JP2002274661A - Paper feeder and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem, in a transfer fence which is thin, and has low rigidity and has a cantilever structure which is easily deflected and elastically deformed in the shifting direction of a paper sheet, and the upper part of a second sheaf of paper sheets after transfer is not returned to the initial aligned and loaded state resulting in the trouble to cause non-feeding, multiple feeding or change of order. SOLUTION: The transfer fence is integrally provided with a paper shifting preventing means for preventing the upper part of a sheaf of paper sheets 3B from shifting backward in collectively transferring the sheaf of paper sheets 3B to a first paper storing part A. In the paper sheet shifting preventing means, a paper abutting surface 1a with an inclination for correcting shifting of paper sheets as it directs from the lower part to the upper part is provided on the face of the transfer fence 1 on the abutting side to the sheaf 3 of paper sheets 3B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder and an image forming apparatus having the paper feeder.

[0002]

2. Description of the Related Art Paper feeders used in connection with an image forming apparatus such as an electrophotographic copying machine or a stencil printing machine include:
For example, a paper feeding device as shown in FIGS. 11 and 12 is known. The sheet feeding device shown in these figures has a bottom plate 2 serving as a sheet feeding table for loading a plurality of first sheets (not shown).
And a loading table 17 for loading a plurality of second sheets 3 disposed rearward of the first sheet storage section A in the sheet feeding direction C with respect to the first sheet storage section A. And a transfer fence 100 as a transfer member that collectively transfers the second sheet bundle 3B composed of a plurality of second sheets 3 to the first sheet storage section A. It has a transfer means (not shown) and a paper feed means (consisting of a paper feed roller 6 and a separation roller pair 7) for feeding a first sheet (not shown).

The first sheet storage section A is also provided with a lifting means (not shown) for vertically moving the bottom plate 2 while keeping the bottom plate 2 substantially horizontal. By this elevating means, the bottom plate 2
A plurality of first sheets (not shown) stacked on the sheet are collectively transferred to a position where the sheet can be fed by the sheet feeding roller 6 of the sheet feeding unit and to the first sheet storage unit A by the transfer fence 100. The bottom plate 2 can face a position where the transported second sheet bundle 3B (which becomes a first sheet bundle (not shown)) can be stacked and stored. In addition, not only the above-mentioned elevating means,
A relatively small-capacity paper size of, for example, about 300 sheets A4
There is also provided a so-called cantilever type raising / lowering means for stacking a first sheet bundle of (horizontal) sheets and moving up and down only in front of the sheet bundle in contact with the feed roller.

The transfer means includes a transfer fence 100 which is movable in the sheet feeding direction C by contacting the rear end face of the second sheet bundle 3B, and guides the transfer fence 100 to the vicinity of the second sheet storage section B. It mainly comprises a pair of guide shafts (not shown) as transfer member guiding means, and transfer member driving means (not shown) for moving the transfer fence 100. The transfer member driving means includes a stepping motor as a driving source, a driving pulley provided on an output shaft of the stepping motor, a plurality of driven pulleys, and a plurality of driven pulleys. It is mainly composed of a stretched endless timing belt, and a connecting member that locks and couples the timing belt and the hanging base end of the transfer fence 100.
As described above, the transfer fence 100 has a fixed end because its hanging base end portion is locked to the timing belt, and has a cantilever structure in which the upper portion is a free end.

In FIGS. 11 and 12, reference numeral 4 denotes
1 shows a sheet feeding tray having a first sheet storing section A, a second sheet storing section B, and the above-described transfer means. Reference numeral 4a denotes a sheet feeding front wall for abutting and aligning a front end face of a first sheet bundle formed of a plurality of first sheets stacked and stored on the bottom plate 2 of the first sheet storage unit 1. Show.

[0006] First paper storage section A and second paper storage section B
Is configured to be able to perform so-called tandem sheet feeding. That is, in the paper feeding device, the bottom plate 2 of the first paper storage unit A and the loading table 17 of the second paper storage unit B can load paper of a relatively small size and the same paper size,
The bottom plate 2 of the first sheet storage section A and the loading table 17 of the second sheet storage section B can store, for example, 1000 sheets 3 each having a sheet size A4 (horizontal), that is, about 2000 sheets in total. When the feeding of the sheet (not shown) on the bottom plate 2 of the first sheet storing section A is completed, the transfer fence 100 is moved from left to right, that is, in the sheet feeding direction C by the operation of the transfer means. Accordingly, the second sheet bundle 3B on the loading table 17 in the second sheet storage section B is transferred collectively onto the bottom plate 2 of the first sheet storage section A, and then the first sheet storage section A
The sheet transported onto the bottom plate 2 of the first sheet accommodating section A comes into contact with the sheet feeding roller 6 and is fed by the operation of the above-described elevating means. Such a sheet feeding operation by the sheet feeding method is commonly called tandem sheet feeding.

[0007]

However, a first sheet bundle (not shown) composed of 1000 sheets 3 of the above-mentioned sheet size A4 (horizontal),
4 (horizontal), a second sheet bundle 3B composed of 1000 sheets 3 is accommodated, and a mechanism composed of a number of components (such as the elevating unit and the transfer member driving unit) is installed in the sheet feeding tray 4. In the sheet feeding device as shown in FIG.
From the viewpoint of efficiently arranging the components of each mechanism and saving the space of machines and devices, design restrictions are imposed on the size and weight shared by the components of each mechanism. As a matter of course, the transfer fence 100 is no exception, and the transfer fence 1 is used in order to save space of machines and devices.
The size and weight of 00 are also limited. For this reason, the transfer fence 100 is usually formed with a thin resin mold (for example, a synthetic resin such as an ABS resin), and its rigidity cannot be unnecessarily increased. Therefore, simply adding an insert such as a sheet metal to the transfer fence 100 which is thinly formed by a resin mold and simply increasing the rigidity is achieved by using a stepping motor or a DC motor which constitutes the transfer member driving means. Because of the increase in size, etc., there is a limit on the amount of space required for machines and devices.

As shown in FIG. 11, for example, a stack of 1000 sheets 3B having a sheet size of A4 is placed on the loading table 17 of the second sheet storage section B.
The sheet is loaded in a set state in which its rear end face is abutted against 0a, that is, in an aligned loading state. The transfer fence 100 in such a state is moved in the sheet feeding direction C as shown in FIG.
, For example, with a paper size A4 of 10
The second sheet bundle 3B of 00 sheets is collectively stored in the first sheet storage unit A.
As shown in FIG. 12, the upper part of the second sheet bundle 3B is in the opposite direction to the sheet feeding direction C due to the inertia and the weight of the second sheet bundle 3B when the sheet is conveyed onto the bottom plate 2 (ie, the transfer fence 1).
(00 side), a phenomenon called paper misalignment (or paper collapse) occurs. When such a sheet shift occurs, the transfer fence 100 having a thin, low rigidity, and a cantilever structure bends and elastically deforms in the direction of the sheet shift, thereby causing the second transfer after the transfer. The upper part of the sheet bundle 3B is in the original aligned loading state (the second sheet bundle 3B
(In a state where the rear ends are aligned), and finally, problems such as non-feeding (non-feeding), double feeding (continuous feeding), and out-of-order may occur. Here, “out of order” means that, for example, when producing printed products in page order during duplex copying or duplex printing, the upper sheet stacked at the time of previous paper feeding jumps out in the paper feeding direction and is not fed. This means that a lower sheet having a different order is fed at the time of the next sheet feeding, and the page order or the like is out of order.

Accordingly, the present invention has been made in view of such circumstances, and has as its object to provide a paper feeder capable of solving the above-described problems and an image forming apparatus having the paper feeder. .

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems and to achieve the above object, the invention described in each claim employs the following characteristic means and configurations. According to the first aspect of the present invention, there is provided a first sheet storage portion for stacking a plurality of first sheets, and a plurality of first sheet storage portions disposed rearward of the first sheet storage portion in the sheet feeding direction. A second sheet storage unit for loading the second sheet, a transfer unit including a transfer member for transferring the second sheet to the first sheet storage unit, and a sheet supply unit for feeding the first sheet In the sheet feeding device having the above, when the second sheet is collectively transferred to the first sheet accommodating section, sheet shift preventing means for preventing a sheet shift in which an upper portion of the sheet shifts backward is provided to the transfer member. It is characterized by having been provided.

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the sheet deviation preventing means is provided integrally with the transfer member. As a sheet feeding device in which the sheet shift preventing means is provided integrally with the transfer member, the sheet shift preventive means may be provided from a lower portion to an upper portion on a surface of the transfer member on a side in contact with a second sheet. An example in which the sheet is inclined so as to compensate for the sheet deviation as it goes (see the invention according to claim 3).

According to a fourth aspect of the present invention, in the paper feeder of the first aspect, the sheet misalignment preventing means is provided separately from the transfer member. As a sheet feeding device in which the sheet misalignment preventing means is provided separately from the transfer member, the sheet misalignment preventive means may include a portion from a lower portion to an upper portion on a surface of the transfer member that contacts the second sheet. (See the invention according to claim 5).

The invention according to claim 6 is the invention according to claims 1 to 5
In the paper feeding device according to any one of the above, when the second paper is collectively transferred to the first paper storage unit, the first paper storage unit is in a substantially horizontal state with respect to the second paper storage unit. There is a feature.

According to a seventh aspect of the present invention, there is provided an image forming apparatus having an image forming means for forming an image on a fed sheet, comprising the sheet feeding device according to any one of the first to sixth aspects. It is characterized by the following. The image forming apparatus includes an exposing device, a charging device, an image carrier (photoreceptor, an intermediate transfer member), a developing device, a transfer device and the like, which constitute an image forming unit, a printer, and the like. In addition, a printing machine including a stencil printing machine equipped with a plate cylinder and pressing means such as a press roller or an impression cylinder for pressing a sheet onto a plate-making master on the plate cylinder, and a printing apparatus including an offset printing machine are also included. Specific examples of the copying machine in the image forming apparatus include, for example, JP-A-7-137851 and JP-A-7-17851.
One having the same image forming means as disclosed in Japanese Patent Application Publication No. 137852 is cited. As a specific example of the stencil printing machine in the image forming apparatus, for example,
Japanese Patent Application Laid-Open No. 229243/1992 includes an image forming unit similar to that disclosed in Japanese Patent Application Laid-Open No. 229243.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention including embodiments (hereinafter, referred to as "embodiments") will be described below with reference to the drawings. In the above-described prior art examples and the respective embodiments, components having the same function, shape, and the like, such as members and components, are denoted by the same reference numerals, and description thereof is omitted. In the drawings, components that are configured as a pair and do not need to be specifically distinguished and described will be replaced with the description by appropriately describing one of them in order to simplify the description. For the sake of simplicity of the drawings and description, components that do not need to be particularly described in the drawings may be omitted without omission, even if they are components to be shown in the drawings.

First, referring to FIGS. 7 to 10, an example of an image forming apparatus provided with a sheet feeding device to which the present invention is applied will be described in terms of operation while supplementing a configuration not described in the prior art. explain. In FIG.
Denotes an image forming apparatus provided with an image forming means for forming an image on a fed sheet. Below the image forming apparatus 15, a paper feeder 5 for feeding paper to the image forming apparatus 15 is arranged.

The paper feeding device 5 is substantially the same as the conventional example shown in FIGS. 11 and 12 (for example, see Japanese Patent Application Laid-Open Nos. Hei 7-137851 and Hei 7-137852). As shown in FIGS. 7 and 8, in order to eliminate dead space for small-size paper such as A4 and to facilitate paper replenishment,
The following configuration is provided inside the paper feed tray 4 capable of storing small-size papers in the paper feed direction C. That is, a first sheet bundle 3 </ b> A (hereinafter, referred to as a “sheet bundle 3”) including a plurality of first sheets 3 is provided inside the sheet feed tray 4.
A "), the first sheet storage section A provided with the bottom plate 2 on which the second sheet storage section B is provided, and the second sheet bundle 3B (hereinafter, referred to as" sheet bundle 3B "). The above-described transfer fence 100 that transfers the sheet to one sheet storage unit A at a time.
And a lifting means (not shown) for raising and lowering the bottom plate 2 of the first sheet storage unit A, and the like. Each sheet bundle 3A, 3B on the bottom plate 2 of the first sheet storage section A and on the loading table 17 of the second sheet storage section B
Although the reference numerals are changed to distinguish them for convenience of explanation, sheets 3 of the same small size are stacked.

The paper feed tray 4 is configured to be detachable from the main body of the paper feed device 5 so that a user can supply paper.
To set the sheet, in FIG. 7, the sheet supply tray 4 is pulled out from the apparatus main body toward the near side of the sheet to supply and set the sheets. Above the first sheet accommodating section A mounted and set in the apparatus main body, the sheet stack 3A stacked on the bottom plate 2 comes into contact with the uppermost sheet 3 and is fed in the sheet feeding direction C. A paper feed unit including a paper feed roller 6 and a separation roller pair 7 that separates and feeds the paper 3 fed thereby one by one is provided. Further, a transport roller pair 8 that transports the paper 3 fed by the paper feeding unit toward the image forming apparatus 15 is disposed downstream of the paper transport path in the separation roller pair 7. The sheet 3 is fed one by one from the uppermost sheet 3 of the sheet bundle 3A stacked on the bottom plate 2 to the image forming apparatus 15 one by one by such a well-known sheet feeding unit and the pair of conveying rollers 8. It is going to be done. The sheet feeding means is not limited to the above-described one, and may be a member composed of a separation roller and a separation pad pressed against the separation roller instead of the separation roller pair 7.

In FIG. 7, reference numeral 10 denotes an upper limit detection sensor. By detecting the position of the paper feed roller 6 with the upper limit detection sensor 10, the upper limit detection sensor 10 is controlled so as to always maintain a constant paper feed height. . Reference numeral 9 denotes a paper end sensor that detects the presence or absence of the paper 3 stacked on the bottom plate 2. Reference numeral 16 denotes a lower limit detection sensor that detects a lower limit position of the bottom plate 2.

Reference numeral 11 denotes a paper end sensor,
The presence or absence of the paper 3 loaded on the loading table 17 is detected. Reference numeral 12 denotes a home position sensor that detects an initial stop position of the transfer fence 100. Sign 1
Reference numerals 3 and 14 denote remaining amount detection sensors for detecting the remaining amount of the sheet bundle 3B stacked on the stacking table 17, and in the example of this embodiment, by providing two same sensors, three levels of remaining sensors are provided. The amount is being detected.

Incidentally, when the sheet bundle 3B on the loading table 17 is transferred collectively onto the bottom plate 2 of the first sheet container A,
Bottom plate 2 occupying the lower limit position in first paper storage section A
The lower limit position of the bottom plate 2 is set in advance so that the upper surface of the bottom plate 2 is in a substantially horizontal state at the same height as the upper surface of the loading table 17 in the second sheet storage portion B.

Next, a series of operations of the sheet feeding device 5 will be described with reference to FIGS. The operations described below are based on a control operation sequence according to a program or the like stored in a ROM (read-only storage device) or the like in a control device including a microcomputer (not shown) except for operations performed by a user. , Automatically performed by a command from a CPU (Central Processing Unit).

First, as shown in FIG. 9A, while the uppermost sheet 3 of the sheet bundle 3A on the bottom plate 2 in the first sheet accommodating section A is being fed, FIG. As shown,
When the sheet bundle 3A is exhausted after the sheet 3 on the bottom plate 2 is fed, the paper end sensor 9 detects the absence of the sheet, and the elevation means operates, whereby the bottom plate 2 descends to its lower limit position. . Note that, on the loading table 17 of the second sheet storage section B, a sheet bundle 3B composed of, for example, 1000 sheets 3 of sheet size A4 abuts its rear end face against the sheet contact surface 100a of the transfer fence 100. They are loaded in an aligned set state, that is, in an aligned loading state.

When the lower limit detecting sensor 16 detects the lower limit of the bottom plate 2 and the bottom plate 2 descends to the lower limit position, as shown in FIGS. 9 (c) to 10 (d), the operation of the transfer member driving means is performed. As the transfer fence 100 is moved from left to right, that is, along the sheet feeding direction C, the sheet bundle 3B on the loading table 17 in the second sheet storage section B is placed on the bottom plate 2 of the first sheet storage section A. Are transferred and pushed together. As described above, when the sheet bundle 3B on the loading table 17 is collectively transferred onto the bottom plate 2 of the first sheet storage unit A, the upper surface of the bottom plate 2 occupying the lower limit position in the first sheet storage unit A Since it is in a substantially horizontal state at the same height as the upper surface of the loading table 17 in the second sheet storage section B,
The sheet bundle 3B can be stably and reliably transferred to the first sheet storage section A.

At this time, the problem phenomenon described above with reference to FIG. 11 and FIG. 12, that is, a sheet shift occurs in which the upper portion of the sheet bundle 3B shifts backward due to inertia and its own weight during movement, and is thin and has low rigidity. The transfer fence 100 having the cantilever structure flexes and elastically deforms in the direction of the sheet shift, and the upper part of the second sheet bundle 3B after the transfer is in the original aligned loading state (second state). (The rear end of the sheet bundle 3B is aligned) in some cases. 9 (c) to 10 (d), etc., for simplification of the explanation of the operation, the operation in which the sheet is transported in a normal aligned loading state in which no sheet shift has occurred.

When the pushing / transfer of the sheet bundle 3B into the first sheet accommodating section A is completed, the sheet bundle 3B is moved by the operation of the elevating means in the first sheet accommodating section A as shown in FIG. The loaded bottom plate 2 is raised to occupy the sheet feeding position where the uppermost sheet 3 can be fed, and at the same time, the transfer fence 100 is moved to the initial position by the reverse operation of the transfer member driving means. A transfer return operation of transferring in the reverse sheet feeding direction D is performed. On the other hand, the sheet bundle 3 on the bottom plate 2
If the uppermost sheet 3 of B contacts the paper feed roller 9 and the upper limit detection sensor 10 detects that the paper feed roller 9 is slightly lifted to occupy the paper feed position, the paper can be fed immediately. State. In the paper feeding operation, when the paper misalignment shown in FIGS. 11 and 12 occurs, a paper feeding problem such as non-feeding (non-feeding), double feeding (continuous feeding), or out-of-order occurs. there is a possibility.

The transfer fence 10 during the transfer operation
0 stop control is performed by controlling the clock to the motor driver IC of the stepping motor (not shown) in the transfer member driving means by the CPU in the microcomputer.
The internal counter measures and counts. That is, the transfer operation is continued from the start of transfer of the transfer fence 100 until the predetermined count is reached, and the transfer fence 100 is stopped when the internal counter counts the predetermined count. Then, the transfer operation is completed. Since the stepping motor has a predetermined step angle corresponding to the input clock, the position of the transfer fence 100 can be accurately controlled at the time of transfer. The transfer return operation of the transfer fence 100 in the reverse sheet feeding direction D is performed by the home position sensor 12.
Then, the transfer fence 100 is returned and stopped at the initial position until the ON state is detected. (First Embodiment) A first embodiment will be described with reference to FIGS. The first embodiment is different from the image forming apparatus 15 including the paper feeder 5 having the conventional transfer fence 100 shown in FIGS. 7 to 12 in that the transfer fence 100 is used as a transfer member. The only difference is that the transfer fence 1 is provided.

The transfer fence 1 prevents the upper part of the sheet bundle 3B from being shifted rearward when the sheet bundle 3B is collectively transferred to the first sheet storage section A, as compared with the transfer fence 100. Transfer fence 1
The only difference is that it is provided in the upper part of. One of the features of the present invention is that the paper misalignment prevention means is provided integrally with the transfer fence 1. That is, the above-mentioned sheet misalignment prevention means is configured by forming a slope on the sheet abutting surface 1a, which is the surface of the transfer fence 1 on the side abutting the sheet bundle 3B, so as to compensate for the sheet misalignment from the bottom to the top. It is characterized by:

The transfer fence 1 has a substantially wedge shape in a sectional view, and its thickness increases from the lower part to the upper part. The height to the upper end of the transfer fence 1 is
Naturally, the loading table 17
The height of the sheet bundle 3B stacked thereon is higher than the sheet height when the maximum capacity is stacked. This applies to so-called obvious matters in the respective transfer members of the modified examples and the embodiments described later, so that the description thereof will be omitted below. The transfer fence 1 is integrally molded with a suitable resin (for example, a synthetic resin such as an ABS resin) similar to the transfer fence 100 of the conventional example. The surface of the transfer fence 1 on the rear wall side of the paper feed tray 4 is formed substantially perpendicular to the upper surface of the loading table 17. Symbol θ indicates an inclination angle for compensating for a sheet shift in the transfer fence 1. Transfer fence 1
Has a simple shape as described above, so that it can be formed easily and inexpensively, for example, by slightly changing the injection mold.

Next, the operation of the transfer fence 1 of the sheet feeding device in the first embodiment will be described with reference to FIGS. 2 (a) and 2 (b). As shown in FIG. 2A, similarly to the conventional example, on the loading table 17 of the second sheet storage unit B, for example, a sheet bundle 3B of 1000 sheets of the sheet size A4 (horizontal) is In the set state in which the rear end face is aligned with the sheet contact surface 1a, that is, in this state, the sheet shift is anticipated. Therefore, the upper part of the sheet bundle 3B is fed in the sheet feeding direction by the inclination angle θ that complements the sheet shift. It is loaded in a state shifted to the front of C.

When the transfer fence 1 is moved in the paper feeding direction C as shown in FIG. 2B by the operation of the transfer member driving means, the upper part of the second sheet bundle 3B is moved by inertia and Due to its own weight, the sheet shifts backward in the direction opposite to the sheet feeding direction C, whereby the sheet contact surface 1a on the upper part of the transfer fence 1 is shifted from the sheet feeding direction C by the inclination angle θ to compensate for the sheet shift. As a result, the sheet is bent backward and elastically deformed in the opposite direction, and the sheet contact surface 1a of the transfer fence 1 is substantially perpendicular to the upper surface of the bottom plate 2. Accordingly, it is possible to prevent the sheet from being shifted, and thus, it is possible to prevent a sheet feeding problem such as non-feeding (non-feeding), double feeding (continuous feeding), or out-of-order. (Modification 1) A modification of the first embodiment (hereinafter, referred to as "Modification 1") will be described with reference to FIG. This modified example 1 is different from the first embodiment only in having a transfer fence 1A as a transfer member instead of the transfer fence 1.

The transfer fence 1A, similar to the transfer fence 1 of the first embodiment, stores the sheet bundle 3B in the first sheet storage section A.
The transfer fence 1A is provided with a sheet shift preventing means for preventing the sheet shift in which the upper portion of the sheet bundle 3B shifts backward when the sheets are collectively transferred to the transfer fence 1A. One of the features of the present invention is that the paper misalignment prevention means is provided integrally with the transfer fence 1A. That is, the sheet misalignment prevention means is provided at the upper central portion of the transfer fence 1A, which is a part of the transfer fence 1A, which is in contact with the sheet bundle 3B. The inclined sheet contact surface 1Aa is integrally formed.

Slant paper contact surface 1Aa of transfer fence 1A
The other parts are plate-shaped in cross-section, like the transfer fence 100 of the conventional example. The transfer fence 1A is made of an appropriate resin (for example, AB) similar to the transfer fence 100 of the conventional example.
Slant paper contact surface 1 with mold of synthetic resin such as S resin)
It is integrally molded including Aa. The surface of the transfer fence 1 </ b> A on the rear wall side of the paper feed tray 4 is formed substantially perpendicular to the upper surface of the loading table 17. Transfer fence 1A
Has a simple shape as described above, and can be formed relatively easily and inexpensively, for example, only by changing the injection mold.

Next, with reference to FIGS. 2A and 2B, the operation of the transfer fence 1A of the sheet feeding device according to the first modification will be briefly described. 2A and 2B, the transfer fence 1A is shown in parentheses. The operation of the transfer fence 1A in FIGS. 2A and 2B is the same as the above-described operation of the transfer fence 1 in the first embodiment.
May be read as the transfer fence 1A, the sheet contact surface 1a as the inclined sheet contact surface 1Aa, and the inclination angle θ as the inclined shape. Therefore, according to the first modification, the sheet can be prevented from being shifted as in the first embodiment. Paper defects can be prevented.

The inclination angle θ of the transfer fence 1 in the first embodiment and the degree of inclination of the inclined sheet contact surface 1Aa in the transfer fence 1A of the first modification are determined when the transfer fences 1 and 1A are moved. By carrying out design calculations or conducting experiments by taking into account the transfer speed of the sheet bundle 3B, the weight and height of the stack of sheets 3B stacked on the stacking table 17, and the bending strength and dimensions of the transfer fences 1 and 1A. It should be noted that this is set by (Second Embodiment) A second embodiment will be described with reference to FIGS. The second embodiment is different from the image forming apparatus 15 including the sheet feeding device 5 having the conventional transfer fence 100 shown in FIGS. 7 to 12 in that the second embodiment is added to the transfer fence 100 as a transfer member. When the sheet bundle 3B is transferred to the first sheet accommodating section A in a lump, a sheet misalignment preventing means for preventing a sheet misalignment in which an upper portion of the sheet bundle 3B is shifted rearward is provided at an upper portion of the transfer fence 100. The only difference is that:

As described above, one feature of the second embodiment is that the sheet misalignment preventing means is provided separately on the transfer fence 100. As shown in FIGS. 4 and 5, the sheet misalignment preventing means is provided on the upper part of the transfer fence 100 on the side that comes into contact with the sheet bundle 3B, as a leaf spring 21 as an elastic body that complements the sheet misalignment from the lower part to the upper part. It is composed of the one with attached and fixed. Leaf spring 21
Is mounted and fixed on the upper part of the transfer fence 100 by a fastening means such as a screw, or a double-sided adhesive tape or an appropriate adhesive.

The height of the leaf spring 21 up to the upper end is, of course, higher than the height of the sheet bundle 3B loaded on the loading table 17 when the maximum capacity is loaded. ing. The leaf spring 21 has an inclined shape that compensates for a sheet shift from the lower part to the upper part, and the surface that contacts the sheet bundle 3B is a sheet contact surface 21a.

4 and 5, reference numeral 20 denotes a transfer fence assembly in which the leaf spring 21 is attached and fixed to the transfer fence 100 in the above-described state. As described above, the transfer fence assembly 20 is the transfer fence 1 of the conventional example.
Since the leaf spring 21 having a relatively simple shape is attached to and fixed to the sheet No. 00, it can be formed relatively easily and inexpensively following the first modification. In place of the leaf spring 21, an elastic body such as mylar having an appropriate thickness may be used to have a shape and an elastic force substantially similar to those of the leaf spring 21.

Next, referring to FIGS. 5A and 5B, the transfer fence assembly 20 of the sheet feeding device according to the second embodiment will be described.
Will be described. As shown in FIG. 5A, similarly to the conventional example, a sheet bundle 3B of, eg, a sheet size A4 (horizontal) of 1000 sheets is placed on the loading table 17 of the second sheet storage unit B, In the set state where the rear end faces of the sheet abutment surfaces 20a and 21a are aligned with each other, that is, in this state, the sheet shift is expected, so that the upper part of the sheet bundle 3B is inclined by the amount of inclination to complement the sheet shift. The sheets are stacked in a state shifted forward in the sheet feeding direction C.

When the transfer fence assembly 20 is moved in the sheet feeding direction C as shown in FIG. 5B by the operation of the transfer member driving means, the upper part of the second sheet bundle 3B is moved when the transfer fence assembly 20 is moved. Due to the inertia and the weight of the sheet, the sheet is shifted backward in the direction opposite to the sheet feeding direction C, and the sheet contact surface 21a of the leaf spring 21 is moved in the direction opposite to the sheet feeding direction C by the amount of inclination to compensate for the sheet shift. Will be elastically deformed behind. At this time, the upper end of the leaf spring 21 comes into contact with the upper part of the transfer fence assembly 20 and a part of the inertia force is transmitted, so that the upper part of the transfer fence 100 side also slightly bends rearward to undergo elastic deformation. Occurs. Finally, the sheet contact surface 21 a of the leaf spring 21 in the transfer fence assembly 20 is substantially perpendicular to the upper surface of the bottom plate 2 together with the sheet contact surface 100 a of the transfer fence 100. As a result, it is possible to prevent the sheet from shifting, and therefore, the sheet is not fed (not fed).
In addition, paper feed problems such as double feeding (continuous feeding) and out of order can be prevented. (Modification 2) A modification of the second embodiment (hereinafter, referred to as "modification 2") will be described with reference to FIG. This modified example 2 is different from the second embodiment in that, instead of the leaf spring 21 (sheet shift preventing means) as an elastic body, as shown in FIG. 6, the transfer fence on the side that comes into contact with the sheet bundle 3B. A sponge rubber 31 as an elastic body is attached to and fixed to the upper part of the sheet 100 as an elastic body that compensates for a sheet shift from the lower part to the upper part. As the sponge rubber 31, for example, foamed chloroprene rubber or the like is used, and an appropriate elastic force is given by an appropriate foaming density and hardness. Sponge rubber 3
1 is attached and fixed to the upper part of the transfer fence 100 by, for example, a double-sided adhesive tape or an appropriate adhesive application.

The height of the sponge rubber 31 up to the upper end is naturally higher than the height of the sheet bundle 3B loaded on the loading table 17 when the maximum capacity is loaded. ing. The sponge rubber 31 has a trapezoidal shape that compensates for a sheet shift from the lower portion to the upper portion, and a surface of the sponge rubber 31 that contacts the sheet bundle 3B is a sheet contact surface 31a.

In FIG. 6, reference numeral 30 designates a sponge rubber 31 attached to the transfer fence 100 in the above-described state.
Represents a fixed transfer fence assembly. As described above, the transfer fence assembly 30 includes the transfer fence 100 of the related art.
Since the sponge rubber 31 having a relatively simple shape is attached and fixed thereto, it can be formed relatively easily and inexpensively following the first modification. Instead of the sponge rubber 31 having the specific shape described above, the foam density of the sponge rubber is continuously formed, for example, from the lower portion to the upper portion so that the density increases from the lower portion to the upper portion. It may be formed in a simple plate shape that can be manufactured at a low cost.

Next, with reference to FIGS. 5A and 5B, the operation of the transfer fence assembly 30 of the sheet feeding device according to the second modification will be briefly described. 5A and 5B, the transfer fence assembly 30 is shown in parentheses. FIG. 5 (a),
The operation of the transfer fence assembly 30 in (b) is the same as the operation of the transfer fence assembly 20 in the second embodiment except that the transfer fence assembly 20 is replaced with the transfer fence assembly 30.
The paper contact surface 21a may be replaced with the paper contact surface 31a. Therefore, according to the second modification, it is possible to prevent the sheet from shifting as in the first embodiment, and thus, the non-feed (non-feed), the double feed (continuous feed),
Alternatively, it is possible to prevent paper feeding troubles such as out of order.

The leaf spring 21 according to the second embodiment is
The degree of inclination of the sponge rubber 31 and the degree of inclination of the sponge rubber 31 of Modification 2 are determined by the transfer speed at which the transfer fence assemblies 20 and 30 are moved, the weight of the sheet bundle 3B stacked on the stacking table 17, and the like. It should be noted that the load height is set by design calculation or by conducting experiments in consideration of the elastic deformation capacity and dimensions of each leaf spring 21 and sponge rubber 31.

The present invention is not limited to the above-described embodiment and the modified example applied to the paper feeding device 5 as shown in FIGS.
0-199188) and the like, that is, a bottom plate of the first paper storage unit (the right tray 1 in the above publication) and a loading table of the second paper storage unit (the left tray 2 in the above publication). When a large-sized sheet (for example, A3 portrait) is stacked between the two sheets, the loading table (the left tray 2 in the above publication) of the second paper storage unit is moved to the bottom plate of the first paper storage unit (the right tray 1 in the above publication). The present invention can also be applied to a sheet feeding apparatus having a structure in which a raising / lowering interlocking means is provided for raising while maintaining a substantially horizontal state in conjunction with the raising operation of (1). Further, the present invention is not limited to the one having one sheet feed tray 4 below the image forming apparatus 15 as shown in FIG. 7 and the like, but is also applicable to a multi-stage sheet feeder, that is, a multi-stage sheet feeder and an image forming apparatus having the same. can do. It is needless to say that the present invention is not limited to the application to the image forming apparatus provided with the paper feeding device, but can also be applied to the paper feeding device itself as a moving unit for manufacturing and sales.

[0046]

As described above, according to the present invention, a new paper feeder and image forming apparatus are provided by solving the problems of the conventional paper feeder and image forming apparatus as described above. can do. The effects of each claim are as follows. According to the first aspect of the present invention, when the second sheet is collectively transferred to the first sheet storage portion, the sheet shift preventing means for preventing the sheet shift in which the upper portion of the sheet shifts backward is transferred. By providing the member, it is possible to prevent a paper shift (paper collapse), and it is possible to prevent a paper feeding problem such as non-feed, double feed, or out of order.

According to the second and third aspects of the present invention, the sheet shift preventing means is provided integrally with the transfer member.
2. The effect of the invention according to claim 1, wherein the sheet shift preventing means is formed by making the surface of the transfer member on the side in contact with the second sheet slant so as to compensate for the sheet shift from the lower portion to the upper portion. In addition, it can be made easier and cheaper.

According to the fourth and fifth aspects of the present invention, the sheet shift preventing means is provided separately from the transfer member, and is provided on the surface of the transfer member that contacts the second sheet from below. Since it is provided with an elastic body for compensating the sheet shift toward the upper part, it is relatively easy and inexpensive in addition to the effect of the invention described in claim 1.

According to the sixth aspect of the present invention, when the second sheet is transferred to the first sheet storage section at a time, the first sheet storage section is substantially horizontal with respect to the second sheet storage section. Because there is
In addition to the effects of the above-described inventions, the second sheet can be stably and reliably transferred to the first sheet storage unit by the transfer member provided with the sheet shift prevention unit.

According to the seventh aspect of the present invention, the effect of each of the above-mentioned inventions is exerted also in an image forming apparatus having the sheet feeding device according to any one of the first to sixth aspects.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a transfer fence of a sheet feeding device according to a first embodiment.

FIGS. 2A and 2B are diagrams showing an operation of the sheet feeding device provided with the transfer fence shown in FIGS. 1 and 3, wherein FIG. 2A shows a state in which a sheet bundle is stacked and set in a second sheet accommodating section; Shows the state immediately after the transfer fence has transferred the sheet bundle to the first sheet storage unit,
It is sectional front view shown each.

FIG. 3 is an external perspective view of a transfer fence of a sheet feeding device according to a first modification.

FIG. 4 is an external perspective view of a transfer fence assembly of a sheet feeding device according to a second embodiment.

5A and 5B are diagrams showing an operation of a sheet feeding device provided with the transfer fence assembly of FIG. 4 or FIG. 6, wherein FIG. 5A shows a state in which a sheet bundle is stacked and set in a second sheet accommodating section; FIG. 3B is a cross-sectional front view illustrating a state immediately after the transfer fence assembly has transferred the sheet bundle to the first sheet storage unit.

FIG. 6 is an external perspective view of a transfer fence assembly of a sheet feeding device according to a second modification.

FIG. 7 is a cross-sectional front view of a main part of a conventional sheet feeding apparatus to which the present invention is applied and an image forming apparatus having the same.

FIG. 8 is a plan view of a sheet feeding tray of the sheet feeding device in FIG. 7;

9 (a) to 9 (c) are cross-sectional front views of main parts showing the operation of the sheet feeding device in FIG.

FIGS. 10D and 10E are cross-sectional front views of main parts illustrating a subsequent operation of the sheet feeding device in FIG. 7;

FIG. 11 is a cross-sectional front view showing an operation of a conventional sheet feeding device provided with a transfer fence, showing a state in which a sheet bundle is stacked and set in a second sheet accommodating section.

12 is a cross-sectional front view illustrating a state immediately after the transfer fence has transferred the sheet bundle to the first sheet storage unit, which is a view illustrating a subsequent operation of the sheet feeding apparatus in FIG. 11;

[Explanation of symbols]

1, 1A A transfer fence as a transfer member integrally provided with a means for preventing paper misalignment 2 Bottom plate 4 Paper feed tray 5 Paper feeder 6 Paper feed roller constituting paper feed means 7 Separation roller pair constituting paper feed means DESCRIPTION OF REFERENCE NUMERALS 15 Image forming apparatus 17 Loading table 20 Transfer fence assembly 21 Leaf spring as sheet shift prevention means and elastic body 30 Transfer fence assembly 31 Sponge rubber as sheet shift prevention means and elastic body 100 Transfer fence as transfer member A 1 paper storage section B 2nd paper storage section C Paper feed direction θ Tilt angle

Claims (7)

[Claims] A first sheet storage unit for stacking a plurality of first sheets, and a plurality of second sheets disposed rearward of the first sheet storage unit in a sheet feeding direction; And a transfer unit having a transfer member for transferring the second sheet to the first sheet storage unit at a time, and a sheet feeding unit for feeding the first sheet. In the paper device, when the second paper is collectively transferred to the first paper storage unit,
A sheet feeding device, wherein a sheet shift preventing means for preventing a sheet shift in which an upper portion of the sheet shifts backward is provided in the transfer member. 2. The paper feeding device according to claim 1, wherein said paper misalignment prevention means is provided integrally with said transfer member. 3. The paper feeding device according to claim 2, wherein said paper misalignment prevention means compensates for the misalignment of the paper from the lower part to the upper part of the surface of the transfer member on the side contacting the second paper. A sheet feeding device, characterized in that the sheet feeding device is made of a material having a slope. 4. The paper feeder according to claim 1, wherein said paper misalignment prevention means is provided separately from said transfer member. 5. The paper feeding device according to claim 4, wherein said paper misalignment prevention means complements said paper misalignment from a lower portion to an upper portion on a surface of said transfer member on a side contacting the second paper. A sheet feeding device comprising an elastic body provided. 6. The paper feeding device according to claim 1, wherein when the second paper is collectively transferred to the first paper storage, the first paper storage is provided with the second paper storage. A sheet feeding device being substantially horizontal with respect to a sheet storage unit. 7. An image forming apparatus provided with an image forming means for forming an image on a fed sheet, wherein the image forming apparatus has the sheet feeding device according to any one of claims 1 to 6. Forming equipment.