JPH10129912A - Paper sheet reversing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper sheet reversing device capable of reversing the paper sheet and sorting the paper sheet with simple mechanism without controlling a switching claw. SOLUTION: When a paper sheet reversing device 10 is not mounted on an image forming device 12, the paper sheet is fed to a discharge roller 38 by a switching claw 32. When the paper sheet reversing device is mounted on the image forming device 12, a leaf spring 42 presses an arm 36 to turn the switching claw 32 counterclockwise. The paper sheet M is guided to a paper sheet discharge port 44. When a rear end of the paper sheet M passes through a folded part 92A, a drive motor is driven in the reverse direction, and the paper sheet M is fed to a feeding part 54 by a switch-back roller 100 and a pinch roller 122. The paper sheet M fed to the feeding part 54 is re- carried to a carrying roller 20 through an insert port 56, and the paper sheet M on each side of which the image is formed is discharged on a discharge tray 40 by a switch-back roller 94 and a pinch roller 124.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing device mounted on an image forming apparatus such as a printer, for reversing a sheet and feeding the sheet to an image forming section.

[0002]

2. Description of the Related Art In recent years, in image forming apparatuses such as printers, a sheet reversing apparatus for forming an image on both sides of a sheet by providing the apparatus body with a minimum function such as image forming in order to reduce product cost. And a paper sorting device for sorting discharged papers are optionally mounted.

An optional sheet reversing device is detachable from the apparatus main body, and is switched by switching a switching gate provided near a paper discharge section of the apparatus main body.
The sheet has been selectively guided to a sheet discharge section or a sheet reversing device (see Japanese Patent Application Laid-Open No. Hei 6-110274).

[0004] However, the control of the switching gate is complicated and costly, and when a sheet reversing device is mounted, the paper sorting device cannot be easily mounted.

For this reason, as shown in FIG. 18, there has been proposed an image forming apparatus 152 in which a switchback roller 151 constituting a sheet reversing mechanism is disposed in the apparatus main body so that a sheet sorting apparatus 154 can be detachably mounted. ing.

However, in order to distribute the paper to the switchback roller 151 for discharging the paper to the discharge tray 156 or to the sorting roller 158, it is necessary to control the switching claw 160, and the mechanism becomes complicated. Further, conventionally, a connector for connecting the paper sorting apparatus 154 is provided on the image forming apparatus 152 side, so that the cost of the product cannot be reduced.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has as its object to provide a sheet reversing device which does not need to control a switching claw and can reverse and sort sheets by a simple mechanism. Make it an issue.

[0008]

According to the first aspect of the present invention, in a state where the sheet reversing device is not mounted, the sheet on which an image is formed on one side by the image forming section is directed to the discharge roller by the switching means. Guided and discharged onto a discharge tray.

On the other hand, when the sheet reversing device is mounted, the operation member operates the switching means so as to guide the sheet to the sheet discharge port formed above the discharge roller.

[0010] The sheet guided to the sheet outlet is the first sheet.
When the reversing unit performs the normal rotation / reverse rotation operation, the reversing unit is reversed and sent to the feeding unit, and is fed again to the image forming unit through the feeding unit. As a result, an image is formed on the other side of the sheet. The sheet on which the image is formed on both sides is guided again to the sheet discharge port by the switching means, and the first reversing means rotates forward and is discharged onto the discharge tray.

That is, in the present invention, when the sheet reversing device is mounted on the image forming apparatus, the switching means is mechanically operated to guide the sheet to the first reversing means.
The image can be formed on both sides of the sheet and discharged onto the discharge tray simply by rotating the reversing means in the normal and reverse directions. Therefore, there is no need to control the switching means.

According to the second aspect of the invention, the first reversing means is constituted by a slide roller movable in the width direction of the sheet. The position at which the sheet falls on the discharge tray changes by holding the sheet with the slide roller and sliding the sheet in the width direction. As a result, the position of the end of the paper stacked on the discharge tray in the width direction is shifted, and the paper can be sorted.

According to the third aspect of the present invention, when the sheet reversing device is mounted on the image forming apparatus, the position of the second reversing means provided on the sheet reversing device is set to the discharge roller provided on the image forming device. It overhangs to the discharge tray side.
For this reason, the sheet discharged from the second reversing means onto the discharge tray falls farther than the sheet discharged by the discharge roller, and as a result, the end of the sheet stacked on the discharge tray in the transport direction is moved. Since the position is shifted, the sheets can be sorted. Whether the sheet is guided to the second reversing unit or the discharge roller is controlled by a driving unit that switches the switching unit.

According to the present invention, when the sheet reversing device is mounted on the image forming apparatus, the switching of the switching means is controlled by the driving means, and the switching means controls the switching to the second reversing means or the discharge roller. The paper is guided to By providing the driving unit on the sheet reversing device side, the structure of the image forming apparatus can be simplified.

[0015]

1 and 2 show an image forming apparatus 12 to which a sheet reversing device 10 according to a first embodiment is mounted.

The image forming apparatus 12 is loaded with a detachable paper cassette 14, and a semicircular feed roller 16 disposed above rotates to move the uppermost sheet M to a sheet. The sheets are sent out one by one to the transport path 18.

The paper transport path 18 is composed of a plurality of transport rollers 20, and transports the paper M sent from the paper cassette 14 toward the photosensitive drum 22. The photosensitive drum 22 is charged to a predetermined potential by a charger (not shown). Then, the exposing device forms an electrostatic latent image on the photosensitive drum 22 based on the image data.

The electrostatic latent image is converted into a toner image by toner supplied from the developing device, and is transferred to the sheet M by the transfer roller 24. The sheet M to which the toner image has been transferred is thermally fixed while being nipped and conveyed by a fixing device 30 including a pressure roller 26 and a heating roller 28.

Thus, a copy image corresponding to the original image is formed on the sheet M. The sheet M on which the copy image is formed is sent to the switching claw 32 as switching means.

As shown in FIG. 3, this switching claw 32
Shaft 34 spanned across the width of the paper transport path
As shown in FIG. 2, the sheet M is inclined by a leaf spring (not shown) to guide the sheet M to the discharge roller 38 side. The discharge roller 38 is connected to the discharge tray 4
0 is discharged.

Further, the shaft 34 of the switching claw 32
An arm 36 protrudes. The arm 36 is pressed by a leaf spring 42 attached to a side plate of the sheet reversing device 10 when the sheet reversing device 10 is positioned by the guide 37 and mounted on the image forming apparatus 12, and the switching claw 3 is moved.
Rotate 2 counterclockwise. Thereby, as shown in FIG. 1, the sheet M conveyed from the fixing device 30 is guided by the switching claw 32 to the sheet discharge port 44 formed above the image forming apparatus 12.

As shown in FIGS. 3 and 4, the sheet reversing device 10 includes a transport plate 46 laid over a side plate 48. By attaching the side plate 48 to the outer cover 50, a feeding section 54 (see FIG. 1) for feeding the copied paper C is formed between the transport plate 46 and the rib 52 formed on the outer cover 50. Is done.

The lower portions of the transport plate 46 and the ribs 52
The transfer roller 20 is curved toward the insertion port 56 of the image forming apparatus 12, and is fed from the feeding section 54 through the insertion port 56.
The paper M is guided to

The transport plate 46 has openings 58, 60
Are formed. The side plates 4 are provided in the openings 58 and 60.
Rollers 66, 68 mounted on shafts 62, 64, which are pivotally supported by 8, rotatably enter. Shaft 6
2, the torque of the drive motor 72 is transmitted via a gear mechanism 70. A one-way clutch 74 is attached to the shaft 62 so that the shaft 62 rotates only in the reverse direction, that is, in the direction in which the reversed sheet M is transported to the insertion slot 56.

As shown in FIG. 5, pulleys 78 and 80 around which a timing belt 76 is wound are fixed to the ends of the shafts 62 and 64. The driving force of the shaft 62 is transmitted to the shaft 64 by the timing belt 76, and the roller 66 and the roller 68 rotate in the same direction.

On the other hand, as shown in FIG. 1, a driven roller 8 is provided between the ribs 52 at a position corresponding to the rollers 66 and 68.
2, 84 are provided, and are in contact with the rollers 66, 68 with a predetermined nip force. These rollers 66, 68
And the driven rollers 82 and 84, the sheet M sent to the feeding unit 54 is nipped and conveyed to the insertion slot 56.

The transport plate 46 is provided with a sensor 86. The touch element 88 of the sensor 86 projects from the long groove 90 into the feeding section 54. Thereby, it is detected whether or not the sheet M conveyed to the feeding unit 54 has jammed. The outer cover 50 can be opened with the pin 120 as a center, and thereby the feeding unit 5 can be opened.
4 is jammed.

On the other hand, a guide plate 92 is formed at the upper end of the transport plate 46 so as to bend in a V-shape toward the paper transport opening 44. A discharge chute 96 is provided above the bent portion 92A of the guide plate 92.

As shown in FIG. 4 to FIG.
6, pinch rollers 122 and 124 are disposed at predetermined intervals along the sheet transport direction. The side plates 96A of the discharge chute 96 have shafts 126, 12
8 penetrates, and both ends penetrate to the outside of the side plate 48. The switchback rollers 94 and 100 provided on the shafts 126 and 128 serve as the pinch rollers 12.
2 and 124, the sheet M is sandwiched and discharged to the discharge tray 40.

A cap 130 is mounted on the shafts 126 and 128. The cap 130 is pressed against the side plate 96A of the discharge chute 96, and the shaft 12
6, 128 move in the axial direction integrally with the discharge chute 96.

An operation plate 132 extends from the end of the discharge chute 96 toward the side plate 48. This operation plate 1
32 is provided with a U-shaped guide frame 134.
A pin 138 provided at the tip of the arm 136 is accommodated in the guide frame 134. This arm 1
Reference numeral 36 denotes an offset motor 140 which is driven to swing the head in the width direction of the sheet M, pushes the guide frame 134 with the pin 138, and integrally rotates the shaft 12 with the discharge chute 96.
6, 128 are moved in the width direction of the sheet.

As shown in FIG. 4, the shaft 128 of the switchback roller 100 is D-cut, and passes through a gear 108 rotatably attached to the side plate 48. The gear 108 meshes with a drive gear 110 rotated by the drive motor 72. Further, the gear 108 transmits the driving force to the gear 112 rotatably mounted on the side plate via the transmission gear 106. A shaft 126, which has been D-cut, passes through the shaft hole of the gear 112.

With this configuration, the drive motor 72
Is rotated forward and backward, so that the switchback roller 9 is rotated.
4. The switchback roller 100 rotates forward and reverse in the same direction. By swinging the arm 136, the switchback rollers 94 and 100 and the pinch rollers 122 and 124 can pinch and transport the sheet M,
Slide in the width direction of the paper.

Next, the operation of the sheet reversing device according to the first embodiment will be described. When the sheet reversing device 10 is not mounted on the image forming apparatus 12, the switching claw 32 is inclined in a direction to guide the sheet M toward the discharge roller 38. For this reason,
The paper M fed from the paper cassette 14 by the feed roller 16 passes through the paper transport path 18 and an image is formed on one side by the photosensitive drum 22 and the heat fixing device 30. Is discharged on top. By repeating this process, the sheets M having an image formed on one side are sequentially stacked on the discharge tray 40.

On the other hand, the sheet reversing device 10 is
2, the arm 36 is pushed by the leaf spring 42 attached to the side plate 48 of the sheet reversing device 10 to rotate the switching claw 32 counterclockwise. Thereby, the sheet M conveyed from the fixing device 30 is guided to the sheet discharge port 44 of the image forming apparatus 12 by the switching claw 32. As described above, since the transport path is mechanically switched by mounting the sheet reversing device 10, the switching claw 32 does not need to be controlled. For this reason, the switching claw 3
It is possible to prevent a jam that easily occurs at the time of switching between the two.

The connector 114 is connected to the sheet reversing device 1.
Since the image forming apparatus 12 is provided on the 0 side, the configuration of the image forming apparatus 12 can be simplified and the product cost can be reduced.

Here, the sheet M on which an image is formed on one side
As shown in FIG. 12, the sheet is guided by the guide plate 92, passes through the sheet discharge port 44, is nipped and conveyed by the switchback roller 100 and the pinch roller 122, and is discharged.
Through the switchback roller 94 and the pinch roller 1
24.

Then, as shown in FIG. 13, the drive motor 72 is rotated forward until the rear end of the paper M passes through the bent portion 92A of the guide plate 92, and the switchback roller 100 is rotated.
And pinch roller 122 and switchback roller 94
When the sheet M is conveyed to the discharge tray 40 by the pinch roller 124, the rear end of the sheet M jumps upward due to the strength of the waist.

Here, as shown in FIG. 14, the driving motor 72 is rotated in the reverse direction, and the inverted sheet M is fed to the feeding section 54 by the switchback roller 100 and the pinch roller 122, and by the switchback roller 94 and the pinch roller 124. Send out. The sheet M having an image formed on one side sent to the feeding unit 54 is conveyed to the conveying roller 20 through the insertion opening 56 by the rollers 66 and 68 and the driven rollers 82 and 84 as shown in FIG.

The sheet M reversed and sent to the transport roller 20
The image is formed on the surface on which the image is not formed by the photosensitive drum 22 and the fixing device 30, resulting in a sheet M on which the image is formed on both surfaces.

Then, the switching claw 32 guides the sheet tray 44 to the sheet discharge port 44 again, and the switchback roller 100 and the pinch roller 122, which are normally rotating, and the switchback roller 94 and the pinch roller 124, and the upper part of the discharge tray 40 is rotated. Is discharged.

Here, since the switchback roller 94 and the pinch roller 124 are provided above the discharge roller 38, the discharge position of the paper M is increased, and the stacking amount of the paper M discharged to the discharge tray 40 is reduced. growing. Also,
Since the paper M discharged from the discharge tray 40 and the falling position are different, sorting can be performed.

An image is formed on both sides of the sheet M by repeating such a process.
4 and 100 are rotating forward (the sheet is discharged
Side), the one-way clutch 74 functions and the rollers 66 and 68
Has stopped. Therefore, the switchback roller 9
While the sheet 4, 4, 100 is switching back and reversing the sheet, the preceding sheet M can be kept waiting in the feeding section 54. Thus, double-sided copying can be performed intermittently.

When the offset motor 140 is driven to swing the arm 136 when the leading end of the sheet M is sandwiched between the switchback roller 100 and the pinch roller 122, as shown in FIGS. Then, the discharge chute 96 slides in the width direction of the paper M. For this reason, the pinch rollers 122 and 124 move together with the discharge chute 96, and the shafts 126 and 128 move
6 and slides in the width direction of the paper M together with the switchback rollers 94 and 100.

At this time, the shaft 126 reciprocates through the shaft hole of the gear 112, and the shaft 128
Reciprocate through the shaft hole. Then, the driving force is transmitted from the gear to the D-cut shaft, so that the switchback roller 100 and the pinch roller 122, and the switchback roller 94 and the pinch roller 124 pinch and convey the paper M while holding the paper M. Slide in the width direction.

As a result, as shown in FIG. 11, the sheets M to be discharged onto the discharge tray 40 are stacked while being shifted in the width direction, and can be sorted.

Next, a paper reversing device according to a second embodiment will be described. As shown in FIGS. 16 and 17, in the sheet reversing device 148, the upper portion of the outer cover 144 protrudes toward the discharge tray 40,
6 and a pinch roller 147 are provided on the tip side.

As a result, the sheet M discharged onto the discharge tray 40 falls farther than the sheet M discharged by the discharge roller 38, and as a result, as shown in FIG.
The rear end position is different, and sorting becomes possible. The second
Forming Apparatus 1 on Which Paper Reversing Apparatus 148 of Form is Mounted
2 is provided with a solenoid 150 that switches the switching claw 32.

By controlling the solenoid 150, whether the sheet has an image formed on one side or the sheet has an image formed on both sides, the discharge roller 38 or the switchback roller 146 and the pinch roller 147 are selectively used. It can be discharged onto the discharge tray 40. As described above, by controlling the switching claws 32, the paper M can be sorted.

The solenoid 150 may be provided not on the image forming apparatus 12 but on the sheet reversing device 148.

[0051]

Since the present invention has the above-described structure, it is not necessary to control the switching claw, and the paper can be sorted and the paper can be reversed with a simple mechanism. Also, the paper can be sorted by controlling the switching claw. Furthermore, by sliding the switchback roller,
Paper can be sorted.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a state in which a sheet reversing device according to a first embodiment is mounted on an image forming apparatus.

FIG. 2 is a conceptual diagram illustrating an image forming apparatus to which a sheet reversing device according to a first embodiment is mounted.

FIG. 3 is an exploded perspective view of the sheet reversing device and the image forming apparatus according to the first embodiment.

FIG. 4 is a perspective view of an internal mechanism of the sheet reversing device according to the first embodiment as viewed from a side.

FIG. 5 is a perspective view of the internal mechanism of the sheet reversing device according to the first embodiment when the discharge chute is moved to the rear side as viewed from above.

FIG. 6 is a perspective view of the internal mechanism of the sheet reversing device according to the first embodiment when the discharge chute is moved to the near side as viewed from above.

FIG. 7 is a plan view illustrating a state in which the discharge chute has moved downward in the switchback roller moving mechanism of the sheet reversing device according to the first embodiment.

FIG. 8 is a plan view showing a state in which a discharge chute has moved upward in a switchback roller moving mechanism of the sheet reversing device according to the first embodiment.

FIG. 9 is a front view showing a state in which the discharge chute has moved to the right in the switchback roller moving mechanism of the sheet reversing device according to the first embodiment.

FIG. 10 is a front view showing a state in which the discharge chute has moved to the left in the moving mechanism of the switchback roller of the sheet reversing device according to the first embodiment.

FIG. 11 is a plan view showing a sheet discharged on a discharge tray.

FIG. 12 is an explanatory diagram showing the movement of a sheet reversed by the sheet reversing device according to the first embodiment.

FIG. 13 is an explanatory diagram illustrating the movement of a sheet that is reversed by the sheet reversing device according to the first embodiment.

FIG. 14 is an explanatory diagram illustrating the movement of a sheet that is reversed by the sheet reversing device according to the first embodiment.

FIG. 15 is an explanatory diagram showing the movement of a sheet inverted by the sheet reversing device according to the first embodiment.

FIG. 16 is a conceptual diagram illustrating a state where the sheet reversing device according to the second embodiment is mounted on an image forming apparatus.

FIG. 17 is a conceptual diagram illustrating a state in which the sheet reversing device according to the second embodiment is mounted on an image forming apparatus.

FIG. 18 is a conceptual diagram illustrating a conventional image forming apparatus and a sorting apparatus.

[Explanation of symbols]

Reference Signs List 10 sheet reversing device 32 switching claw (switching means) 40 discharge tray 42 leaf spring (operation member) 54 feeding section 94 switchback roller (first reversing means, slide roller) 96 discharge chute 100 switchback roller (first reversing means) , Slide roller) 122 pinch roller (first inversion means, slide roller) 124 pinch roller (first inversion means, slide roller) 126 shaft 128 shaft 136 arm 146 switchback roller (second inversion means) 147 pinch roller (second) Inversion means) 150 Solenoid (drive means)

Claims (4)

[Claims] An image forming section for forming an image on a sheet, a discharge roller for discharging a sheet on which an image has been formed by the image forming section to a discharge tray, and a sheet discharge port provided above the discharge roller. A switching unit that selectively guides the sheet to the discharge roller or the sheet discharge port, a sheet reversing device that is removably mounted to the image forming apparatus, An operation member that operates the switching unit so that a sheet guiding direction is the sheet discharge port, and a feeding unit that feeds a sheet to the image forming unit;
A sheet reversing device, comprising: first reversing means for reversing the sheet sent from the sheet discharge port and conveying the sheet to the feeding section or directly discharging the sheet to the discharge tray. 2. The sheet reversing device according to claim 1, wherein said first reversing means comprises a slide roller movable in the width direction of the sheet. 3. An image forming section for forming an image on a sheet, a discharge roller for discharging a sheet on which an image is formed by the image forming section to a discharge tray, and a sheet discharge port provided above the discharge roller. A sheet reversing device detachably attached to an image forming apparatus, comprising: switching means for selectively guiding a sheet to the discharge roller or the sheet discharge port; and driving means capable of switching the switching means. A second reversing unit provided at a position where the sheet is protruded from the discharge roller toward the discharge tray when the image forming apparatus is mounted on the image forming apparatus; and a sheet reversed by the second reversing unit is supplied to the image forming unit. And a feeding unit for feeding the sheet. 4. An image forming section for forming an image on a sheet, a discharge roller for discharging a sheet on which an image has been formed by the image forming section to a discharge tray, and a sheet discharge port provided above the discharge roller. A switching unit that selectively guides the sheet to the discharge roller or the sheet discharge port, a sheet reversing device that is removably mounted to the image forming apparatus, A second reversing unit provided at a position protruding from the discharge roller toward the discharge tray, a feeding unit for feeding the sheet inverted by the second reversing unit to the image forming unit, and the switching unit. A sheet reversing device, comprising: switchable driving means.