JP2004137017A - Air type sheet feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air type sheet feeder for performing floating of transfer sheet at the uppermost level from a bundle of transfer sheets loaded by one fan and suction of the floated sheet to the perforated conveying belt sheet feed surface by one fan. <P>SOLUTION: The air type sheet feeder comprises a sheet accommodation section, where the transfer sheet is loaded; a perforated conveying belt 3 that is arranged at the upper side of the sheet accommodation section and at least at the tip side in the direction of sheet feed of the bundle of transfer sheets being loaded, and is wound between a pair of rollers for drive; and an air type sheet feeding means 5 that supplies the transfer sheet loaded at the sheet accommodation section to the sheet supply surface of the perforated conveying belt for retention. In the air type sheet feeder, the air type sheet feeding means comprises a single fan 30; a blowing duct pipe 10 interlocked to the blowing side of the fan; and a suction duct pipe 12 interlocked to the suction side of the fan. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder used in an image forming apparatus or the like, and more particularly, to an air-type paper feeder that feeds transfer paper sheet by sheet using air blowing and suction. About.
[0002]
[Prior art]
2. Description of the Related Art In an electrophotographic image forming apparatus such as a copier, a facsimile, or a printer, a toner image formed on a photosensitive drum surface is transferred to transfer paper, and the transferred toner image is transferred to the transfer paper surface by heat or pressure. Image formation is performed by fixing. In such an image forming apparatus, of course, it is necessary to feed the transfer sheets one by one.
As a paper feeding device for feeding the transfer paper one by one, a multi-hole transport belt (air permeable belt) wound and driven between a pair of rollers is used, and the transfer loaded on a predetermined paper storage unit is used. 2. Description of the Related Art There is known an air-type paper feeding device that blows air to a leading end portion of a paper in a paper feeding direction and feeds only the uppermost transfer paper in close contact with the belt using suction force (for example, see Patent Document 1). ).
[0003]
[Patent Document 1]
JP-A-2001-233487 (claims, FIG. 2).
[0004]
[Problems to be solved by the invention]
In the air feeding device of Patent Document 1, a suction duct tube connected to a suction fan is disposed in a region surrounded by a breathable belt stretched between a pair of rollers. A blowing duct tube connected to a blower fan is disposed adjacent to the sheet storage section on which the sheet is loaded. That is, the blowing duct pipe blows air on the leading end portion in the sheet feeding direction of the upper portion of the stacked transfer paper bundle, so that the uppermost transfer paper floats upward. The transfer paper is fed and conveyed by the air permeable belt by suction from the tube and held in close contact with the paper feeding surface of the air permeable belt.
[0005]
Therefore, the above-described air feeding apparatus requires two fans, a suction fan and a blowing fan, and as a result, there is a problem that the cost increases and the volume of the apparatus increases.
[0006]
Accordingly, an object of the present invention is to provide a pneumatic feeder in which a single fan lifts the top transfer paper from a stack of transfer papers stacked by one fan and suctions the lifted transfer paper to a sheet feeding surface of a multi-hole transport belt. A paper device is provided.
[0007]
[Means for Solving the Problems]
According to the aspect of the invention, the paper storage unit on which the transfer paper is stacked, and the upper side of the paper storage unit and at least the leading end side of the stacked transfer paper bundle in the paper feeding direction and wound between the pair of rollers In the pneumatic paper feeder comprising: a multi-hole transport belt driven and driven; and pneumatic paper supply means for supplying and holding the transfer paper stacked in the paper storage unit to the paper feed surface of the multi-hole transport belt,
The air-type sheet feeding means includes a single fan, a blowing duct tube connected to a blowing side of the fan, and a suction duct tube connected to a suction side of the fan,
The blowing duct tube is disposed to face the front surface of the paper storage unit on the paper feeding direction side, and the blowing duct tube feeds the uppermost transfer paper of the transfer paper bundle loaded in the paper storage unit to the paper feeding unit. Air blowing is performed so that it floats at the front end side in the direction,
The suction duct tube is disposed in an area surrounded by the multi-hole transport belt, and the transfer paper floated by blowing air from the spray duct tube by suction by the suction duct tube is held in close contact with the multi-hole transport belt. An air-type paper feeder is provided.
[0008]
In the present invention, a blowing duct tube for blowing air for floating the uppermost transfer paper of the transfer paper bundle, and a suction for sucking and holding the floating transfer paper in close contact with the paper feeding surface of the porous transport belt. The duct tube is connected to a common fan.
Therefore, only one fan may be used in the present invention, which can reduce cost and device volume.
[0009]
In the present invention, since air is blown and sucked by one fan, when the transfer paper is held in close contact with the paper feeding surface of the perforated transport belt, the air blowing force of the fan decreases, and as a result, the paper should be fed. The transfer paper may fall off the belt. To prevent such inconvenience,
1. The suction duct pipe is provided with a paper detection sensor for detecting the transfer paper held in close contact with the perforated transport belt. When the transfer paper is detected by the paper detection sensor, the fan is driven. Output is increased,
2. A plurality of multi-hole transport belts are stretched in parallel between the pair of rollers, and the paper detection sensor is disposed between the multi-hole transport belts,
Is preferred.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 showing the upper surface of the pneumatic paper feeder of the present invention and FIG. 2 showing a schematic side sectional view of the paper feeder, the paper feeder includes a paper storage unit 1 (see FIG. , An air feeding mechanism 5, and the air feeding mechanism 5 includes a blowing duct pipe 10 and a suction duct pipe 12.
[0011]
Transfer papers 15 are stacked in the paper storage unit 1. In FIG. 2, the bundle A of the stacked transfer papers 15 is formed by the end face on the leading end side in the paper feeding direction (indicated by an arrow X) and both sides thereof. Although the surfaces are aligned, and not shown, a bottom plate for supporting the transfer paper bundle A is provided at the bottom of the sheet storage unit 1 in exactly the same manner as in a known device. The transfer paper bundle A can be moved up and down in accordance with the number of the transfer paper bundle A, so that the uppermost position of the transfer paper bundle A is always located at an appropriate height.
[0012]
The perforated transport belt 3 is known per se, has a number of suction holes 3a, and is stretched over a pair of rollers 17, 17 (one is a driving roller and the other is a driven roller). The transfer sheet bundle A stacked in the sheet storage unit 1 is located above the end in the sheet feeding direction. The number of the perforated transport belts 3 may be one, but in this example, as shown in FIG. 3, which will be described later, four perforated transport belts 3 are stretched in parallel with rollers 17 at an appropriate interval. Have been.
[0013]
The suction duct tube 12 of the air feeding mechanism 5 described above is disposed in a portion surrounded by the multi-hole transport belt 3. The suction duct tube 12 has a suction port 12a, and causes the transfer paper 15 (indicated by 15a in FIG. 2) positioned at the uppermost position of the transfer paper bundle A to be tightly held on the belt 3 by suction pressure. Things. That is, the uppermost transfer paper 15a held in close contact with the belt 3 is conveyed in the paper feed direction X by driving the belt 3, and is transferred to a predetermined area via the pair of paper feed rollers 20, 20 (see FIG. 2). The paper is fed.
[0014]
On the other hand, the blowing duct 10 is arranged at a small interval on the front surface (the surface in the sheet feeding direction X) of the sheet storage unit 1, and a guide surface 22 is provided at an upper end in the sheet feeding direction X side. Is formed. That is, the leading end portion of the transfer paper 15 which is transported in close contact with the multi-hole transport belt 3 and discharged from the belt 3 is introduced between the paper feed rollers 20 by the guide surface 18.
[0015]
In particular, as shown in FIG. 1, the blowing duct tube 22 has first blowing ports 24, 24 for directly blowing air onto both ends in the width direction of the transfer paper bundle A, and the transfer paper bundle A. The second blowing ports 26 for indirectly blowing air are formed on upper portions of both ends in the width direction.
[0016]
That is, a relatively large amount of air is blown in a substantially horizontal direction by the first blowing ports 24, 24, so that the transfer paper 15 located above the transfer paper bundle A is wavy. On the other hand, the second blowing ports 26, 26 are formed so as to be inclined, so that air is not directly blown onto the upper portion of the transfer paper bundle A, and once the paper feeding surface (or the suction pipe 12 The air is blown to the outer surface, and the reflected wind is blown to the upper part of the transfer paper bundle A. Therefore, the air is blown downward to the widthwise central part of the transfer paper bundle A.
[0017]
Accordingly, the transfer paper 15 located above the transfer paper bundle A floats in such a manner that both ends in the width direction are wavy when air is blown from the first blowing ports 24, 24, and in this state, A downward airflow is blown from the second blowing ports 26, 26 to the central portion in the width direction. As a result, air enters between the uppermost transfer sheet 15a and the transfer sheet 15b located below the transfer sheet 15a, and the transfer sheet 15a and the transfer sheet 15b are separated at the leading end.
[0018]
Further, when a part of the transfer paper 15a located at the uppermost position comes into contact with the paper feed surface of the multi-hole transport belt 3 by waving, the portion is directly held on the paper feed surface by the suction force, and as a result, the transfer paper 15a at the uppermost position is obtained. Only the entire surface thereof comes into close contact with the sheet feeding surface of the perforated conveying belt 3 and is conveyed and fed by the belt 3.
[0019]
In the above-described sheet feeding device, the blowing duct tube 10 and the suction duct tube 12 provided in the air sheet feeding mechanism 5 are connected to a common fan 30, as shown in FIG. That is, the blowing duct tube 10 is connected to the blowing side of the fan 30, and the suction duct tube 12 is connected to the suction side.
Therefore, in the present invention, the above-described blowing of air by the blowing duct tube 10 and suctioning by the suction duct tube 12 are performed by only one fan 30, and as a result, reduction in apparatus cost and reduction in apparatus volume are achieved. be able to.
[0020]
By the way, when air is blown and sucked by one fan 30 as described above, when the transfer paper 15 (top transfer paper 15a) comes into close contact with the sheet feeding surface of the belt 3, the fan 30 naturally blows air. As a result, the transfer paper 15 to be fed and conveyed may fall off the paper feeding surface of the belt 3.
In order to avoid such inconvenience, a paper detection sensor 35 is attached to the suction duct tube 12.
[0021]
The paper detection sensor 35 itself may be a known one, and has a rocking piece such as an actuator, for example, and the transfer is performed by the movement of the rocking piece when the transfer paper 15 comes into close contact with the paper feeding surface of the belt 3. The paper 15 is detected.
For example, in a case where image formation is performed continuously with the main switch of the image forming apparatus being ON, if the air-supplying device is selected to feed the air, the above-described air blowing and suction are performed by driving the fan 30. At the same time, at this time, the above-described paper detection sensor 35 does not detect the transfer paper 15 and is therefore OFF, so that the fan 30 operates at a low output (for example, the fan 30 Rotate at high speed). Next, when the transfer paper 15 comes into close contact with the paper feeding surface of the belt 3 and the transfer paper 15 is detected and the paper detection sensor 35 is turned on, the fan 30 operates at a high output (for example, rotates at full speed). ). Next, when the transfer paper 15 adhered by the belt 3 is fed and conveyed, the paper detection sensor 35 is turned off, and the fan 30 operates again at a low output. Thereafter, the fan 30 operates in the same manner. I do.
[0022]
By controlling the output of the fan 30 as described above, it is possible to effectively avoid a decrease in the air blowing capacity of the fan 30 when the transfer paper 15 comes into close contact with the paper feeding surface of the belt 3.
The paper detection sensor 35 can be attached by various methods. In general, as shown in FIG. 1, it is preferable to dispose the paper detection sensor 35 at a portion between the multi-hole transport belts 3. .
[0023]
The pneumatic sheet feeding device of the present invention described above may be mounted on a large capacity deck portion inside an image forming apparatus such as a copying machine, or a temporary stock portion of a single-sided copy sheet for double-sided copying. Alternatively, it may be externally attached to the image forming apparatus. In addition, not only the image forming apparatus but also an apparatus such as a scanner can be used as an apparatus for feeding a document to be read to a predetermined area.
[0024]
【The invention's effect】
According to the pneumatic paper feeder of the present invention, the floating of the uppermost transfer paper from the transfer paper stack loaded by one fan and the suction of the supported transfer paper to the paper feed surface of the multi-hole transport belt are performed by one fan. As a result, cost and device capacity can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an upper surface of a pneumatic sheet feeding device of the present invention.
FIG. 2 is a schematic side sectional view of the sheet feeding device of FIG. 1;
[Explanation of symbols]
1: paper storage unit 3: multi-hole transport belt 5: air feeding mechanism 10: blowing duct tube 12: suction duct tube 15: transfer paper 30: fan 35: paper detection sensor

Claims (3)

A sheet storage portion on which transfer paper is loaded, and a multi-hole transport that is disposed above the paper storage portion and at least on the leading end side of the loaded transfer paper bundle in the paper feeding direction, and is wound and driven between a pair of rollers. A pneumatic paper feeder comprising: a belt; and pneumatic paper feed means for supplying and holding the transfer paper stacked in the paper storage unit to a paper feed surface of the multi-hole transport belt,
The air-type sheet feeding means includes a single fan, a blowing duct tube connected to a blowing side of the fan, and a suction duct tube connected to a suction side of the fan,
The blowing duct tube is disposed to face the front surface of the paper storage unit on the paper feeding direction side, and the blowing duct tube feeds the uppermost transfer paper of the transfer paper bundle loaded in the paper storage unit to the paper feeding unit. Air blowing is performed so that it floats at the front end side in the direction,
The suction duct tube is disposed in an area surrounded by the multi-hole transport belt, and the transfer paper floated by blowing air from the spray duct tube by suction by the suction duct tube is held in close contact with the multi-hole transport belt. An air-type paper feeder characterized by the following. The suction duct pipe is provided with a paper detection sensor for detecting the transfer paper held in close contact with the multi-hole transport belt. When the transfer paper is detected by the paper detection sensor, the fan is driven. The pneumatic paper feeder according to claim 1, wherein the output is increased. The pneumatic paper feeder according to claim 2, wherein a plurality of multi-hole transport belts are stretched in parallel between the pair of rollers, and the paper detection sensor is disposed between the multi-hole transport belts. .

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