JP2021059439A - Image forming device and sheet cooling device - Google Patents

Abstract

To provide an image forming device capable of suppressing skew of a sheet to be conveyed as compared with a conventional one.SOLUTION: An image forming device includes: image forming means for forming an image on a sheet; fixing means for fixing the image formed on the sheet; and a plurality of sheet conveyance means 120, 121 for conveying the sheet, on which the image is fixed by the fixing means, at points different from each other on a conveyance path. At least one of the plurality of sheet conveyance means comprises a plurality of center sorting roll bodies 120F, 120R, 120'F, 120'R arranged with intervals in a region on a center side of the sheet in a width direction orthogonal to a conveyance direction, or comprises center roll bodies 121C, 121'C arranged in the region on the center side and both-side roll bodies 121F, 121R, 121'F, 121'R arranged with intervals on both sides of the center roll bodies.SELECTED DRAWING: Figure 5

Description

The present invention relates to an image forming apparatus and a sheet cooling apparatus.

Conventionally, an image forming means for forming an image on a sheet, a fixing means for fixing an image formed on the sheet, and a plurality of sheet transporting means for transporting a sheet on which an image is fixed by the fixing means at different locations on a transport path. An image forming apparatus having the above is known.
For example, Patent Document 1 describes the following image forming apparatus. The rotation axes of the recording medium (sheet) discharged from the fuser (fixing means) are arranged in a parallel relationship so as to sandwich a part of the maximum region forming an image in the orthogonal direction orthogonal to the transport direction. A transport roll member in which a pair of rolls is arranged at one or more locations in the orthogonal direction thereof is provided with a transport means in which a plurality of transport roll members are arranged in the transport direction. The area obtained by adding the areas of the recording medium sandwiched by each pair of rolls covers the entire area orthogonal to the maximum area. According to this, the toner image is uniformly cooled, and unlike the one in which the maximum region is sandwiched by a pair of rolls alone, the occurrence of wrinkles in the recording material can be suppressed.

However, there was still a risk of skewing the sheet to be transported.

In order to solve the above-mentioned problems, the present invention conveys an image forming means for forming an image on a sheet, a fixing means for fixing an image formed on the sheet, and a sheet on which an image is fixed by the fixing means. In an image forming apparatus having a plurality of sheet transporting means for transporting at different locations, at least one of the plurality of sheet transporting means is located in a region on the center side of the sheet in a width direction orthogonal to the transporting direction. A plurality of central distribution roll bodies arranged at intervals, or a central roll body arranged in the central region and a double-sided roll arranged at intervals on both sides of the central roll body. It is characterized by having a body.

According to the present invention, the skew of the sheet to be conveyed can be suppressed as compared with the conventional case.

The perspective view of the image forming apparatus which can adopt the sheet cooling apparatus which concerns on embodiment. The schematic block diagram of the internal structure of an image forming apparatus. Perspective view of the inverted paper ejection path. Explanatory drawing of the reverse paper ejection path. Explanatory drawing of sheet cooling effect in reverse paper ejection path. Explanatory drawing of sheet cooling effect in straight paper discharge path. A front view of a specific example of a straight paper ejection route. Perspective view of the metal guide of the straight paper ejection path. The perspective view of the resin guide member of a straight paper discharge path. The perspective view of the guide member made of the same resin. The perspective view of the guide member made of the same resin. The front view of the specific example of the reverse paper ejection path. The perspective view of the right resin guide member. The perspective view of the entrance resin guide member and the left side resin guide member. The perspective view of the entrance resin guide member. The perspective view of the left resin guide member.

FIG. 1 is a perspective view of an example of an image forming apparatus 1 capable of adopting the sheet cooling apparatus according to the embodiment. The image forming apparatus 1 includes an image forming apparatus main body and an automatic document transporting apparatus (ADF) 2 provided above the image forming apparatus main body. The image forming apparatus main body is composed of a paper feeding unit 3, an image reading unit 4, an image forming unit 5, and an operation unit 6. A toner replenishment unit 7 provided with a front door portion is arranged on the front side F of the image forming unit 5. A drawer unit 8 that can be pulled out to the front side F is configured. On the left side surface, a paper ejection tray 9 is provided as a paper ejection portion. The front side F of the image forming apparatus 1 means the front side of the image forming apparatus 1, and the rear side R means the back side of the image forming apparatus 1.

A fixing device 113, which will be described later, is provided in the drawer unit 8. When removing the fixing device 113, the drawer unit 8 is pulled as shown in FIG. 1, and the attachment / detachment operation is performed in a state where the drawer unit 8 is completely pulled out to the front surface (F direction) of the device.

FIG. 2 is a schematic configuration diagram of the internal structure of the image forming apparatus 1. The image forming apparatus 1 is a full-color copying machine using four color toners of yellow (Y), magenta (M), cyan (C), and black (K). Four image-forming units (image forming units) 101Y, 101M, 101C, and 101K that image with each color toner are arranged side by side in the upper part of the main body of the apparatus. Since the configurations and operations of the image-forming units 101Y, 101M, 101C, and 101K are substantially the same, the image-forming units will be described here by omitting the color symbols (Y, M, C, K). .. In the image forming unit 101, a charger 103, a developing device 104, a cleaning device 105, and the like are arranged around the photoconductor drum 102 as an image carrier. Further, the exposure means 107 is arranged above the photoconductor drum 102.

Below the four image forming units 101Y, 101M, 101C, and 101K, an intermediate transfer belt 108 hung around a plurality of support rollers is arranged. The intermediate transfer belt 108 is driven to travel in the direction of arrow A by rotationally driving one of the support rollers by a driving means. A transfer roller 106 as a primary transfer means is arranged so as to face the photoconductor drum 102 of each image forming unit with the intermediate transfer belt 108 interposed therebetween.

In each image forming unit 101, the photoconductor drum 102 is rotationally driven counterclockwise in the drawing, and the photoconductor surface is uniformly charged to a predetermined polarity by the charger 103. Next, the charged surface is irradiated with a light-modulated laser beam emitted from the exposure means 107, whereby an electrostatic latent image is formed on the photoconductor drum 102. The electrostatic latent image is developed by the toner applied from the developing device 104 and visualized as a toner image. The yellow, magenta, cyan, and black toner images formed by each image forming unit are sequentially superimposed and transferred on the intermediate transfer belt 108.

On the other hand, a feeding section 114 having accommodating trays 114a and 114b is provided in the lower part of the main body of the apparatus, and a sheet such as transfer paper is fed from the feeding section 114. The fed sheet is conveyed toward the resist roller 111 as shown by an arrow B.

The sheet that has been abutted against the resist roller 111 and temporarily stopped is sent out from the resist roller 111 at the timing of the toner image on the intermediate transfer belt 108, and the secondary transfer roller 109 and the intermediate transfer belt 108 are in contact with each other. It is sent to the next transfer section. A voltage opposite to the charging polarity of the toner is applied to the secondary transfer roller 109, whereby the layered toner image (full-color image) on the intermediate transfer belt 108 is transferred onto the sheet. The sheet after the toner image is transferred is conveyed to the fixing device 113 by the conveying belt 112, and the toner is fixed to the sheet by heat and pressure in the fixing device 113. The sheet after the toner image is fixed is discharged to the outside of the machine as shown by an arrow C, and is discharged onto the paper ejection tray 9.

The sheet discharge path after the toner image is fixed includes a straight paper discharge path and a reverse paper discharge path (switchback path). The straight paper ejection route is a route that is conveyed by the paper ejection relay roller 130 in the direction indicated by the arrow E and is ejected by the paper ejection roller 131 to the paper ejection tray 9 outside the machine as shown by the arrow C. The reversing paper ejection path (switchback path) is conveyed to the sheet reversing portion 115 in the transport path direction as shown by the arrow D via the reversing inlet roller 120 and the paper ejection reversing roller 121, and then temporarily stopped, and then temporarily stopped. This is a path in which the 121 rotates in the reverse direction to switch back and feed the paper to the paper ejection roller 131, and as shown by the arrow C, the paper is ejected to the paper ejection tray 9 outside the machine. This reverse paper ejection route is used for single-sided printing and backside ejection (face-down ejection).

In the case of double-sided printing, the sheet after fixing is fed to the double-sided reversing portion 116 via the reversing inlet roller 120 and the paper ejection reversing roller 121, where the front end and the rear end of the transfer are exchanged and sent to the refeed path 117. It is re-delivered to the registration roller 111 via the re-feeding path 117. Then, the toner image is transferred from the intermediate transfer belt 108 to the back surface of the sheet. The sheet after the toner image transfer is fixed by the fixing device 113, and as shown by the arrow C from the fixing device 113 as in the case of single-sided printing, or as shown by the arrow C via the sheet reversing portion 115, the sheet is removed from the machine. It is ejected and ejected onto the output tray. Switching claws 118 and 119 for switching the sheet transport direction are appropriately arranged.

Between the switching claw 118 that switches the sheet transport direction between the straight paper ejection path and the inverted paper ejection path (or the double-sided inverted portion) and the fixing device 113, outlets 140 and 141 that blow air for cooling are provided. Have been placed. In addition to the cooling by the air, the sheet is cooled by the contact of the roll body, the paper ejection relay roller 130 and the paper ejection roller 131 in the straight paper ejection path, and the reversing inlet roller 120 and the paper ejection reversing roller in the reversing paper ejection path. 121 is used. Each of the two rollers (130 and 131, 120 and 121) in each path corresponds to a plurality of sheet transporting means for transporting the fixed sheets at different locations on the transport path.

FIG. 3 is a perspective view showing the reversing inlet roller 120 and the paper ejection reversing roller 121 in the reversing paper ejection path. 4 (a) is a front view, FIG. 4 (b) is a plan view of standing on the left side surface, and FIG. 4 (c) is a left side view. The reversing inlet roller 120 includes a reversing inlet drive first roller 120F and a reversing inlet drive first roller 120F having a predetermined width provided at a predetermined interval X press-fitted into the paper ejection reversing drive roller shaft 120a and the paper ejection reversing drive roller shaft 120a. It has two rollers 120R. Further, it has a reversing inlet driven first roller 120'F and a reversing inlet driven second roller 120'R facing the drive roller. The reversing inlet driven first roller 120F, the reversing inlet driven second roller 120R, the reversing inlet driven first roller 120'F, and the reversing inlet driven second roller 120'R correspond to the intermediate distribution roll body. The reversing inlet driven first roller 120'F and the reversing inlet driven second roller 120'R are pivotally supported by their respective shafts. A specific example will be described later.

The paper ejection reversing roller 121 has a width Y equal to or greater than the predetermined interval X pressed into the paper ejection reversing drive roller shaft 120a and the paper ejection reversing drive roller shaft 120a, and faces the predetermined interval X (all predetermined intervals X are all). The paper ejection reversing drive 1st roller 121C and the paper ejection reversing drive 1st roller 121C are arranged adjacent to each other so as to fit within the width Y). It has 121R and. The output reversing drive second roller 121F and the paper ejection reversing drive third roller 121R have a smaller roller width than the paper ejection reversing drive first roller 121C. Further, it has a paper ejection reversing driven first roller 121'C, a paper ejection reversing driven second roller 121'F, and a paper ejection reversing driven third roller 121'R facing the drive roller. The paper ejection reversal drive first roller 121C and the paper ejection reversal driven first roller 121'C correspond to the central roll body. The paper ejection reversal drive second roller 121F, the paper ejection reversal drive third roller 121R, the paper ejection reversal driven second roller 121'F, and the paper ejection reversal driven third roller 121'R are on both side rolls. Equivalent to. The paper ejection reversal driven first roller 121'C, the paper ejection reversing driven second roller 121'F, and the paper ejection reversal driven third roller 121'R are pivotally supported by their respective shafts. A specific example will be described later.

The reversing inlet roller 120 is driven by a DC motor 122 and rotates via a pulley 123, a timing belt 124, and a pulley 125. The paper ejection reversing roller 121 is driven by a DC motor 126 and rotates via a pulley 127, a timing belt 127a, a gear pulley 128a, a gear pulley 128b, a timing belt 129, and a pulley 129a.

FIG. 5 is an explanatory view of the sheet cooling effect of each roller during transportation in the direction indicated by the arrow D in FIG. 2 by the reversing inlet roller 120 and the paper ejection reversing roller 121. When the sheet heated by the fixing device 113 and whose temperature has risen is conveyed by the reversing inlet roller 120, the temperature of the sheet decreases because the range E shown in FIG. 5A is nipated. Further, when the paper is conveyed by the paper ejection reversing roller 121, the temperature of the range F shown in FIG. 5B and the temperature of the range G overlapping the reversing inlet roller 120 are lowered. The decrease in sheet temperature is larger in G than in the range of E. It is desirable that the range of contact between the transport rollers and the sheet exceeds the maximum area width of the image, but the range of contact between the transport roller pair and the sheet is not necessarily the maximum because the temperature of the edge of the sheet drops faster than that of the center of the sheet. It does not have to exceed the area width.

Since the heat of the sheet is taken away by the transfer roller pair in the range nipped into the roll body pair of the transfer roller, the sheet temperature changes depending on the total contact amount between the roller pair and the paper. It is preferable to arrange a plurality of rollers that come into contact with the entire width of the sheet in terms of cooling performance, but if the roller width is set to the entire width of the sheet, the strength of the transfer guide plate is lowered and it becomes difficult to arrange the transfer sensor. Further, if the center of the roller is bent, it may cause a transfer problem such as wrinkles. Therefore, in the present embodiment, the rollers are brought into contact with a wide range of the sheet, and the overlapping portion of the contact portion is provided to improve the cooling performance. It should be noted that providing the overlapping portion is effective in preventing the occurrence of a seat portion that does not come into contact with any of the rollers due to variations in the positions of the rollers in the axial direction, but when sufficient assembly accuracy can be ensured, , It is not necessary to generate overlapping parts. This is advantageous in that uneven glossiness due to variations in the degree of cooling can be suppressed.

FIG. 6 is an explanatory diagram of the sheet cooling effect of each roller during transportation in the direction indicated by the arrow C in FIG. 2 by the paper discharge relay roller 130 and the paper discharge roller 131 in the straight paper discharge path. The paper ejection roller 131 has the same configuration as the reversing inlet roller 120. The paper ejection drive roller shaft 131a, the paper ejection drive first roller 131F having a predetermined width provided at a predetermined interval press-fitted into the shaft, the paper ejection drive second roller 131R, and the paper ejection driven second roller facing the drive roller. It consists of a 1-roller 131'F and a paper ejection-driven second roller 131'R. Each of these rollers corresponds to an intermediate distribution roll body, and the paper discharge driven first roller 131'F and the paper discharge driven second roller 131'R are pivotally supported by their respective shafts.

The paper ejection relay roller 130 has the same configuration as the paper ejection reversing roller 121. The paper discharge relay roller 130 includes a paper discharge relay drive roller shaft 130a and a paper discharge relay drive first roller 130C having a width equal to or larger than the predetermined interval press-fitted into the shaft and arranged so as to face the predetermined interval. It has a paper discharge relay drive second roller 130F and a paper discharge relay drive third roller 130R which are arranged adjacent to each other on both sides of the paper discharge relay drive first roller 130C and have a width smaller than the roller width. Further, it has a paper discharge relay driven first roller 130'C, a paper discharge relay driven second roller 130'F, and a paper discharge relay driven third roller 130'R facing the drive roller. The paper discharge relay drive first roller 130C and the paper discharge relay driven first roller 130'C correspond to the central roll body. The paper discharge relay drive second roller 130F, the paper discharge relay drive third roller 130R, the paper discharge relay driven second roller 130'F, and the paper discharge relay driven third roller 130'R are on both sides of the roll body. Equivalent to. The paper discharge relay driven first roller 130'C, the paper discharge relay driven second roller 130'F, and the paper discharge relay driven third roller 130'R are pivotally supported by their respective shafts.

Also in this straight transfer path, the same cooling as that by the reversing inlet roller 120 and the paper ejection reversing roller 121 shown in FIG. 5 can be performed. It should be noted that the paper discharge relay drive second roller 130F, the paper discharge relay drive third roller 130R, the paper discharge relay driven second roller 130'F, and the paper discharge relay driven, which are roll bodies on both sides in the straight transport path shown in FIG. As is clear from the comparison with FIG. 5, the third roller 130'R is a double-sided roll body in the switchback path (paper ejection reversal drive second roller 121F, paper ejection reversal drive third roller 121R, paper ejection reversal driven first). It is located inside (center side) in the width direction from the 2 rollers 121'F and the paper discharge reversal driven third roller 121'R). Conversely, the latter is located outside the former in the width direction. This is due to the following reasons.

As described above, the temperature of the edge of the sheet drops faster than that of the center of the sheet. Conversely, the temperature in the center of the seat is less likely to drop. In the straight transport path, by arranging the roll bodies on both sides relatively inward in the width direction, the overlapping points are concentrated in the central portion of the sheet, and the temperature drop in the central portion of the sheet is promoted. On the other hand, in the reverse paper discharge path, the paper discharge reverse roller 121 provided with the roll bodies on both sides is arranged at a position where the tip end portion of the sheet after stitching back is conveyed. Therefore, after the switchback, there is a time when the sheet is conveyed by driving only the paper ejection reversing roller 121. In order to convey the sheet without causing skew, it is desirable to sandwich the outside with a pair of rollers as much as possible in the width direction of the sheet. Therefore, the paper ejection reversing drive second roller 121F, the paper ejection reversing drive third roller 121R, the paper ejection reversal driven second roller 121'F, and the paper ejection reversing driven third roller 121'F, which are both side rolls in the paper ejection reversing roller 121. The roller 121'R is arranged outside the rolls on both sides of the paper ejection relay roller 130. The paper ejection relay roller 130 has a fixing device 113 and other transport rollers on the upstream side, and does not transport the sheet tip independently.

As described above, in the present embodiment, as a plurality of sheet transporting means for transporting the sheets on which the image is fixed by the fixing means at different locations on the transport path, the paper discharge relay roller 130 and the paper discharge roller 131 on the straight transport path and the paper ejection roller 131 are inverted. The reversing inlet roller 120 and the paper ejection reversing roller 121 in the paper ejection path are composed of a sheet transporting means including a plurality of central distribution roll bodies and a sheet transporting means including a central roll body and both side roll bodies. On the other hand, the plurality of transport means arranged in the transport direction after fixing described in Patent Document 1 include a transport means having a roller extending from the center in the width direction to one end side in the width direction and a transport means having a width from the center in the width direction. It comprises a transport means including a roller extending on the other end side in the direction. Therefore, since both ends in the width direction of the sheet are not held and conveyed at the same time, skew is likely to occur. In the present embodiment, as compared with the one of Patent Document 1, a plurality of central distribution rolls and double-sided rolls, which are sheet transporting means capable of simultaneously holding and transporting both ends of the sheet, are used. Therefore, the occurrence of skew can be suppressed as compared with the conventional case.

Further, for example, as shown in FIG. 4B, the paper ejection reversing drive first roller 121C has a width Y equal to or greater than the distance XX between the reversing inlet driving first roller 120F and the reversing inlet driving second roller 120R. It is arranged so as to face the predetermined interval X (all the predetermined intervals X are within the width Y). As a result, the total range in the width direction in which each roll body (for example, 120F, 121C, 120R) comes into contact with the sheet is continuous in the width direction. Therefore, uniform cooling is possible as compared with the case where a non-contact range occurs in the middle.

If it is possible to omit it from the viewpoint of transportability and cooling performance, the double-sided roll body may be omitted in the roller provided with the central roll body and the double-sided roll body in the example of FIG. 6, for example. Also in this case, the rollers (131F, 131'F, 131R, 131'R) provided with the central distribution roll body can suppress the occurrence of skew as compared with Patent Document 1, and the central distribution roll body can also be suppressed. The portion in the sheet width direction corresponding to the interval between them can be cooled by the central roll body (130C, 130'C).

Further, since the illustrated example is a so-called center-based image forming apparatus, the central distribution roll body or the center so as to be symmetrical with respect to the central position of the maximum image region in the width direction defined by the apparatus. A roll body and a roll body on both sides were arranged. In the so-called edge-based image forming apparatus, the arrangement of the central distribution roller body and the like is set based on the central side region in the width direction common to each size so that sheets of each size can be held and transported on both sides as much as possible. To do. When considering the minimum size, if there is no common central area for all sizes, the common central area from the larger size to the relatively frequently used size may be used as a reference.

7 to 11 show a specific configuration example of the straight paper ejection path. FIG. 7 is a front view showing a schematic configuration. A metal guide plate 150 made of metal on the lower side in the drawing and a resin guide member 151 made of resin on the upper side in the drawing are provided between the paper ejection relay roller 130 and the paper ejection roller 131 constituting the straight paper ejection path. There is. Each of the driven rollers of the paper ejection relay roller 130 and the paper ejection roller 131 is supported by the resin guide member 151.

FIG. 8 is a perspective view of the metal guide plate 150 side with the resin guide member 151 removed. Each drive roller (130F, 130C, 130R, 131F, 131R) appears. FIG. 9 is a perspective view of the resin guide member 151 as viewed from the transport path side. The resin guide member 151 has openings (151a to 151a) for projecting each driven roller (131'F, 131'R, 130'F, 130'C, 130'R) pivotally supported on the side opposite to the transport path side. 151e) is formed. The members indicated by reference numerals 161 in FIG. 8 and their openings (161a to 161c) will be described later in the section relating to the reverse transfer path (see FIGS. 12 and 15).

FIG. 10 is a perspective view of the resin guide member 151 as viewed from the transport path side. In this perspective view, the shaft support parts of the driven rollers (131'F, 131'R) of the paper ejection roller 131 are disassembled and shown. The shafts of the driven rollers (131'F, 131'R) are attached to the roller holder 152 by the shaft attachment member 152a, and the roller holder 152 is fixed to the resin guide member 151, for example, with screws.

FIG. 11 is also a perspective view of the resin guide member 151 as viewed from the transport path side. In this perspective view, the driven rollers (130'F, 130'C, 130'R) of the paper ejection relay roller 130 are for shaft support. The parts are disassembled and shown. The shafts of the driven rollers (130'F, 130'C, 130'R) are attached to the roller holder 153 by the shaft attachment member 153a, and the roller holder 153 is fixed to the resin guide member 151, for example, with screws.

As is clear from FIGS. 10 and 11, since the rollers are composed of each roller as a plurality of roll bodies arranged at intervals from each other, the total width is compared with the case where the entire width is composed of one roll body. Therefore, openings for projecting rolls of the resin guide member can also be formed at intervals. Therefore, a so-called ribbed portion is formed between the openings, and the strength of the resin guide member can be relatively increased. The same can be said for materials other than resin. The same applies to the case where a resin guide member having an opening for projecting each roller of the driving roller is also used instead of the driven roller.

In addition, since each roller of the driven roller is pivotally supported, there are also the following advantages. That is, it is possible to suppress the occurrence of wrinkles on the seat by giving some play to the shaft-supporting portion. This is because when a stress that causes wrinkles is generated in the seat, the stress can be released by changing the posture of each driven roller. If wrinkles are less likely to occur, it is possible not to adopt such an independent shaft support structure.

12 to 16 show a specific configuration example of the inverted paper ejection path. FIG. 12 is a front view showing a schematic configuration. Between the reversing inlet roller 120 and the paper ejection reversing roller 121 constituting the reversing paper ejection path, a resin inlet resin guide member 161 on the upper right side in the drawing, a resin right resin guide member 160 on the lower right side in the drawing, Further, a left resin guide member 162 made of resin on the left side in the drawing is provided. Each driven roller of the reversing inlet roller 120 is supported by the inlet resin guide member 161, and each driven roller of the paper ejection reversing roller is supported by the left resin guide member 162.

FIG. 13 is a perspective view of the right side resin guide member 160 side with the inlet resin guide member 161 and the left side resin guide member 162 removed. The right resin guide member 160 is formed with openings (160a, 160b, 160c) for projecting the drive rollers (120C, 120F, 120R) of the paper ejection reversing roller 121.

FIG. 14 is a perspective view of the inlet resin guide member 161 and the left resin guide member 162 with the right side resin guide member 160 removed. A roller holder 163 for holding each driven roller (120'F, 120'R) of the reversing inlet roller 120 is fixed to the inlet resin guide member 161 with a screw or the like. Openings (161a, 161b, 161c) through which the drive rollers (130F, 130C, 130R) (see FIG. 8) of the paper discharge relay rollers 130 constituting the straight transfer path are entered are also formed.
The left resin guide member 162 has openings (162a to 162c) for projecting the driven rollers (121'F, 121'C, 121'R) of the paper ejection reversing rollers 121 pivotally supported on the side opposite to the transport path side. ) Is formed.

FIG. 15 is a perspective view of the inlet resin guide member 161 as viewed from the transport path side. In this perspective view, the shaft support parts of the driven rollers (120'F, 120'R) of the reversing inlet roller 120 are disassembled and shown. The shafts of the driven rollers (120'F, 120'R) are attached to the roller holder 163 by the shaft attachment member 163a, and the roller holder 163 is fixed to the inlet resin guide member 161 with, for example, a screw.

FIG. 16 is a perspective view of the left side resin guide member 162 as viewed from the opposite side (back side) to the transport path. In this perspective view, the shaft support parts of the driven rollers (121'F, 121'C, 120'R) of the paper ejection reversing roller 121 are disassembled and shown. The shafts of the driven rollers (121'F, 121'C, 120'R) are attached to the roller holder 164 by the shaft attachment member 164a, and the roller holder 164 is fixed to the left resin guide member 162, for example, with a screw.

This specific configuration example of the inverted paper ejection route also has advantages such as increasing the strength of the guide member and suppressing wrinkles of the sheet, as in the specific configuration example of the street paper ejection route.

Although the sheet cooling device in the paper ejection path in the image forming apparatus has been described above, the sheet cooling apparatus having the same configuration can be applied to other than the image forming apparatus. Furthermore, various modifications are possible.

1: Image forming device 113: Fixing device 115: Sheet reversing part 116: Double-sided reversing part 117: Refeeding path 118: Switching claw 119: Switching claw 120: Reversing inlet roller 120F: Reversing inlet drive First roller 120R: Reversing inlet Drive 2nd roller 120a: Paper discharge reversing drive roller shaft 120'F: Reversing inlet driven 1st roller 120'R: Reversing inlet driven 2nd roller 121: Paper discharging reversing roller 121C: Paper discharging reversing drive 1st roller 121F: Discharging Paper reversal drive 2nd roller 121R: Paper discharge reversal drive 3rd roller 121'C: Paper discharge reversal driven 1st roller 121'F: Paper discharge reversal driven 2nd roller 121'R: Paper discharge reversal driven 3rd roller 122: DC motor 123: Pulley 124: Timing belt 125: Pulley 126: DC motor 127: Pulley 127a: Timing belt 128a: Gear pulley 128b: Gear pulley 129: Timing belt 129a: Pulley 130: Paper discharge relay roller 130C: Paper discharge relay drive first Roller 130F: Paper discharge relay drive 2nd roller 130R: Paper discharge relay drive 3rd roller 130a: Paper discharge relay drive roller shaft 130'C: Paper discharge relay driven 1st roller 130'F: Paper discharge relay driven 2nd roller 130 ´R: Paper discharge relay driven third roller 131: Paper discharge roller 131F: Paper discharge drive first roller 131R: Paper discharge drive second roller 131a: Paper discharge drive roller shaft 131 ´F: Paper discharge driven first roller 131 ′ R: Paper discharge driven second roller 140: Outlet 141: Outlet 150: Metal guide plate 151: Resin guide member 152: Roller holder 152a: Shaft mounting member 153: Roller holder 153a: Shaft mounting member 160: Right resin guide member 161: Inlet resin guide member 162: Left side resin guide member 163: Roller holder 163a: Shaft mounting member 164: Roller holder X: Predetermined interval

Japanese Unexamined Patent Publication No. 2005-284245

Claims (11)

An image forming means for forming an image on a sheet and
A fixing means for fixing the image formed on the sheet,
In an image forming apparatus having a plurality of sheet transporting means for transporting sheets on which an image is fixed by the fixing means at different locations on the transport path.
At least one of the plurality of sheet transporting means includes a plurality of central distribution rolls arranged at intervals in a region on the center side of the sheet in a width direction orthogonal to the transport direction, or. An image forming apparatus comprising: a central roll body arranged in the central region and both side roll bodies arranged at intervals on both sides of the central roll body. In the image forming apparatus of claim 1,
The plurality of sheet transporting means include a sheet transporting means including the plurality of central distribution roll bodies, and a sheet transporting means including the central roll body and both side roll bodies. apparatus. In the image forming apparatus of claim 1 or 2.
The plurality of sheet transporting means include one or more roll bodies, and the total range in the width direction in which each roll body of the plurality of sheet transporting means contacts the sheet is continuous in the width direction. An image forming apparatus characterized by being In the image forming apparatus of claim 3,
An image forming apparatus, wherein a range in which the width directions in contact with the sheet are adjacent to each other has overlapping portions. In the image forming apparatus of claim 3 or 4,
An image forming apparatus, wherein the integrated range includes a maximum image region in the width direction. In the image forming apparatus according to claim 3 or 4.
An image forming apparatus, wherein the total range is narrower than the maximum image area in the width direction. In the image forming apparatus according to any one of claims 1 to 6.
At least one of the plurality of sheet transporting means is a sheet transporting means including the central roll body and the both side roll bodies.
An image forming apparatus characterized in that the length in the width direction of the double-sided roll body is shorter than that of the central roll body. In the image forming apparatus according to any one of claims 1 to 7.
The plurality of sheet transporting means are provided with a pair of roll bodies on both side surfaces of the sheet, and the plurality of rotationally driven roll bodies are coaxially provided, and the sheet is sandwiched between the plurality of rotationally driven roll bodies for driven rotation. An image forming apparatus characterized in that the plurality of roll bodies to be formed are axially supported for each roll body. In the image forming apparatus according to any one of claims 1 to 8.
The image forming apparatus, wherein the plurality of sheet conveying means has a resin guide member provided with an opening for projecting the roll body. In the image forming apparatus according to any one of claims 1 to 9.
It has a switchback path for ejecting paper to the outside of the device after switching back, and a straight output path for ejecting paper to the outside of the device without passing through the switchback path.
Each of the switchback path and the straight paper ejection path is provided with the plurality of sheet transporting means including the sheet transporting means including the central roll body and the both side roll bodies.
As a sheet transporting means for transporting the tip end portion of the sheet after stitching back in the switchback path, a sheet transporting means provided with the central roll body and the both side roll bodies is used.
An image forming apparatus characterized in that the double-sided rolls in the switchback path are located outside the double-sided rolls in the straight paper ejection path in the width direction. A sheet cooling device including the plurality of sheet transporting means according to any one of claims 1 to 4 and 7 to 9.

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