JP2003040476A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device capable of securely separating and feeding a paper loaded in a bundle sheet by sheet with a simple structure. SOLUTION: The paper feeding device includes a paper loading plate 31 for loading a paper bundle 6, a pickup roller 4 for carrying the paper bundle 6 loaded on the paper loading plate 31, a separating plate 21 contact with an undermost surface in a carrying direction of the paper bundle 6 loaded on the paper loading plate 31, a paper feeding guide 7 for guiding the paper bundle 6 carried by the pickup roller 4 out of the paper bundle 6 loaded on the paper loading plate 31, and a feed roller 51 and a retard roller 52 for separating and carrying the paper bundle 6 carried by the pickup roller 4 sheet by sheet out of the paper bundle 6 loaded on the paper loading plate 31. When the separating plate 21 rotates and moves, a tip end part of the supported and fixed paper bundle 6 is bent to an upper surface of the paper, is loosened, and is separated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device which is provided in an image forming apparatus such as a printer, a copying machine or a fax machine and which separates and feeds a bundle of sheets one by one.

[0002]

2. Description of the Related Art In image forming apparatuses such as printers, copiers and fax machines, many apparatuses set a certain number of sheets and feed them one by one from a bundle of sheets using a sheet feeder. There are various types of sheet feeding devices used at this time, and they are selected and used in consideration of sheet feeding speed and durability.
For example, a method of flipping the front end of the paper with a nail, a method of using a friction plate or a reverse roller, an air suction method, or the like. More sure 1
As an apparatus for separating and feeding sheets one by one, Japanese Patent Laid-Open No. 6-3
The devices described in JP 12846, JP 7-41199 A, or JP 7-196186 A are conventionally known.

[0003]

However, in any of the above-mentioned paper feeding methods, due to factors such as the surface roughness of the paper, cutting of the paper, static electricity, and the adsorption state of the paper due to wetting, etc.
Originally, the second and subsequent sheets were sometimes fed together with the top sheet or the bottom sheet and fed. In other words, there is a problem in that the stack of sheets at the time of sheet feeding is insufficient and the top sheet or the bottom sheet and the second and subsequent sheets are not reliably separated and are double-fed.

To address this problem, Japanese Patent Laid-Open No. 6-312
The apparatus described in Japanese Patent No. 846 is provided with a paper feed double feed prevention member, but there is a possibility that it cannot handle paper of various thicknesses.

The device described in Japanese Patent Laid-Open No. 7-41199 is capable of reliably separating and feeding each sheet one by one, but since the application is large and for high-speed machines, the device is large and the cost is high. .

Further, although the apparatus described in Japanese Patent Laid-Open No. 7-196186 has a simple structure, its reliability is not sufficient in terms of reliable and separate feeding.

The present invention has been made in view of the above circumstances, and an object thereof is to reliably separate and feed the sheets stacked in a bundle one by one with a simple structure. An object of the present invention is to provide a paper feeding device that can do this.

[0008]

In order to achieve the above object, the present invention provides a sheet stacking means for stacking and supporting a stack of sheets,
Delivery means for delivering the paper from the paper stacking means,
In a paper feeding device having a separating unit that separates and conveys the sheets sent from the sending unit one by one, the sheet stacking unit abuts a lower surface of a sheet bundle stacked and supported by the sheet stacking unit, It is characterized in that it is provided with a separating means for separating the sheets by swinging a part of the sheet bundle.

The stacking means has a stacking stand for stacking the sheet bundle, and a part of the stacking table, which is the leading end portion of the sheet bundle in the feeding direction, functions as the separating means. Is preferred. Further, at this time, it is preferable that the separating means swings as a part of the stacking table about an axis center substantially orthogonal to the sheet feeding direction and pushes the leading end portion of the sheet bundle from the lower surface.

Another aspect of the present invention is a sheet stacking unit for stacking and supporting a stack of sheets, a sending-out unit for sending out the sheets from the sheet stacking unit, and a separating unit for separating and conveying the sheets sent out from the sending-out unit one by one. And a side end portion in the feeding direction of the sheet bundle stacked and supported by the sheet stacking means or a side end portion in the vicinity of the sheet bundle, the elastic body sliding along a substantially normal direction of the sheet surface. Be prepared and
The paper stacking means has a stacking base for stacking the stack of papers, and as a part of the stacking base, a portion corresponding to the leading end of the paper in the sheet feeding direction is lowered.

Further, as a part of the stacking table, it is preferable that a portion corresponding to a leading end portion of the sheet bundle in the feeding direction swings about an axis substantially orthogonal to the sheet feeding direction.

Another aspect of the present invention is a sheet stacking unit for stacking and supporting a stack of sheets, a sending-out unit for sending out the sheets from the sheet stacking unit, and a separating unit for separating and conveying the sheets sent out from the sending-out unit one by one. A sheet feeding device having: and a separating unit for separating sheets by sandwiching opposite ends of a bundle of sheets stacked and supported by the sheet stacking unit.

Further, in each of the above-mentioned constitutions, it is preferable to provide a pressure contact holding means for pressing a part of the sheet bundle stacked and supported by the sheet stacking means in the normal direction of the sheet surface to hold the sheet bundle.

The feeding means may also have a function of holding a sheet bundle by pressing a part of the sheet bundle supported by the sheet stacking means in a direction normal to the sheet surface.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view showing the operation of separating a bundle of sheets, which is performed when the sheet feeding device according to the first embodiment of the present invention raises the separating plate.

As shown in FIG. 1, in the configuration of the first embodiment, the sheet stacking plate 31 for stacking the sheet stack 6 and the sheet stack 6 stacked on the sheet stacking plate 31 are conveyed. The pickup roller 4, the separation plate 21 contacting the lowermost surface of the sheet stack 6 stacked on the sheet stacking plate 31 in the transport direction, and the sheet transported by the pickup roller 4 from the sheet stack 6 stacked on the sheet stacking plate 31. The paper feed guide 7 that guides the bundle 6 and the paper bundle 6 conveyed by the pickup roller 4 from the paper bundle 6 stacked on the paper stacking plate 31
It has a feed roller 51 and a retard roller 52 for separating and conveying the sheet.

The sheet feeding operation of the sheet feeding device according to the present embodiment having the above-mentioned structure will be described below.

FIG. 2 shows a state in which the sheet feeding device according to the present embodiment stacks the sheet bundle 6 on the sheet stacking plate 31. At this time, the pickup roller 4 moves the sheet bundle 6
It is arranged at a position above the paper surface where it is not pressed against. Next in FIG.
At, the non-rotating pickup roller 4 descends and comes into pressure contact with the upper surface of the sheet bundle 6. At this time, since the lower surface of the sheet bundle 6 is supported by the sheet stacking plate 31, the sheet bundle 6 is sandwiched between the pickup roller 4 and the sheet stacking plate 31, and is supported and fixed. Alternatively, as the sheet stacking plate 31 rises, the sheet bundle 6 rises, and the upper surface of the sheet bundle 6 comes into pressure contact with the non-rotating pickup roller 4 to bring about the same state.

As a result, it is possible to utilize a part of the conventional device configuration (pickup roller 4) as it is and support the sheet bundle 6 in the paper surface direction.

Next, the leading edge of the sheet bundle 6 which is supported and fixed is bent toward the upper surface of the sheet by rotating the separating plate 21. At this time, since the sheet bundle 6 is pressed and supported and fixed by the pickup roller 4 and the sheet stacking plate 31, the leading end portion is displaced. As a result, the sheet bundle 6 is loosened and separated. That is, it is possible to loosen the sticking of the sheets due to the cutting of the leading edge of the sheet bundle.

Next, the separating plate 21 returns to its original position, and the sheet bundle 6 also returns to its original state by its own weight. At this time, since the sheet bundle 6 remains supported in the surface direction, the leading edge, the side surface, and the rear end of the sheet bundle 6 do not shift, and the sheet bundle 6 can be separated by the separating plate 21.

Further, while the sheet stacking plate 31 and the pickup roller 4 keep the sheet bundle 6 in pressure contact, the pickup roller 4 rotates in the conveying direction of the sheet bundle 6 to convey the sheet bundle 6. The sheet bundle 6 conveyed by the pickup roller 4 is sent to the nip portion between the feed roller 51 and the retard roller 52 by the paper feed guide 7. Since the method of separating the feed roller 51 and the retard roller 52 and the structure relating to drive transmission are well known, description thereof will be omitted (for example, Japanese Patent Laid-Open No. 7-117880).

In the apparatus disclosed in Japanese Patent Laid-Open No. 7-196186, the sheet is separated by pushing down the sheet separating member called a sheet material leading edge regulating member by the pressing force of the sheet sent by the sheet feeding means. However, in the present embodiment, the separating plate 21 is pressed against the lower surface of the sheet bundle 6 to positively perform the separating operation, and more reliable sheet separation of the sheet bundle 6 can be performed.

(Second Embodiment) Next, a second embodiment will be described.

With regard to the configuration of the present embodiment, the same reference numerals are given to the constituent members and parts common to those of the above-mentioned first embodiment, and the duplicated description here is omitted.

FIG. 4 is a side view schematically showing the main part of the paper feeding device according to the second embodiment.

The sheet feeding device according to the present embodiment is also similar to the sheet feeding device according to the first embodiment described above, and the sheet bundle 6,
It has a sheet stacking plate 31, a pickup roller 4, a sheet feed guide 7, a feed roller 51, and a retard roller 52.

A separating blade 22 is arranged at a position where it comes into contact with the end face of the bundle of sheets 6 stacked on the sheet stacking plate 31 in the transport direction. The separation blade 22 is formed of an elastic body. Further, a separating blade driving device 8 for moving the separating blade 22 up and down in the surface direction so as to trace the end face of the sheet stack 6, and a movable sheet stacking device which is in contact with the lowermost surface of the sheet stack 6 stacked on the sheet stacking plate 31. Board 32
have.

The sheet feeding operation in this embodiment having such a configuration will be described below. In addition, sheet bundle 6
The pickup roller 4 and the sheet stacking plate 31 in the non-rotating state
The process up to being sandwiched between and supported by is the same as that of the first embodiment described above, and thus the duplicated description here is omitted.

Next, the sorting blade driving device 8 moves the sorting blade 22 from the upper surface to the lower surface of the sheet bundle 6 while contacting the end faces of the sheet bundle 6, so that the sheet bundle 6 is loosened and separated. Become.

At the same time, the movable sheet stacking plate 32 moves in a direction away from the lower surface of the sheet bundle 6 to partially open the stacking support of the sheet bundle 6. As a result, the blade 2 for separating the sheet bundle 6
The sorting operation by 2 can be performed more efficiently, and the sticking of the sheets due to the cutting of the leading edge of the sheet bundle can be loosened.

Next, the movable sheet stacking plate 32 returns to its original position, and the sheet stack 6 also returns to its original state. At this time, as in the above-described first embodiment, the sheet stacking plate 31 and the pickup roller 4 are pressed against the sheet bundle 6 and remain supported, so that the front end, the side surface, and the rear end of the sheet bundle 6 are displaced. It is possible to separate the sheet bundle 6 by the separating plate 21.

Since the sheet feeding operation thereafter is the same as that of the first embodiment, the duplicated description is omitted here.

Here, a conventional device (for example, Japanese Patent Laid-Open No. 7-4
In the apparatus described in Japanese Patent Publication No. 1199), the paper near the top of the paper is judged in the upward direction of the paper surface. However, in the present embodiment, the entire paper bundle 6 is judged in the downward direction of the paper surface by the separating blade 22. The movable sheet stacking plate 32, which is a part of the stacking plate 31, is rotated downward to move the sheet stack 6 more reliably. Further, since the sheet bundle 6 is sandwiched and supported and fixed by the pickup roller 4 and the sheet stacking plate 31, it is also possible to prevent the edges of the sheet bundle 6 from being misaligned due to the separating operation.

(Third Embodiment) Next, the third embodiment of the present invention will be described.
Embodiments will be described with reference to FIGS. 5, 6, 7, and 8.

With respect to the configuration of this embodiment as well, the components common to the above-described first and second embodiments,
The same reference numerals are given to the parts, and the duplicated description here is omitted.

In FIG. 5, the apparatus according to the present embodiment is also similar to the first and second embodiments described above, and the sheet bundle 6, the pickup roller 4, the paper feed guide 7, the feed roller 51, and the retard roller 52. And have. Further, the sheet stacking plate 33, which is convex in the upper surface direction of the sheet stack 6 and has a shape that regulates the rear end of the sheet stack 6, and the end face in the transport direction of the sheet stack 6 stacked on the sheet stacking plate 33, are contacted. It has a front end separating plate 23 arranged at a position where it can contact.

The sheet feeding operation in this embodiment having such a configuration will be described below. FIG. 5 shows a state in which the sheet bundle 6 is stacked on the sheet stacking plate 33. In this state, the sheet stacking plate 33 is convexly warped upward, and therefore the sheet bundle 6 is also warped in the upward convex state following the surface thereof.

Next, in FIG. 6, when the leading edge separating plate 23 is rotationally moved so as to come into pressure contact with the leading end portion of the sheet bundle 6, the trailing edge of the sheet bundle 6 is regulated by the sheet stacking plate 33. 6 bends. Since the tip separating plate 23 is arranged so that the pressure contact amount by the tip separating plate 23 is larger on the upper surface of the sheet bundle 6 and smaller on the lower surface thereof, this deflection causes more gaps between the respective sheets forming the sheet bundle 6. Yes (see Figure 6). Further, since the sheet bundle 6 is convexly upwardly warped, a gap can be easily formed between the sheets by pressing the leading edge separating plate 23 into contact with each other. As a result, the sheet bundle 6 is loosened and separated. In other words, it is possible to loosen the sticking of paper. At this time, the pickup roller 4 is arranged at a position where it does not press against the sheet bundle 6.

At this time, as shown in FIG. 7, the rear end side of the sheet stack 6 of the sheet stacking plate 33 is constituted by a rear end separating plate 24, and as shown in FIG. 8, a front end separating plate 23 and a rear end separating plate. Even if the plate 24 is simultaneously rotated in the direction in which the sheet bundle 6 is sandwiched,
The same effect can be obtained.

Next, the leading edge sorting plate 23 or the trailing edge sorting plate 24 returns to the original position, and the sorted sheet bundle 6 also returns to the original position on the upper surface of the sheet stacking plate 33 due to its own weight.

Next, the pickup roller 4 descends and comes into pressure contact with the upper surface of the sheet bundle 6, and the pickup roller 4 rotates in the conveying direction to convey the sheet bundle 6. Further, as the sheet stacking plate 33 rises, the sheet bundle 6 rises, and the pickup roller 4 rotates in the conveying direction while the upper surface of the sheet bundle 6 is in pressure contact with the pickup roller 4 to convey the sheet bundle 6. You can also

Subsequent sheet feeding operations are the same as those in the first and second embodiments described above, and therefore, redundant description will be omitted here.

[0045]

As described above, according to the present invention,
By flexing and unraveling the sheets before separating and feeding the sheets, the sheets are separated and the sticking between the sheets forming the bundle of sheets is eliminated, so that the subsequent separating and feeding can be performed more reliably. As a result, the reliability of separated sheet feeding is further improved.

[Brief description of drawings]

FIG. 1 is a side view illustrating a sorting operation performed by a sheet feeding device according to a first embodiment of this invention.

FIG. 2 is a side view illustrating the configuration of the paper feeding device according to the embodiment.

FIG. 3 is a perspective view illustrating the overall configuration of the paper feeding device according to the embodiment.

FIG. 4 is a side view illustrating a sorting operation performed by the paper feeding device according to the second embodiment of the invention.

FIG. 5 is a side view illustrating a configuration of a sheet feeding device according to a third embodiment of the invention.

FIG. 6 is a side view for explaining a sorting operation by the paper feeding device according to the embodiment.

FIG. 7 is a side view illustrating a modified example of the paper feeding device according to the embodiment.

FIG. 8 is a side view illustrating a sorting operation according to a modified example of the sheet feeding device according to the embodiment.

[Explanation of symbols]

1 Paper feeder 21 Search board 22 Saki blade 23 Tip separation board 31 paper stacking board 4 pickup roller 51 Feed roller 52 retard roller

Claims (5)

[Claims] 1. A paper feeding unit comprising: a sheet stacking unit for stacking and supporting a stack of sheets; a sending-out unit for sending out a sheet from the sheet stacking unit; and a separating unit for separating and conveying the sheets sent out from the sending-out unit one by one. In the paper apparatus, the paper stacking unit includes a separating unit that contacts the lower surface of the paper stack stacked and supported by the paper stacking unit and swings a part of the paper stack to separate the paper. Paper feeding device. 2. A sheet feeding unit for loading and supporting a stack of sheets, a feeding unit for feeding the sheets from the sheet loading unit, and a separating unit for separating and transporting the sheets fed by the feeding unit one by one. In the paper apparatus, an elastic body that slides a leading end portion of a sheet bundle stacked and supported by the sheet stacking unit or a side end portion in the vicinity thereof along a substantially normal direction of the sheet surface, and The sheet stacking device includes a stacking platform for stacking the sheet stack, and a part of the stacking platform, which is a front end portion of the sheet in the sheet feeding direction, descends. 3. A sheet feeding unit for stacking and supporting a bundle of sheets, a feeding unit for feeding the sheets from the sheet loading unit, and a separating unit for separating and conveying the sheets fed from the feeding unit one by one. A sheet feeding device, comprising: a sheet separating unit that separates sheets by sandwiching opposite ends of a bundle of sheets stacked and supported by the sheet stacking unit. 4. A press contact holding unit for pressing a part of a sheet bundle stacked and supported by the sheet stacking unit in a direction normal to a sheet surface to hold the sheet bundle.
The sheet feeding device according to any one of 3 to 3. 5. The feeding means further has a function of holding a sheet bundle by pressing a part of the sheet bundle supported by the sheet stacking means in a direction normal to the sheet surface. The sheet feeding device according to any one of items 1 to 3.