of the second tension roller 53 .

[0229] Comparison method 1

[0230] In the said aspect, Fig. 22 In the posture adjustment mechanism 150' of the comparative embodiment 1 shown in (c), the position constraint mechanism 151 of the embodiment is not used and only the displacement mechanism 160 is used, for example. Fig. 22 (c) Fig. 22 As shown in (d), when the transfer conveyor belt 54' of the transfer belt unit 51' is studied, even if the axial distance between the first tension roller 52' ​​and the second tension roller 53' is dimension Lc at the rear side, since the front side is dimension Lc' (≠Lc), the circumferential speeds of both ends of the transfer conveyor belt 54' in the width direction become v1≠v2 and are different. Therefore, there is a concern that the transfer conveyor belt 51' is prone to meandering.

[0231] -Positional relationship between the secondary transfer device and surrounding parts-

[0232] In this embodiment, if Figure 6 and Figure 7As shown, a de-staticizing component (for example, a de-staticizing needle) 180 or a plate-shaped guide groove 185 serving as a guiding element for guiding and conveying the medium is provided on the downstream side of the transfer conveyor belt 54 of the transfer belt unit 51 in the conveying direction. Even if the position of the transfer belt unit 51 changes, the relative relationship between the de-staticizing component 180 or the guide groove 185 and the transfer belt unit 51 will not change, so the de-staticizing effect of the de-staticizing component and the guiding performance of the medium based on the guide groove 185 are maintained well.

[0233] Furthermore, the second tension roller 53 is arranged in contact with the contact point 190 which is a connection portion with the high resistor 58 , and the relative positional relationship between the second tension roller 53 and the contact point 190 is well maintained even if the position of the transfer belt unit 51 changes.

[0234] Furthermore, the transfer belt unit 51 is provided with the cleaning unit 170 . Even if the position of the transfer belt unit 51 changes, the cleaning unit 170 moves following the transfer belt unit 51 . Therefore, the relative positional relationship between the two is well maintained.

[0235] Comparison method 2

[0236] Fig.23 An example of an image forming apparatus according to Comparative Example 2 is shown.

[0237] In the figure, the secondary transfer device 50' includes a transfer belt unit 51' in the form of a transfer conveyor belt 54' mounted between a first tensioning roller 52' ​​and a second tensioning roller 53'. In this example, it includes: a clamping pressure adjustment mechanism 310 for pressing the opposing roller 56' of the intermediate transfer body 40 against the transfer belt unit 51' side; and a parallelism adjustment mechanism 320 for adjusting the parallelism of the opposing roller 56' in a horizontal direction intersecting the clamping pressure adjustment direction.

[0238] In this example, the nip pressure adjustment and the like are not performed on the transfer belt unit 51 ′ side, and the nip pressure and parallelism of the facing roller 56 ′ are adjusted.

[0239] In this example, it is difficult to achieve both the nip pressure and the parallelism of the facing roller 56 ′. If the parallelism of the facing roller 56 ′ is not adjusted sufficiently, the transfer conveyor belt 54 ′ of the transfer belt unit 51 ′ may easily tilt.

[0240] As described above, it can be understood that the nip pressure and parallelism adjustment of the image forming apparatus of Comparative Example 2 are likely to be insufficient compared to the present embodiment.

[0241] Deformation method

[0242] In this embodiment, a form including a clamping pressure switching mechanism 120 and a clamping pressure adjustment mechanism 130 is disclosed. For example, for a medium processing device in which the type of medium to be used is predetermined, it is of course possible to set it to not use the clamping pressure switching mechanism 120 and only use the clamping pressure adjustment mechanism 130.

[0243] In addition, in the present embodiment, the following configuration is adopted: a rotating eccentric member (cam member) is used for the retraction mechanism 110, the clamping pressure switching mechanism 120, the clamping pressure adjustment mechanism 130 and the posture adjustment mechanism 150, but this is not limited to this. Instead of the rotating eccentric member, an advance and retreat member or an actuator capable of moving in an advance and retreat curve may be used to perform displacement.

[0244] Furthermore, in the present embodiment, the clamping pressure adjustment mechanism 130 is respectively provided at two locations, the front side and the rear side of the belt transfer module 200, but in consideration of the operability of the adjustment, it may be provided only at the front side (near front side) of the belt transfer module 200. In addition, regarding the posture adjustment mechanism 150, in consideration of the operability of the adjustment, a form in which it is provided only at the front side (near front side) of the belt transfer module 200 is disclosed, but in the case where it is desired to be able to pre-adjust the posture of the transfer belt unit 51 before the belt transfer module 200 is mounted in the device frame 21, it is of course possible to also provide the posture adjustment mechanism 150 at the rear side (inner side) of the belt transfer module 200.

[0245] In addition, in this example, the clamping pressure adjustment mechanism 130 and the posture adjustment mechanism 150 are adjusted manually by the user or using a clamp, but if a driving source or an actuator is used to drive the fine adjustment cam 131 of the clamping pressure adjustment mechanism 130 or the displacement adjustment cam 169 of the posture adjustment mechanism 150, the control device 100 can also be used to check whether it is suitable for the clamping pressure state or the running state of the conveyor belt, thereby performing automatic adjustment.

Claims

1. A medium transport device, characterized in that: include: A conveyor belt is arranged facing the image holding element holding the image, and is used to convey the medium, and the conveyor belt can move cyclically; a first tensioning roller, which tensions a portion of the conveyor belt and is disposed opposite to the image holding element, sandwiches the medium between the image holding element and the conveyor belt and conveys the medium, and transfers the image held by the image holding element to the medium; a second tensioning roller for tensioning the conveyor belt from a tensioning position based on the first tensioning roller to a position located downstream in a conveying direction of the medium; a contact adjustment element that uses one axial end of the first tensioning roller as a fulcrum and swings the other end to adjust the contact state of the image holding element and the conveyor belt in the longitudinal direction of the contact area between the image holding element and the conveyor belt; and a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one end of the axial direction of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller, The posture adjustment element includes: a position restraining mechanism, which is provided at both ends of the first tensioning and stretching roller and the second tensioning and stretching roller, and allows the rotation of the two rollers and keeps the distance between the two rollers constant; The position constraint mechanism comprises: Limiting rollers are arranged at both ends of the first tensioning roller and the second tensioning roller, and each of the limiting rollers is arranged coaxially with the first tensioning roller and the second tensioning roller; a gap adjustment roller interposed between the limiting rollers and arranged in contact with the limiting rollers; and The holding frames each hold the two regulating rollers and the one interval adjusting roller so that the respective axes are rotatable, and hold the axes of the regulating roller and the interval adjusting roller so as to be aligned in a straight line.

2. A medium transport device, characterized in that: include: A conveyor belt is arranged facing the image holding element holding the image, and is used to convey the medium, and the conveyor belt can move cyclically; a first tensioning roller, which tensions a portion of the conveyor belt and is disposed opposite to the image holding element, sandwiches the medium between the image holding element and the conveyor belt and conveys the medium, and transfers the image held by the image holding element to the medium; a second tensioning roller for tensioning the conveyor belt from a tensioning position based on the first tensioning roller to a position located downstream in a conveying direction of the medium; a contact adjustment element that uses one axial end of the first tensioning roller as a fulcrum and swings the other end to adjust the contact state of the image holding element and the conveyor belt in the longitudinal direction of the contact area between the image holding element and the conveyor belt; and a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one end of the axial direction of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller, A static eliminating element for eliminating static electricity from the medium is provided on the downstream side of the conveying belt in the conveying direction of the medium, and the static eliminating element moves following the swing of the second tension roller.

3. A medium transport device, characterized in that: include: A conveyor belt is arranged facing the image holding element holding the image, and is used to convey the medium, and the conveyor belt can move cyclically; a first tensioning roller, which tensions a portion of the conveyor belt and is disposed opposite to the image holding element, sandwiches the medium between the image holding element and the conveyor belt and conveys the medium, and transfers the image held by the image holding element to the medium; a second tensioning roller for tensioning the conveyor belt from a tensioning position based on the first tensioning roller to a position located downstream in a conveying direction of the medium; a contact adjustment element that uses one axial end of the first tensioning roller as a fulcrum and swings the other end to adjust the contact state of the image holding element and the conveyor belt in the longitudinal direction of the contact area between the image holding element and the conveyor belt; and a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one end of the axial direction of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller, A guide element for guiding the medium is provided on a downstream side of the conveyance belt in a conveyance direction of the medium, and the guide element moves following the swing of the second tension roller.

4. A medium transport device, characterized in that: include: A conveyor belt is arranged facing the image holding element holding the image, and is used to convey the medium, and the conveyor belt can move cyclically; a first tensioning roller, which tensions a portion of the conveyor belt and is disposed opposite to the image holding element, sandwiches the medium between the image holding element and the conveyor belt and conveys the medium, and transfers the image held by the image holding element to the medium; a second tensioning roller for tensioning the conveyor belt from a tensioning position based on the first tensioning roller to a position located downstream in a conveying direction of the medium; a contact adjustment element that uses one axial end of the first tensioning roller as a fulcrum and swings the other end to adjust the contact state of the image holding element and the conveyor belt in the longitudinal direction of the contact area between the image holding element and the conveyor belt; and a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one end of the axial direction of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller, The second tension roller is grounded via a high resistor, and a connection portion to the high resistor moves following the swing of the second tension roller.

5. A medium transport device, characterized in that: include: A conveyor belt is arranged facing the image holding element holding the image, and is used to convey the medium, and the conveyor belt can move cyclically; a first tensioning roller, which tensions a portion of the conveyor belt and is disposed opposite to the image holding element, sandwiches the medium between the image holding element and the conveyor belt and conveys the medium, and transfers the image held by the image holding element to the medium; a second tensioning roller for tensioning the conveyor belt from a tensioning position based on the first tensioning roller to a position located downstream in a conveying direction of the medium; a contact adjustment element, which uses one axial end of the first tensioning roller as a fulcrum and swings the other end thereof, thereby adjusting the contact state of the image holding element and the conveyor belt in the long side direction of the contact area between the image holding element and the conveyor belt; a posture adjustment element, which keeps the distance between the center of the first tensioning roller and the center of the second tensioning roller constant, and uses one axial end of the second tensioning roller as a fulcrum to swing the other end, thereby adjusting the posture of the second tensioning roller relative to the first tensioning roller; and a cleaning element for cleaning the conveyor belt at a portion of the conveyor belt that is tensioned by the first tensioning roller; The cleaning element moves following the swing of the first tension roller.

6. The medium transport device according to any one of claims 1 to 5, characterized in that: The contact adjustment member includes a displacement mechanism that causes the other axial end of the first tension roller to swing toward the image holding member side facing the first tension roller.

7. The medium transport device according to claim 6, characterized in that: The displacement mechanism linearly advances and retreats a holding member via an eccentric rotating member, and the holding member rotatably holds the other axial end of the first tension roller.

8. The medium transport device according to claim 1, characterized in that: The posture adjustment element further includes a displacement mechanism that swings the other axial end of the second tension roller using the other axial end of the first tension roller as a fulcrum.

9. The medium transport device according to claim 8, characterized in that: The displacement mechanism moves the other axial end of the second tension roller forward and backward in a direction perpendicular to a reference line connecting the axial centers of the first tension roller and the second tension roller.

10. The medium transport device according to any one of claims 2 to 4, characterized in that: The conveyor belt, the first tension roller, and the second tension roller are mounted on a swing frame that is swingable relative to a fixed frame, and each element that moves following the swing of the second tension roller is provided on the swing frame.

11. The medium transport device according to claim 5, characterized in that: The cleaning frame of the cleaning element moves around a predetermined fulcrum to follow the swing of the first tension roller.

12. A medium processing device, characterized in that include: An image holding element for holding the image; The medium conveying device according to any one of claims 1 to 11 is arranged to face the image holding element, and transfers and conveys the image held by the image holding element.

13. The medium processing device according to claim 12, characterized in that Including pick-up and drop-out components, The contacting and separating element causes the medium transport device to contact with and separate from the image holding element.

14. The medium processing device according to claim 12, characterized in that: The image holding element includes a second contact adjusting element that adjusts a contact state between the image holding element and the conveying belt in the contact region separately from the contact adjusting element of the medium conveying device.

15. The medium processing device according to claim 14, characterized in that: The medium transport device is disposed below the image holding element and is provided to be able to be pulled out relative to a housing of the medium processing device.

16. The medium processing device according to claim 14, characterized in that: The opposing constituent member on the medium conveying device side that faces each other across the contact region has a lower hardness than the opposing constituent member on the image holding element side.

Images