Image Formation Apparatus

Abstract

A cooling device has: first and second guide rollers disposed in the body of a cooling device on upstream and downstream sides, respectively, as seen in a direction in which a continuous medium is fed, and guiding a cooling belt to move in that direction; and a path selection mechanism allowing selection between a non-abutting transport path which does not cause the continuous medium to abut against the cooling belt and an abutting transport path which causes the continuous medium to abut against the cooling belt.

Claims

1. An electrophotographic image formation apparatus capable of forming an image on a continuous medium, comprising: a sheet feeding device configured to feed the continuous medium; a winding device configured to wind up the continuous medium fed from the sheet feeding device; and a body of the image formation apparatus configured to form an image on the continuous medium while the continuous medium is transported between the sheet feeding device and the winding device, the body of the image formation apparatus including: a transfer device configured to transfer a prescribed toner image to the continuous medium; a fixing device configured to apply heat to fix the toner image transferred to the continuous medium; and a cooling device configured to cool the continuous medium heated, the cooling device having: a cooling belt disposed only on a side of one surface of the continuous medium and having a region which at least abuts against the continuous medium moved in a direction in which the continuous medium is fed; a body of the cooling device abutting against the cooling belt on a side of the cooling belt opposite to that thereof abutting against the continuous medium; first and second guide rollers disposed in the body of the cooling device on upstream and downstream sides, respectively, as seen in the direction in which the continuous medium is fed, and guiding the cooling belt to move in that direction; and a path selection mechanism allowing selection between a non-abutting transport path which does not cause the continuous medium to abut against the cooling belt and an abutting transport path which causes the continuous medium to abut against the cooling belt.

2. The image formation apparatus according to claim 1, wherein, in a state where the path selection mechanism selects the abutting transport path, relative to a passing path allowing the continuous medium passing between the first guide roller and the second guide roller to abut against the cooling belt, a passing path of the continuous medium located upstream oldie first guide roller is a path inclined in a direction to turn around the first guide roller and a passing path of the continuous medium located downstream of the second guide roller is a path inclined in a direction to turn around the second guide roller.

3. The image formation apparatus according to claim 2, wherein: the path selection mechanism, as seen in the direction in which the continuous medium is fed, has an upstream movable guide roller which is upstream of the first guide roller and located opposite to the first guide roller with the continuous medium posed therebetween, an upstream fixed guide roller which is upstream of the upstream movable guide roller and located opposite to the upstream movable guide roller with the continuous medium posed therebetween, a downstream movable guide roller which is downstream of the second guide roller and located opposite to the second guide roller with the continuous medium posed therebetween, and a downstream fixed guide roller which is downstream of the downstream movable guide roller and located opposite to the downstream movable guide roller with the continuous medium posed therebetween; and by moving the upstream movable guide roller toward the first guide roller and moving the downstream movable guide roller toward the second guide roller, the abutting transport path which causes the continuous medium to abut against the cooling belt is selected, and from a state where the abutting transport path is selected, by moving the upstream movable guide roller in a direction away from the first guide roller and moving the downstream movable guide roller in a direction away from the second guide roller, the non-abutting transport path which does not cause the continuous medium to abut against the cooling belt is selected.

4. The image formation apparatus according to claim 3, wherein, depending on a type of the continuous medium, a pressing force exerted to abut the continuous medium against the cooling belt is determined by selecting an amount of moving the upstream movable guide roller toward the first guide roller and an amount of moving the downstream movable guide roller toward the second guide roller.

5. The image formation apparatus according to claim 1, wherein while the continuous medium, after having passed through the fixing device, runs meandering, the path selection mechanism selects the non-abutting transport path.

6. The image formation apparatus according to claim 1, wherein, in a state where the path selection mechanism selects the abutting transport path, a rate applied to transport the cooling belt is set to be slower than a rate applied to feed the continuous medium to allow the cooling belt to follow movement of the continuous medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic diagram showing a general configuration of an image formation apparatus of an embodiment.

[0018] FIG. 2 is a schematic diagram showing an internal configuration o an image formation apparatus of an embodiment.

[0019] FIG. 3 is a schematic diagram showing a state where a non-abutting transport path of an embodiment is selected.

[0020] FIG. 4 is a schematic diagram showing a state where an abutting transport path of the embodiment is selected.

[0021] FIG. 5 is an enlarged view of an area surrounded by a circle V shown in FIG. 4.

[0022] FIG. 6 represents a relationship between types of continuous media and inclination angles.

[0023] FIG. 7 is a chart figure schematically representing a state of a continuous medium meandering in an embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An image formation apparatus in an embodiment based on the present invention will be described hereinafter with reference to the drawings. Note that in any embodiment described hereafter, when numbers, amounts and the like are referred to, the present invention is not necessarily limited in scope thereto unless otherwise indicated. Identical and corresponding components and parts are identically denoted and may not be described repeatedly. Furthermore, the drawings are not shown in accordance with an actual dimensional ratio, and to help understanding a structure, there is a portion shown with a modified ratio to clarify the structure.

[0025] (1) Image Formation Apparatus 1

[0026] With reference to FIGS. 1 and 2, a schematic configuration of an image formation apparatus 1 in the present embodiment will be described. FIG. 1 is a schematic diagram showing a general configuration of image formation apparatus 1, and FIG. 2 is a schematic diagram showing an internal configuration of the image formation apparatus.

[0027] Image formation apparatus 1 includes a sheet feeding device 1A, a main body 1B of the image formation apparatus, and a winding device 1C. Sheet feeding device 1A has a continuous medium P1 wound in the form of a roll, and continuous medium P1, after being fed from sheet feeding device 1A in a feeding direction A1, passes along a transport path through main body 1B of the image formation apparatus, and after a prescribed image is formed, continuous medium P1 is wound up in winding device 1C in the form of a roll.

[0028] When continuous medium P1 is transported, it receives tension T, which is adjusted by a rate of sheet feeding device 1A to feed a sheet and a rate of winding device 1C to wind up the sheet. For example, setting the rate of winding device 1C to wind up a sheet to be faster than the rate of sheet feeding device 1A to feed the sheet allows continuous medium P1 to experience larger tension.

[0029] Main body 1B of the image formation apparatus is internally provided with a transfer device 40 which transfers a prescribed toner image to continuous medium P1, an image fixing device 50 which applies heat to fix the toner image transferred to continuous medium P1, and a cooling device 60 which cools continuous medium P1 heated, and they configure a portion of a transport path.

[0030] (Cooling Device 60)

[0031] Subsequently, with reference to FIG. 3 and FIG. 4, a configuration of cooling device 60, and a configuration of a path selection mechanism 70 allowing selection between a non-abutting transport path A11 which does not cause continuous medium P1 to abut against a cooling belt 62 and an abutting transport path A12 which causes continuous medium P1 to abut against cooling belt 62, will be described. FIG. 3 is a schematic diagram showing a state where non-abutting transport path A11 is selected, and FIG. 4 is a schematic diagram showing a state where abutting transport path A12 is selected.

[0032] With reference to FIG. 3, cooling device 60 has cooling belt 62 which is disposed only on the side of one surface of continuous medium P1 (in the present embodiment, on an upper side) and has a region which at least abuts against continuous medium P1 moved in direction A1 in which continuous medium P1 is fed. In the present embodiment, cooling belt 62 in a side view forms a rectangular, infinite loop track.

[0033] As seen in direction A1 in which continuous medium P1 is fed, a first guide roller R1 is disposed upstream, a second guide roller R2 is disposed downstream, a third guide roller R3 is disposed over second guide roller R2, and a fourth guide roller R4 is disposed upstream of third guide roller R3 and over first guide roller R1. Cooling belt 62 is wound around these four guide rollers to form the rectangular, infinite loop track in the side view.

[0034] Between first guide roller R1 and second guide roller R2, a body 61 of the cooling device is provided which abuts against cooling belt 62 on a side of cooling belt 62 opposite to that thereof abutting against continuous medium P1 (in the present embodiment, on an upper side of cooling belt 62). Although body 61 of the cooling device is not limited in form in particular, a cooling device including a heat sink system, a water cooling system, etc. is adopted.

[0035] Furthermore, cooling device 60 includes path selection mechanism 70 allowing selection between non-abutting transport path A11 which does not cause continuous medium P1 to abut against cooling belt 62, as shown in FIG. 3, and abutting transport path A12 which causes continuous medium P1 to abut against cooling belt 62, as shown in FIG. 4.

[0036] (Path Selection Mechanism 70)

[0037] In the present embodiment, as an example, path selection mechanism 70, as seen in direction A1 in which continuous medium P1 is fed, has an upstream movable guide roller R11 which is upstream of first guide roller R1 and located opposite to first guide roller R1 with continuous medium P1 posed therebetween, and an upstream fixed guide roller R21 which is upstream of upstream movable guide roller R11 and located opposite to upstream movable guide roller R11 with continuous medium P1 posed therebetween.

[0038] Specifically, first guide roller R1 and upstream fixed guide roller R21 are located above continuous medium P1, and upstream movable guide roller R11 is located below continuous medium P1 between first guide roller R1 and upstream fixed guide roller R21.

[0039] Upstream movable guide roller R11 is provided to be movable between a direction to approach first guide roller R1 and a direction to move away from first guide roller R1. FIG. 3 shows a state where upstream movable guide roller R11 has moved to a position remotest from first guide roller R1, and FIG. 4 shows a state where upstream movable guide roller R11 has moved to a position closest to first guide roller R1.

[0040] Upstream fixed guide roller R21 is disposed such that it is fixed at a position in contact with continuous medium P1.

[0041] Furthermore, path selection mechanism 70 has a downstream movable guide roller R12 which is downstream of second guide roller R2 and located opposite to second guide roller R2 with continuous medium P1 posed therebetween, and a downstream fixed guide roller R22 which is downstream of downstream movable guide roller R12 and located opposite to downstream movable guide roller R12 with continuous medium P1 posed therebetween.

[0042] Specifically, second guide roller R2 and downstream fixed guide roller R22 are located above continuous medium P1, and downstream movable guide roller R12 is located below continuous medium P1 between second guide roller R2 and downstream fixed guide roller R22.

[0043] Downstream movable guide roller R12 is provided to be movable between a direction to approach second guide roller R2 and a direction to move away from second guide roller R2. FIG. 3 shows a state where downstream movable guide roller R12 has moved to a position remotest from second guide roller R2, and FIG. 4 shows a state where downstream movable guide roller R12 has moved to a position closest to second guide roller R2.

[0044] Downstream fixed guide roller R22 is disposed such that it is fixed at a position in contact with continuous medium P1.

[0045] In the above configuration, as shown in FIG. 3, by moving upstream movable guide roller R11 in a direction away from first guide roller R1, and similarly moving downstream movable guide roller R12 in a direction away from second guide roller R2, non-abutting transport path A11 serves as a path which does not cause continuous medium P1 to abut against cooling belt 62.

[0046] In contrast, as shown in FIG. 4, by moving upstream movable guide roller R11 toward first guide roller R1, and similarly moving downstream movable guide roller R12 toward second guide roller R2, abutting transport path A12 serves as a path which causes continuous medium P1 to abut against cooling belt 62.

[0047] As described above, path selection mechanism 70 moves upstream movable guide roller R11 and downstream movable guide roller R12 to allow selection between non-abutting transport path A11 which does not cause continuous medium P1 to abut against cooling belt 62 and abutting transport path A12 which causes continuous medium P1 to abut against cooling belt 62.

[0048] Thus, path selection mechanism 70 is included to allow selection between non-abutting transport path A11 which does not cause continuous medium P1 to abut against cooling belt 62 and abutting transport path A12 which causes continuous medium P1 to abut against cooling belt 62, and continuous medium P1 can thus be cooled without being sandwiched at the opposite sides.

[0049] Accordingly, if continuous medium P1 should meander, continuous medium P1 has only one side surface pressed, and when compared with the belt-sandwiched cooling in which continuous medium P1 is sandwiched at the opposite sides, an effect on continuous medium P1 can be reduced.

[0050] (Winding Angle)

[0051] With reference to FIG. 5 and FIG. 6, a winding angle of continuous medium P1 around first guide roller R1 and second guide roller R2 by path selection mechanism 70 will be described. FIG. 5 is an enlarged view of an area surrounded by a circle V shown in FIG. 4, and FIG. 6 represents a relationship between types of continuous media and inclination angles.

[0052] With reference to FIG. 5, in a state where path selection mechanism 70 selects abutting transport path A12, relative to a passing path A21 allowing continuous medium P1 passing between first guide roller RI and second guide roller R2 to abut against cooling belt 62, a passing path A22 of continuous medium P1 located upstream of first guide roller R1 will be a path inclined in a direction to turn around first guide roller R1. Such an inclination angle θ of passing path A22 relative to passing path A21 will he referred to as a winding angle.

[0053] Similarly, in the state where path selection mechanism 70 selects abutting transport path A12, relative passing path A21, a passing path A23 of continuous medium P1 located downstream of second guide roller R2 will be a path inclined in a direction to turn around second guide roller R2. This inclination angle θ of passing path A23 relative to passing path A21 will also be referred to as a winding angle.

[0054] Inclination angle θ on the side of first guide roller RI and inclination angle θ on the side of second guide roller R2 are equal and accordingly, hereinafter, inclination angle θ on the side of first guide roller R1 will be described.

[0055] Tension T applied to continuous medium P1 is normally set to 20 N to 40 N. In a state where abutting transport path A12 is selected, a pressing force F exerted to press continuous medium P1 toward first guide roller R1 is obtained by F=2Tsinθ. When T is fixed, F has a magnitude determined by sinθ, sine has a value increasing as inclination angle θ increases. Accordingly, when the inclination angle is increased, pressing force F is also increased.

[0056] Depending on the type of continuous medium P1, pressing force F exerted to abut continuous medium P1 against cooling belt 62 may be determined by selecting an amount of moving upstream movable guide roller R11 toward first guide roller R1 and an amount of moving downstream movable guide roller R12 toward second guide roller R2.

[0057] When upstream movable guide roller R11 is moved toward first guide roller R1 in an increased amount, inclination angle θ has an increased value. As a result, pressing force F exerted to abut continuous medium P1 against cooling belt 62 can be increased. Downstream movable guide roller R12 can be similarly discussed.

[0058] FIG. 6 represents a relationship between types of continuous medium P1 and inclination angles. A case will be described in which continuous medium P1 is divided in sheet weight in grams per square metre (gsm) into three types of 105 (gsm) or less, 106 (gsm) or more and 176 (gsm) or less, and 177 (gsm) or more. Sheet weight in grams per square metre is a representation of a weight of a sheet representing the weight of the sheet per area of 1 m.sup.2.

[0059] When continuous medium P1 has a sheet weight of 105 gsm, then normally, continuous medium P1 is small in thickness. As a result, it is preferable that the medium be pushed with a large amount of pressure. Upstream movable guide roller R11 is moved in an amount adjusted so that inclination angle θ is 2 degrees. Downstream movable guide roller R12 is also moved in an amount similarly adjusted.

[0060] When continuous medium P1 has a sheet weight of 106 (gsm) or more and 176 (gsm) or less, then normally, continuous medium P1 has a standard thickness. As a result, it is preferable that the medium be pushed with a medium amount of pressure. Upstream movable guide roller R11 is moved in an amount adjusted so that inclination angle θ is 1.5 degrees. Downstream movable guide roller R12 is also moved in an amount similarly adjusted.

[0061] When continuous medium P1 has a sheet weight of 177 gsm or more, then normally, continuous medium P1 is large in thickness. As a result, it is preferable that the medium be pushed with a small amount of pressure. Upstream movable guide roller R11 is moved in an amount adjusted so that inclination angle θ is 1 degree. Downstream movable guide roller R12 is also moved in an amount similarly adjusted.

[0062] Thus, by adjusting the inclination angle based on the type of continuous medium P1, a pressing force appropriate for continuous medium P1 used can be exerted to bias continuous medium P1 toward cooling belt 62. As a result, continuous medium P1 can be optimally cooled.

[0063] Furthermore, when continuous medium P1 meanders, then, until the meandering of continuous medium P1 converges, path selection mechanism 70 operates to select non-abutting transport path A11 which does not cause continuous medium P1 to abut against cooling belt 62, and a load on continuous medium P1 and cooling device 60 can be eliminated.

[0064] FIG. 7 is a chart figure schematically representing a state of continuous medium P1 meandering. The axis of ordinate represents the position (or deviation) of continuous medium P1, and the axis of abscissa represents time. A line L1 represents an amount of deviation of continuous medium P1. A line L2 represents starting to draw an image by transfer device 40.

[0065] After image fixing device 50 has finished fixing and pressing and thus settling, continuous medium P1 runs meandering in an amount exceeding −2 mm. Accordingly, starting to draw an image by transfer device 40 is in an OFF state. Thereafter, continuous medium P1 runs meandering in air amount within −2 mm. Accordingly, starting to draw an image by transfer device 40 is set to an ON state.

[0066] Thus, while continuous medium P1 runs meandering, path selection mechanism 70 operates to select non-abutting transport path A11 to prevent continuous medium P1 from abutting against cooling device 60, and continuous medium P1 and cooling device 60 can avoid damage (e.g., being flawed by the belt).

[0067] Furthermore, in a state where path selection mechanism 70 selects abutting transport path A12, cooling belt 62 may be transported at a rate set to be slower than continuous medium P1 is, and cooling belt 62 may thus follow the movement of continuous medium P1.

[0068] In this case, at least one of first guide roller R1, second guide roller R2, third guide roller R3, and fourth guide roller R4 is provided with a drive device, and the drive device can include a one-way mechanism to prevent slipping between continuous medium P1 and cooling belt 62 to prevent continuous medium P1 from being flawed by the belt.

[0069] Thus, image formation apparatus 1 in the present embodiment, in a case where continuous medium P1 is used, can dispense with belt-sandwiched cooling in cooling the continuous medium after fixing by heating while preventing the continuous medium from meandering while running.

[0070] Furthermore, the apparatus is not increased in size and path selection mechanism 70 that allows selection between non-abutting transport path A11 which does not cause continuous medium P1 to abut against cooling belt 62 and abutting transport path A12 which causes continuous medium P1 to abut against cooling belt 62 is adopted to allow the continuous medium after fixing by heating to be cooled appropriately.

[0071] The present image formation apparatus is an image formation apparatus of an electrophotographic system capable of forming an image on a continuous medium, comprising: a sheet feeding device configured to feed the continuous medium; a winding device configured to wind up the continuous medium fed from the sheet feeding device; and a body of the image formation apparatus configured to form an image on the continuous medium while the continuous medium is transported between the sheet feeding device and the winding device.

[0072] The body of the image formation apparatus includes: a transfer device configured to transfer a prescribed toner image to the continuous medium; a fixing device configured to apply heat to fix the toner image transferred to the continuous medium; and a cooling device configured to cool the continuous medium heated.

[0073] The cooling device has: a cooling belt disposed only on the side of one surface of the continuous medium and having a region which at least abuts against the continuous medium moved in a direction in which the continuous medium is fed; a body of the cooling device abutting against the cooling belt on a side of the cooling belt opposite to that thereof abutting against the continuous medium; first and second guide rollers disposed in the body of the cooling device on upstream and downstream sides, respectively, as seen in the direction in which the continuous medium is fed, and guiding the cooling belt to move in that direction; and a path selection mechanism allowing selection between a non-abutting transport path which does not cause the continuous medium to abut against the cooling belt and an abutting transport path which causes the continuous medium to abut against the cooling belt.

[0074] In another form, in a state where the path selection mechanism selects the abutting transport path, relative to a passing path allowing the continuous medium passing between the first guide roller and the second guide roller to abut against the cooling belt, a passing path of the continuous medium located upstream of the first guide roller will be a path inclined in a direction to turn around the first guide roller and a passing path of the continuous medium located downstream of the second guide roller will be a path inclined in a direction to turn around the second guide roller.

[0075] In another form, the path selection mechanism, as seen in the direction in which the continuous medium is fed, has: an upstream movable guide roller which is upstream of the first guide roller and located opposite to the first guide roller with the continuous medium posed therebetween; an upstream fixed guide roller which is upstream of the upstream movable guide roller and located opposite to the upstream movable guide roller with the continuous medium posed therebetween; a downstream movable guide roller which is downstream of the second guide roller and located opposite to the second guide roller with the continuous medium posed therebetween; and a downstream fixed guide roller which is downstream of the downstream movable guide roller and located opposite to the downstream movable guide roller with the continuous medium posed therebetween.

[0076] By moving the upstream movable guide roller toward the first guide roller and moving the downstream movable guide roller toward the second guide roller, the abutting transport path which causes the continuous medium to abut against the cooling belt is selected, and, from a state where the abutting transport path is selected, by moving the upstream movable guide roller in a direction away from the first guide roller and moving the downstream movable guide roller in a direction away from the second guide roller, the non-abutting, transport path which does not cause the continuous medium to abut against the cooling belt is selected.

[0077] In another form, depending on the type of the continuous medium, a pressing force exerted to abut the continuous medium against the cooling belt is determined by selecting an amount of moving the upstream movable guide roller toward the first guide roller and an amount of moving the downstream movable guide roller toward the second guide roller.

[0078] In another form, while the continuous medium, after having passed through the fixing device, runs meandering, the path selection mechanism selects the non-abutting transport path.

[0079] In another form, in a state where the path selection mechanism selects the abutting transport path, a rate applied to transport the cooling belt is set to be slower than a rate applied to feed the continuous medium to allow the cooling belt to follow movement of the continuous medium.

[0080] The present image formation apparatus is configured such that when a continuous medium is used, the continuous medium, after fixing by heating, can be cooled without belt-sandwiched cooling adopted.

[0081] While the present invention has been described in embodiments, it should be understood that the embodiments disclosed herein are illustrative and non-restrictive in any respect. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims.