JP3711069B2 - Sheet conveying and separating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying / separating apparatus having a retard roller mechanism that separates and conveys a plurality of sheets into one in a scanner, a copying machine, and the like.
[0002]
[Prior art]
In recent years, an image forming apparatus such as an image reading apparatus, a printer, a copying machine, or a facsimile is provided with a sheet feeding device for separating sheets one by one and feeding them to the image reading section or the image forming section. As such a sheet feeding device, a device that employs a retard separation system capable of separating a sheet with high reliability from a low speed to a high speed is widely used as a mechanism for separating the sheet.
[0003]
For example, as shown in FIG. 5, in the retard separation system, the feed roller 1 that rotates in the sheet feeding direction (arrow A in FIG. 5) is pressed against the feeding roller 1 with a predetermined pressure and the direction opposite to the sheet feeding direction. In other words, the sheet S is separated and fed one by one by the separation roller 2 (retard roller) that rotates in the direction to return the sheet S.
[0004]
Here, a torque limiter is provided in the driving force transmission path of the separation roller 2 to cause slippage at a specified load or more. This torque limiter is normally operated by a load consisting of a frictional force between the feed roller 1 and the sheet S. As a result, the separation roller 2 follows and rotates (follows) the sheet S so as to convey one sheet.
[0005]
On the other hand, when a plurality of overlapping sheets S enter between the roller nips that are pressed against each other, the sheet S that is in contact with the feeding roller 1 due to slippage between the sheets S is conveyed in the feeding direction. The sheet in contact with the separation roller 2 side is returned by the reverse rotation of the separation roller 2.
[0006]
Further, when a large number of stacked sheets S are set, the bundle S enters the roller nip, and a multi-sheet multi-feed occurs. In order to prevent this, a slope portion is formed in front of the separation roller 2 as shown in FIG. 5B, or a wall portion is formed as shown in FIG. An apparatus provided with such a guide portion 10 is also known.
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional example, particularly in the case of a vertical sheet feeding mechanism, a stack of a large number of sheets is directly placed on the conveying / separating device roller nip portion. It will cause non-feed failure. Further, even if the guide portion 10 shown in FIG. 5B or 5C is provided, a sheet having a high friction coefficient in combination with the weight of the sheet S enters between the guide portion 10 and the conveyance guide more than necessary. It becomes unfeed due to multiple feeds or paper jams.
[0008]
The present invention has been made to solve the above-described problems of the prior art. The purpose of the present invention is to reliably separate and convey a single sheet even when a large number of sheets are set, and to process the sheet material without feeding. An object of the present invention is to provide a sheet conveying / separating apparatus that eliminates the situation of stagnation.
[0009]
[Means for Solving the Problems]
A sheet conveying / separating apparatus according to the present invention is a sheet conveying / separating apparatus that separates and conveys a plurality of sheets into one sheet by a pair of opposed feed rollers and separating rollers, and the separating roller is formed of an elastic body. In addition, a conveyance restriction guide is provided in the vicinity of the separation roller so as to relatively protrude by deformation of the elastic body.
[0010]
In the sheet conveying / separating apparatus according to the present invention, the conveyance regulating guide may be formed such that the closer to the nip portion of the roller pair, the larger the deformation amount of the separating roller required to protrude. Features.
[0011]
In the sheet conveyance separating apparatus according to the present invention, the conveyance regulation guide is formed in a staircase shape.
[0012]
In the sheet conveying / separating apparatus according to the present invention, the conveyance regulating guide is formed of a flexible material, and is in contact with a vicinity of a roller pair nip portion of the feeding roller.
[0013]
In the sheet conveying / separating apparatus according to the present invention, the conveying regulation guide is formed of a flexible material that can be elastically deformed, and is disposed on the feeding roller side so as to block sheet conveyance in the vicinity of the roller-to-nip portion of the feeding roller. It is characterized by the non-contact approach.
[0014]
In the sheet conveying / separating apparatus according to the present invention, a concavo-convex shape is formed on the surface of the conveying regulation guide on the side of the feeding roller.
[0015]
According to the present invention, with the above configuration, even when a large number of overlapping sheet bundles enter, the sheet is received by the conveyance regulation guide having a sheet receiving function without hindering the operation of the separation roller, and an appropriate small number of sheets between the roller and the nip. It is possible to suppress the entry of the sheet. Further, even if the sheet is caught by the conveyance regulation guide, the separation roller made of an elastic body pushes out the sheet, so that a non-feed failure can be avoided.
[0016]
In addition, even in a conveyance regulation guide that is in contact with or in non-contact with the feed roller, a large number of overlapping sheet bundles can be prevented from entering an appropriate small number of sheets, and the concave and convex shapes can be used to reliably roll the leading edge of the sheet. It can be separated into one sheet.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 23 is a diagram showing a configuration of an image reading apparatus as an application example of the present invention. The outline of the image reading apparatus will be described below.
Reference numeral 100 denotes an image reading apparatus, 100A denotes an image reading apparatus main body, 100B denotes a sheet stacking section that is a sheet storing section for stacking and storing sheets S, 102 and 103 denote front and back image reading sections that read an image of the sheet S, and 100C denotes a sheet. This is a sheet feeding device that feeds sheets S stored in the stacking unit 100 </ b> B to the front and back image reading units 102 and 103.
[0018]
The sheet feeding device 100C includes a feeding roller 1 that is a feeding rotating body and a separation roller 2 that is a separating rotating body that is in pressure contact with the feeding roller 1, and includes one sheet S stacked on the sheet stacking unit 100B. Separating and feeding means for separating each one is provided. Reference numeral 3 denotes a main motor for driving the feed roller 1, the separation roller 2, and the like.
[0019]
Next, an image reading operation in the image reading apparatus 100 configured as described above will be described. When the image reading operation is started, the plurality of sheets S placed on the sheet stacking unit 100 </ b> B are separated into one sheet by the feeding roller 1 and the separation roller 2 that are in pressure contact with each other. Thereafter, the sheet passes through the platen rollers 102a and 103a in close contact with the front and back image reading units 102 and 103.
[0020]
The image formed on the front surface or the back surface of the sheet S during the passage is line-scanned by passing through the front and back image reading units 102 and 103 and is output to the outside as an electric signal. Further, after the image is read in this way, the sheet S is discharged to the outside by the discharge roller 104 (discharge roller pair 104a, 104b).
[0021]
In FIG. 2, reference numeral 101 denotes an upper unit that constitutes a sheet feeding apparatus body including the separation roller 2, the back surface image reading unit 103, the upper sheet discharge roller 104 a, and the like. The upper unit 101 is normally closed as shown in FIG. 2A. However, for example, in the case of jam processing, cleaning and maintenance of rollers, etc., the upper unit 101 is separated from the sheet conveyance path R in FIG. As shown in b), it opens upward. By opening in this way, the separation roller 2 can be separated from the feed roller 1.
[0022]
Next, FIG. 1 is a drawing that best represents the sheet conveying and separating apparatus of the present invention. FIG. 1 illustrates the configuration of the present invention. The sheet conveying / separating apparatus of the present invention includes a feeding roller 1 and a separating roller 2 which are opposed to each other, the feeding roller 1 rotates in the sheet conveying direction, and the separating roller 2 is formed of an elastic body so as to rotate in the reverse direction. Power is transmitted.
[0023]
In addition, a torque limiter is provided in the drive transmission path of the separation roller 2, and in the state where there is no sheet S or when one sheet is conveyed between the feed roller 1 and the separation roller 2, the rotation follows the sheet conveyance direction. (Turn around). In a state where a plurality of overlapping sheets S have entered between these rollers, the separation roller 2 is configured to rotate in the reverse direction. Further, in this configuration, the conveyance regulation guides 4 are formed on both side surfaces of the separation roller 2 so that the sheets S that are overlapped more than specified do not enter.
[0024]
The conveyance regulating guide 4 is formed inside the outer periphery of the separation roller 2 as shown in the figure, and the distance from the outer periphery of the sheet entry side surface increases as it approaches the nip, that is, as shown in FIG. It is formed in a staircase shape so that x1> x2. The surface facing the feed roller 1 is formed to have a gap y1 calculated from the separable number of sheets S.
[0025]
With this configuration, when a large number of sheets S that have a high friction coefficient and are easy to enter are deformed and rushed into the separation roller 2, the conveyance regulation guide 4 is formed to protrude relatively so as to be exposed from the separation roller 2. ing. As a result, even if a large number of sheets S enter, they are received by the staircase shape of the conveyance regulation guide 4, and only the separable number of sheets corresponding to the gap y1 are overlapped, and the retard roller unit reliably rolls one sheet to the image processing unit. Can be transported.
[0026]
Here, even when the sheet S is caught on the stepped shape portion of the conveyance regulation guide 4, the separation roller 2 formed of an elastic body starts to reversely rotate, so that the sheet S is kicked out and sent between the roller nips. It is possible to get out of the non-feed state. As a result, even if a large number of sheets S are set, they can be reliably separated and conveyed into one sheet, and the situation where the sheet material processing is delayed due to non-feeding can be eliminated.
[0027]
In another embodiment, as shown in FIG. 3, the conveyance regulation guide 4 is formed of a flexible material that can be elastically deformed. Then, as shown in FIG. 3A, the front end portion of the conveyance regulating tongue plate 5 is brought into contact with the feed roller 1. In this case, the same effect can be obtained by forming the abutted surface in an uneven shape (groove 5a) as shown in FIG.
[0028]
Further, as shown in FIG. 3B, the conveyance regulating tongue plate 5 is not brought into contact with the outside diameter of the feed roller 1 but is brought into contact with the feed roller 1 in a non-contact manner so as to block sheet conveyance. Similar effects can be obtained.
[0029]
Further, when the conveyance regulation guide 4 and the conveyance tongue plate 5 are used in combination as shown in FIG.
[0030]
【The invention's effect】
As described above, according to the present invention, in this type of sheet conveying / separating apparatus, even when a large number of sheets are set, the sheets are reliably separated and conveyed into one sheet, and the sheet material processing is delayed due to non-feeding. Can be eliminated. As a result, a smooth operation and a highly reliable device can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a main configuration of a sheet conveying / separating apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an image reading apparatus according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a configuration of a sheet conveying and separating apparatus according to another embodiment of the present invention.
FIG. 4 is a perspective view showing a sheet conveying / separating apparatus according to another embodiment of the present invention.
FIG. 5 is a diagram illustrating a configuration of a sheet conveying and separating apparatus according to a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Feed roller 2 Separation roller 3 Main motor 4 Conveyance restriction guide 5 Conveyance restriction tongue plate 100 Image reading apparatus 100A Image reading apparatus main body 100B Sheet stacking part 100C Separation apparatus 101 Upper unit 102 Front surface reading unit 103 Back surface reading unit 104 Paper discharge part S Sheet

Claims (6)

A sheet conveying / separating device that separates and conveys a plurality of sheets into one sheet by a roller pair of a feed roller and a separating roller arranged oppositely,
A sheet conveying / separating apparatus, wherein the separating roller is formed of an elastic body, and a conveying restriction guide is provided in the vicinity of the separating roller so as to protrude relatively by deformation of the elastic body. 2. The sheet conveyance according to claim 1, wherein the conveyance regulation guide is formed such that the closer to the nip portion of the roller pair, the larger the deformation amount of the separation roller required to protrude. Separation device. The sheet conveyance separating apparatus according to claim 1, wherein the conveyance regulation guide is formed in a staircase shape. The sheet conveying / separating apparatus according to claim 1, wherein the conveyance regulating guide is formed of a flexible material and abuts in the vicinity of a roller pair nip portion of the feeding roller. The conveyance regulation guide is made of a flexible material that can be elastically deformed, and is made to enter the feed roller side in a non-contact manner so as to block sheet conveyance in the vicinity of the roller pair nip portion of the feed roller. The sheet conveying and separating apparatus according to claim 4. 6. The sheet conveying / separating apparatus according to claim 4, wherein an uneven shape is formed on a surface of the conveying regulation guide on the side of the feeding roller.

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