JPH07121782B2 - Paper reversing device for copier - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing device provided in a sheet conveying path of a copying machine, and more particularly to a switching path which is arranged in an introduction path part of the sheet reversing device and arranged in an intermediate part. The present invention relates to a sheet reversing device for a copying machine, which is configured so that a sheet can be conveyed in an arbitrary mode by a claw and a reversible rotation roller device provided in the sheet reversing device.

(Prior Art) In an automatic double-sided copying machine that has been generally used in the past, a single-sided copied sheet is reversed in the middle of its sheet conveying path, stored in a double-sided intermediate tray, and then a toner image transfer portion is transferred again. A means for forming a toner image on the back surface of the one-side copied sheet is used. Further, the sheet reversing device having the same configuration may be used when a sorter is connected to a copying machine to automatically sort copies. In this case, while the copy is ejected from the copier in the mode in which the image side is ejected, the copy is ejected on the tray of the sorter, with the image side facing down. It is used when it is necessary to do so, and is provided with a sheet reversing device in the main body of the copying machine so that it can correspond to the sheet accommodating mode of the sorter.

As the above-described sheet reversing device, a reversing mechanism generally called an invert chute is used, but in such a chute device, a roller mechanism of an introduction portion generally called a three-roller device and a corrugated roller mechanism are used. In advance, the three-roller device performs the operation of introducing and reversing and ejecting the paper in the chute, and the corrugated roller mechanism forms a corrugate on the paper inside the chute to strengthen the rigidity of the paper. Therefore, it is possible to prevent the occurrence of bending and the like, and it is possible to favorably move within the chute.

Instead of using the above-described sheet reversing device, as shown in FIG. 3, there is also used a device in which a switching claw is provided for the sheet conveyance path and the switching claw is used to perform the sheet reversing operation. May be In the copying machine shown in FIG. 3, the paper feed path 1 is provided with paper feed cassettes 2 and 2a in the paper feed path 1 so that paper can be fed.
Further, at a predetermined position of the paper transport path 1, the photosensitive drum 8,
A fixing device 9 and a sheet reversing device 10 are provided. Further, a double-sided intermediate tray 5 is arranged in the same row as the paper feed cassette 2 so as to accommodate a single-sided copied sheet and to feed the double-sided intermediate tray 5 when performing back side copying. ing.

Therefore, in the copying machine shown in FIG. 3, in the normal copying mode, the paper is fed from the paper feed cassette 2 by the paper feed roller 3, and the registration roller 7 in the paper feed path 1 causes the photosensitive drum to move. 8 is conveyed toward the image transfer portion in synchronism with the toner image formed on the sheet 8, and the sheet on which the toner image has been transferred from the photosensitive drum 8 is introduced into the fixing device 9 to complete a copy. And
If the copy mode is single-sided copy, the paper transfer device 10
Is closed by the switching claw 11, the copy is conveyed as it is and discharged to the discharge tray.

On the other hand, when the copy mode is automatic double-sided copying, the copy that has been fixed passes through the switching claw 11 and the transport path is switched by the switching claw 12, and the double-sided copy is performed via the discharge roller 13. It is discharged to the intermediate tray 5. In addition, when copying is performed on the image surface and when performing reversal discharge, the paper is introduced into the paper reversing device 10 through the switching claw 11 and is reversed, and then the switching claw 12 is used. And is conveyed toward the double-sided intermediate tray 5 or the discharge tray.

(Problems to be Solved by the Invention) However, in the case of configuring the above-described paper transport path, each device such as a paper feed cassette, a double-sided intermediate tray, and a photoconductor drum is provided with respect to the paper transport path. , Which can be used only in the case of the arrangement shown in the figure,
In addition to this, the device is effective only when the paper feeding unit and the discharging unit are provided on the right side of the photosensitive drum. Forming an apparatus having such a structure has a drawback that design conditions are limited depending on the type of copying machine. Further, the conventionally used invert chute has drawbacks such that the paper is apt to cause a jam in the chute or be bent, depending on the type and size of the paper.

(Object of the Invention) The present invention solves the above-mentioned drawbacks of the conventionally used apparatus, and has four modes of reverse discharge, multiplex copy, automatic double-sided copy, and direct discharge of normal copy. It is therefore an object of the present invention to provide a sheet reversing device having a simple structure and capable of easily responding.

(Means for Solving the Problems) In the present invention, the reversible path is provided to the transport path arranged between the fixing device of the copying machine and the discharge tray via the first switching means for switching the transport path. The first reversible transport means and the second reversible transport means provided in a direction farther from the transport path than the first reversible transport means are switched to the reversible path. For this purpose, a second switching means provided between the first reversible transport means and the second reversible transport means and both sides for temporarily stacking sheets from the second switch means And a discharge path provided in the intermediate tray.

Then, by the operation of directly discharging the paper discharged from the fixing device toward the discharge tray and the reverse rotation of the first reversible transporting unit for the paper guided to the reversible path,
The operation of reversing and ejecting toward the ejection tray via the first switching means, and the first arranging in the reversible path.
From the reversible conveying means to the double-sided intermediate tray through the second switching means, and the second reversible conveying means reversely conveys the sheet to the second switching means. There is provided control means for selectively controlling the operation of guiding the sheet toward the double-sided intermediate tray via the sheet feeding information.

(Operation) Therefore, in the paper reversing device of the copying machine of the present invention, the structure of the paper conveyance path can be simplified, and the conveyance direction of the paper can be arbitrarily set. It is possible to cope with the operation of the copying machine in the four modes of copying and copying in the normal mode.

Further, the apparatus of the present invention can easily cope with the case where the paper feed cassette, the discharge tray, and the double-sided intermediate tray are set at arbitrary positions with respect to the paper conveyance path, and the design of the copying machine is restricted. Will not be added.

(Embodiment) The configuration of the sheet reversing device of the present invention will be described according to the illustrated embodiment. The example shown in FIG. 1 shows the structure of the main part of the sheet conveying path of the present invention.
FIG. 3 is a diagram showing a configuration of a sheet reversing device 20 provided subsequently to the above. In the example shown in FIG. 1, following the fixing device 9 provided in the sheet conveying path 1 of the copying machine, the conveying roller 16
And a paper sensor 15 are provided, and the paper reversing device 20 is provided downstream of the paper sensor 15 via an upper switching claw 21 as a first switching means.
Is provided. Further, on the discharge side of the paper transport path, a discharge roller 17 is provided following the upper switching claw 21.
A discharge tray or the next sheet processing apparatus is connected via 17. The upper switching claw 21 is provided so as to be swingable about a shaft 22, and both sides of the projecting portion on the side of the sheet transport path 1 form a guide surface of the sheet. Is in the position shown by the solid line in the figure,
The sheet that has passed the transport roller 16 is directly sent to the discharge roller 17 through the upper surface of the upper switching claw 21.

On the other hand, when the upper switching pawl 21 is swung as shown by the chain line, the paper passes through the lower guide surface of the upper switching pawl 21 and enters the reversible path 35 of the paper reversing device 20. be introduced. In this case, as shown in the figure, a plastic sheet 23 is provided below the upper switching claw 21, so that the sheet is pushed away from the sheet 23 and the sheet reversing device is pushed.
When the sheet enters the inside of the sheet 20, but is reversed and exits from the sheet inverting device 20, the sheet 23 prevents the sheet from moving in the returning direction, so that the sheet is conveyed to the discharge roller 17 side.

In the sheet reversing device 20 of the present invention, an intermediate tray discharge path 40 is provided in the middle of the reversible path 35, and a side switching claw 30 as a second switching means is provided at a branch portion thereof. The side switching claw 30 also has a structure similar to that of the above-described upper switching claw 21, and is configured to be swung about a shaft 31, and the seat 32 is projected to a portion projecting to the lower part thereof. It is provided so that it can perform the function of guiding the sheet downward and the function of guiding the reversed sheet toward the double-sided intermediate tray. A reversible conveying means is provided on the upper and lower portions of the side switching claw 30. As the reversible conveying means, a reversible rotary roller device 25 at an upstream portion as a first reversible conveying means and a second reversible conveying means. A reversible rotary roller device 36 at the downstream portion is provided as a means. These first and second reversible rotation roller devices will be described by taking the case of the reversible rotation roller device 25 at the upstream part as an example. The drive roller 26 and the pinch roller 27 are arranged so as to sandwich the paper conveyance path. The drive roller can be driven in the forward and reverse directions by a drive mechanism (not shown).

Therefore, when the drive roller 26 is driven in the counterclockwise direction in the figure with respect to the sheet introduced into the sheet reversing device 20,
The paper is carried into the paper reversing device 20, and the drive roller 26
When is driven clockwise, the paper is ejected from the paper reversing device 20. The above-described operation of the reversible conveying means is performed by the reversible rotating roller device as the second reversible conveying means arranged in the downstream portion.
The same applies to 36, and by driving the drive roller 37 forward and reverse with respect to the paper nipped between the drive roller 37 and the pinch roller 38 of the reversible rotation roller device 36, the paper is fed to the reversible path 35. An operation of inserting the reversible rotation roller device 36 downward and an operation of pulling the reversible rotation roller device 36 upward are performed. In the device of the present invention, the side switching claw of the reversing device 20.
Including the vertical paper transport path portion corresponding to 30 and the paper transport path formed in the lower portion of the reversible rotation roller device 36,
It is configured as a reversible path 35, and in the following description, the vertical transport path portion in the drawing is also described as a reversible path.

A discharge roller 41 is provided in the discharge path 40 for the intermediate tray, which is connected via the side switching claw 30, and a double-sided intermediate tray 5 is provided at the end portion thereof. The double-sided intermediate tray 5 is a tray used for temporarily stacking paper sheets, like the conventionally used double-sided intermediate tray, and has a bottom feeder type paper feeding means. Then, the sheets accommodated in the double-sided intermediate tray are ejected from below by the sheet feeding roller 6 and are conveyed toward the image transfer position via the conveying roller 16a.

In the apparatus of the present invention, the paper sensor 15 provided at the branching portion of the paper transport path 1 is provided to set the timing of the inversion drive of the drive roller after the paper passes the sensor. There is. Then, after the sheet is guided to the reversible path, the timings of driving the drive roller and the switching claw are controlled so that both reverse ejection and multiple copy modes can be supported.

Next, the operation of conveying the sheet in the sheet reversing device of the copying machine of the present invention configured as described above will be described with reference to FIGS. 2 to 2c. The example shown in FIG.
When performing one-sided copying in normal mode, the upper switching claw 21
By setting the
The sheet that has passed 16 advances in the direction of arrow A as it is, passes the upper surface of the upper switching claw 21, and is conveyed to the discharge path via the discharge roller 17. Of course, in this case, the sheet reversing device 20 does not participate in the sheet.

FIG. 2a shows a case where automatic two-sided copying is performed, in which the upper switching claw 21 and the side switching claw 30 are respectively swung in the direction of switching the paper transport path, and the paper passing through the lower surface of the upper switching claw 21 is , The reversible rotary roller device 25 conveys downward (in the direction of arrow B), passes through the upper slope of the side switching claw 30 and is transferred to the intermediate tray discharge path 40, and passes through the discharge roller 41 to the double-sided intermediate tray. It is discharged to 5. Therefore, in this case, the sheets accumulated on the double-sided intermediate tray 5 are
When the paper is fed by the paper feed roller 6, the back surface of the paper feed roller 6 corresponds to the photosensitive drum, and the toner image is transferred to the back surface of the paper.

The example shown in FIG. 2b shows the sheet path when the sheet is reversed and ejected, and the upper switching claw 21 is set in the switching direction and the side switching claw 30 is set in the inoperative state. Then, the paper that has passed through the upper switching claw 21 and is introduced into the paper reversing device 20 and conveyed in the direction of the arrow C has passed a predetermined time after the rear end of the paper has passed the paper sensor 15 ( After the trailing edge of the sheet passes through the sheet 23 of the upper switching claw 21), the drive roller of the reversible rotation roller device 25 is reversely driven by the output from the control device, whereby the sheet is fed with the arrow C '. Is conveyed in the direction, passes through the other guide surface of the upper switching claw 21, and is conveyed toward the discharge roller 17. Therefore, in this case, both of the reversible rotary roller devices 25 and 36 can be driven in the forward and reverse directions.

The example shown in FIG. 2c shows an example in which multiple copying is performed, in which the upper switching claw 21 is set in the operating state and the side switching claw 30 is in the non-operating state. Then, the sheet introduced into the sheet reversing device 20 by the upper switching claw 21 is driven in the direction of arrow D by the reversible rotary roller devices 25 and 36 until the rear end of the sheet finishes passing the side switching claw 30. Then, the sheet is inserted toward the lower part of the reversible path 35.
After a lapse of a predetermined time after the trailing edge of the sheet has passed the sheet sensor 15, that is, after the trailing edge of the sheet has passed the sheet 32 portion of the side switching claw 30, the reversible rotation roller device 36 moves in the reverse direction. Since it is driven, it moves in the direction of the arrow D'of the sheet, and passes through the lower slope of the side switching claw 30 to the double-sided intermediate tray 5
Is discharged to. In this case, since the sheets accumulated on the double-sided intermediate tray 5 are in the same state as when passing through the sheet conveying path 1, the sheets sent to the sheet conveying path by the sheet feeding roller 6 are on the same surface. The toner images are transferred in a superposed state.

As described above, in the sheet reversing device of the copying machine of the present invention, the sheet conveying direction can be arbitrarily set by the switching operation of the switching claw and the switching of the driving direction of the reversible rotation roller device. These controls can be performed using the information on the sheet conveyance input via the control panel of the copying machine and the information on the sheet detection by one sensor. Further, in the above-described paper reversing device for a copying machine of the present invention, the switching claw can be oscillated by a driving member such as a solenoid, and the driving roller is provided through a driving mechanism provided in the paper conveyance path of the copying machine. Can be configured to operate.

(Effects of the Invention) Since the sheet reversing device of the copying machine of the present invention has the above-described configuration, the configuration can be simplified as compared with the conventionally used sheet transport path. Therefore, the number of operating members can be reduced. Further, in the paper reversing device of the copying machine of the present invention,
It is possible to set the sheet conveyance state in four modes, and operations such as switching of the respective operation members according to the sheet conveyance mode can be reliably performed by reducing the number of operation members. Further, in the paper reversing device of the present invention, since the paper can be conveyed in the forward and reverse directions by the reversible rotation roller device, an unreasonable force is not applied to the paper and a jam may occur in the paper reversing device. It can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of a sheet reversing device of a copying machine according to the present invention, and FIGS. 2 and 2a to 2c show movement states of sheets in the sheet reversing device of a copying machine according to the present invention. FIG. 3 is an explanatory diagram showing a conventional paper transport path. Reference numeral 1 in the drawing 1 ... Paper transport path, 5 ... Intermediate tray for double-sided, 9 ... Fixing device, 10 ... Paper reversing device, 11.12 ... Switching claw, 15
…… Paper sensor, 16 …… Conveying roller, 17 …… Discharging roller, 20 …… Paper reversing device, 21 …… Upper switching claw, 25 ……
Reversible rotation roller device, 30 ... Side switching claw, 35 ... Reversible path, 36 ... Reversible rotation roller device, 40 ... Discharge path for intermediate tray.

Claims (1)

[Claims] 1. A reversible path is connected to a carrying path arranged between a fixing device of a copying machine and a discharge tray via a first switching means for switching the carrying path. A first reversible conveyance means, a second reversible conveyance means provided in a direction farther from the conveyance path than the first reversible conveyance means, and a first reversible conveyance means for switching the conveyance path A second switching means provided between the second reversible conveying means and a discharge path provided on the double-sided intermediate tray for temporarily stacking sheets from the second switching means; The first switching is performed by an operation of directly ejecting the paper discharged from the fixing device toward the discharge tray and a reverse rotation of the first reversible conveying unit for the paper guided to the reversible path. Flipping towards the output tray via means An operation of discharging, an operation of guiding a sheet to the double-sided intermediate tray from the first reversible conveying means arranged in the reversible path via the second switching means, and the second reversible conveying And a control means for selectively controlling an operation of reversing and conveying the sheet by means for guiding the sheet toward the double-sided intermediate tray through the second switching means according to the sheet conveying information. Paper reversing device for copiers.