JP2002284363A - Paper feeding device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the wrong operation, for example the wrong setting, of an end fence for detecting paper sheets by keeping the paper sheets from load shifting thereof. SOLUTION: This paper feeding device is provided with a mechanism having several loading paper sheets housing parts for automatically supplying the paper sheets from other paper sheets housing part when the paper sheets are used up. The end fence 17 provided between the housing parts presses an end of the loaded and housed paper sheet 6A to keep it from the load shifting, and detects wrong size or wrong setting of the paper sheets. In the current device, at the same time when an impact generates, the inertia moment generated around a support point C rotates the end fence in a direction F, the loaded paper sheets are shifted, and the end fence in the normal open condition is closed to generate the wrong operation. In this invention, the shape of the end fence is changed, and weight is added to generate the inertia moment in a direction J to take a balance with the direction F, and the wrong operation is thereby avoided.

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 for feeding stacked sheets one by one, for example, for use in a copying machine or the like. In a device having a replenishing mechanism for performing a replenishing operation from another paper storing part when a paper in a paper storing part runs out, a paper feeding device configured to eliminate a malfunction that may occur in relation to the replenishing mechanism. The present invention relates to an image forming apparatus (copying machine, printer, etc.) equipped with a paper feeding device.

[0002]

2. Description of the Related Art Conventionally, as a paper feeding device, a replenishing mechanism having a plurality of paper storage units for storing stacked papers and performing a replenishing operation from another paper storage unit when one of the paper storage units is out of paper. Those with are known. The configuration and operation of the apparatus will be described with reference to FIGS. 1 to 7 showing an example of such a conventional sheet feeding apparatus. FIG. 1 is a schematic diagram of the entire sheet feeding apparatus (FIG. 1A is a front view, and FIG. 1B is a partial plan view). Here, an example of sheet feeding to an image forming apparatus is shown. 2 shows a state in which a sheet feeding device 2 is installed below the image forming apparatus 1. The paper feeding device 2 is provided with a first paper storage section A and a second paper storage section B inside the tray 3 so that small-sized paper can be stored side by side in order to eliminate dead space due to small-sized paper. The tray 3 is configured so that it can be inserted into and removed from the paper feeding device 2.
Is pulled out to set the sheet bundles 6A and 6B. Paper feed means (pickup rollers 12, paper feed rollers 13, separation rollers 14, and transport rollers 15) are provided on the first sheet storage section A, and an image is formed from the uppermost surface of the sheet bundle 6A stacked on the bottom plate 4. Paper is fed to the forming apparatus 1. An upper limit sensor 7 is provided above the sheet feeding means, and detects the position of the pickup roller 12 with this sensor, and controls so that the sheet feeding height is always maintained. A paper end sensor 8 is provided near the upper surface of the sheet bundle 6A, and detects the presence or absence of sheets stacked on the bottom plate 4 with this sensor. A lower limit detection sensor 9 is provided below the tray 3 to detect that the bottom plate 4 is at the lower limit position. When the paper in the first paper storage unit A runs out, the second
The sheet bundle 6B stacked in the sheet storage unit B is supplied. At the time of replenishment, the stacked paper bundle 6B is transported as it is in a lump,
The transfer fence 5 is used to push the transfer fence into the first sheet storage section A. At this time, the initial stop position of the transfer fence 5 is detected by the home position sensor 10, and the push stop position of the transfer fence 5 is detected by the push sensor 11.

[0003] An end fence 17 provided with a stopping member for holding a sheet is provided between the first sheet storing section A and the second sheet storing section B (see FIG. 1B). End fence 17
Is rotatable about a fulcrum C, is closed in the normal state shown in which sheets are accommodated, and holds the rear end of the sheets 6A stacked in the first sheet accommodating section A with the end fence surface of the stopping member. It has a role to control the collapse of cargo. Also, when the sheet is pushed by the sheet from the second sheet accommodating portion B side at the time of sheet transfer, it is opened to enable a smooth transfer of the sheet bundle. The end fence 17 includes an opening / closing detection sensor 16 that detects opening / closing of the end fence 17. Open / close detection sensor 16
The role of is to make it possible to detect a state where a sheet is erroneously set, as shown in FIG. 5 or FIG. The example of FIG. 5 shows a state in which the sheet bundle 6A of A4 is set over the first sheet storage section A and the second sheet storage section B, and the example of FIG. A bundle of A3 paper 6A
Is set. All of these are erroneous sets, and it is necessary to inform the user to that effect. As described above, the open / close detection sensor 16 provided on the end fence 17
Is used to detect an abnormal state, so it is usually necessary to set it to the OFF state. The configuration for this is shown in FIG.
Shown in FIG. 4B is an enlarged view of a portion surrounded by a circle in the plan view of the tray 3A, and the spring 18 pushes the end fence 17 rotating at the fulcrum C in the G direction at all times. Normally operates to keep the open / close detection sensor 16 in a state where the end fence 17 does not act (OFF state).

With reference to FIGS. 2 and 4, a series of operations related to paper supply of the paper supply device will be described. FIG. 2 shows the transition of the operation state, and the operation proceeds in the order of FIGS.
FIG. 4 shows a transition of the operation state of the end fence 17 in the operation of FIG. 2, and the operation proceeds in the order of FIGS. The sheet bundle 6A loaded in the first sheet accommodating section A in the state of FIG. 2A is fed, and the state of FIG. 2B is reached. When the sheet bundle 6A runs out, the paper end sensor 8 runs out of paper. Is detected, the bottom plate 4 descends to the lower limit position, and the bottom plate 4 in FIG. Here, when the lower limit sensor 9 detects the lower limit, the transfer of the sheet bundle 6B stacked in the second sheet storage unit B to the first sheet storage unit A is started.
The sheet bundle 6B is kept loaded by the transfer fence 5 in FIG.
It is moved in the direction D shown in FIG. 2C, and is pushed into the first sheet storage section A through the state shown in FIG. As shown in FIG. 4, the operation state of the end fence 17 during the transfer process of the sheet bundle 6B is such that the transfer fence 5 moves in the direction D from the state at the start of transfer in FIG. The end fence 17 is pushed open, that is, as shown in FIG.
4 is rotated in the direction F about the fulcrum C against the fulcrum 8 and the sheet bundle 6B loaded in the second sheet storage section B is pushed in the direction of the first sheet storage section A and is stored. As shown in ()), the spring 18 rotates in the G direction by the urging force of the spring 18 and returns to the normal state.
In FIG. 2, when the pushing of the sheet bundle 6B into the first sheet accommodating section A is completed, the bottom plate 4 is raised as shown in FIG. When the sheet bundle 6B is positioned, the sheet can be fed. Simultaneously with this operation, the transfer fence 5 returns to the initial position in the E direction and performs the operation.
The return operation after the paper transfer is performed by the home position sensor 10.
Until is turned on, the transfer fence 5 is returned and stopped at the initial position.

As described above, the conventional paper feeder is provided with an L-shaped end fence 17 between the first paper storage section A and the second paper storage section B, and the first paper storage section A The rear end of the stacked paper 6A was pressed (see FIGS. 1, 3). The end fence 17 includes an opening / closing detection sensor 16 for detecting opening / closing of the end fence.
Incorrect setting between the paper storage section A and the second paper storage section B
The detection of a sheet such as an incorrect sheet size is performed by the open / close sensor 16 when the tray is inserted (see FIGS. 5 and 6). in this way,
The end fence 17 has a function of holding down the rear end of the sheet 6A and preventing collapse of the load and a function of detecting a sheet such as an erroneous setting.
8, the urging force is always applied in the G direction. By the way, looking at the related operation between the end fence 17 and the sheet, the end fence 17 closed in the steady state by the urging force of the spring 18 during the sheet transfer operation from the second sheet storage portion B to the first sheet storage portion A is considered. It is configured to be pushed open by the leading end of the moving loaded paper 6B. In order to perform this operation without difficulty, the spring force of the spring 18 is set as small as possible. This is to prevent the problem that the end fence 17 cannot be pushed open at the leading end of the paper 6B when transferring a small volume of paper 6B when the spring is increased, and the paper 6B is damaged.

[0006]

Conventionally, the spring force of the spring 18 is set small for the above-described reason, but this causes another problem. This problem impairs the function of holding down the rear end of the sheet 6A of the end fence 17 and suppressing the collapse of the load and the function of detecting the sheet such as an erroneous setting. This is a problem that may occur when the sheet 6A is loaded in the first sheet accommodating portion A and returned to the apparatus and set again. FIG. 7 shows a mechanism in which such a problem occurs. As shown in FIG. 7A, for example, the paper 6A is stored in the first paper storage portion A of the tray 3 pulled out from the paper feeding device 2.
In order to replenish the tray 3 and return the tray 3 to the original state, the tray 3 may be moved in the H direction and strongly set (inserted). 7C, an inertia moment acts on the end fence 17 in the direction F around the end fence fulcrum C as shown in FIG. Here, the moment due to the spring force of the spring 18 is acting, but since the spring force is weak, the moment due to the spring 18 is overcome and the end fence 17 is opened. At the same time as the end fence 17 operation described above,
The impact force is also applied to the paper 6A stacked in the first paper storage unit A, and the rear end of the paper 6A pressed by the end fence 17 loses its support due to the movement of the end fence in the F direction described above. Therefore, as shown in FIG. 7B, the load collapses in one direction, and the state shown in FIG. 7C is obtained.

In the state shown in FIG. 7 (c), the end fence 17 does not play the role of holding down the rear end of the paper 6A and preventing collapse of the load. The end fence 17 is shown in FIG.
The opening / closing sensor 16 is turned on as shown in FIG.
When the tray is set (inserted) in the paper feeding device and the apparatus main body is in an operable state, an abnormality is detected in the same state (FIGS. 5 and 6) as that of erroneous setting of paper, and a problem that erroneous detection occurs. . The present invention is directed to a paper feeding apparatus having a plurality of paper storage units for storing stacked papers and having a replenishing mechanism for performing a replenishing operation from another paper storage unit when one of the paper storage units runs out of paper. In view of the problems of the prior art, it is an object of the present invention to prevent the end fence of the paper feeder, which suppresses the collapse of the load and the like, and detects an incorrectly set paper sheet. , A paper feeder that performs appropriate operations, and has high performance and reliability, and an image forming apparatus equipped with the paper feeder (copier, printer, etc.)
Is to provide.

[0008]

According to a first aspect of the present invention, there is provided a first sheet storage unit for storing stacked sheets, a unit for feeding sheets stored in the first sheet storage unit, and a first sheet storage unit. A second sheet accommodating section which is arranged side by side with the sheet accommodating section and accommodates stacked sheets of paper, a sheet transferring means for transferring the sheets accommodated in the second sheet accommodating section to the first sheet accommodating section in a stacked state, and a fulcrum And an end fence provided with a stop member for pressing the rear end of the sheet stored in the first sheet storage unit that is rotatable around the sheet transfer unit and stored in the first sheet storage unit. The end fence is configured to generate an inertia moment that balances the inertia moment of the stop member with respect to a fulcrum.

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the structure for generating a balanced inertia moment is obtained by changing a shape of an end fence.

According to a third aspect of the present invention, in the paper feeder according to the first or second aspect, the structure for generating a balanced inertia moment is obtained by adding weight to an end fence. .

According to a fourth aspect of the present invention, in the paper feeder according to any one of the first to third aspects, a hole is formed in a part of the stop member in order to reduce the moment of inertia of the stop member. It is characterized by having made it.

According to a fifth aspect of the present invention, in the paper feeder according to any one of the first to fourth aspects, the restraining member is formed to be thin in order to reduce the moment of inertia of the restraining member. It is characterized by the following.

According to a sixth aspect of the present invention, in the paper feeder according to any one of the first to fifth aspects, the end fence outputs a signal at a predetermined rotation position to detect an operation related to the paper. It is characterized by having a detecting means for detecting the change.

According to a seventh aspect of the present invention, there is provided an image forming apparatus including the sheet feeding device according to any one of the first to sixth aspects.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sheet feeding apparatus according to the present invention. The embodiment apparatus described below can also be applied as a component in an image forming apparatus such as a copying machine. 1 to 6
1 shows a sheet feeding device according to an embodiment of the present invention.
Although the examples shown in FIGS. 1 to 6 are also shown as an example of a conventional paper feeder, the present invention relates to improvement of an end fence in the paper feeder shown as a conventional example.
Based on a conventional device, the examples shown in FIGS. 1 to 6 correspond to this basic part. Therefore, FIGS. 1 to 6 shown as the above prior art are also used as showing an embodiment of the present invention, and the description regarding FIGS. Here, no duplicate description is made.

Here, an embodiment relating to the improvement of the end fence will be described in detail. In the prior art, as shown in FIG. 7, a moment of inertia due to an impact is generated around the fulcrum C of the end fence 17, and the rotational force due to this moment of inertia overcomes the spring force of the spring 18 to move the end fence 17 in the F direction. This rotation caused a malfunction. Therefore, in the following embodiment, the rotation of the end fence 17 is suppressed by eliminating or reducing the influence of the moment of inertia.

In the first embodiment relating to the improvement of the end fence, in order to eliminate the influence of the moment of inertia, an inertia moment which balances the moment of inertia generated in the conventional example is generated. This is realized by changing the shape of the fence. FIG.
Shows the end fence 17 of this embodiment, which is placed in a steady state at the rear end of the sheet 6A. As shown in FIG. 8, the same shape is formed on the side opposite to the end fence function side (the contact portion that is pushed open at the leading end of the sheet, the side having the end fence surface that presses the rear end of the sheet 6 </ b> A) with respect to the fulcrum C of the end fence 17. It has a symmetrical part. Since the tray 3 has a symmetrical shape with respect to the fulcrum C, the tray 3 pulled out from the sheet feeding device 2 is returned to the original state. A moment of inertia in the J direction acts. At this time, the end fence 17
Is symmetric, the moment of inertia acting in the F direction and the moment of inertia acting in the J direction are the same as shown in FIG. 8, so that no force is generated to rotate the end fence 1 about the fulcrum C. . Naturally, the fulcrum C
By making the opposite side larger, so that the opposite side to the end fence function side is unbalanced,
The moment of inertia acting in the J direction can be made larger than the moment of inertia acting in the direction, and a force in the G direction (see FIG. 3 (b)) at which the end fence closes when the tray 3 is inserted can be configured. Thus, the effect of stopping the collapse of the paper 6A is enhanced.

The second embodiment relating to the improvement of the end fence is different from the first embodiment in that, in order to eliminate the influence of the moment of inertia, an inertia moment which balances the moment of inertia generated in the conventional example is generated. This is the same as that described above, but is realized by attaching a heavy object here. FIGS. 9 and 10 show the end fence 17 of this embodiment placed in a steady state at the rear end of the sheet 6A.
Is shown. As shown in FIG. 9 and FIG.
7, a heavy object 19 is provided on the side opposite to the end fence function side (the contact portion which is pushed open at the leading end of the sheet, the side having the end fence surface which presses the rear end of the sheet 6A). By providing the heavy object 19, the position of the center of gravity from the fulcrum C on the side added as a balance configuration can be reduced, and the end fence 17 can be reduced in size. The moment of inertia acting in the J direction can be increased by increasing the distance from the fulcrum C and increasing the weight, and can be set as appropriate. Comparing the embodiments of FIGS. 9 and 10, FIG. 9 is generally L-shaped and has a simpler shape, but has a larger size, and FIG. 10 has a whole key-shaped and more complex shape. However, the size can be made smaller.

In the third embodiment relating to the improvement of the end fence, this is achieved by reducing the weight of the members constituting the end fence 17 in order to reduce the influence of the moment of inertia. FIG. 11 shows members constituting the end fence 17 of this embodiment. As shown in FIG. 11, a hole is formed in a part of a member constituting the end fence 17 to reduce the weight. By reducing the weight of the portion far from the fulcrum C, the moment of inertia acting in the F direction can be further reduced. Therefore, here, a hole is formed in a portion of the end fence surface that holds the rear end of the sheet 6A. In this case, it is necessary not to impair the function of pressing the rear end of the sheet 6A, and it is appropriate to form a hole in the center of the surface as shown.

In the fourth embodiment relating to the improvement of the end fence, in order to reduce the influence of the moment of inertia, this is realized by reducing the weight of the members constituting the end fence 17 as in the third embodiment. It is intended. FIG.
Indicates members constituting the end fence 17 of this embodiment. As shown in FIG. 12, the weight of the end fence 17 is reduced by thinning a part of the members. By reducing the weight of the portion far from the fulcrum C, the moment of inertia acting in the F direction can be further reduced. Therefore, here, the portion of the end fence surface that holds the rear end of the sheet 6A is thinned. It is also possible to simultaneously carry out the weight reduction shown in the third and fourth embodiments and the balance adjustment of the moment of inertia shown in the first and second embodiments,
In this case, more effective improvement is achieved.

[0021]

(1) Effects corresponding to the first aspect of the invention The end fence has a structure that generates an inertia moment that balances the inertia moment of the fulcrum by the restraining member with respect to the fulcrum. The end fence does not open due to the impact of the above, and it is possible to avoid the loss of the function of the end fence to prevent the collapse of the paper load that the end fence has conventionally caused by the illegal operation of opening the end fence. Can be provided. (2) Effects corresponding to the second aspect of the invention In addition to the effect of the above (1), a change in the shape of the end fence generates a balanced moment of inertia. A fence can be obtained, it is easy to manufacture, and it is easy to obtain accuracy. (3) Effects corresponding to the third aspect of the invention In addition to the effects of the above (1) and (2), a weight is added to the end fence to generate a balanced inertia moment, so that the size and size can be reduced. Can be simplified. (4) Effects corresponding to the invention of claim 4 In addition to the effects of the above (1) to (3), the hole is formed in a part of the end fence member to reduce the moment of inertia, so that the size is further reduced. And the shape can be simplified.

(5) Advantages Corresponding to the Invention of Claim 5 In addition to the advantages (1) to (4), the thickness of the end fence member is reduced to reduce the moment of inertia. Simplification is possible and fabrication is easier. (6) Effects corresponding to the invention of claim 6 In addition to the effects of the above (1) to (5), detecting means for outputting a signal at a predetermined rotational position in order for the end fence to detect an operation related to a sheet. With this, the end fence does not open due to the impact when inserting the tray,
It is possible to avoid an erroneous detection by a detection function such as an erroneous setting of a sheet included in the end fence, which is caused by an illegal operation of opening the end fence, and it is possible to provide a paper feeder with high performance and reliability. (7) Effects corresponding to the invention of claim 7 The effects (1) to (6) can be realized in an image forming apparatus such as a copying machine, a printer, and the like, and the performance of the image forming apparatus is improved. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an entire sheet feeding apparatus according to an embodiment of the present invention.

FIG. 2 shows a transition of a series of operation states related to sheet supply of a sheet feeding apparatus according to an embodiment of the present invention.

FIG. 3 shows the relationship between an open / close detection sensor for detecting the open / closed state of the end fence and the end fence.

FIG. 4 shows a transition of an operation state of an end fence in the operation of FIG. 2;

FIG. 5 illustrates a state where a sheet is incorrectly set on a tray.

FIG. 6 illustrates a state in which an erroneous sheet is set on a tray.

FIG. 7 is a diagram illustrating an illegal operation of the end fence that occurs when an impact occurs.

FIG. 8 shows the end fence of the embodiment placed in a steady state at the trailing edge of the sheet.

FIG. 9 illustrates another embodiment of an end fence resting on the trailing edge of a sheet in a steady state.

FIG. 10 illustrates another embodiment of an end fence resting on the trailing edge of a sheet in a steady state.

FIG. 11 shows an example of a member constituting a lightweight end fence.

FIG. 12 shows another example of a member constituting a lightweight end fence.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Paper feeder 3
... Tray, 4 ... Bottom plate, 5 ... Transfer fence, 6A, 6B ... Paper, 12 ... Pickup roller, 15 ... Transport roller, 16 ... Open / close detection sensor, 17 ... End fence, 18 ...
Spring, 19 ... heavy.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F048 AA02 AB01 BA23 BA24 CA08 CB12 CB16 DA01 DB12 DC02 EB03 EB06 3F343 FA02 FB02 FC18 GA01 GB01 HD07 HD09 HD14 HE08 HE14 HE20 KB02 KB20 LA02 LA16 MA08 MA32 MC27 MC28

Claims (7)

[Claims] A first sheet storage unit for storing sheets in a stacked state; a unit for feeding sheets stored in the first sheet storage unit; A second sheet accommodating section for accommodating the first sheet accommodating section, sheet transferring means for transferring the sheets accommodated in the second sheet accommodating section to the first sheet accommodating section in a stacked state, and rotatable about a fulcrum. And an end fence provided with a stop member for pressing a rear end of the sheet stored in the first sheet storage unit and transferred by the first sheet storage unit.
A sheet feeding device having a structure for generating an inertia moment that balances the inertia moment of the stop member with respect to a fulcrum. 2. The sheet feeding device according to claim 1, wherein the structure for generating a balanced moment of inertia is obtained by changing a shape of an end fence. 3. The sheet feeding device according to claim 1, wherein the structure for generating a balanced moment of inertia is obtained by adding weight to an end fence. 4. The sheet feeding device according to claim 1, wherein a hole is formed in a part of the stop member to reduce a moment of inertia of the stop member. Paper feeder. 5. The sheet feeding device according to claim 1, wherein the stopping member is formed to be thin in order to reduce the moment of inertia of the stopping member. apparatus. 6. The sheet feeding device according to claim 1, wherein the end fence includes a detection unit that outputs a signal at a predetermined rotation position to detect an operation related to a sheet. A paper feeding device characterized in that: 7. An image forming apparatus comprising the sheet feeding device according to claim 1.