JPH0891605A - Paper sheet feed device - Google Patents

Abstract

PURPOSE: To prevent a mechanism from being damaged, which presses printing paper against the paper end sensor of a paper sheet feed unit at the time of fitting a paper sheet feed unit of large capacity onto one paper feed port of a device body so as to open and close sideways, and fitting a manual feed tray so as to open and close in the vertical direction. CONSTITUTION: An elastic member 26 for pressing printing paper 2 against a paper end sensor 5 is mounted onto a paper sheet feed unit 24 at a position where a manual feed tray makes no interference at the time of opening and closing to prevent the elastic member 26 from being damaged at the time of opening or closing the paper sheet feed unit 24 or the manual feed tray.

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 used in a copying machine or a printing machine.

[0002]

2. Description of the Related Art Conventionally, a paper feeding device has been used as a device for automatically feeding a printing paper to a copying machine or a printing machine, and there are various forms of such a paper feeding device.

For example, as shown in FIG. 7, a paper feeding device 1 disclosed in Japanese Patent Laid-Open No. 2-204224 has a large number of printing papers 2.
The paper feed table 3 on which the sheets are stacked is vertically movable, and a paper feed roller 4 is arranged above the paper feed table 3 so as to be vertically movable. A paper end sensor 5 is mounted on the bottom surface of the paper feed tray 3 at a position facing the paper feed roller 4. More specifically, the photo interrupter 6 of the paper end sensor 5 is arranged below the paper feed table 3, and the rotatable filler 7 of the paper end sensor 5 is attached to the paper feed table 3.
Projecting upward from the opening hole 8. Elevating control means (not shown) is provided that does not raise the paper feed table 3 unless the paper end sensor 5 detects the printing paper 2.

With such a structure, when feeding the printing paper 2 placed on the paper feed table 3, the paper feed roller 4 descends and abuts the printing paper 2, and in this state, the paper feed roller 2 moves. The printing paper 2 is rotated to be fed to a separating and feeding mechanism (not shown). When the printing paper 2 on the paper feed tray 3 is reduced by such feeding, the paper feed tray 3 is raised and the uppermost position of the printing paper 2 is maintained at an appropriate position. When the paper end sensor 5 detects the end of the printing paper 2, the paper feed table 3 is not raised, so that the mechanism for raising and lowering the paper feed tray 3 is properly stopped to prevent damage.

Further, a sheet feeding device (not shown) disclosed in Japanese Utility Model Laid-Open No. 1-121038 also allows a sheet feeding table on which a large number of printing sheets are stacked to be movable in the vertical direction and above the sheet feeding table. A paper feed roller is arranged in the above so as to be vertically displaceable. A pair of side fences are arranged on the upper surface of the paper feed table so that they can come into contact with and separate from each other, and a paper holding member is provided so as to project inward from the upper front ends of these side fences. These paper holding members are rotatably supported in the vertical direction and are linked to the paper feed table by a link. When the paper feed table is lowered to the lowest position, the paper holding member rotates upward.

With such a structure, when the paper feed tray is lowered to the lowest position to replenish printing paper, the paper holding member automatically rotates upward and retracts from the upper surface of the paper feed tray. Printing paper can be easily replenished to the paper feed table. When the paper feed table is raised after the completion of such a replenishing work, the paper holding member automatically rotates downward to hold the printing paper, so that the paper feeding operation can be favorably performed.

Further, the sheet feeding device 9 disclosed in Japanese Patent Laid-Open No. 4-317930 is a part of the image forming apparatus 10 as shown in FIGS. 8 and 9. This image forming apparatus 10
The image forming unit (not shown) is arranged in the upper part of the apparatus main body 11, and the sheet feeding cassette (not shown) is arranged in the lower part. A large-capacity sheet feeding unit 12 is provided on the rear surface of the apparatus main body 11.
Is attached to the side of the paper feed unit 12 such that the paper feed path 13 that is openably and closably attached to the side and communicates from the paper feed cassette to the image forming unit.
Through the gap between the front surface of the device and the rear surface of the device body 11.
A sheet feed port 14 communicating with the sheet transport path 13 is formed on the rear surface of the apparatus main body 11, and the sheet feed roller 4 and the separation sheet feed mechanism 15 are arranged therein. A pair of side fences 16 is arranged on the upper surface of the paper feeding unit 12 so as to be freely contactable and separable.

With such a structure, the rigidity of the paper feed path 13 is increased by the paper feed unit 12 which is stronger than a general guide plate, and the feeding performance of the printing paper 2 is improved.
By rotating the sheet feeding unit 12, the sheet conveying path 13 can be freely opened to facilitate jam processing.

Further, as shown in FIG. 10, the present inventor also proposed a paper feed device 18 in which a manual tray 17 is mounted at the position of the paper feed port 14 so as to be vertically openable and closable. This paper feeder 1
In FIG. 8, the manual feed tray 17 and the paper feed unit 12 share the paper feed roller 4 and the separate paper feed mechanism 15, so that the structure is simple and the number of parts can be reduced. The paper feeding device 18 includes a paper holding member 19 from the upper front end of the side fence 16 to the inside.
Is protruding.

[0010]

In the paper feeding device 1 disclosed in Japanese Patent Application Laid-Open No. 2-204224, the printing paper 2 is detected by the paper end sensor 5 mounted on the bottom surface of the paper feeding base 3, and therefore the printing paper 2 shown in FIG. As shown in, when the print paper 2 is thin and light, the paper end sensor 5 may be lifted and the end of the paper may be erroneously detected. Such erroneous detection is caused by printing paper 2
It also occurs when is curved due to moisture absorption and reuse.

As means for solving such a problem,
It is conceivable that the paper feed table 3 is raised and stopped at an appropriate position, the paper feed roller 4 is lowered and the printing paper 2 is pressed from above, and the detection of the paper end sensor 5 is executed in this state. However, in this case, in order to detect the end of the sheet, it is necessary to raise and stop the sheet feeding table 3 and then lower the sheet feeding roller 4, and it is also necessary to control the timing of the detection of the paper end sensor 5. Is complicated and not preferable.

Therefore, the present inventor considered providing a mechanism (not shown) for constantly pressing the printing paper 2 in the apparatus main body 11, but such a mechanism is disclosed in Japanese Patent Laid-Open No. 4-317930. It was found that it is difficult to provide it to the paper feeding device 9.

That is, in the paper feeding device 9 of the above publication, the paper feeding unit 12 can be opened and closed laterally with respect to the main body 11 of the device, and the manual tray 17 can be opened and closed vertically. There is little space to provide a mechanism for holding the paper feed unit 12, and even if such a mechanism is provided, the paper feed unit 12 and the manual tray 17 are likely to be damaged by interference when opening and closing.

Further, as in the paper feeding device disclosed in Japanese Utility Model Laid-Open No. 1-121038, providing a paper holding member projecting inward from the upper front end of the side fence is also effective for good conveyance of printing paper. However, it has been found that it is difficult to provide such a sheet holding member in the sheet feeding device 9 disclosed in Japanese Patent Laid-Open No. 4-317930.

That is, as shown in FIG. 10, when the sheet holding member 19 is provided on the side fence 16 of the sheet feeding unit 12, the manual tray 17 may interfere with the sheet holding member 19 at the time of opening and closing and may be damaged. high.

[0016]

According to the first aspect of the present invention,
A paper feed unit is formed in the main body of the apparatus, and a paper feed unit that supports a paper feed tray on which a large number of printing papers are stacked is vertically movable. The paper feed unit is provided at a position communicating with the paper feed opening of the apparatus main body. A paper unit is installed so that it can be opened and closed laterally, and a manual feed tray is installed so that it can be opened and closed in the vertical direction at a position that communicates with the paper feed port of the apparatus body, and this manual feed tray and the paper feed unit are shared. A paper feed roller is arranged at the paper feed port of the apparatus body, a paper end sensor is provided at a position facing the paper feed roller of the paper feed table from below, and the paper end sensor of the paper feed unit is opposed from above. Then, an elastic member for pressing the printing paper downward is provided at a position where the manual tray does not interfere with opening and closing.

According to a second aspect of the present invention, there is provided a paper feed unit in which a paper feed port is formed in the main body of the apparatus, and a paper feed table on which a large number of printing sheets are stacked is movably supported in the vertical direction. The paper feed unit is attached to the side of the paper feed port of the apparatus such that the paper feed unit can be opened and closed laterally, and the manual tray is attached to the position of the paper feed port of the apparatus body which can be opened and closed vertically. A sheet feeding roller shared by the tray and the sheet feeding unit is arranged at the sheet feeding port of the apparatus main body, and a pair of side fences which can be freely contacted and separated is arranged on the upper surface of the sheet feeding table. A paper holding member is projected inward from the front end of the upper portion at a position where the manual tray does not interfere with opening and closing, and an elastic member for pressing the printing paper downward is projected forward from these paper holding members.

The front, rear, left, and right directions referred to in the present invention are defined for convenience in order to simplify the description, and do not limit the actual installation and use directions of the apparatus.

According to a third aspect of the invention, in the first or second aspect of the invention, the elastic member is a flexible elastic plate.

According to a fourth aspect of the invention, in the third aspect of the invention, the front edge portion of the elastic plate is bent downward.

[0021]

According to the invention described in claim 1, since the elastic member provided in the paper feeding unit at the position where the manual tray does not interfere with the opening and closing of the manual tray always presses the printing paper downward, the paper located below the printing paper. The end sensor does not erroneously detect the end of paper even when the print paper is thin and light or curved.

According to a second aspect of the present invention, a sheet holding member protruding inward from the upper front end of the side fence at a position where the manual tray does not interfere when opening and closing, and an elastic member protruding forward from these sheet holding members. However, since the printing paper is constantly pressed downward, the leading edge of the printing paper to be fed is held and skew does not occur.

According to the third aspect of the invention, since the elastic member is a flexible elastic plate, the elastic force of the elastic plate holds the printing paper.

According to the fourth aspect of the invention, since the front edge portion of the elastic plate is bent downward, the manual tray is unlikely to interfere.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. The sheet feeding device 20 of the present embodiment
With respect to the above, the same parts as those of the above-described sheet feeding devices 1, 6, and 18 use the same names and reference numerals, and detailed description thereof will be omitted. Further, the front, rear, left, and right directions in the present embodiment are defined for convenience in order to simplify the explanation, and this does not limit the actual installation or use direction of the device.

First, in the image forming apparatus 10 including the sheet feeding device 20 of this embodiment as a part, as shown in FIGS.
The image forming unit 21 is arranged on the upper part of the apparatus main body 11, and the paper feed cassettes 22 and 23 are arranged on the lower part.
A paper feed port 14 is provided on the rear surface of the apparatus body 11 of the image forming apparatus 10.
Is formed, and the paper feed unit 24 is mounted to be opened and closed laterally and the manual tray 17 is mounted to be opened and closed vertically in a position communicating with the paper feed port 14. The sheet conveying path 13 that communicates from the sheet feeding cassettes 22 and 23 to the image forming unit 21 passes through a gap between the front surface of the sheet feeding unit 24 and the rear surface of the apparatus main body 11 and communicates with the sheet feeding port 14.

In the paper feeding unit 24, a paper end sensor 5 is mounted on a paper feeding table 3 movably supported in the vertical direction, and the paper end sensor 5 is located below the paper feeding roller 4 of the apparatus main body 11. Facing from. A stay 25 is provided at the upper front end of the sheet feeding unit 24, and an elastic plate 26, which is an elastic member made of a polyester film having a plate thickness of 0.18 (mm), is attached to the lower surface of the stay 25. The elastic plate 26 projects forward and downward from the stay 25 so as to face the paper end sensor 5 from above at a position where the manual tray 17 does not interfere with the opening and closing of the manual tray 17 by a tip portion 27 that is bent substantially horizontally. The printing papers 2 loaded on the paper feed table 3 are elastically pressed downward.

An upper limit detection sensor 29 for detecting the uppermost printing paper 2 placed on the paper feed table 3 is mounted on the bracket 28 which supports the paper feed roller 4 so as to be rotatable in the vertical direction. There is. The paper feeding unit 24 can store 1000 sheets of printing paper 2.

In such a structure, first, the operation of feeding the printing paper 2 from the paper feeding unit 24 to the image forming section 21 will be described below.

First, as shown in FIG. 2, the manual tray 17
Closed upwards. When a switch (not shown) is operated in such a state, the paper feed roller 4 descends to come into contact with the uppermost printing paper 2, and then rotates in this state to rotate the printing paper 2.
Is fed to the paper feed port 14. The printing paper 2 is separated into one sheet by the separating and feeding mechanism 15 and fed to the paper feeding path 13, so that the one printing paper 2 is fed to the image forming unit 21.

The printing paper 2 is fed by the above-mentioned feeding.
Is decreased, the paper feed tray 3 is raised until the upper limit detection sensor 29 detects the print paper 2, thereby arranging the uppermost print paper 2 at an appropriate position communicating with the paper feed opening 14 of the apparatus body 11. . At this time, when the end of the printing paper 2 is detected by the paper end sensor 5, the raising of the paper feed table 3 is stopped to prevent the lifting mechanism (not shown) from being damaged.

Next, from the manual tray 17 to the image forming unit 2
The operation of feeding the printing paper 2 to the sheet 1 will be described below.

First, as shown in FIG. 3, the manual tray 17
Open downward and place the printing paper. When the switch is operated in such a state, the paper feed roller 4 descends and comes into contact with the print paper 2 in the manual tray 17, and rotates in this state to feed the print paper 2 to the paper feed port 14. The printing paper 2 is separated into one sheet by the separating / feeding mechanism 15 and fed to the paper transport path 13, so that this one printing paper 2 is transferred to the image forming unit 2.
It is transported to 1.

As described above, the sheet feeding device 20 of this embodiment
Since the manual feed tray 17 and the paper feed unit 24 share the paper feed roller 4 and the separate paper feed mechanism 15, the structure is simple and the number of parts is reduced.

As shown in FIG. 1, the elastic plate 26 provided in the paper feeding unit 24 elastically presses the printing paper 2 downward at a position facing the paper end sensor 5 from above. Therefore, even when the printing paper 2 is thin and light or curved, the paper end sensor 5 does not erroneously detect the end of the paper.

Moreover, the elastic plate 26 constantly presses the printing paper 2 due to its elasticity, and it is not necessary to rotate it up and down like the paper feeding roller 4, so that the structure is simple and the productivity is high. Is also good. The elastic plate 26 is provided in the paper feeding unit 24 which can be freely opened and closed in the apparatus main body 11. Since the structure is simple, the occupied space is extremely small, and the manual tray 1
Since 7 is arranged at a position where it does not interfere with opening and closing, it is not damaged by opening and closing the paper feeding unit 24 or the manual tray 17.

Further, since the elastic member that presses the printing paper 2 downward is the elastic plate 26 that can be bent, the elastic member is formed with an extremely simple structure. Such elastic plate 2
As the elastic member that does not depend on 6, it is possible to envisage, for example, a member (not shown) in which a high-rigidity flat plate is pivotally supported in the vertical direction and is urged downward by a spring.

Next, a second embodiment of the present invention will be described below with reference to FIGS. With respect to the sheet feeding device 30 of the present embodiment, the same parts as those of the sheet feeding device 20 described as the first embodiment are denoted by the same names and reference numerals, and detailed description thereof will be omitted.

First, in the paper feeding device 30 of this embodiment, as shown in FIG.
Further, as shown in FIG. 5, the sheet holding member 32 extends inward from the upper front ends of the pair of side fences 16 of the sheet feeding unit 31.
However, the front edges of these paper holding members 32 are retracted to positions where the manual tray 17 does not interfere when the manual tray 17 is opened and closed. The elastic plate 33, which is an elastic member made of a polyester film having a plate thickness of 0.18 (mm), is attached to the upper surface of the sheet holding member 32 instead of the stay 25. The elastic plate 33 projects forward and downward from the paper holding member 32, and a tip portion 34 is bent downward.

In such a structure, the paper feeding unit 3
When the printing paper 2 is fed from 1 to the paper transport path 13, the front edge of the printing paper 2 is held from above by the paper holding member 32 and the elastic plate 33, so that the printing paper 2 has good skew and curl. Are prevented by.

Since the paper holding member 32 and the elastic plate 33 provided in the paper feeding unit 31 elastically press the printing paper 2 downward above the paper end sensor 5, the printing paper 2 Is thin and light, or the printing paper 2 is curved due to moisture absorption and reuse, the paper end sensor 5 does not erroneously detect the end of the paper.

Moreover, since the paper holding member 32 is disposed at a position where the manual tray 17 does not interfere with the opening and closing of the manual tray 17,
It is not damaged by opening and closing the paper feeding unit 31 or the manual tray 17. The elastic plate 33 projecting forward from the sheet holding member 32 may interfere with the manual tray 17 when it is opened or closed, but since it is elastically bendable, it does not matter even if the manual tray 17 interferes from above. . For example, as shown in FIG. 6, it is conceivable that the elastic plate 33 may be caught when the manual tray 17 opened downward is closed upward, but the tip end 34 of the elastic plate 33 of this embodiment is bent downward. Therefore, such a possibility is extremely low. Since the elastic member that presses the printing paper 2 downward is the elastic plate 33 that can bend freely, the elastic member is formed with an extremely simple structure.

In the present embodiment, it is assumed that the paper holding member 32 is fixedly formed at the upper front end of the side fence 16, but the present invention is not limited to the above-mentioned embodiment. It is also possible to mount a lever on the inner surface of 16 so as to be rotatable in the vertical direction, and to provide the paper holding member 32 at the tip of this lever.

[0044]

According to the first aspect of the invention, the apparatus main body is provided with a sheet feeding port, and a sheet feeding unit for supporting a sheet feeding table on which a large number of printing sheets are stacked is vertically movable. Install the paper feed unit to the side that communicates with the paper feed port of the main unit so that it can be opened and closed laterally, and install the tray that can open and close vertically to the position that communicates with the paper feed port of the main unit. By arranging the paper feed roller shared by the tray and the paper feed unit at the paper feed port of the main body of the device, the structure can be simplified and the number of parts can be reduced. Since the paper end sensor is provided at a position opposite to the paper end sensor, and the elastic member that presses the print paper downward at a position that does not interfere with the manual tray when opening and closing the paper end sensor of the paper feeding unit from above is provided, If the paper is thin and light or curved Even if the elastic member is pressed against the paper end sensor, it is possible to prevent the paper end sensor from erroneously detecting the end of the paper, and it is not necessary to rotate the elastic member in the vertical direction, so the structure is simple. The productivity is good, and the structure is simple, so the occupied space is very small and the manual feed tray is installed in the paper feed unit at a position where it does not interfere when opening and closing, so it will be damaged by opening and closing the paper feed unit or manual feed tray. It has the effect of never happening.

According to a second aspect of the present invention, a paper feed unit is provided in which a paper feed port is formed in the main body of the apparatus, and a paper feed table on which a large number of printing papers are stacked is movably supported in the vertical direction. Attach the paper feed unit to the side that communicates with the paper feed port so that it can be opened and closed laterally, and attach the manual feed tray to the position that communicates with the paper feed port of the main unit so that it can be opened and closed vertically. By arranging the paper feed roller that is shared with the paper feed unit at the paper feed port of the main body of the device, the structure can be simplified and the number of parts can be reduced. Side fences are arranged, paper holding members project inward from the upper front ends of these side fences at positions where the manual tray does not interfere when opening and closing, and the printing paper is pressed downward from these paper holding members forward. Due to the protruding elastic member, Since the front edge portion of the printing paper is held from above by the holding member and the elastic member, it is possible to favorably prevent skew of the printing paper fed, and the paper holding member is used when the manual tray is opened and closed. Since it is provided in the paper feeding unit at a position where it does not interfere, it will not be damaged by opening and closing the paper feeding unit or the manual tray, and the elastic member will
Even if the manual tray interferes, it has the effect of not being damaged due to elasticity.

According to the third aspect of the present invention, the elastic member is formed of a bendable elastic plate, so that the elastic member can be formed with a simple structure.

According to the fourth aspect of the present invention, the front edge of the elastic plate is bent downward, so that the manual tray can be effectively prevented from interfering with the elastic plate.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional side view showing a state in which a manual tray is closed in an image forming apparatus including a paper feeding device as a part.

FIG. 3 is a vertical sectional side view showing a state where a manual tray is opened.

FIG. 4 is a vertical sectional side view showing a sheet feeding device according to a second embodiment.

FIG. 5 is a vertical cross-sectional side view showing an image forming apparatus including a sheet feeding device as a part.

FIG. 6 is a vertical cross-sectional side view showing a state where an elastic plate, which is an elastic member, is hooked on the manual tray.

FIG. 7 is a vertical sectional side view showing a sheet feeding device of a first conventional example.

FIG. 8 is a perspective view showing a sheet feeding device of a second conventional example.

FIG. 9 is a vertical sectional side view showing a sheet feeding device of a second conventional example.

FIG. 10 is a vertical sectional side view showing a paper feeding device devised by the present inventor.

FIG. 11 is a vertical cross-sectional side view showing a state in which the printing paper is released upward in the paper feeding device of the first conventional example.

[Explanation of symbols]

 2 Printing Paper 3 Paper Feeding Table 4 Paper Feeding Roller 5 Paper End Sensor 11 Device Main Body 14 Paper Feeding Port 16 Side Fence 17 Manual Tray 20,30 Paper Feeding Device 24,31 Paper Feeding Unit 26,33 Elastic Member, Elastic Plate 34 Tip

Claims (4)

[Claims] 1. A paper feed unit is provided which has a paper feed port formed in the apparatus body and supports a paper feed table on which a large number of printing papers are stacked so as to be vertically movable, and communicates with the paper feed port of the apparatus body. Attach the paper feed unit to the side to open and close freely,
A manual feed tray is mounted at a position communicating with the paper feed port of the apparatus body so that it can be opened and closed in the vertical direction, and a paper feed roller shared by the manual feed tray and the paper feed unit is provided at the paper feed port of the device body. A paper end sensor is provided at a position facing the paper feed roller of the paper feed table from below, and the paper end sensor of the paper feed unit is faced from above so that the manual tray does not interfere when opening and closing. A paper feeding device characterized in that an elastic member for pressing the printing paper downward is provided on the paper. 2. A paper feed unit having a paper feed port formed in the main body of the apparatus and supporting a paper feed table on which a large number of printing papers are stacked so as to be vertically movable, and is connected to the paper feed port of the main body of the apparatus. Attach the paper feed unit to the side to open and close freely,
A manual feed tray is mounted at a position communicating with the paper feed port of the apparatus body so that it can be opened and closed in the vertical direction, and a paper feed roller shared by the manual feed tray and the paper feed unit is provided at the paper feed port of the device body. A pair of side fences that can be brought into and out of contact with each other are arranged on the upper surface of the paper feed table, and a paper holding member is projected inward from the upper front end of these side fences at a position where the manual tray does not interfere when opening and closing. A paper feeding device characterized in that an elastic member for pressing the printing paper downward is projected from the paper holding member forward. 3. The sheet feeding device according to claim 1, wherein the elastic member is a flexible elastic plate. 4. The paper feeding device according to claim 3, wherein a front edge portion of the elastic plate is bent downward.