JPH0680261A - Paper feeding device - Google Patents

Abstract

PURPOSE:To prevent a slipping in the lateral direction of paper sheets fed by utilizing the absorbing force of the air. CONSTITUTION:The uppermost sheet Y of a laminated paper sheets P is absorbed and lifted up by a suction belt 45. The air jet from the first air jet nozzle 55 flows between the uppermost sheet Y and the next lower sheet Y, and only the uppermost sheet Y is absorbed to the suction belt 45. The sheet Y is absorbed and conveyed without slipping in the lateral direction by a pair of guide plates 47a provided on both sides of the suction belt 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and the like, and more particularly to a paper feeding apparatus for adsorbing and stacking stacked sheets by suction of air onto a conveyor belt.

[0002]

2. Description of the Related Art As a paper feeding device in a conventional copying machine,
It is known that the suction force of air is used to separate and feed sheets one by one from the accumulated sheets. This paper feeder is
As shown in FIGS. 6 and 7, a conveyor belt 3 disposed above a paper feed deck 2 on which sheets 1 are stacked and placed, a pair of front and rear drive rollers 4 and 5 for driving the conveyor belt 3, and A suction unit 6 arranged between the drive rollers 4 and 5 for sucking a sheet.
It has and.

In front of the paper feed deck 2, there is arranged a nozzle 7 for ejecting an air flow for separating the paper adsorbed on the conveyor belt 3 from the remaining paper. In addition, in FIG.
Is a vent formed in the conveyor belt, and 9 is a suction port of the suction unit 6.

[0004]

Generally, when paper is fed from a multi-manual paper feed tray or paper feed cassette by a paper feed roller, it is fed by a side plate or a rear end plate attached to the paper feed tray or paper feed cassette. The deviation of the width of the fed sheet and the variation of the leading edge are prevented.

However, in the conventional sheet feeding apparatus utilizing the air suction force, the sheets are separated by the air flow from the nozzles 7 and sucked by the conveying belt 3, so that the side plate of the sheet feeding deck 2 and the conveying belt 3 are separated. A gap H of about 3 to 10 mm between
Is provided.

Therefore, the lifted sheet cannot be regulated in the width direction, and immediately before the sheet is sucked by the conveying belt 3 or when the sheet is being fed by the conveying belt 3, the nozzle 7 or the suction unit 6 is also used. Due to the variation in the air pressure in the sheet, the sheet may be fed while being displaced from the normal transport position, which may cause a transfer failure or a sheet jam.

In view of the above, it is an object of the present invention to prevent misalignment of sheets to be fed in a sheet feeding device utilizing air suction force.

[0008]

As shown in FIG. 1, the means for solving the problems according to the first aspect of the present invention includes a conveying belt 45 for sucking and conveying the sheets Y stacked on the sheet supply base 40, and a conveying belt 45. In a paper feeding device including a suction unit 46 for sucking the paper Y and a separating unit 44 for ejecting air for separating the sucked paper Y and the remaining paper Y, on both sides of the conveyor belt 45, Guide plates 47a and 47b for preventing the suctioned sheet Y from shifting in the width direction are provided.

The problem solving means according to the second aspect is provided with a moving means 60 for moving the guide plates 59a and 59b in the width direction of the sheet.

[0010]

In the problem solving means according to the first aspect, the suction force from the suction portion 46 causes the uppermost sheet Y on the sheet supply table 40 to be sucked up by the conveyor belt 45 and lifted. Further, the air ejected from the separating unit 44 flows between the uppermost sheet Y and the sheet Y below it, and only the uppermost sheet Y is adsorbed to the transport belt 45. At this time, the paper Y is fed by the pair of guide plates 47 a, which are arranged on both sides of the conveyor belt 45.
By 47b, it is adsorbed without shifting in the width direction.

Then, the paper Y is fed by the movement of the conveyor belt 45. Also at this time, the paper Y is fed to the guide plate 47.
It does not shift in the width direction due to a and 47b. For this reason, the sheet Y is not transported with its leading end part dislocated with respect to the normal transport position, or laterally displaced, or skewedly displaced.

In the problem solving means according to the second aspect, when the guide plates 59a and 59b are moved in the width direction of the sheet Y,
Since the guide plates 59a and 59b are closely spaced from each other, the distance is set according to the width of the sheet Y. Therefore, the deviation of the paper Y in the width direction can be prevented, and moreover, the paper of plural sizes can be fed.

[0013]

【Example】

<First Embodiment> FIG. 1 is a vertical sectional view showing the structure of a paper feeding device according to the first embodiment of the present invention, and FIG. 2 is an overall structure diagram of a copying machine equipped with the paper feeding device of the first embodiment. 3 is a plan view of a main part of the transport unit, and FIG. 4 is a schematic side view of the sheet feeding device.

A copying machine equipped with the sheet feeding device of the first embodiment is
As shown in FIG. 2, a document feeder 11 is mounted on the top of the copying machine body 10. The main body 10 of the copying machine is provided with an exposure glass 12 which constitutes an exposure part on the upper part thereof,
Below the exposure glass 12, an optical system 1 including a light source lamp 13, mirrors 14, 15, 16 and a lens 17 is provided.
8 are arranged.

The optical system 18 optically scans an original document conveyed to the exposure section by the original document conveying device 11 by the irradiation light from the light source lamp 13, and reflects the reflected light on the respective mirrors 14, 15, 16 and. By irradiating the exposure point A on the surface of the photosensitive drum 19 through the lens 17, an electrostatic latent image corresponding to the image of the original is formed on the surface of the photosensitive drum 19.

Around the photosensitive drum 19, a main charger 20 for charging the surface of the photosensitive drum 19 to a predetermined potential, a developing device 21, and a transfer charger 22.
And a peeling charger 23 are provided.

The electrostatic latent image formed on the surface of the photosensitive drum 19 is developed as a toner image by the developing device 21,
This toner image is transferred to the paper Y by the transfer charger 22, and then the transferred paper Y is peeled off by the charger 23.
By this, it is peeled off from the photosensitive drum 19.

Below the photosensitive drum 19, there is provided a paper transport path 24 for transporting the toner image transfer paper Y to the photosensitive drum 19 by a transport roller 24a.
The paper feed decks 25,
A sheet feeding device 26 that feeds the sheet Y from a sheet feeding cassette or the like is provided. On the other hand, on the downstream side of the paper transport path 24, a paper transport belt 27 that transports the paper Y on which the toner image is transferred, and a fixing device 2 that fixes the toner image on the paper Y.
And 8 are provided.

On the downstream side of the fixing device 28, there is provided a post-processing device 29 for performing post-processing such as stapling on the transferred paper Y and a re-transporting path 30 and a deflector 31 for branching the transport direction of the paper Y. ing.

In the re-conveyance path 30, the paper Y on which the toner image is transferred by the photosensitive drum 19 is re-photosensitive.
The intermediate tray 32 is disposed in the middle of the circulation path to convey the sheet to the sheet 9, and enables double-sided copying on the sheet Y.

The paper feed deck 25 is, as shown in FIG. 1, a paper feed table 40 on which a pile P is placed and a pile of paper Y is placed on the deck body 25a, and a paper feed table 40 is arranged behind the paper feed table 40 and piled up. A rear end plate 41 for aligning the rear end portions of the object P and a rear end plate 4
1 and an upper limit switch 42 which is arranged on the upper part of the upper part 1 and contacts the rear part of the upper surface of the deposit P.

The paper supply table 40 is urged upward by a spring having elasticity, and the rear end plate 4 is provided at the center of the rear portion.
1 long groove for movement is formed.

The rear end plate 41 is L-shaped and is movably supported in the longitudinal direction of the sheet Y at the rear portion of the deck body 25a via a rack and a pinion (not shown). Therefore, the deposit P is positioned in the lengthwise direction by bringing the rear end plate 41 into contact with the rear end of the deposit P. The upper limit switch 42 is a switch for detecting the upper surface of the uppermost sheet Y.

As shown in FIGS. 1 and 3, the sheet feeding device 26 sucks and transports the uppermost sheet Y of the deposit P in the sheet feeding deck 25, and the sucked sheet Y and the remaining sheet Y. And a separating unit 44 for separating the sheet Y from the sheet.

The carrying unit 43 is a unit body 4
3a, a conveyance (suction) belt 45, a suction portion 46 for sucking the paper Y by the suction belt 45, a guide plate 47a for preventing the width of the paper Y sucked by the suction belt 45 in the width direction, And 47b.

The suction belt 45 is arranged above the paper feeding deck 25 with a space of 3 to 10 mm, and four endless belts 51 are attached to the unit main body 43a by the shafts 48a, 48a.
It is wound around rollers 49 and 50 rotatably supported around 48b with an interval in the axial direction. In the endless belt 51, a large number of ventilation holes 52 that are inserted in the thickness direction are formed dispersedly.

The suction part 46 is provided with a suction belt 45.
Intake duct 53 that communicates with the vent hole 52 from the inside to the bottom
And an intake fan that sucks air from the ventilation hole 52 through the intake duct 53, and a DC servo motor that drives the intake fan.

As shown in FIG. 3, the intake duct 53 is guided between the rollers 49 and 50 and between the endless belts 51, and the opening 54 thereof faces the lower center of the suction belt 45. . Thereby, the suction force of the intake fan is guided to the endless belt 51 running on the lower side.

The guide plates 47a and 47b are shown in FIGS.
As described above, it is hung from both sides of the unit main body 43a in the side plate direction of the paper feed deck main body 25a so as to be opposed to each other with the suction belt 45 interposed therebetween. Each guide plate 47a, 47b
Is spaced from the sheet feeding deck body 25a by 1 mm so that the sheet feeding deck 25 does not interfere with the loading and unloading of the sheet feeding deck 25 into and from the copying machine body 10. In addition, the respective guide plates 47a, 4a
The interval of 7b is slightly larger than the width of the paper Y.

In FIG. 1, reference numeral 58 denotes a detection switch which is provided in the transport unit 43 and detects whether or not the sheet Y is sucked by the suction belt 45.

The separating section 44 comprises a plurality of first air jet nozzles 55, a plurality of second air jet nozzles 56, and an exhaust fan for supplying air to the first and second air jet nozzles 55, 56. .

As shown in FIG. 3, the first air jet nozzle 55 is arranged on the front end side of the deposit P below the suction belt 45, and the paper P is fed from the suction belt 45 to the upper front end of the deposit P. Air can be blown toward. Therefore, an air pocket is generated between the sheets, and the sheet Y can be separated.

The second air ejection nozzle 56 is arranged above the first air ejection nozzle 55, and the suction belt 45 is provided.
Thus, air can be blown toward the lower side of the sheet Y being fed. Therefore, it is possible to assist the suction of the sheet Y to the suction belt 51 by blowing air to the lower side of the fed sheet Y.

The air ejection nozzles 55 and 56 and the exhaust port of the exhaust fan are connected to the rollers 49 and 50 of the suction belt 45.
The exhaust fan is driven by a DC servo motor that drives the intake fan.

An operation of guiding the sheet Y for transferring the toner image from the sheet feeding deck 25 to the photosensitive drum 19 by the sheet feeding device 26 in the above configuration will be described.

First, the intake fan and the exhaust fan are rotated by driving the DC motor. Further, the rotational force from the motor is transmitted to the rollers 49 and 50 of the suction belt 45, and the suction belt 45 moves. Due to the suction force of the intake fan, the air above the deposit P on the sheet supply table 40 is sucked from the ventilation hole 52 of the suction belt 45. Air is ejected from the first and second air ejection nozzles 55 and 56 through the exhaust duct 57 by the air blown from the exhaust fan.

Then, the uppermost sheet Y of the deposit P is sucked and lifted by the suction belt 45, and the air blown out from the first air jet nozzle 55 is between the uppermost sheet Y and the sheet Y below it. , And only the uppermost sheet Y is adsorbed to the suction belt 45.

At this time, the paper Y is the suction belt 4
By a pair of guide plates 47a and 47b arranged on both sides of 5, the sheet is adsorbed without being displaced in the width direction. Therefore,
Even if the air pressures of the ventilation hole 52 and the first air ejection nozzle 55 vary, the paper Y does not come off.

The paper Y is the suction belt 45.
Is moved while being pressed against the suction belt 45 by the air jetted from the second air jet nozzle 56 and fed. Also at this time, the paper Y is guided by the guide plates 47a and 47b
Therefore, it does not shift in the width direction. After that, the paper Y separates from the suction belt 45 and reaches the photoconductor drum 19 through the paper transport path 24.

As described above, when the sheet Y is sucked onto the suction belt 45 and when the sheet Y is drawn by the suction belt 45,
When the paper is fed, the paper Y is fed to the pair of guide plates 47a and 47b.
Thus, the sheet is sucked and fed without shifting in the width direction. For this reason, the sheet Y is prevented from being transported while the leading end portion thereof is not aligned with the normal transport position, is displaced in the left-right direction, or is skewedly displaced, and thus it is possible to prevent transfer failure and sheet jam.

<Second Embodiment> FIG. 5 is a block diagram showing the moving means of the guide plate of the second embodiment. The members having the same functions as those in the first embodiment are designated by the same reference numerals.

The sheet feeding device of the second embodiment has a guide plate 59.
A moving means 60 is provided to move a and 59b in the width direction of the paper Y.

This moving means 60 is used for the suction belt 4
5 is installed inside the unit main body 43a and is attached to the rear portion of the respective guide plates 59a and 59b.
The rack plates 61 and 62 that support the a and 59b, and the pinion 63 that meshes with the rack plates 61 and 62.

The rack plates 61, 62 include a rack 61.
a, 62a are formed so as to face each other, and the racks 61a,
A pinion 63 is rotatably arranged between the 62a.

In the above structure, the guide plates 59a, 59
When b is manually moved in the width direction of the sheet Y, the guide plates 59a and 59b move close to and away from each other, so that the spacing can be set freely.

As described above, since the distance between the guide plates 59a and 59b can be set according to the size of the sheets Y stacked in the sheet feeding deck 25, the deviation of the sheets Y in the width direction can be prevented, Moreover, the single transport unit 43 can feed the sheets Y of a plurality of sizes.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, the moving means 60 of the second embodiment may be incorporated in the rollers 49 and 50 of the suction belt 45. Further, the motor of the moving means 60 may be drive-controlled in accordance with the size of the sheet Y on the sheet feeding table 40.

[0049]

As is apparent from the above description, according to claim 1 of the present invention, the sheet is displaced in the width direction by the guide plate when the sheet is sucked into the conveyor belt and when the sheet is fed by the conveyor belt. Sucked and delivered without. For this reason, the leading edge of the sheet does not fluctuate with respect to the normal transport position, or the sheet does not shift in the left-right direction, or is skewedly displaced, and thus it is possible to prevent transfer failure and sheet jam.

According to the second aspect, the distance between the guide plates can be set in accordance with the size of the sheets stacked on the sheet supply table, so that the deviation of the sheets in the width direction can be prevented and a plurality of sheets can be prevented. It has the excellent effect of being able to feed paper of a size.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the configuration of a paper feeding device according to a first embodiment of the invention.

FIG. 2 is an overall configuration diagram of a copying machine including the paper feeding device according to the first embodiment.

FIG. 3 is a plan view of a main part of a transport unit.

FIG. 4 is a schematic side view of a sheet feeding device.

FIG. 5 is a configuration diagram showing a moving means of a guide plate according to a second embodiment.

FIG. 6 is a vertical sectional view of a conventional paper feeding device.

FIG. 7 is a plan view of a main part of a conventional paper feeding unit.

[Explanation of symbols]

 40 Paper Supply Stand 44 Separation Part 45 Conveyor Belt 46 Suction Part 47a, 47b Guide Plate 59a, 59b Guide Plate 60 Moving Means

Claims (2)

[Claims] 1. A conveyor belt for sucking and conveying the sheets stacked on a sheet supply table, a suction unit for adsorbing the sheets to the conveyor belt, and an air for separating the sucked sheets and the remaining sheets. A sheet feeding device having a jetting separating portion, wherein guide plates are provided on both sides of the conveyor belt to prevent the suctioned sheet from shifting in the width direction. 2. The paper feeding device according to claim 1, further comprising a moving means for moving the guide plate in the width direction of the paper.