JP2577384B2 - Copier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to copying provided with a re-copying function such as double-sided copying in which an image is copied on both sides of a copy sheet, composite copying in which a different image is overlapped on one side of a copy sheet, and the like. Related to the device.

2. Description of the Related Art In the above-described copying apparatus, an image forming apparatus that forms an image on one side of a copy sheet, and a sheet return device that conveys the copy sheet discharged from the image forming apparatus to the image forming apparatus again are provided. A copy sheet discharged from a forming apparatus and carrying an image on one side is fed to the image forming apparatus by the sheet returning apparatus, and an image is formed again on the copy sheet. In this type of copying machine,
A sheet re-feeding device is provided in a sheet re-feeding path of a sheet re-feeding apparatus, and a plurality of copy sheets sequentially fed along the sheet re-feeding path are stacked in the sheet re-feeding apparatus once. Thereafter, it is general that the copy sheets from the stacked copy sheet bundle are re-supplied one by one to a sheet transport path for re-feeding and re-sent to the image forming apparatus.

In this copying apparatus, there is no particular problem when copying a plurality of copies of the same image (so-called copies). However, when copying one copy product, it is not necessary to copy the product in the sheet re-feeding apparatus. Must be retransmitted to the image forming apparatus. Generally, the sheet refeeding device
The function of stacking a large number of copy sheets and the function of separating and conveying one copy sheet from the stacked sheet bundle must be provided, and the structure thereof is complicated. Therefore, if the copy sheet is re-sent via this sheet re-feeding device when both-side copying or the like is performed on only one copy sheet, it takes longer than necessary to convey the sheet, and complicated sheets are required. Because of being transported along the transport path, there is a high possibility of occurrence of jam, skew, and the like.

Therefore, in a copying apparatus having a re-copying function such as multiple image formation (so-called composite copy) and double-sided image formation (so-called double-sided copy) on the same copy sheet, the number of copy sheets for performing multiple image formation is one. A configuration in which the conveyance path of the copy sheet is automatically switched depending on the number of sheets and the image forming operation can be processed quickly and efficiently with less waiting time for any number of sheets is disclosed in, for example, JP-A-61-260267. It has been disclosed.

An object of the present invention is to provide such a prior art with more options and to enable retrofitting of a sheet re-feeding device, while maintaining the re-copying function and efficiently performing one-sheet copying. It is an object of the present invention to prevent occurrence of conveyance failure.

To achieve the above object, the present invention provides an image forming means for forming an image on one side of a copy sheet, and a method for forming a copy sheet discharged from the image forming means again through a sheet feeding path for returning. Sheet returning means for transporting the sheet, a branch path branching from the sheet transport path for return sheet, and stacking the copy sheets sequentially fed through the branch path, and then stacking the plurality of copy sheets one by one. Sheet re-feeding means for feeding the sheet to the return sheet transport path; and transport path switching means for switching the transport path of the copy sheet between the return sheet transport path and the branch path. At the time of one-sheet copying in which image forming processing is performed on two copy sheets, the conveyance path switching means selects the return sheet conveyance path, and at the time of multi-sheet copying in which image formation processing is repeatedly performed on a large number of copy sheets,
A copying apparatus configured to select a branch path by the transport path switching unit and capable of repeatedly forming an image on a copy sheet, wherein the sheet re-feeding unit includes the image forming unit and the sheet When the multi-sheet copying is performed after the sheet re-feeding unit is detachably provided from the image forming unit and the sheet returning unit, the conveyance path switching is performed. The means selects the return sheet transport path, and the copy sheets of the number of copies are sequentially returned using the return sheet transport path, and the sheet re-feed means is mounted. The paper path switching means, which can be freely switched when the sheet is being fed, performs the sheet conveyance to the branch path in conjunction with the sheet re-feeding means being separated from the image forming means and the sheet returning means. Automatically forcibly change to a blocking position It is a reproduction apparatus according to claim which is way.

 Hereinafter, the present invention will be described based on examples.

FIG. 1 is a sectional view of one embodiment. In the drawing, a copying apparatus according to this embodiment includes a main body 1 and a sheet re-feeding device 2.
It is composed of A sorter 3 and an automatic document feeder (ADF) 4 are attached to the copying apparatus.

A drum-shaped photoconductor 5 is disposed slightly to the right of the center of the copying apparatus main body 1, and an exposure optical device 6 is disposed further above the drum-shaped photoconductor 5. The exposure optical device 6 includes a lamp 7, mirrors m1, m2,
m3, m4, m5, m6 and a lens 8, and a light image of the image of the original placed on the contact glass 9 is guided to the surface of the photoconductor 5 by optical scanning by each of these optical systems. Is exposed.

The photoreceptor 5 is charged before the above image exposure.
The surface is uniformly charged by 10, and an electrostatic latent image corresponding to a document image is formed on the surface of the photoconductor 5 by this image exposure. This electrostatic latent image is transferred to the color developing device 11
Alternatively, the toner image is developed by one of the black developing devices 12 to be a visible image. Color developing device 11
Contains a toner of a desired color in advance. A color filter 13 is provided at the end of the optical path of the exposure optical device 6 corresponding to the toner color. The toner image is carried to a position (transfer position) facing the transfer charger 14 in accordance with the clockwise rotation of the photoconductor 5.

Three sheet cassettes 15 are provided at the lower right of the copying apparatus main body 1.
A sheet feeding device including a, 15b, and 15c is provided.
While the above-described toner image forming process is performed, one sheet, for example, a copy sheet, is sent from any one of the sheet cassettes to the registration roller 20, and further moved to the transfer position in view of the timing with the toner image on the photoconductor 5. Will be sent out.

The fed copy paper is superimposed on the toner image at the transfer position, and the toner image is transferred onto the copy paper by the discharge of the transfer charger 14. Then a separate charger
The copy paper is peeled off from the photoreceptor 5 by the action of 16 and the separation claw 17, and is conveyed to the fixing device 19 by the conveyor belt 18.
A copy image of a document image is fixed on one side of the copy paper that has passed through the fixing device 19.

As described above, in the present embodiment, each device for forming a visible image on the surface of the photoconductor 5, such as the exposure optical device 6, the photoconductor 5, and the developing devices 11 and 12, and the fixing device 19, etc. An image forming unit for forming an image on one side is configured.

On the downstream side of the fixing device 19, a paper discharge path 25 for discharging the copy paper to the sorter 3 via the paper discharge roller 24 is provided. Further, a return sheet transport path 21 extending from the sheet outlet of the fixing device 19 to the registration roller 20 through the lower portion of the copying apparatus main body 1 and sheet transport rollers 22a, 22b, A sheet return means 23 including 22c, 22d, 22e, 22f, 22g, and 22h is also provided. A branch path 26 for guiding the copy paper to the sheet re-feeding means 27 is provided in the middle of the return sheet transport path 21 (immediately below the first transport roller 22a). A reversing path 29 for guiding the copy paper to the base 28 of the copying machine main body 1 is provided in the middle of the return sheet conveyance path 21 (just below the second conveyance roller 22b). This reversal path
The sheet conveying roller 30 provided in the printer 29 rotates in a forward or reverse direction at an appropriate time according to a command from a control device (not shown) for controlling a copying process by the copying device.

A path switching claw 31 is provided at a branch point between the return sheet transport path 21 and the paper discharge path 25, a path switching claw 32 is provided at a branch point between the return path 26 and the reversing path 29. At the junction between
33 are provided, and an appropriate sheet conveyance path is selected by the switching operation of each switching claw.

The copying apparatus performs a copying process in three modes: a normal copying mode, a composite copying mode, and a duplex copying mode. In each of these modes, a single copy product (so-called copy) or a large number of copy products can be freely copied as desired.

Normal Copy Mode This mode is a commonly used copy mode in which an image is copied onto one side of a copy sheet and discharged. In this case, the paper path 25
Is selected, and one or many copy products are sequentially discharged into the sorter 3 and sorted into the bins 34. If one discharge tray is arranged in place of the sorter 3, the copy products are stacked on the tray one after another.

Synthetic Copy Mode In this mode, two copy processes are performed on one side of a copy sheet, and different original images are synthesized and copied on one copy sheet. In this mode, the transfer path of the copy paper differs between when obtaining one copy product and when obtaining a large number of copy products.

(In the case of one copy) Each of the transport path switching claws 31, 32 and 33 selects the return sheet transport path 21. The copy paper (image formed on one side) coming out of the fixing device 19 is transported by conveying rollers 22a, 22b, 22c and 22.
d, 22e, 22f, 22g, and 22h again to register roller 2
It is returned to 0, and is again subjected to copying processing by the photoconductor 5 and the like. In this case, a different toner image is formed on the photoreceptor 5 in advance than in the previous copying process, and thus two different images are synthesized and copied by this re-copying process. After exiting the fixing device 19, the copy paper having undergone the composite copy is sent to the paper discharge path 25 by the transport path switching claw 31 that has already been switched and is discharged.

(In the case of copying a large number of sheets) The transport path switching claw 31 selects the sheet feeding path 21 for return feeding, and the switching claw 33 selects the reversing path 29. Then, the transport path switching claw 32 selects the branch path 26. Therefore, the copy paper sequentially discharged from the fixing device 19 is discharged to the sheet re-feeding device 27 via the branch path 26.

In the sheet re-feeding device 27, the copy paper fed through the branch path 26 is stacked on a tray 36 by a draw-in roller 35. Above the tray 36, a roller 38 that moves up and down by a swing lever 37 is provided. The rollers repeatedly move up and down each time one copy sheet is fed onto the tray 36, and abut these copy sheets against the stopper plate 39. When a predetermined number of copy papers (all of which have a copy image formed on one side) are stacked on the tray 36,
By a paper feed mechanism including a pressure arm 40, a paper feed roller 41, and a friction pad 42, the copy paper on the tray 36 is returned one by one to the return sheet transport path 21 (in particular, immediately above the second transport roller 22b). Position). Thereafter, unlike the case of one-sheet copying, the conveyance path switching claw 33 passes through the reversing path 29 and is switched back by forward / reverse of the sheet conveyance roller 30, passes through the conveyance roller 22 c, and passes through the registration roller 20.
And the composite copy is performed on each copy paper.

Double-sided copy mode In this mode, a copy image is formed on both sides of a copy sheet. Also in this mode, as in the case of the above-described composite copy mode, the conveyance path of the copy sheet differs between the case of single copy and the case of multiple copy.

(In the case of one-sheet copying) The return sheet transport path 21 is selected by the transport path switching claws 31 and 32. Then, the reversing path 29 is selected by the transport path switching claw 33. The copy paper exiting the fixing device 19 (an image is formed on one side) moves along the return sheet transport path 21 until it reaches the second transport roller 22b, and then enters the reversing path 29, where it is forwarded. -It is sent to the main body base 28 by the reverse roller 30. When the trailing edge of the copy paper enters the reversing path 29, the forward / reverse roller 30
Starts reverse rotation, and the copy sheet once sent into the main body base 28 is sent out again to the sheet transport path 21 for returning. At this time, the front and back of the copy sheet are reversed. Thereafter, copying is performed on the back side of the copy paper as in the above description.

(In the case of multi-sheet copying) The return path sheet feed path 21 is selected by the transfer path switching claw 31, the branch path 26 is selected by the transfer path switching claw 32, and the return path sheet feed path 21 is selected by the transfer path switching claw 33. . With this, the fixing device
A large number of copy papers sequentially discharged from 19 are temporarily stacked in the sheet re-feeding device 27 and then returned to the sheet transport path for return.
The image is sequentially sent again to the image forming means including the photoreceptor 5 and the like via 21 to copy the image on the back surface.

As is apparent from the above description, according to the present embodiment,
This is a copy mode in which copying is performed a plurality of times on one copy sheet as in the case of composite copying or double-sided copying. In the case of one copy, the one sheet is copied using the sheet return means 23. The sheet is re-sent to the forming means (photoreceptor 5 or the like), and when copying a large number of sheets, the sheets are once stacked by the sheet re-feeding device 27 and then re-sent to the image forming means.

In FIG. 1, reference numeral 43 denotes a jogger device provided in advance in the sheet transport path 21 for return feeding. In the jogger device 43, there is provided a jogger fence 44 which is movable in a direction perpendicular to the paper surface, that is, in a direction perpendicular to the transport direction of the copy paper. One copy sheet conveyed into the jogger device 43 is temporarily stopped there (it is not necessary to stop it in some cases), the skew is corrected by moving the jogger fence, and then sent to the registration roller 20.

In the embodiment shown in FIG. 1, a sheet re-feeding device 23 is previously incorporated in the copying apparatus main body 1 and a sheet re-feeding device 27 is provided.
Is attached to the main body 1. That is, the sheet re-feeding device 27 is configured to be detachable from the main body 1, and in a state where the sheet re-feeding device 27 is taken out, one sheet is The process of combining or double-sided copying on the copy paper is repeated for a predetermined number of sheets. The transport path switching claw 32 for feeding the copy paper to the sheet re-feeding device 27 is associated with the sheet re-feeding device 27 as described below.

As shown in FIG. 2, the transport path switching claw 32 is configured to rotate around a pin 45, and a bracket 46 is integrally attached thereto. A swing arm 48 is provided below the bracket 46 so as to be rotatable about a pin 47. A pin 50 on the bracket 46 fits into an elongated hole 49 formed at one end of the swing arm 48. I agree. Swing arm 48
A protrusion 51 is formed at the other end of the. The sheet refeeding device 27 which is attached to and detached from the copying machine main body 1 has a solenoid.
52 and an actuating plate 53 driven by the solenoid in the direction of arrow AA 'are provided.

A tension spring 54 is provided above the swing arm 48, and when the sheet re-feeding device 27 is not mounted as shown in FIG. Pulled, as shown, return sheet transport path
21 is open and branch 26 is closed. Accordingly, no copy paper is discharged from the branch path 26. When the sheet re-feeding device 27 is mounted as shown in FIG. 2, the position of the tip (right end) of the plate 53 and the position of the pin 51 at the lower end of the swing arm 48 coincide with each other. Switching claw
32 can be switched freely.

In the above description, particularly, the contact glass 9
The original placed on (FIG. 1) is not mentioned. FIG. 1 shows a case where the document is automatically fed using the ADF 4, but the document can be manually replaced without using the ADF. In the ADF 4, a document D placed on a document table 55 is sent to a conveyor belt 58 by paper feed rollers 56 and 57, and the contact glass 9
It is transported to the above predetermined stop position and stopped, and is subjected to a copying process (document exposure). Thereafter, the sheet is discharged to the sheet discharge tray 60 by the reverse / discharge roller 59.

The above is the flow of an original when only one side of the original is copied. Alternatively, when copying both sides of the original,
The original that has been exposed on one side is not immediately discharged to the tray 60 by the reversing / discharge roller 59, but is sent to the transport belt 58 again by largely circumventing the reversing / discharge roller 59, where Set to. After the exposure of the back side is completed, the tray is turned
The paper is ejected on top of 60.

According to the present invention, the sheet re-feeding means is detachably provided to the image forming means and the sheet returning means, and the sheet re-feeding means is detached from the image forming means and the sheet returning means. When a large number of copies are to be made, the transport path switching means selects a return sheet transport path, and the number of copied sheets is sequentially returned using the return sheet transport path. When the sheet re-feeding means is mounted, the conveyance path switching means, which can be freely switched when the sheet re-feeding means is removed from the image forming means and the sheet returning means, moves to a branch path. , So that it can be forcibly displaced to a position where the sheet re-feeding device is not disturbed. No transport failure No.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of one embodiment, and FIGS. 2 and 3 are enlarged views of a main part of the embodiment. 5, 6, 10, 11, 12, 19 image forming means 21 sheet return path for return 23 sheet return means 26 branch path 27 sheet refeeding means 32 transport path Switching means

Claims (1)

(57) [Claims] An image forming means for forming an image on one side of a copy sheet; and a sheet feeding means for feeding the copy sheet discharged from the image forming means again to the image forming means via a return sheet feeding path. Feeding means, a branch path branching from the return sheet conveying path, stacking copy sheets sequentially fed through the branch path, and then stacking the plurality of copy sheets one by one. A sheet re-feeding means for feeding the sheet to the path, and a conveyance path switching means for switching the conveyance path of the copy sheet between the return sheet conveyance path and the branch path. At the time of one-sheet copying for forming processing, the return sheet conveying path is selected by the above-mentioned conveyance path switching means, and at the time of multi-sheet copying at which image formation processing is repeatedly performed on a large number of copy sheets, branching is performed by the conveyance path switching means. Down the road A copying machine configured to form an image on a copy sheet repeatedly, wherein the sheet re-feeding means is provided detachably with respect to the image forming means and the sheet returning means. When the multi-sheet copying is performed after the sheet re-feeding unit is removed from the image forming unit and the sheet returning unit,
The transport path switching means selects the return sheet transport path, and uses the return sheet transport path to sequentially return the number of copy sheets by the number of copies. The conveying path switching means, which can be freely switched when the means is mounted, is connected to the branch path in conjunction with the sheet re-feeding means being separated from the image forming means and the sheet returning means. Characterized in that the copying machine is automatically displaced to a position where the sheet is not conveyed.