JPH10338407A - Sheet conveyance device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin sheet with stiffness to improve the loading property and prevent load increase of thick sheet by elastically supporting a guide member which curves sheet and provides stiffness in the direction of conveyance. SOLUTION: Since a plate spring 101 is scarcely deformed or is slightly deformed when comparatively thin paper S1 is conveyed, the paper S1 is formed between discharge rollers 105 with which curved parts which protrude downward by a guide face 104a of a rib 104 are adjacent. As a result, the sheet S1 is stiffened in the conveyance direction and is discharged in good condition. Moreover, when thick paper is conveyed, the plate spring 101 gives in to the rigidity of the thick paper and is deformed so that the rib 104 is displaced upward. Consequently, the paper can be conveyed without giving large load to the paper by the rib 104 and giving traces of the rib on the paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an image forming apparatus such as a copying machine, a printer, a facsimile or the like, or a processing apparatus for performing processing such as reading of a document, for discharging or conveying a sheet onto a tray. The present invention relates to a sheet conveying device.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional conveying roller pair for discharging a sheet.

[0003] The sheet is rotated by a discharge roller 20 which is driven.
1 and the pressing roller 202, and is discharged to a tray provided outside the apparatus main body. If the rigidity of the discharged sheet in the transport direction is insufficient at the time of discharging the sheet, the sheet will buckle and cannot be stacked at a predetermined position on the tray. Therefore, in order to improve the stackability of the sheet, a flange 201a is provided on the outer periphery of the discharge roller 201, the sheet is curved in a wavy shape in the width direction, and the sheet is bent in the conveyance direction.
Buckling was prevented.

FIG. 9 shows another conventional example.

[0005] In FIG. 9, a protruding portion (rib) 250a which protrudes a part of the upper guide 250 is provided. When the protruding portion 250a hits the sheet conveyed while being nipped by the discharge roller 210 and the pressing roller 211, the sheet is curved in a wavy shape in the width direction to make the conveyance direction stiff, thereby preventing buckling.

[0006]

In the above conventional example, if the sheet is bent greatly by enlarging the flange 201a and the rib 250a so as to prevent relatively thin paper from buckling, when the thick paper is conveyed. Transport resistance increases.

Therefore, in order to convey the thick paper, it is necessary to increase the conveying force, and therefore, it is necessary to increase the pressing force of the pressing roller and use a powerful motor having a large torque for driving the discharging roller. Was.

Further, when the pressing force of the pressing roller is increased, marks of flanges and ribs are sometimes formed on the paper.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet conveying apparatus in which a thin sheet is stiffened to improve the stackability of the sheet and does not increase the load even when the sheet is thick. Aim.

[0010] In order to achieve the above object, the present invention comprises a conveying means for pinching and conveying a sheet, a guide member for contacting the sheet held by the conveying means and curving the sheet, and And a supporting means for movably supporting the member in accordance with the rigidity of the sheet.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) The following describes an embodiment of the present invention.
This will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a copying machine, a printer, etc.
An image forming apparatus for forming an image on a sheet is provided with a pair of discharge rollers 2 and 3 for discharging the sheet on which the image is formed from the image forming apparatus main body 1 to the outside.

A sorter 100 sorts and discharges the sheets discharged from the image forming apparatus 1 onto a plurality of bin trays 110 to 11n. A discharge roller 105 is driven to rotate in the direction of arrow A by a motor (not shown). , 10
A pressing roller 6 presses the sheet against the discharge roller 105.

Reference numeral 104 denotes a guide member (rib) for curving the discharged sheet so as to undulate in the width direction to give a stiffness. The rib 104 is attached to the sorter 100 via a leaf spring 101 which is an elastic member as a support means.
One end of the leaf spring 101 is fixed to a frame of a sorter 100 (not shown) by a screw 102, and a rib 104 is fixed to the other end of the leaf spring 101 by a screw 106.

FIG. 2 shows the discharge roller 1 from the direction of arrow a in FIG.
FIG. 5 is a view of a pressing roller and a pressing roller. 105b is a roller shaft on which the discharge roller 105 is provided.

A guide surface 104a that contacts the sheet is formed below the rib 104. When the sheet is not conveyed as shown in FIGS.
04a is located below the nip 105a between the discharge roller 105 and the pressing roller 106.

When conveying relatively thin paper S1, FIG.
As shown in FIG. 4, since the leaf spring 101 is hardly deformed or is slightly deformed, the paper S1 is
The curved portion S protruded downward by the guide surface 104a of No. 4
1a is formed between the adjacent discharge rollers 105. As a result, the stiffness of the sheet S1 in the transport direction is increased, and the sheet S1 can be discharged well.

When the thick paper S2 is transported, as shown in FIGS. 5 and 6, the leaf spring 101 is deformed to lose the rigidity of the thick paper S2, and the rib 104 is displaced upward. Therefore, the ribs 104 can be conveyed without imposing a large load on the paper and leaving no trace of the ribs on the paper.

(Embodiment 2) The present invention is not limited to the discharge port of the sorter, but may be provided at the discharge port 10 for discharging sheets from the image forming apparatus main body 1 to the discharge tray 20, as shown in FIG.

A rib 14 is fixed to a free end of a cantilever leaf spring 11 fixed to a housing of the apparatus main body by a screw 13. When the sheet is not being conveyed, the lower guide surface 14a of the rib 14 is provided with the nip 3a of the discharge rollers 2, 3.
Arrange so that it is located below.

The elastic member supporting the guide member (rib) is not limited to a leaf spring, but may be sponge or rubber. Alternatively, the rib may be swingably attached to the support shaft so as to urge the sheet by its own weight.

A plurality of guide members may be provided.

Further, the present sheet conveying apparatus can be applied to a processing apparatus for performing processing such as reading of an original, in addition to a sorter and an image forming apparatus.

[0024]

As described above, since the guide member for curving the sheet and providing the stiffness in the conveying direction is elastically supported, the thin sheet is stiffened to improve the stacking property and the thick sheet is thickened. In this case, since the load is not increased, high-performance driving means is not required.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a part of an image forming apparatus and a sorter according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a discharge roller.

FIG. 3 is a vertical sectional side view of a part of the image forming apparatus and a sorter when thin paper is being discharged.

FIG. 4 is a diagram illustrating a discharge roller when discharging thin paper.

FIG. 5 is a vertical sectional side view of a part of the image forming apparatus and a sorter when a thick paper is being discharged.

FIG. 6 is a diagram illustrating a discharge roller when discharging thick paper.

FIG. 7 is a longitudinal sectional side view of a part of an image forming apparatus according to a second embodiment of the present invention.

FIG. 8 is a view showing a conventional discharge roller.

FIG. 9 is a view showing a conventional discharge roller and guide.

[Explanation of symbols]

 Reference Signs List 101 leaf spring 104 guide member 105 discharge roller 106 pressing roller

Claims (9)

[Claims] A conveying means for nipping and conveying the sheet, a guide member for contacting the sheet held by the conveying means and bending the sheet, and the guide member can be moved according to the rigidity of the sheet. And a supporting means for supporting the sheet conveying device. 2. The sheet conveying apparatus according to claim 1, wherein said support means has an elastic member which is deformed by being pushed by a sheet. 3. The sheet conveying device according to claim 2, wherein the amount of deformation of the elastic member changes according to the rigidity of the sheet. 4. The sheet conveying device according to claim 3, wherein said elastic member includes a leaf spring. 5. The sheet conveying apparatus according to claim 1, wherein the guide member moves in a direction in which the curvature formed on the sheet decreases as the rigidity of the sheet increases. 6. A tray on which sheets are placed, discharge means for holding the sheets, and discharging the sheets onto the tray, and a guide member for bending the sheets in contact with the sheets held by the discharge means And a supporting means for supporting the guide member movably according to the rigidity of the sheet. 7. A sheet processing unit for performing processing on a sheet, a tray on which the sheet processed by the processing unit is placed, and holding the sheet processed by the processing unit,
Discharging means for discharging the sheet onto the tray; a guide member for bending the sheet in contact with the sheet held between the discharging means; and a support for movably supporting the guide member in accordance with the rigidity of the sheet Means, and a sheet discharging device. 8. The sheet discharging apparatus according to claim 7, wherein said processing means forms an image on a sheet. 9. The sheet discharging apparatus according to claim 7, wherein said processing means reads an image on a sheet.