JP2016160096A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device which can prevent excessive stacking of paper stacked on a tray and the occurrence of paper feeding failures due to feeding of deformed paper, with a simple constitution.SOLUTION: A paper feeding device comprises: a tray 23 for stacking a plurality of paper P; paper feeding means for feeding the paper P stacked on the tray 23 one by one from the top; and side fences 21 for guiding the side faces of the paper P along a paper feeding direction. It is provided with, at the front end side of the side fences 21 in the paper feeding direction, stacking amount restriction members 22 for restricting the stacking amount of the stacked paper and rotating members 31 which are arranged so as to be capable of moving up and down in the stacking direction of the paper P and are capable of rotating while being in contact with the paper P that is being fed.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet feeding device and an image forming apparatus.

  In an image forming apparatus such as a printer, a facsimile machine, or a copier, paper is fed to a place where a set document is fed to an image reading unit or a sheet stored in a paper feed tray is fed to the image forming unit. The device is used. Among these, as a manual sheet feeding device, one provided in the main body of the image forming apparatus and one provided in an ADF attached to the image forming apparatus are known.

  As a manual sheet feeding device, a device (multi-manual feeding) having a multifeed prevention unit is known. In this multi-manual paper feeder, the bottom plate of the manual tray is generally fixed, and the paper that is sequentially fed from the uppermost paper among the loaded paper by the paper feeding means is generally used.

In such a multi-manual paper feeder, when a large number of sheets are placed on the manual tray, the pressure characteristics of the paper feeding means such as the paper feed roller and the difference in the transport characteristics due to the difference in the entrance height. The number of sheets that can be placed is regulated so as not to cause a problem in conveyance.
As a method for regulating, it is known that, for example, a side fence that regulates the width direction of a sheet is provided with a roof or a ridge, and the sheet is restricted from being placed beyond the roof or the ridge.

  However, there are cases where sheets exceeding the stacking regulation number are set to be pushed into the roof or the buttock. In such a case, the uppermost sheet may come into pressure contact with the roof or the buttock, which may cause non-feeding or feeding failure. In addition, when a paper is not loaded or a paper feeding failure occurs due to overloading after the paper is set, the user needs to remove the paper.

On the other hand, a mechanism for preventing non-feeding and feeding failure due to stacking of sheets exceeding the stacking regulation number (hereinafter also referred to as “overloading”) has been proposed (see, for example, Patent Documents 1 to 3). ).
Patent Document 1 discloses a mechanism that detects overloading with a sensor in conjunction with the operation of a paper feed pickup mechanism. However, the apparatus disclosed in Patent Document 1 has a problem in that overloading cannot be detected unless a paper feeding operation is started.

  Patent Document 2 discloses a mechanism for lifting an overload prevention member during paper feeding in conjunction with the operation of the paper feeding pickup mechanism. However, the apparatus of Patent Document 2 requires a link mechanism that is linked to the pickup, which increases the driving load and complicates the configuration, and thus there is a problem that space saving is difficult.

  On the other hand, in Patent Document 3, as a mechanism for preventing the occurrence of problems associated with the uppermost sheet coming into contact with an upper component member due to overloading of sheets, a lower tray and a lower tray are provided. In a multi-stage paper cassette that includes an upper tray that is slidably displaceable between a feedable position and a retracted position in the upper part, the lower tray includes an edge guide that regulates the edge of the paper. The guide is provided with a flange that regulates the number of sheets stacked, and the upper tray is provided with a roller that protrudes from the lower surface of the upper tray. Has disclosed a mechanism capable of preventing pressure contact with the lower surface of the upper tray.

  However, in the mechanism of Patent Document 3, the detection mechanism does not function when the roller is overloaded so that the roller is locked, and when the roller is overloaded until it is locked, the sheet feeding operation is actually performed. There is a problem that the overloading state cannot be detected unless the paper is fed and no paper is fed.

By the way, deformations such as curling (curving) other than overloading can be cited as causes of non-feeding and poor feeding due to the paper placed on the manual feed tray.
With the mechanism of Patent Document 3, it is difficult to prevent non-feeding due to deformed paper and damage to the paper that may occur due to passing the deformed paper.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that can suppress the occurrence of sheet feeding failure due to overloading of sheets stacked on a tray and feeding of deformed sheets with a simple configuration. .

  In order to achieve this object, a paper feeding device according to the present invention includes a tray for stacking a plurality of sheets, and a sheet feeding unit for feeding the sheets stacked on the tray one by one from the top. And a side fence that guides an end surface along a paper feeding direction of the paper, for regulating a loading amount of the stacked paper on a front end side of the paper feeding direction of the side fence. It is characterized in that a stacking amount regulating member and a rotating member that is disposed so as to be movable up and down in the stacking direction of the paper and that can rotate in contact with the fed paper are provided.

  According to the present invention, it is possible to provide a sheet feeding device capable of suppressing the occurrence of sheet feeding failure due to overloading of sheets stacked on a tray and feeding of deformed sheets with a simple configuration.

1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an exemplary embodiment. It is a perspective view which shows an example of the conventional paper feeder (manual feed tray). It is a perspective view which shows an example of the conventional paper feeder (manual feed tray). It is a schematic diagram for demonstrating the overloading state of a paper. FIG. 10 is a schematic diagram illustrating a state where a sheet deformed by a conventional sheet feeding device is fed. It is a perspective view which shows an example of the paper feeder concerning 1st embodiment. It is a perspective view which shows an example of the principal part of the paper feeder concerning 1st embodiment. FIG. 10 is a schematic diagram illustrating a state in which a deformed sheet is fed by the sheet feeding device according to the embodiment. It is a schematic diagram which shows the example (comparative example) from which arrangement | positioning of a rotation member differs. It is a perspective view which shows an example of the principal part of the paper feeder concerning 2nd embodiment. It is a perspective view which shows an example of the principal part of the paper feeder concerning 3rd embodiment. It is a top view which shows an example of the principal part of the paper feeder concerning 4th embodiment.

  Hereinafter, a paper feeding device and an image forming apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

An image forming apparatus (for example, a copying machine, a printer, a facsimile machine, and a multifunction machine of these) according to the present embodiment includes a sheet feeding device of the present invention described later as a sheet feeding device.
The paper feeding device is, for example, a manual paper feeding device including a manual tray.
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present exemplary embodiment.
As shown in FIG. 1, the main body 101 of the image forming apparatus includes a paper feed cassette 103 (103a, 103b) for storing standard-size paper P (P2, P3). In order to cope with printing on a desired small number of sheets P (P1) such as a sheet of a size that cannot be accommodated in the sheet cassette 103, a sheet feeder (hereinafter referred to as "manual sheet feeder") including a manual feed tray. 104).
In the drawing, the conveyance path of the paper P from the paper feed cassette 103 and the manual feed tray 104 is shown.

2 and 3 are perspective views of a conventional general manual sheet feeder.
The manual sheet feeder is a pickup roller 13 that feeds paper P placed on the manual tray 23 and feeds it as a paper feed unit, a paper feed position where the pickup roller 13 is in contact with the paper P, and a separation position that is separated from the paper P. And a separation roller 11 and 12 for feeding the paper P fed from the pickup roller 13 one by one.

  As shown in FIG. 3, when the paper P is placed on the manual feed tray 23, the filler 41 of the paper end detection device rotates by the contact of the paper P. The sensor 42 of the paper end detection device determines the presence or absence of the paper P on the manual feed tray 23 by detecting the rotation of the filler 41.

In the manual sheet feeder shown in FIGS. 2 and 3, the position of the manual tray 23 is fixed, the bottom is not raised, and the pickup roller 13 is brought into contact with the uppermost sheet placed on the tray. The paper is fed sequentially.
When a large number of sheets P are placed on the tray 23, the contact pressure of the pickup roller 13 is different between the uppermost sheet and the lowermost sheet, and the inlet of the uppermost sheet and the lowermost sheet is different. The entry height level with respect to the guide plate is also different.

  Therefore, the stacking amount of the sheets stacked on the tray 23 is set so that a problem such as a paper feeding failure does not occur due to a difference in pressure characteristics of the pickup roller 13 and a difference in conveyance characteristics due to an entrance height with respect to the entrance guide plate. It is regulated. The specific stacking amount is, for example, about 100 sheets of plain paper. If the regulation of the number of stacked sheets is not strictly performed, there is a high possibility that a paper feeding problem will occur. For example, a user is alerted by a decal that describes the upper limit of the number of stacked sheets. However, overloading cannot be reliably prevented.

As shown in FIGS. 2 and 3, the manual sheet feeder includes a side fence 21 that guides an end surface along the sheet feeding direction of the sheet P. The side fence 21 is provided with a stacking amount regulating member 22 for regulating the stacking amount of the stacked sheets P on the leading end side in the sheet feeding direction.
Although the paper P is regulated so as not to be placed beyond the stacking amount regulating member 22, as shown in FIG. 4, the paper P may be stacked beyond the stacking regulation number.

FIG. 4 schematically shows an overloaded state of the paper P.
FIG. 4 is a cross-sectional view in the region of the side fence 21 having the stacking amount regulating member 22, and the paper P is stacked until it is in contact with or pressed against the roof-like or bowl-like loading amount regulating member 22. When paper feeding is started in this state, since a large load is applied to the paper P at the contact portion with the stacking amount regulating member 22, it is difficult to feed the uppermost paper with the pickup roller 13. May cause clogging.

On the other hand, a paper feed failure may occur due to a difference in the height of entry due to deformation (for example, curl or the like) of the paper P rather than overloading of the paper P.
FIG. 5 is a diagram illustrating a state where the deformed paper P is fed. The deformation of the paper P may be caused by the ambient temperature and humidity. If the deformation amount of the paper P is large, the paper does not enter the separation rollers 11 and 12 and the paper P may not be fed, or the end may be bent and normal output may not be performed.

In view of this, the paper feeding device of the present embodiment includes a mechanism for suppressing the occurrence of non-paper feeding or paper feeding failure due to overloading or deformation of the paper P.
FIG. 6 is a perspective view of the sheet feeding device according to the first embodiment, and FIGS. 7 and 8 are enlarged views of main parts.
As shown in FIGS. 6, 7, and 8, the sheet feeding device according to the present embodiment has a tray 23 on which a plurality of sheets P are stacked and a sheet P stacked on the tray 23 one by one from the top. The sheet feeding device includes a sheet feeding unit that feeds and a side fence that guides an end surface along a sheet feeding direction of the sheet P, and is loaded on a front end side of the sheet P in the sheet feeding direction of the side fence 21. A stacking amount regulating member 22 for regulating the stacking amount of the sheet P, and a rotating member 31 that is disposed so as to be movable up and down in the stacking direction of the sheet P, and that can rotate in contact with the fed sheet P. Is provided.

For example, in the overloaded state of the paper P as shown in FIG. 4, a large load is applied to the paper P pressed against the stacking amount regulating member 22 in the conventional paper feeding device, whereas in the paper feeding device of the present embodiment, By contacting the rotating member 31, the surface contact becomes a line contact, and the load is reduced. Furthermore, since the rotating member 31 rotates with the paper P to be fed, the load is further reduced.
That is, even when the paper P is stacked until it is in contact with or pressed against the stacking amount regulating member 22, it is possible to suppress the occurrence of non-feeding and poor feeding.

As shown in FIG. 7, the rotary member 31 is supported by the side fence 21 so that the rotary shaft 31 a can move up and down.
The rotating shaft 31 a protruding from the surface of the rotating member 31 facing the side fence is held on the rotating shaft holding portion 21 a formed on the side fence 21 so as to be rotatable and vertically movable.
The position and size of the rotating shaft holding part 21a can be appropriately set according to the size and moving range of the rotating member 31. For example, the lower limit position when the rotating member 31 is lowered may be set so as to be a position where the rotating member 31 comes into contact with the tray 23, and there is a position where there is a space between the bottom surface without contacting the tray 23. You may set as follows.

Since the rotating member 31 descends by its own weight downward in the stacking direction of the sheets P, the rotating member 31 and the sheet P are always in contact with each other when the sheets P are stacked at a certain height or more (FIG. 8). reference).
As shown in FIG. 8, the paper P is pressed at the contact portion with the rotating member 31 and is fed while being pressed by the rotating member 31 even when it has deformation such as curl (curvature). Occurrence of paper defects is suppressed.

The rotating member 31 is always disposed at the lower limit position (the bottom surface of the tray 23 or the uppermost surface of the stacked sheets P) by descending due to its own weight downward in the stacking direction of the sheets P.
Here, when the rotating member 31 is arranged as shown in FIG. 9 and cannot be moved in the vertical direction, the upper end portion of the rotating member 31 always protrudes to a position higher than the load amount regulating member 22. It becomes. On the other hand, the rotating member 31 of the paper feeding device of the present embodiment can be moved up and down in the stacking direction, and is accommodated without exceeding the height of the stacking amount regulating member 22 when the sheets P are not stacked. Therefore, space saving can be realized.

FIG. 10 is an enlarged view of a main part of the sheet feeding device according to the second embodiment.
As shown in FIG. 10, the sheet feeding device of the present embodiment includes a biasing member 32 that can press the rotating member 31, and the rotating member 31 is pressed by the biasing member 32 to be below in the stacking direction of the sheets P. Go down.
Since the paper P is fed while being pressed at the abutting portion by the rotating member 31 pushed down by the urging member 32, even if the paper P has a deformation such as a curl (curvature), a paper feed failure occurs. It is suppressed.
Further, by providing the urging member 32, it is possible to suppress vibration caused by the rotation of the rotating member 31 in the movable direction during paper feeding.

  The urging member 32 is not particularly limited as long as it can press the rotating member 31 or the rotating shaft 31a of the rotating member, and examples thereof include an elastic body such as a spring.

FIG. 11 is an enlarged view of a main part of the sheet feeding device according to the third embodiment.
As shown in FIG. 11, the paper feeding apparatus according to the present embodiment includes an overload detection unit 51 that detects that the paper P has been stacked exceeding a specified stacking amount. The overload detection unit 51 is a unit that detects, for example, that the rotating member 31 or the rotating shaft 31a of the rotating member has moved to the upper limit position of the up-and-down movement range.

When the overloading state of the paper P becomes excessive, the rotary member 31 is pushed up and pressed to such an extent that it does not follow the paper P to be fed. Hereinafter, this state is referred to as an “overloaded state”.
For example, the overload detection means 51 is provided on the upper side of the side fence 21 as shown in FIG. 11, and by detecting that the rotating member 31 or the rotating shaft 31a of the rotating member is pushed up to a predetermined position (upper limit position). The overloaded state can be determined.

As the overload detection means 51, for example, an on / off switch such as a push switch or a photo interrupter, or various sensors can be used. Examples of the sensor include a pressure sensor that detects contact of the rotating member 31 or the rotating shaft 31a of the rotating member.
As shown in FIG. 11, space saving can be realized by disposing a sheet-shaped pressure sensor as the overload detecting means 51 on the stacking amount regulating member 22.

In addition, it is preferable that the paper feeding device of the present embodiment includes a unit that warns that paper feeding is impossible.
If the overload detection unit 51 detects an excessively stacked state of the sheets P, it determines that the sheet cannot be fed, and does not perform feeding and issues a warning that the sheet cannot be fed.
The warning is preferably notified, for example, by a display unit provided in a sheet feeding device or an image forming apparatus main body including the sheet feeding device. Examples of the display means include a user operation panel and a light emitting means (LED or the like) provided so as to be visible on the upper side or side of the side fence.

FIG. 12 is an enlarged view (top view) of a main part of the sheet feeding device according to the fourth embodiment.
As shown in FIG. 12, the sheet feeding device of the present embodiment includes a driving unit that rotationally drives the rotating member 31, calculates the starting torque of the rotating member 31 from the current value of the driving unit, and calculates the calculated torque. Whether or not the paper P can be fed is determined according to the value.
The drive means includes a drive source 53 and drive transmission means 52 such as a gear.

The rotation member 31 can be driven to rotate by a drive source 53 such as a motor, thereby assisting the feeding of the paper P in contact with the rotation member 31 and suppressing the occurrence of non-feeding or feeding failure.
However, when the paper P is in an overloaded state, the rotation member 31 or the rotation shaft 31a of the rotation member is pushed up, and the load of rotation driving increases. Therefore, the starting torque of the rotating member 31 is calculated from the current value of the drive source 53, and when the calculated torque is equal to or greater than a set threshold value, it is determined that the paper cannot be fed.
When it is determined that the paper cannot be fed, it is preferable to warn to that effect by the warning means.

  In addition, when the above-described overload detection unit 51 detects that the paper P has been stacked exceeding the specified stacking amount (overloading state), the warning is performed without rotating the rotating member 31. It is preferable to warn that the sheet cannot be fed by means.

  As described above, the stacking amount regulating member 22 and the sheet P are arranged so as to be movable up and down in the stacking direction of the sheet P on the leading end side in the sheet feeding direction of the side fence 21, and contact the sheet P to be fed. The sheet feeding device of the present invention provided with the rotatable rotating member 31 has a simple configuration, and is poor in sheet feeding due to overloading of sheets P stacked on the tray 23 and feeding of deformed sheets. Can be suppressed.

11, 12 Separate roller 13 Pickup roller 21 Side fence 22 Loading amount regulating member 23 Tray (manual feed tray)
31 Rotating member 31a Rotating shaft 33 Biasing member P Paper

JP-A-6-255836 JP 2012-176844 A JP 2012-136326 A

Claims (10)

A tray for loading multiple sheets of paper,
Paper feeding means for feeding the paper stacked on the tray one by one from the top;
In a paper feeding device comprising a side fence that guides an end surface along the paper feeding direction of the paper,
On the front end side of the paper feeding direction of the side fence, a loading amount regulating member for regulating the loading amount of the loaded paper and a vertically moving movement in the paper loading direction are arranged and fed. A sheet feeding device, comprising: a rotating member that is rotatable in contact with the sheet.   The sheet feeding device according to claim 1, wherein the rotating member is supported by the side fence so that the rotating shaft can move up and down.   The sheet feeding device according to claim 1, wherein the rotating member is lowered by its own weight downward in the stacking direction of the sheets. An urging member capable of pressing the rotating member;
3. The sheet feeding device according to claim 1, wherein the rotating member is pressed by the biasing member and descends downward in the sheet stacking direction. Comprising an overload detection means for detecting that the paper has been loaded exceeding a specified load capacity;
5. The sheet feeding device according to claim 1, wherein the overload detection unit is a unit that detects that the rotating member has moved to an upper limit position of an up-and-down movement range.   The sheet feeding device according to claim 5, wherein the overload detection unit is an on / off switch.   The sheet feeding device according to claim 5, wherein the overload detection unit is a pressure sensor. Drive means for rotationally driving the rotating member;
The start torque of the rotating member is calculated from the current value of the driving means, and whether or not the sheet can be fed is determined according to the calculated torque value. The paper feeder described. There is a warning means to warn you that paper feed is not possible,
When the overload detection unit detects that the sheet is stacked exceeding a predetermined stacking amount, the rotating member is not driven to rotate, and the warning unit warns that the sheet cannot be fed. The sheet feeding device according to claim 8.   An image forming apparatus comprising the paper feeding device according to claim 1.