JPH04358637A - Paper feeding device of image forming unit - Google Patents

Abstract

PURPOSE:To enable easy separation of paper sheets subjected to duplicate feed by taking advantage of the bending strength of the paper sheets when the papersheets laminated in a paper-feeding tray of the like are fed by means of a suckingly carrying device. CONSTITUTION:A paper-feeding device 1 arranged at the paper sheet-feeding paper of a paper-feeding tray 10 is composed of a sucking chamber 2 which is constituted by a papersheet guide surface as a bent surface, and a belt 6 arranged around the sucking chamber 2. There are provided a papersheet guide surface 3 underside of the sucking chamber 2 and air sucking holes, and the papersheet are carried in their pushingly pressed condition to the belt, and at the same time, a shuffling nozzle 15 is arranged by being faced to the inflected part of the papersheets guide surface 3. By blowing air into a clearance formed between the papersheets subjected to duplicate feed at the inflected part of the papersheet guide surface, the underside papersheet is separated and only the sucked upper papersheet is carried toward a paper passage.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a paper feeding device for feeding paper while handling it in an image forming apparatus such as an electronic copying machine or a printer, and in particular, the present invention relates to a paper feeding device for feeding paper while handling it in an image forming apparatus such as an electronic copying machine or a printer. , moving the paper along a curved path,
The present invention relates to a device that makes it easy to carry out screening operations.

0002

2. Description of the Related Art In image forming apparatuses such as electronic copying machines and printers, a paper feeder is provided with a paper sorting means in order to feed paper from a device such as a paper feed tray attached to a paper feeder toward a recording section. A device is used to feed the paper while separating it one by one. Furthermore, when sending out the original from the original tray toward the reading section, a means for sending out the original while preventing double feeding of the original is used. As the sorting means provided in the paper feeding device as described above, for example, a retard roller type means, a sorting means using a pad, etc. are used, and even when sheets are fed from the tray in a multi-feed state, The paper is separated so that it can be sent out one by one toward the recording section.

In addition to the paper feeding device using a roller device as described above, a paper feeding device using a suction belt means may also be used, as shown in, for example, Japanese Utility Model Application Laid-Open No. 63-130435. In the paper feeding device using the suction belt means, air is blown from a nozzle toward the leading edge of the paper to facilitate separation of the paper when the paper is fed while being attracted to the belt. It uses means that cause the action to take place. Note that the paper feeding device using a suction means shown in the conventional example is configured as a device that feeds paper from the bottom of the paper stacked on the tray, but when feeding paper from the top of the tray, Figure 4
A device as shown in can be constructed.

The paper feeding device 1 shown in FIG. 4 is arranged above the paper feeding tray 10, and includes a suction chamber 2 connected to a suction mechanism, and a plurality of suction chambers arranged around the suction chamber 2. It consists of a book belt 6... The belt 6 is wound around a driving roller 8 and a driven roller 9, and is driven along the lower surface of the suction chamber 2 in the paper conveyance direction. Then, by suctioning air toward the suction chamber 2 through the holes provided in the belt, the paper feed tray 1
The upper part of the paper P stored in 0 is fed out while being sucked into the belt. Further, a sorting nozzle 15 and a guide member 12 are arranged at the bottom of the paper feeding device, and a means is provided for separating double fed sheets by air blown from the sorting nozzle 15 and locking them by the guide member 12. I am using it.

In the paper feeding device, in order to facilitate paper separation, rib members 5 are protruded between belts 6 disposed on the lower surface of the suction chamber 2, as shown in FIG. The belt 6 is arranged so that the paper sucked by the belt 6 is curved in a wavy manner (forming corrugation) in the width direction of the paper. Then, the upper paper P1 in contact with the belt is curved into a wavy shape corresponding to the paper guide surface of the suction chamber, but the lower paper P2 does not have a strong suction action, so the stiffness of the paper is As a result, a gap S is formed between the two sheets of paper. Therefore, by blowing air from the separation nozzle 15 into the gap formed between the sheets, it is possible to separate the sheets in a good manner.

[0006]

[Problems to be Solved by the Invention] As shown in FIG. 5, corrugations are formed in the width direction of the paper, and air blown from the sorting nozzle enters between the paper sheets.
In order to perform paper separation better, the wider the width of the corrugation formed on the paper, the better the paper handling performance can be exhibited. However, when corrugations are formed over the entire width of the paper, the stress applied to the paper becomes large, causing a problem in that the paper becomes strongly wrinkled. When the paper is moved within the paper path, the curved portion in the width direction of the paper comes into contact with the joint of the guide plate or other members, which tends to cause jamming. Therefore, conventional paper feeding devices are configured to feed paper while forming corrugations in a narrow area at the center of the paper.

[0007] However, if you try to blow air from a sorting nozzle only to the center of the paper to perform a sorting action, the air blown from the sorting nozzle will get into the spaces between the overlapping sheets. , since it takes time to separate the sheets, there is a problem that the paper handling performance in the sheet feeding section deteriorates. Further, although the paper feeding device is capable of feeding paper at a relatively high speed unlike a paper handling mechanism using a roller method, etc., there are cases where the paper cannot be separated properly by blowing air. In this case, the paper feeding performance of the device cannot be effectively utilized. Furthermore, when using a paper handling means having the above-mentioned configuration, the separation performance differs depending on the size of the paper, and there is a problem that sufficient separation performance cannot be achieved for all sizes of paper. There is.

[0008]

OBJECTS OF THE INVENTION The present invention solves the drawbacks of the conventional paper feeding device using the suction method as described above. When the paper is bent along the shape of the paper, a gap is formed between the paper that is sucked and the paper below it due to the stiffness of the paper. The purpose is to provide a device for

[0009]

[Means for Solving the Problems and Effects] The present invention relates to a device that is disposed on the paper feed side of a paper feed tray and feeds paper from the top of the paper stored in the paper feed tray using a suction conveyance means. . In the paper feeding device of the present invention, the paper feeding device is constituted by a suction chamber provided with a suction means, a plurality of belts provided with suction holes, and an air blowing device for separating the sheets, A paper guide surface is disposed in the suction chamber, and the leading end in the paper feeding direction is formed as an upwardly curved surface, and a rib member that protrudes toward the paper conveyance surface between the belts is disposed on the paper guide surface. It is placed.

As described above, by forming the paper guide surface as a curved surface, even when the sheets conveyed along the paper guide surface are in a multi-feed state, the paper below the suctioned paper is not curved. Due to the stiffness of the paper, a gap is likely to form between the paper and the paper being sucked. Therefore, by blowing air with a handling nozzle onto the curved part of the paper, the paper can be easily separated by utilizing the air blown between the sheets and the stiffness of the paper. can be done. Furthermore, even if the sheets are of different sizes, the paper can be easily separated by blowing air using the separation nozzle located corresponding to the center of the paper. The configuration of the handling mechanism can be simplified.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper feeding device for an image forming apparatus according to the present invention will be explained according to the illustrated example. In the example of the present invention shown in FIG. 1, similarly to the conventional example, a paper feed device 1 is arranged at the upper part of the paper feeding side of the paper feed tray 10, and the paper feed device 1 is Suction chamber 2 and multiple belts 6
It is composed of... Further, as in the case of a general suction conveyance device, the belt 6 is stretched around a driving roller 8 and a driven roller 9, and is driven along the lower surface of the suction chamber 2 in the paper conveyance direction. As a result, the paper is fed. In the example shown in FIG. 1, the paper sent out using the paper feeder 1 is fed toward the image recording section via the paper path 11. As shown in the figure, the paper guide surface 3 formed on the lower surface of the suction chamber 2 is arranged in a substantially horizontal state above the paper stored in the tray, and is arranged in a substantially horizontal state at the paper feeding side end of the tray. The belt 6 is configured as a surface curved upward in the paper feeding direction, and is configured to guide the belt 6 along the surface of the paper guide surface 3.

A guide member 12 is disposed at a predetermined position downstream of the curved portion of the paper guide surface, and a sorting nozzle 15 is disposed upstream of the guide member 12. and,
A handling nozzle 15 is arranged at the bend between the horizontal plane and the upwardly curved part of the paper guide surface, and from the nozzle 15,
The air blown toward the sheets acts to separate sheets that are fed in duplicate. Then, the leading edge of the separated multi-feed paper is stopped by the guide member 12,
Only the top sheet of paper is sucked into the belt 6 and sent out toward the paper path 11. In the embodiment described above, in addition to the sorting nozzle 15, nozzle members 16 are arranged on both sides of the paper feed tray. The nozzle members 16 are disposed on both sides of the paper feed tray, and are arranged at both sides of the paper feed tray.
Perform the action of blowing air. Then, by the air blowing action, the leading edge of the paper is slightly lifted, so that the paper stacked on the paper feed tray 10 can be easily separated, and the paper is sucked into the lower surface of the suction chamber 2. do it like this.

The relationship between the suction chamber 2 and the belt 6 is constructed as shown in FIG. The example shown in FIG. 2 is shown as a cross section taken along the line A-A in FIG. Means is connected and adapted to apply negative pressure to the interior of the housing. The lower surface of the suction chamber 2 is configured as a paper guide surface 3 for paper, and a plurality of belts 6 are arranged parallel to the paper conveyance direction along the paper guide surface 3. . In addition, each of the belts 6
The rib members 5 are disposed in such a way as to protrude downward between the belts 6, and the tips of the rib members 5 are configured to protrude lower than the belt 6. In the paper feeding device, the sorting nozzle 15 arranged at the curved portion of the paper guide surface 3 is arranged at a predetermined position below the conveyance section by the suction chamber, as shown in FIG.

On the paper guide surface 3 of the suction chamber 2, suction holes 4 are arranged in a row in the direction of movement of the belt in a portion corresponding to the guide path of the belt 6.
Also, a large number of suction holes 7... are provided. Then, the negative pressure applied to the housing causes air to be sucked through the suction holes 4 and 7 to press the paper against the surface of the belt, and the friction between the paper and the belt causes a conveying action on the paper. I am trying to make it possible. Further, when the paper is sucked along the paper guide surface 3 as described above, the sucked paper P1 is undulated in the width direction of the paper along the lower surfaces of the belt 6 and the rib member 5. A state in which corrugations are formed. On the other hand, the double-fed paper P2, which is sucked at the same time while sticking to the lower surface of the sucked paper P1, does not have a strong suction effect, so the upper paper P1 Corrugations similar to the above are not formed, and a slight gap S is formed between the two sheets of paper. Therefore, by arranging the sorting nozzle 15 in the gap between the two sheets of paper, the double feeding is separated and the lower paper P2 is moved to the guide member 1.
2 and prevent it from moving toward the paper path.

In the paper feeding device, when two sheets of paper are simultaneously sucked along the paper guide surface 3, the sucked upper paper P1 is moved along the belt at the bent portion of the paper guide surface 3. When bent, the suction pressure causes the paper to be guided along the paper guide surface 3. On the contrary,
As shown in FIG. 3, the lower paper P2, which is sucked at the same time, separates from the upper paper P1 at the bending portion of the paper guide surface 3 due to the stiffness of the paper. Then, air is blown from the sorting nozzle 15 toward the gap shown in FIG. 2 so as to face the paper moving direction at the bent portion of the paper guide surface 3, thereby separating the paper. can be encouraged. Therefore, in the paper feeding device of the present invention, in addition to configuring the paper guide surface as a curved surface and forming corrugations in the width direction of the paper sucked along the paper guide surface. By performing the air blowing action by the handling nozzle 15 in such a manner that they are opposed to each other in the conveyance direction of the paper, the paper handling action can be performed satisfactorily.

In the paper feeding device of the present invention constructed as described above, the state of curvature of the paper guide surface 3 formed in the suction chamber 2, the width of the belt 6 disposed on the paper guide surface, Conditions such as the interval between belts can be arbitrarily set depending on the type of paper used and the like. Further, the paper feeding device of the present invention can be used as a means for feeding paper from a paper feeding tray, but it can also be used as a means for feeding a document from a document tray. Further, the separating nozzle arranged with respect to the paper guide surface of the suction chamber is arranged at the most suitable position for separating the paper sheets.For example, the paper guide surface 3 is curved with a uniform curvature. If there is a curved surface, it can be placed at any position on the curved surface.

[0017]

Effects of the Invention Since the paper feeding device of the image forming apparatus of the present invention is configured as described above, the paper guide surface is formed as an upwardly curved surface with the paper guide surface facing the paper conveyance direction. Even if the paper being conveyed along the paper guide surface is in a double-feed state, when the paper below the suctioned paper is bent, the stiffness of the paper causes it to overlap with the suctioned paper. A gap can be formed between them. Therefore, by blowing air with a handling nozzle onto the curved part of the paper, the paper can be easily separated by utilizing the air blown between the sheets and the stiffness of the paper. It becomes possible to do so. Furthermore, even if the paper sizes are different, the paper can be easily separated by blowing air using the separation nozzle located corresponding to the center of the paper. In addition to being able to prevent paper feeding, the configuration of the paper handling mechanism can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a paper feeding device of the present invention.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is an explanatory diagram showing a paper separating action at a bending portion of a paper guide surface.

FIG. 4 is a side view showing the configuration of a conventional paper feeding device.

5 is an explanatory diagram of the paper separation action in the apparatus shown in FIG. 4. FIG.

[Explanation of symbols]

1 paper feeder, 2 suction chamber,
3 Guide surface, 5 Rib member, 6
Belt, 10 Paper feed tray, 12
Guide member, 15 Judging nozzle, 1
6 Nozzle member.

Claims (1)

[Claims] Claim 1: A paper feeding device that is disposed on the paper feeding side of a paper feeding tray and feeds paper from the top of the paper stored in the paper feeding tray, comprising: a suction chamber provided with a suction means; and a suction hole. The paper feeding device includes a plurality of belts and an air blowing means for separating the paper, and the suction chamber includes a paper guide whose tip in the paper feeding direction is formed as an upwardly curved surface. Set up a surface,
A paper feeding device for an image forming apparatus, characterized in that a rib member is disposed between the belts, and the rib member is provided to protrude downward from the surface of the belt.