JPH11222330A - Sheet separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the enlargement of a structure in a sheet separating position and easily take out sheets jammed inside without causing rupture or the like. SOLUTION: In this separating device, a carrier roller provided with a plurality of rollers along an axial direction is provided on one opposed side with a sheet delivered from a sheet stacking part, placed in between, and a tension roller 4 provided with a plurality of rollers arranged in the axial direction being positioned between the rollers of the carrier roller is provided on the other side. The carrier roller is rotated in the same direction as the tension rollers 4 and in a sheet delivery direction so as to feed only the sheet brought into opposed contact with the carrier roller out of a plurality of sheets delivered from the sheet stacking part. In this case, constitution 5 is provided to release pressure application to the sheet S by spacing the carrier roller and the tension rollers 4 from each other along the height direction of the sheet stacking part, interlockingly with the movement of the sheet stacking part in a pull-out direction right-angled to the delivery direction of the sheet S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet separating apparatus, and more particularly, to a mechanism for preventing a sheet from being multi-fed by moving a pair of rollers facing each other across a sheet at opposite positions in opposite directions. About.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine, a facsimile machine, or a printer, a sheet such as a transfer sheet housed in a sheet cassette is transferred to an image transfer position with an image carrier such as a photosensitive member. It is designed to feed out. At a position where the sheet is fed, a sheet separating device for preventing multiple feeding of the sheet is provided.

One of the constructions of a sheet separating apparatus utilizes the difference between the coefficient of friction between overlapping sheets and the coefficient of friction between conveying members abutting on the sheets, and makes it possible to determine the maximum among the overlapping sheets. There is a configuration in which only a higher-order one can be fed out (for example, see Japanese Patent Application Laid-Open No. 7-22836).
No. 3). In the above publication, a sheet feeding roller that rotates in the sheet feeding direction is disposed on a side facing a top sheet with a sheet fed by a pickup roller or the like from a sheet feeding cassette corresponding to a sheet stacking section. Further, there is shown a sheet separating apparatus having a configuration in which a separation mechanism having a friction pad is disposed on a side facing the sheet feeding roller, and only a sheet in contact with the sheet feeding roller is fed out.

On the other hand, the sheet conveying section is provided with a structure for removing the sheet when a so-called jam occurs, in which the fed-out sheet is jammed in the middle of the conveying path. According to the above publication, as a configuration for removing a sheet, a cam portion is formed in a sheet guide portion of a sheet feeding cassette, and the cam portion is caused to interfere with the separating mechanism to swing the separating mechanism away from the sheet feeding roller. The configuration is shown. In this configuration, the feed cassette is moved in a direction perpendicular to the sheet feeding direction with respect to the separation mechanism normally biased in the direction in which the friction pad comes into contact with the feed roller. By causing the portion to interfere with the separation mechanism, the separation mechanism is pushed down, the friction pad is pulled away from the paper feed roller, and the sheet holding operation using the paper feed roller and the friction pad is released to enable the sheet to be taken out.

[0005]

However, in such a sheet separating apparatus, the internal structure of the apparatus may be large. In the sheet separating apparatus, when the friction pad is separated from the sheet feeding roller, a cam portion is formed by forming an end wall located on the leading end side in the sheet feeding direction of the sheet feeding cassette toward the separating mechanism, and the cam portion is formed. The wide portion interferes with the separation mechanism. For this reason, the area occupied by the sheet cassette in the space on the leading end side in the sheet feeding direction is required to be large, and the apparatus is increased in size.

When a sheet is jammed in the sheet conveying path, the sheet is pulled out of the sheet feeding cassette to release the nipping of the sheet. The impact force acts in the axial direction of the swing support shaft, which is a direction perpendicular to the swing direction of the swing support shaft. For this reason, not only is it difficult to separate the paper feed roller from the friction pad, but also there is a risk that the sheet may be broken because a large operation force is required to pull out the friction roller.

SUMMARY OF THE INVENTION In view of the above problems in the conventional sheet separating apparatus, it is an object of the present invention to prevent an increase in the size of a structure at a position where a sheet is separated and to remove a sheet jammed inside without causing breakage or the like. To provide a sheet separating apparatus that can easily perform the sheet separation.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of rollers are provided along one axial direction on one side opposed to a sheet fed from a sheet stacking section. A tension roller having a plurality of axially disposed rollers located between the rollers of the transport roller is provided on the other side, and the sheet can be fed out in the same direction as the tension roller. In the sheet separating device that feeds only the sheet that comes into contact with the conveyance roller among the plurality of sheets that are fed from the sheet stacking unit by rotating the sheet stacking unit, the sheet stacking unit is perpendicular to the sheet feeding direction. The conveyance roller and the tension roller are moved along the height direction of the sheet stacking portion in conjunction with moving in the By spaced There is characterized by having a configuration for releasing the pressure to the sheet.

According to a second aspect of the present invention, in the sheet separating apparatus according to the first aspect, the structure for releasing the pressurization includes a swingable roller supporting portion rotatably supporting the tension roller; A pressure release unit provided on the sheet stacking unit and capable of interfering with a swinging end of the roller support unit when the sheet stacking unit moves in the pull-out direction, wherein the roller support unit includes the sheet A guide portion that guides toward a facing portion between the transport roller and the tension roller, and a guide surface that is inclined along a height direction of the sheet stacking portion at an end of the guide portion in the pull-out direction are formed. Features.

According to a third aspect of the present invention, in the sheet separating apparatus according to the second aspect, the sheet stacking section is configured to move the sheet stacking section in the pulling-out direction so that the pressure releasing section abuts on the guide surface to thereby carry the sheet. The roller support portion is swung in a direction in which the tension roller is separated from the roller, and the sheet located on the guide portion is pushed and moved by the pressure release portion to be pulled out from the holding position.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a schematic diagram for explaining a main configuration of a sheet separating apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a sheet stacking section such as a paper feed cassette;
Denotes a pickup roller, reference numeral 3 denotes a transport roller, reference numeral 4 denotes a tension roller, and reference numeral 5 denotes a roller support.

The sheet stacking section 1 has a sheet stacking plate (not shown) loaded therein so that the leading end of the sheet stacking plate in the sheet feeding direction (the direction indicated by arrow A in the figure) is pushed upward. It has become. The sheet stacking unit 1 is provided in a direction perpendicular to the sheet S feeding direction (hereinafter, referred to as a sheet S
For example, it is provided so as to be slidable with respect to a sheet feeding unit of an electrophotographic copying machine so that the sheet can be pulled out in the drawing direction.

The pick-up roller 2 is rotatably supported by a support member 6 provided in a paper feeding section of the electrophotographic copying machine, and the leading end of the sheet S is moved by a driving force from a motor (not shown) to the sheet stacking section 1. To transport roller 3
And the tension roller 4 are rotated by an amount that can be fed toward the opposing nip portion.

The transport roller 3 is rotatably supported by a rotating shaft 3A provided on a support bracket 7 located at the paper feeding section, and is provided in a predetermined direction in the sheet S feeding direction by a driving source such as a motor (not shown). The amount of rotation can be adjusted.

The tension roller 4 is rotatably supported by a rotating shaft 4A provided at a free end of a roller support portion 5 described later, and rotates in the same direction as the transport roller 3 in synchronization with the transport roller 3. The peripheral surface facing the transport roller 3 moves in the direction opposite to the sheet S feeding direction.

In FIG. 1, the roller supporting portion 5 is composed of a pair of lever members which are swingably supported by a supporting bracket 7 via a supporting shaft 5A, and is provided by a biasing member such as a spring (not shown). Normally, a swing bias is applied in a direction in which the tension roller 4 comes into contact with the transport roller 3. The roller supporting portion 5 has a swinging end provided with a guide piece 5B extending toward the sheet stacking portion 1 from a position where the tension roller 4 is supported, that is, a position where the rotating shaft 4A is provided. It is bent in parallel with the end wall 1A of the sheet stacking section 1 to form a sheet receiving section 5C (see FIG. 3).

The sheet stacking section 1 and the roller supporting section 5
Is provided with a pressure release mechanism for separating the tension roller 4 from the transport roller 3. In FIG. 1, the pressing release mechanism is a pressing release driving piece 8 fixed to an end wall 1A on the leading end side in the sheet feeding direction of the sheet stacking unit 1.
And a guide surface 5B1 provided on a guide piece 5B of the roller support portion 5.

In FIG. 1, the pressure release driving piece 8 is
A is fixed to an end wall 1A on the leading end side in the sheet feeding direction of the sheet stacking unit 1, and a driving piece 8B projecting from a base piece 8A toward a guide piece 5B of the roller supporting unit 5 is formed by bending. The drive piece 8B is bent so as to be parallel to the guide piece 5B of the roller support portion 5 when the tension roller 4 is in contact with the transport roller 3, and the drive piece 8B is bent from the base of the base piece 8A. The height up to the portion (the height indicated by the symbol H in FIG. 1) is set to a height at which the swing amount of the roller supporting portion 5 capable of separating the tension roller 4 from the transport roller 3 can be set. Further, as shown in FIG. 2, the pressure release driving piece 8 is attached to the end wall 1A so as to face the side plate of the roller supporting portion 5 at a rear position in the pulling-out direction of the sheet stacking portion 1 (the direction indicated by arrow B). Have been.

As shown in FIGS. 2 and 3, the guide surface 5B1 provided on the guide piece 5B of the roller support portion 5 has a direction perpendicular to the sheet feeding direction (the direction indicated by the arrow A in the drawing). In the sheet width direction corresponding to
The pressure release driving piece 8 in a state where the sheet stacking unit 1 is pushed out to a so-called predetermined position of the sheet feeding unit without being pulled out.
And is formed by an inclined surface formed at an end portion facing the front surface.
As shown in FIG. 3, the guide surface 5B1 has an outer surface lower than a position continuous with the guide piece 5B and is inclined along the height direction of the sheet stacking unit 1.

Since the present embodiment has the above configuration,
At the time of normal sheet separation, as shown in FIGS. 1 and 2, the sheet stacking unit 1 is pressed into a predetermined position of the sheet feeding unit, and the pressure release driving piece 8 of the sheet stacking unit 1 is Guide surface 5B1 of the fifth guide piece 5B
Is not interfered with. Therefore, the roller support 5
Keeps the tension roller 4 in contact with the transport roller 3 by urging means (not shown). When the sheet S is fed out from the sheet stacking unit 1 by the pickup roller 2, the sheet S is nipped by the opposing portion of the transport roller 3 and the tension roller 4. As for the nipped sheet S, the conveying roller 3 and the tension roller 4 rotate in the same direction, and only the sheet S in contact with the conveying roller 3 is fed out.
The sheet S overlapping the sheet S is returned to the sheet stacking unit 1 according to the rotation direction of the tension roller 4 whose peripheral surface facing the conveyance roller 3 is moving in the opposite direction to the conveyance roller 3.

When the sheet S fed from the sheet stacking unit 1 in the conveying path is jammed, and a so-called jam occurs, the pressing and clamping of the sheet S by the conveying roller 3 and the tension roller 4 is released and the sheet is released. An operation to take out S is performed. In this case, the sheet stacking unit 1 is moved in the pull-out direction.

When the sheet stacking section 1 moves in the pulling-out direction, the driving piece 8B of the pressure releasing driving piece 8 comes into contact with and interferes with the guide surface 5B1 of the guide piece 5B in the roller support section 5. The pressure releasing drive piece 8 that interferes with the guide surface 5B1 moves the guide surface 5 with the movement of the sheet stacking unit 1 in the pull-out direction.
It is put on the upper surface of B1. Therefore, the roller support 5
Swings counterclockwise in FIG. 4 with the support shaft 5A as a fulcrum, pushes down the roller support portion 5, and separates the tension roller 4 from the transport roller 3.

When the sheet stacking unit 1 is pulled out, the pressure releasing drive piece 8 moves from the guide surface 5B1 to the upper surface of the guide piece 5B as shown in FIG. The state in which the support portion 5 is pressed down is maintained, and the tension roller 4 of the roller support portion 5 is maintained in a state of being separated from the transport roller 3. As a result, when the sheet stacking unit 1 is pulled out, as shown in FIG. 4, the pressure applied to the sheet S by the transport roller 3 and the tension roller 4 is released, so that the transport roller 3 and the tension roller 4 are released. The sheet S held between the sheet stacking unit 1 and the sheet stacking unit 1 is moved in a direction away from the holding position. Further, the guide piece 5 is formed by the side end of the drive piece 8B of the pressure release drive piece 8 interlocked with the pull-out movement of the sheet stacking unit 1.
Since the sheet S located at B is pushed and moved in the pulling-out direction, the sheet S is easily pulled out from the state in which the pressing force is released.

According to the embodiment described above, the guide surface 5B1 of the roller support 5 is inclined along the height direction of the sheet stacking unit 1, in other words, in the swing direction of the roller support 5. Since the pressure release driving piece 8 starts to interfere with the pressure release driving piece 8 and starts to be lifted on the guide surface 5B1, a force in the swing direction can be applied to the roller supporting portion 5. Thereby, since the roller supporting portion 5 easily starts swinging, it is possible to perform a smooth pulling-out operation while suppressing a large operation force required for pulling out the sheet stacking portion 1.

[0026]

As is apparent from the embodiments described above, according to the first and second aspects of the present invention, the transport roller and the tension roller are moved in conjunction with the movement of the sheet stacking section in the pull-out direction. They can be separated from each other along the height direction of the loading section. In particular, according to the second aspect of the present invention, since the guide surface that is inclined along the height direction of the sheet stacking section is formed at the end of the roller support section in the pull-out direction, the pressure release section of the sheet stacking section and The space occupied by the configuration necessary for the interference can be included in the height of the sheet stacking section. Accordingly, it is not necessary to provide a space for the sheet stacking unit occupied inside the apparatus, particularly, a space in the horizontal direction, so that it is possible to prevent the sheet stacking unit from becoming unnecessarily large.

According to the third aspect of the present invention, when the conveying roller and the tension roller are separated from each other in the height direction of the sheet stacking section in conjunction with the pulling out of the sheet stacking section, the pressure is released from the pressure releasing section to the guide surface. Since the impact force promotes the swing of the roller support portion and acts in a direction to easily separate the two rollers, the pull-out force of the sheet stacking portion can be reduced, and the breakage of the sheet due to shearing can be suppressed. . In addition, since the sheet is pushed and moved in the pulling-out direction by the pressure releasing portion, the sheet can be smoothly removed without remaining on the guide piece.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a main configuration of a sheet separating apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a main configuration of the sheet separating apparatus shown in FIG.

FIG. 3 is a perspective view for explaining a relationship between a pressure releasing section and a guide section of a roller supporting section of the sheet separating apparatus shown in FIG.

FIG. 4 is a schematic diagram for explaining one embodiment of the sheet separating device shown in FIG.

FIG. 5 is a plan view showing one embodiment shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet loading part 3 Conveyance roller 4 Tension roller 5 Roller support part 5A Support shaft 5B Guide piece 5B1 Guide surface 8 Pressure release drive piece corresponding to pressure release part 8A Base piece 8B Drive piece A Sheet feeding direction S Sheet

Claims (3)

[Claims] 1. A conveying roller having a plurality of rollers along an axial direction is provided on one side opposed to a sheet fed from a sheet stacking section, and the other side is provided between rollers of the conveying roller. A tension roller having a plurality of rollers arranged in the axial direction is provided, and the transport roller is rotated in a direction in which the sheet can be fed in the same direction as the tension roller. In the sheet separating device that feeds only the sheet that abuts against the conveyance roller, the conveyance roller and the tension roller are interlocked with the movement of the sheet stacking unit in the drawing direction perpendicular to the sheet feeding direction. A configuration for releasing the pressure on the sheet by separating from each other along the height direction of the sheet stacking unit. Characteristic sheet separation device. 2. The sheet separating device according to claim 1, wherein the pressure is released from a swinging roller supporting portion rotatably supporting the tension roller and the sheet stacking portion. A pressure release portion that is capable of interfering with the swinging end of the roller support portion when the sheet stacking portion moves in the pull-out direction, wherein the roller support portion is configured to transfer the sheet to the transport roller and the tension roller. A sheet separating device, wherein a guide portion for guiding toward the opposite portion of the sheet stacking portion and a guide surface inclined along a height direction of the sheet stacking portion at an end of the guide portion in the pull-out direction are formed. . 3. The sheet separating device according to claim 2, wherein the sheet stacking unit moves the tension roller from the transport roller by the pressure release unit abutting on the guide surface in a process of moving in the pull-out direction. A sheet separating apparatus characterized by swinging the roller supporting portion in a separating direction and pushing and moving a sheet located at the guide portion by the pressure release portion from the holding position.