JP2001019254A - Sheet reversing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent stain in case of reversing a sheet in a state of passing with each other. SOLUTION: A side fence 9 is narrowed to width of paper 15 so as to position a width direction of former paper 16 on a reversing tray 10 at the time of discharging the paper 15 finished with one surface copying to the reversing tray 10 by a discharge roller 8, when the paper 15 is discharged from the discharge roller 8 in this state, the paper 15 is discharged to a penthouse type rib of the side fence 9 and does not make contact with the preceding paper 16 below the penthouse rib. When discharge is completely finished, the rib (and the side fence 9) opens, the paper 15 drops on the reversing tray 10 below, the paper 15 dropped on the reversing tray 10 is positioned in a central standard as the side fence 9 (and the rib) is narrowed down to paper width, a drawing roller 11 thereafter makes contact with the paper 15 and it delivers the paper 15 to a recarrying roller 12.

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 for performing a sheet reversing process in a PPC (plain paper copying machine), a printer, a facsimile, and other image forming apparatuses.

[0002]

2. Description of the Related Art At present, attention has been paid to environmental issues, and copiers, printers, and faxes have become important technical issues for which energy saving is required. Among them, double-sided copying, which reduces paper consumption, is a very effective method for energy saving, but has lower productivity (takes longer time) than single-sided passing.
Since it is difficult to use, various measures have been taken to improve the productivity of double-sided copying.

[0003]

An important point for improving the productivity of double-sided copying is that the sheet (transfer sheet) on which single-sided copying has been completed is reversed and sent to the copying process quickly and continuously again. It is in. However, in the reversing section, a large space is set between the two sheets during double-sided copying in order to prevent the succeeding sheet from coming in during the reversing of the preceding sheet, thereby deteriorating productivity.

As a method for solving this problem, (1) a method of reversing and transporting a sheet on which copying on one side is completed at an increased speed.

(2) A method using passing reversal so that the succeeding paper can enter the reversing section during the reversal of the preceding paper. Is used.

However, in the method (1), the paper is reversed at an increased speed. Therefore, if the speed is increased, the same interval as in the case of one side is made possible and the efficiency is increased. However, if the transport speed is increased, skew and jam occur. Rates increase, leading to lower reliability. Further, in the method (2), the single-sided copy-finished paper between the continuous papers can be reversed without increasing the speed, so that the transport quality is higher than the method (1). However, since the preceding sheet and the succeeding sheet come into contact with each other and are rubbed when the preceding sheet is reversed, dirt is easily generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the problem of the above method (2), and has as its object to provide a sheet reversing device capable of preventing dirt when a preceding sheet and a succeeding sheet are reversed by passing each other. The purpose is to do.

[0008]

In order to achieve the above object, a first means comprises a reversing tray for reversing sheets, a discharge roller for discharging sheets to the reversing tray, and the reversing tray. A pair of side fences that can be opened and closed in the width direction of the paper in order to align the paper discharged in the width direction, and can be opened and closed in the width direction of the paper integrally with the side fences, and in a closed state, A rib for receiving the sheet discharged by the discharge roller so as not to fall on the reversing tray, and a rib for dropping the received sheet on the reversing tray in an open state, so that the preceding sheet does not come into contact with the succeeding sheet. The side fence and the rib are configured to be opened and closed.

The second means includes a re-conveying roller which is positioned by the side fence in the first means and re-conveys the sheet, and a moving roller which is positioned by the side fence and conveys the sheet to the re-conveying roller. In addition, the apparatus is configured such that the preceding sheet and the succeeding sheet are aligned by the side fence so as not to come into contact with each other, the preceding sheet is sent to the re-conveying roller by the pulling roller, and the succeeding sheet is discharged onto the rib by a discharge roller. did.

The third means is that the side fence is provided when the distance L for conveying the preceding sheet to the re-conveying roller by the pulling roller in the second means is larger than the distance Y for the succeeding sheet to be bitten by the discharge roller. And the ribs were opened.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of a sheet reversing device according to the present invention. FIG. 2 is an enlarged front view showing the reversing tray section of FIG. 1, and FIG. 3 is an enlarged view of the reversing tray section of FIG. FIG. 4 is a right side view showing the end of the reversing tray section of FIG. 1 at the end of discharge, FIG. 5 is a right side view showing the reversing tray section of FIG. 1 at the time of alignment, and FIG. FIG. 8 is a front view showing a re-transportation (reversal) of the reversal tray section of FIG.

In FIG. 1, a sheet set on a sheet feed tray 1 is taken in by a sheet feed roller 2 and conveyed, and then conveyed by a registration roller 3 so as to coincide with a surface toner image on a drum 4. The surface toner image on the drum 4 is transferred, then the surface toner image is fixed by the fixing roller 5 and the pressure roller 6, then selectively conveyed by the branching pawl 7 in the direction of the reversing tray 10, and then discharged by the discharging roller 8. It is discharged onto the reversing tray 10.

The paper on the reversing tray 10 is
The front and rear ends are reversed by the re-conveying roller 12 and re-conveyed to be turned upside down, and then conveyed by the registration roller 3 so as to match the back side toner image on the drum 4, and then the back side toner on the drum 4 The image is transferred, and then the backside toner image is fixed by the fixing roller 5 and the pressure roller 6, and then selectively discharged to the outside by the branch claw 7.

Next, referring to FIGS.
The structure in the vicinity will be described in detail. A pair of side fences 9 that are movable in the width direction of the paper 15 are provided on the reversing tray 10 to align the paper 15 with reference to the center of the width. As shown in detail in FIGS. 3 to 5, the structure of the side fence 9 is formed in an L-shape so that the sheet can be stored in the bottom of the reversing tray 10 and the sheet is discharged by the discharge roller 8 above. An eave-shaped rib 13 is formed to receive the paper 15 so as not to fall directly on the bottom of the reversing tray 10.

The eaves-shaped ribs 13 are provided on the eaves-shaped ribs 13 so that the paper 13 can easily fall below the eaves-shaped ribs 13.
The taper 14 is formed so as to be positioned at a substantially center of the taper. Further, on the side fence 9, an approach roller 11 is arranged to approach the sheet stored in the bottom of the reversing tray 10 in the re-transport direction and to bring the leading end of the reversible tray 12 so that the re-transport roller 12 can grip it. The pulling roller 11 is rotatably attached to one end of a rotating arm so that it can contact the preceding paper and does not interfere with the succeeding paper, and the rotating arm can be rotated around the other end by a solenoid (not shown). It is provided in.

In such a configuration, when the paper 15 on which single-sided copying has been completed is discharged onto the reversing tray 10 by the discharging roller 8, a side fence is provided to align the width direction of the preceding paper 16 on the reversing tray 10. Reference numeral 9 indicates the width of the paper 15. In this state, the paper 15
Is released, the paper 15 is released onto the eave-shaped ribs 13 of the side fence 9 as shown in FIG. 3, and therefore does not contact the preceding paper 16 below the eave-shaped ribs 13.

When the release of the paper 15 to the rib 13 is completed, the rib 13 (and the side fence 9) is opened and the paper 15 falls on the reversing tray 10 below as shown in FIG. At this time, the preceding paper 16 has already been fed by the re-conveying roller 12. The paper 15 that has fallen on the reversing tray 10 is aligned with the center reference by the side fence 9 (and the rib 13) being reduced to the paper width as shown in FIG.
Next, as shown in FIG. 6, the approach roller 11 comes into contact with the paper 15 and sends the paper 15 to the re-conveying roller 12. Then paper 15
Is sent to the re-conveying roller 12, the approach roller 11 returns to its original position, and the next paper 15 can be released. Due to the repetition of this operation, there is no rubbing between the sheets despite the reversal.

<Second Embodiment> In the first embodiment, the ribs 13 (and the side fences 9) are opened after the paper 15 is completely discharged to the ribs 13. In the case of paper having a weak stiffness, there is a problem that the paper does not fall down while still on the rib 13. Therefore,
As shown in FIG. 7, the distance (distance from the discharged position to the re-conveying roller 12) for re-conveying the paper 15 by the approach roller 11 is L, and as shown in FIG.
(The distance from the discharge roller 8 to the trailing edge of the paper)
Is set to Y, and when L> Y, the side fence 9 is expanded and the paper 15 is dropped, so that as shown in FIG.
5 and 16 do not rub against each other, and the discharge roller 8 still bites the paper 15.
Since it will open and drop down, there will be no failure to drop down.

Also, for the preceding paper 16, since the side fence 9 (and the rib 13) is opened when L> Y, the side fence 9 must be opened after being always bitten by the re-conveying roller 12. Skew caused by opening the side fence 9 before biting by the transport roller 12;
There is no lateral displacement, and the position aligned by the side fence 9 can be maintained.

[0021]

As described above, according to the first aspect of the present invention, the side fence and the rib are integrally opened and closed so that the preceding sheet does not come into contact with the succeeding sheet. In the case of inversion, dirt can be prevented.

According to the second aspect of the present invention, the preceding sheet and the succeeding sheet are aligned by the side fence so as not to come into contact with each other, the preceding sheet is sent to the re-conveying roller by the pulling roller, and the succeeding sheet is placed on the rib by the discharging roller. , The contamination can be prevented when the preceding paper and the succeeding paper are reversed by passing each other.

According to the third aspect of the present invention, the side fence and the rib are opened when the distance for transporting the preceding paper to the re-conveying roller by the roller is greater than the distance for the succeeding paper to be engaged by the discharge roller. Therefore, even the paper having a large curl or the paper having a weak stiffness can be reliably dropped from the rib.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a sheet reversing device according to the present invention.

FIG. 2 is an enlarged front view showing a reversing tray section of FIG. 1;

FIG. 3 is an enlarged right side view showing a reversing tray section of FIG. 1;

FIG. 4 is a right side view of the reversing tray of FIG. 1 at the end of discharging.

FIG. 5 is a right side view showing the position of the reversing tray unit in FIG.

FIG. 6 is a front view showing the reversing tray unit of FIG. 1 when re-transporting.

FIG. 7 is a front view illustrating a distance in which a preceding sheet is conveyed to a re-conveying roller by a roller in a second embodiment.

FIG. 8 is a front view showing a remaining distance in which a discharge roller is engaged with a subsequent sheet in the second embodiment.

FIG. 9 is a right side view of FIG.

[Explanation of symbols]

 Reference Signs List 8 discharge roller 9 side fence 10 reversing tray 11 approach roller 12 re-transport roller 13 eave-shaped rib 14 taper

Claims (3)

[Claims] 1. A reversing tray for reversing a sheet, a discharge roller for discharging the sheet to the reversing tray, and a sheet for aligning the sheet discharged to the reversing tray in the width direction. A pair of side fences that can be opened and closed in the width direction of the sheet, and that can be opened and closed in the width direction of the sheet integrally with the side fences, and do not drop the sheet discharged by the discharge roller onto the reversing tray in a closed state. And a rib for dropping the received sheet onto the reversing tray in an open state, wherein the side fence and the rib are opened and closed so that a preceding sheet does not come into contact with a succeeding sheet. apparatus. 2. A re-conveying roller which is positioned by the side fence and re-conveys the sheet, and a moving roller which is positioned by the side fence and conveys the sheet to the re-conveying roller, further comprising: And the succeeding paper is sent to the re-conveying roller by the pulling rollers, and the succeeding paper is discharged onto the ribs by the discharge roller. The sheet reversing device according to claim 1, wherein 3. The side fence and the rib are opened when a distance for conveying the preceding sheet to the re-conveying roller by the shift roller is greater than a distance for the succeeding sheet to be engaged by the discharge roller. The sheet reversing device according to claim 2.