JP3329740B2 - Conveyor of image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveying device for an image forming apparatus, and more particularly, to a refeeding unit for forming images on both sides of a sheet, a sorter and a finisher for sorting processed sheets, and other devices. The present invention relates to a conveying device of an image forming apparatus having a branching unit for selectively conveying a sheet to a job separator or the like for distinguishing the sheet from processed sheets.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, and a facsimile apparatus, a document is placed on a document table provided on an upper surface of the apparatus, and the document image is irradiated with light and reflected from the document. The document image is read based on the. Based on the read document image, an electrostatic latent image is formed on the surface of the photosensitive drum. The photoreceptor drum is charged to a predetermined polarity by the main charging device, and when light is irradiated based on a document image, the charge at that portion is removed to form an electrostatic latent image.

[0003] A developing device for storing toner therein is provided adjacent to the photosensitive drum. The toner contained in the developing device is charged to the same polarity as that of the photoconductor drum, and is attracted to a portion of the photoconductor drum where there is no charge at a position close to the photoconductor drum. Therefore, the electrostatic latent image formed on the peripheral surface of the photosensitive drum is visualized as a toner image.

A transfer device is provided adjacent to the photosensitive drum. This transfer device applies a voltage of the opposite polarity to the toner from the back of the paper to the paper conveyed between the photoconductor drum and attracts the toner on the peripheral surface of the photoconductor drum onto the paper. Transfer the image. A separation device is disposed downstream of the transfer device in the sheet conveyance direction. This separating device sucks the sheet from the back side so that the sheet does not wind around the photosensitive drum. For example, a separating needle to which a predetermined voltage is applied is employed.

Thereafter, the sheet having the toner image formed on the surface thereof is conveyed to a fixing device, and the toner image is heated and fused. The fixing device is provided with a heating roller having a built-in heater therein, and a pressure roller pressed against the heating roller. The fixing roller conveys the paper while nipping the paper between the heating roller and the pressure roller. The heat of the heater is transmitted by the heating roller to fuse and fix the toner image on the paper surface.

A discharge port for discharging paper is provided on the downstream side of the fixing device in the paper transport direction, and a discharge tray for receiving the discharged paper is provided outside the discharge port. The discharge port is provided with a pair of discharge rollers that convey the sheet to the discharge tray side while holding the sheet by pressing the peripheral surfaces thereof to each other. The discharge tray has a certain depth for storing a large number of discharged sheets, and is set such that the end of the bottom surface on the upstream side in the sheet discharge direction is located below the discharge port. .

[0007]

In the above-described apparatus, when forming images on both sides of a sheet, a first branch portion is provided in the middle of the sheet conveying path from the fixing device to the discharge tray. A re-feeding unit is provided for re-feeding paper from the first branch to the photosensitive drum. In this case, the sheet on which image formation has been completed on the first surface is conveyed to the discharge tray side, and the conveyance of the sheet is stopped immediately before the rear end of the sheet is discharged from the discharge port.
The sheet is conveyed to the re-feeding unit side by inverting the conveying roller, and further conveyed to the photosensitive drum side via the re-feeding unit. This makes it possible to form an image on the second surface of the sheet.

Further, the apparatus may be provided with a sorter for performing sorting on the processed paper, a finisher for performing stapling, punching of punch holes, and the like. In order to transport the processed paper to the sorter or finisher, the paper is guided from the first branch to the refeeding unit side, and the second paper provided before reaching the refeeding unit. It is conceivable that the paper is guided to the sorter or the finisher side in the branch road.

Further, a printer function for receiving data from a personal computer, a word processor and the like connected to a network and printing out the data, and receiving and printing out data from an external communication device connected to a telephone line. Some devices have a facsimile function. In such an apparatus, there is an apparatus configured to discharge a sheet to a sub-tray called a job separator in order to distinguish a sheet on which an image forming process has been performed by an interruption process such as data reception. Also in this case, a second branch portion is provided in the middle of the sheet transport path from the first branch portion to the discharge tray, and the sheet is transported to the job separator via the first branch portion and the second branch portion. It is conceivable to configure as follows.

[0010] When an apparatus having both a sorter, a finisher, and a job separator as described above is constructed, a branching section corresponding to each of the sections is formed in a transport path, or a branching path capable of branching to a plurality of transport paths. It is conceivable to constitute a part. In such a branch portion, a branch claw having a wedge-shaped cross section for switching the sheet conveyance direction is employed. The branch claw has a wedge-shaped acute angle formed on a guide surface for guiding a sheet, and is rotatably supported by the branch portion. An actuator of a solenoid is connected to rotate the branch claw, and by driving the solenoid, it is possible to select a sheet conveyance direction. In order to make the paper transport direction in the branching section three or more directions, it is possible to branch in three directions or three or more directions by further providing a branching claw.

However, when three or more branch claws are provided, 4
It is difficult to branch beyond the direction. Therefore,
If there are four or more transport paths for transporting the paper, such as a discharge tray, a sorter or finisher, a re-feed section, and a job separator, at least two or more branch sections having branch claws are required. Each of the branch claws arranged at each branch portion is connected to a solenoid actuator and is rotatable, and the rotation position of each branch claw is selected by each solenoid to determine a paper transport path. It is possible to do.

For this reason, solenoids are required as many as the number of branch claws, so that it is difficult to reduce the size of the device and to reduce the cost. SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of driving units by interlocking the driving of a branching claw provided at a branching portion in a paper transport path, reduce costs, and reduce the size of the apparatus.

[0013]

A transport device of an image forming apparatus according to the present invention is a transport device for selectively transporting a sheet transported from a first transport path to a second transport path or a third transport path. An image forming apparatus comprising: a first branch portion; and a second branch portion for selectively transporting a sheet transported from a third transport route to a fourth transport route or a fifth transport route.
It has a first branch claw, a second branch claw, and a connection driving means. The first branch claw is configured to guide a sheet conveyed from the first conveyance path to the second conveyance path, and a second conveyance claw for guiding the sheet conveyed from the first conveyance path to the third conveyance path. The first branch portion is rotatably disposed so as to be able to take a transport posture. The second branch claw is configured to guide a sheet conveyed from the third conveyance path to the fourth conveyance path side, and a second conveyance claw to guide the sheet conveyed from the third conveyance path to the fifth conveyance path side. It is rotatably arranged in the second branch so as to be able to take the transfer posture. The connection driving means is such that the first branch claw is the first
When in the transfer position, the second branch claw is in the first transfer position,
When the first branch claw is in the second transport position, the second branch claw is
The first branch claw and the second branch claw are rotated in conjunction with each other so as to be in the transporting posture.

[0014] Thus, the first branch claw and the second branch claw can be driven in conjunction with one connecting drive means, so that the number of parts can be reduced and the cost can be reduced. It is possible to reduce the size of the device. Here, the connection driving means includes a connection member that connects the first branch claw and the second branch claw so as to rotate in synchronization with the movement in the predetermined direction, and a drive that moves the connection member in the predetermined direction. Means.

[0015] The first transport path may be configured to transport the paper conveyed from a first processing unit that performs a first process on the paper, and the first processing unit may be configured to convey the paper. An image forming unit that forms a toner image on the surface and a fixing unit that fuses and fixes the toner image on the surface of the sheet can be employed. The second transport path may be configured to transport the paper to a first discharge unit from which the processed paper is discharged, and a forward drive for discharging the paper to the first discharge unit; And a reversing roller capable of driving in the reversing direction to convey the sheet.

The fourth transport path may be configured to transport the sheet to a second processing unit that executes a second process on the sheet on which the first process has been completed in the first processing unit,
The second processing unit may be configured to include a paper re-feeding unit during double-sided image formation. Further, the fifth transport path may be configured to transport the paper to a second discharge unit from which the processed paper is discharged, and the second discharge unit includes a sorter for sorting the discharged paper, a staple, and the like. It can be constituted by one or more of a finisher having a function or a punch function or a job separator for distinguishing from a processed sheet.

[0017]

FIG. 1 is a longitudinal sectional view of a copying machine to which an embodiment of the present invention is applied. The copying machine 1 has a main body 10 and a document holder 11 mounted on the upper part of the main body 10 so as to be openable and closable. An original platen 15 on which an original is placed is disposed on the main body 10 at an upper portion thereof. Inside the main body 10, an image forming unit 16 is provided at the left end as viewed from the front and substantially at the center in the vertical direction.
Further, a paper supply unit 17 for supplying paper to the image forming unit 16 is provided at a lower portion.

The paper supply section 17 is detachably attached to the main body 10 and has paper supply cassettes 18 and 19 for storing paper.
And a stack bypass 20 provided thereabove. An optical system 21 for reading image information of a document placed on the document table 15 is provided below the document table 15. The optical system 21 includes a light source 22 for irradiating light to the surface of the document placed on the document table 15 and mirrors 23, 24, and 2 for deflecting light reflected from the surface of the document.
5 and a lens 2 for converging the light from the mirror 25
6 and an image sensor 27 such as a CCD sensor that receives light converged by the lens 26 and generates an image data signal corresponding to an original image.

The image forming section 16 has a photosensitive drum 30 on the surface of which an electrostatic latent image is formed.
0, a main charging device 31, a developing device 32,
It has a transfer roller 33 and a cleaning device 34. The main charging device 31 is a device for charging the surface of the photoconductor drum 30, and is disposed diagonally above and to the right of the photoconductor drum 30. The photosensitive drum 3 is disposed diagonally below and to the right of the photosensitive drum 30 with a predetermined gap from the main charging device 31.
A developing device 32 for forming a toner image on the image sensor 0 is disposed. The developing device 32 stores toner inside, and visualizes the electrostatic latent image formed on the photosensitive drum 30 by the toner. The transfer roller 33 is a device for transferring the toner image on the photosensitive drum 30 to a sheet, and is disposed on the left side of the photosensitive drum 30. The cleaning device 34 is a device for removing residual toner and the like on the surface of the photoconductor drum 30.
0.

On the right side of the photosensitive drum 30, a laser unit 35 for forming an electrostatic latent image on the peripheral surface of the photosensitive drum 30 is provided. The laser unit 35 forms an electrostatic latent image on the peripheral surface of the photosensitive drum 30 based on an image data signal obtained from the image sensor 27. The paper feed unit 17 includes a vertical transport path 41 for transporting paper from each of the paper cassettes 18 and 19 toward the image forming unit 16 and a bypass transport path for transporting paper from the stack bypass 20 to the image forming unit 16. 42 are provided. Each paper cassette 1
Pickup rollers 43, 4 for taking out the stored paper are provided in the stack bypasses 8, 19 and the stack bypass 20.
4, 45 and a pair of paper feed rollers 46, 47, 48 for feeding the paper one by one to the transport path. The vertical transport path 41 is provided with pairs of transport rollers 49 and 50, and the bypass transport path 42 is provided with a pair of transport rollers 51. The vertical transport path 41 and the bypass transport path 42 join below the transfer position where the photosensitive drum 30 and the transfer roller 33 face each other. At the confluence, a registration roller 52 for stopping the conveyed sheet at a predetermined position is provided.

Above the photosensitive drum 30 and the transfer roller 33, a fixing device 53 for fusing and fixing the toner transferred onto the paper is provided. The fixing device 53
A heating roller 54 having a built-in heater and a pressure roller 55 pressing the heating roller 54 are provided. The sheet is nipped between the rollers and transported, and the toner image formed on the surface of the sheet is heated and fixed. Things.

Further above the fixing device 53, a branch 5
6 are provided. On the right side of the branch portion 56, a discharge tray 57 for discharging sheets via a discharge roller pair 60 is provided.
And a discharge roller pair 6 disposed above the discharge tray 57.
1 and a sub-eject tray 58 from which sheets are ejected. Further, a re-feed unit 59 for re-feeding a sheet at the time of duplex copying is disposed at the lower left of the branch unit 56. The branching portion 56 is provided with a branching claw 62 for switching the sheet conveying direction between the direction of the discharge tray 57 and the direction of the re-feeding portion 59. On the left side of the branch claw 62, 2
Two branch claws 63 and 64 are provided. Below the two branch claws 63 and 64, a re-feeding conveyance path 65 for guiding the sheet to the re-feeding section 59 is provided, and above it, a sub-tray conveyance path 66 for guiding the sheet to the sub-discharge tray 58 is provided. A finisher transport path 67 for transporting a sheet to a finisher such as a sorter or a staple sorter (not shown) is provided between the two branch claws 63 and 64.
The branch claws 63 and 64 are switchable so that the conveyed sheet is guided to any one of the re-feeding conveyance path 65, the sub-tray conveyance path 66, and the finisher conveyance path 67. [Branch] The sheet is transported downstream of the fixing device 53 in the sheet transport direction, as shown in FIG. 2, to one of the discharge tray 57, the sub-discharge tray 58, the re-feed unit 59, and the finisher transport path 67. Branching section 56 is provided. The branch portion 56 includes a first branch portion 221 having the branch claws 62 and a second branch portion 222 having the branch claws 63 and 64.
Are provided.

The first branch 221 includes a first transport path 223 from the fixing device 53 to the first branch 221 and a discharge transport path 224 from the first branch 221 to the discharge roller pair 60.
The second branch from the first branch 221 to the second branch 222
It is located at a connection point with the transport path 225, and when the branch pawl 62 rotates, the first transport path 223 and the discharge transport path 22 are rotated.
4. The unloading transport path 224 and the second transport path 225 or the first transport path 223 and the second transport path 225 can be connected.

The second branching section 222 includes a second conveying path 225,
It is located at the connection point of the re-feeding conveyance path 65, the sub-tray conveyance path 66, and the finisher conveyance path 67, and the branching claws 63, 64 are rotated to rotate the second conveyance path 225, the re-feeding conveyance path 65, and the second The transport path 225 and the sub-tray transport path 66 or the second transport path 225 and the finisher transport path 67 can be connected.

The branch claw 62 is rotatably supported by a support shaft 231 and has a first link member 232 which can rotate integrally. In addition, the branch claw 63
Is rotatably supported by a support shaft 233,
A second link member 234 that can rotate integrally is attached. The first link member 232 and the second link member 234 are connected by a third link member 235. The third link member 235 is supported so as to be movable in the direction of the arrow in the figure, and as shown in FIG.
Fixed to the actuator 242 of the solenoid 241
It is configured to be driven and moved. The first link member 232 and the second link member 234 are
The joint with the link member 235 is pivotally mounted so as to be relatively rotatable.

Thus, when the solenoid 241 is in the off state, the third link member 235 is located rightward in FIG. 2, and the branch pawl 62 connects the first transport path 223 and the discharge transport path 224. , The branch claw 63 is in the second conveying path 2
25 and the re-feeding conveyance path 65. At this time, the upper surface of the branch claw 62 is
And a guide surface for guiding a sheet conveyed in reverse from the second conveyance path 225 side. Also, the solenoid 241
Is turned on, the third link member 23 in FIG.
5 is moved to the left, and as shown by the dotted line in FIG.
2 connects the first transport path 223 and the second transport path 225,
The branch claw 63 is positioned to guide the sheet conveyed from the second conveyance path 225 to the branch claw 64 side.

The branch claw 64 is also rotatably supported, and is configured to be driven to rotate by a solenoid (not shown). As a result, the second transport path 225
The paper conveyed from the sheet and guided to the branch claw 64 by the branch claw 63 is guided by the branch claw 64 to either the sub-tray conveyance path 66 or the finisher conveyance path 67.

In the case of normal image forming processing, the fixing device 53
Is discharged to the discharge tray 57. In this case, the branch claw 62 of the first branch portion 221 is in a rotating position as shown in FIG. As a result, the first transport path 223 and the discharge transport path 224 are connected, and the fixing device 5
3 is conveyed to the discharge roller pair 60 side through the discharge conveyance path 224 and discharged to the discharge tray 57. At this time, the branch claws 63 of the second branch portion 222
Is a rotational position that connects the second transport path 225 and the re-feed transport path 65.

In the case where images are formed on both sides of a sheet, when the sheet on which the image forming processing on the first side is completed is conveyed, first, the branch claw 62 is set to the position shown in FIG. In this state, the sheet is conveyed in the discharge direction by the pair of discharge rollers 60, and stopped just before the rear end of the sheet passes through the pair of discharge rollers 60. At this time, the discharge conveyance path 224, the second conveyance path 225, and the re-feed conveyance path 65 are connected by the branch claws 62 and 63. In this state, if the discharge roller pair 60 is driven in reverse, the paper is discharged and conveyed. The sheet is conveyed via the path 224, the second conveyance path 225, and the re-feed conveyance path 65, and the image forming process can be performed on the second surface of the sheet. When the sheet on which the image formation on the second surface has been completed is to be discharged to the discharge tray 57, if the branch claws 62 and 63 are kept in the same state, the sheet conveyed from the fixing device 53 side is discharged via the discharge conveyance path 224. Can be discharged.

A finisher (not shown),
When a sheet is conveyed to the finisher to perform sorting or stapling, the sheet on which the image forming process has been completed is conveyed to the finisher conveyance path 67 side. In this case, the solenoid 241 is turned on and the first branch 22
1 branch claw 62, branch claw 63, 64 of second branch portion 222
Are located as shown in FIG. In this case, the first transport path 223, the second transport path 225, the finisher transport path 6
7 are connected. Accordingly, the sheet conveyed from the fixing device 53 is conveyed via the first conveyance path 223, the second conveyance path 225, and the finisher conveyance path 67.

To discharge the sheet to the sub-discharge tray 58, the solenoid 241 is turned on and the first branch 2
21 and the branch claws 63 and 6 of the second branch portion 222.
4 is positioned as shown in FIG. In this case, the first
The transport path 223, the second transport path 225, and the sub-tray transport path 66 are connected. Accordingly, the sheet conveyed from the fixing device 53 is conveyed to the discharge roller pair 61 via the first conveyance path 223, the second conveyance path 225, and the sub-tray conveyance path 66, and is discharged to the sub-discharge tray 58. .

When the paper is discharged to the sub-discharge tray 58, if the apparatus is connected to a telephone line and can receive data from an external facsimile apparatus, the received data is printed out and the paper is normally printed. May be distinguished from the paper on which the copying process has been performed. Also, if the device is connected to a network and can print out data sent from a personal computer or word processor, the received data is printed out, and this paper is distinguished from paper that has undergone normal copying. Such cases are also conceivable. When such an interrupt process occurs, the printed-out sheet is discharged to the sub-discharge tray 58, so that it can be distinguished from the sheet by the normal copying operation discharged to the discharge tray 57.

At the time of normal discharge in which the sheet on which the image forming process has been completed is discharged to the discharge tray 57, the position of the branch claw 63 is arbitrary. However, when images are formed on both sides of the sheet, the branch claws 62, 63 are linked. Then, it is necessary to set the rotation position as shown in FIG. Further, when discharging the sheet on which the image forming process has been completed to the sub-discharge tray 58 or the finisher, it is necessary to position the branch claws 62 and 63 in conjunction with the rotation positions as shown in FIGS. . Branch claws 62, 63
Can be synchronized with each other, so that it is not necessary to provide a driving means such as a solenoid for each of them. The solenoid 241 can simultaneously drive the two branch claws 62 and 63 to guide the sheet. Therefore, it is possible to reduce the number of parts, to reduce the cost, and to reduce the size of the device.

Depending on the mounting direction of the solenoid 241,
The positions of the branch claws 62 and 63 in the ON state and the OFF state may be reversed. Also, the solenoid 241
Alternatively, a configuration in which a rack and a pinion are provided and the third link member 235 is moved by a drive motor is also possible. Further, a gear may be attached to the support shaft 231 of the branch claw 62 and the support shaft 233 of the branch claw 63, and a gear train and a drive motor may be arranged so as to rotate the gear in synchronization.

[0035]

According to the present invention, the first branch claw and the second branch claw are linked by the connecting drive means, so that there is no need to separately provide a drive means for driving each of the first and second branch claws, thereby reducing the cost. In addition to this, the size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a copying machine employing an embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view of a main part.

FIG. 3 is a schematic plan view of a main part.

FIG. 4 is an explanatory longitudinal sectional view showing the operation of a branching unit.

FIG. 5 is an explanatory longitudinal sectional view showing the operation of a branching unit.

FIG. 6 is an explanatory longitudinal sectional view showing the operation of a branching unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 copier 53 fixing device 56 branch portion 57 discharge tray 58 sub discharge tray 60 discharge roller pair 61 discharge roller pair 62 branch claw 63 branch claw 64 branch claw 65 re-feeding conveyance path 66 sub-tray conveyance path 67 finisher conveyance path 221 first Branch 222 Second branch 223 First transport path 224 Discharge transport path 225 Second transport path 232 First link member 234 Second link member 235 Third link member 241 Solenoid

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-308147 (JP, A) JP-A-3-211161 (JP, A) JP-A-6-250463 (JP, A) JP-A-7- 137909 (JP, A) JP-A-8-169608 (JP, A) JP-A-57-184056 (JP, A) JP 5-44363 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 29/60 B41J 13/00 B65H 85/00 G03G 15/00

Claims (9)

(57) [Claims] A sheet conveyed from a first conveyance path is fed to a second conveyance path.
A first transport path for selectively transporting to a transport path or a third transport path;
A conveying device for the image forming apparatus, comprising: a branching unit; and a second branching unit for selectively conveying a sheet conveyed from the third conveying path to a fourth conveying path or a fifth conveying path. A first conveyance posture for guiding the paper conveyed from the first conveyance path to the second conveyance path, and a second conveyance posture for guiding the paper conveyed from the first conveyance path to the third conveyance path. A first branching claw that is rotatably arranged on the first branching section so as to be able to take the form; a first transporting posture that guides a sheet transported from the third transporting path toward the fourth transporting path; A second branching claw rotatably disposed on the second branching portion so as to be able to take a second transporting posture for guiding a sheet transported from the third transporting path toward the fifth transporting path; When the first branch claw is in the first transfer position, the second branch claw is in the first transfer position. And connection driving means for interlockingly rotating the first branch claw and the second branch claw such that the second branch claw is in the second transfer position when the first branch claw is in the second transfer position. When, wherein the coupling the drive means, the second with the movement in a predetermined direction
The first branch claw and the second branch claw are connected so as to rotate synchronously.
Moving the connecting member in a predetermined direction;
And a driving unit for the image forming apparatus. 2. The conveying device of the image forming apparatus according to claim 1 , wherein the first conveying path conveys a sheet conveyed from a first processing unit that executes a first process on the sheet. 3. The conveying device of the image forming apparatus according to claim 2 , wherein the first processing unit includes an image forming unit that forms a toner image on the sheet surface and a fixing unit that melts and fixes the toner image on the sheet surface. . Wherein said second conveying path, the sheet processing is completed to convey the paper to the first discharge section to be discharged, claims 1-3
The transport device of the image forming apparatus according to any one of the above. 5. The apparatus according to claim 1, wherein the second transport path includes a reversing roller capable of performing forward drive for discharging the paper to the first discharge section and reverse driving for transporting the paper in the third transport path. A transport device for the image forming apparatus according to claim 4 . 6. A sheet processing apparatus according to claim 1, wherein said fourth conveyance path conveys a sheet to a second processing section which executes a second processing on a sheet on which the first processing has been completed in said first processing section. 5. The conveying device of the image forming apparatus according to any one of 5 . 7. The conveying device of the image forming apparatus according to claim 6 , wherein the second processing unit includes a sheet re-feeding unit during double-sided image formation. Wherein said fifth transport path, the sheet processing is completed to convey the paper to the second discharge section to be discharged, claims 1-7
The transport device of the image forming apparatus according to any one of the above. 9. The printer according to claim 1, wherein the second discharge unit is a sorter for sorting discharged sheets, a finisher having a staple function or a punch function, or a job separator for distinguishing the processed sheets from other processed sheets. The conveying device of the image forming apparatus according to claim 8 .