JP2000044078A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly feed even a curled sheet of papers without complicating its configuration. SOLUTION: A curled sheet of papers P is pressed at its upper surface side by the paper contacting surface of a rib part 3, and brought upward by a bottom plate 22. When a paper P at the uppermost position comes up to the piled-up upper limit position, it is pressed by the paper contacting surface 31a and the bottom plate 22 so as to allow curling to be suppressed in such a way as to be brought into a shape roughly close to a horizontal condition with respect to the bottom plate 22, so that the tip end Pa of the paper P is brought to a specified nip N position formed between a feeding roller 21 and a separation pad 25. In this case, the tip end Pa of the paper P is surely directed to the nip N so as to allow excellent separation and carrying to be performed by letting the paper feeding roller 21 be drivingly rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a paper feeding section of a facsimile machine, a printer, a copying machine, etc.
The present invention relates to a sheet feeding device configured to be able to convey a plurality of recording sheets or the like one by one in a predetermined direction regardless of a sheet width size without installing a corner claw or the like.

[0002]

2. Description of the Related Art FIG. 10 is a schematic configuration diagram of a facsimile apparatus for explaining a conventional paper feeding apparatus.
Denotes an image forming unit installed inside the apparatus main body 1, 4 denotes a paper feed cassette installed below the apparatus main body 1, 5 denotes an apparatus main body 1
Is a paper feeder unit installed on the side of the printer.

The document reading section 2 includes a paper feed roller 7 for feeding a document stacked on a document set table 6, and a separation conveyance roller 8.
And a contact sensor 9 for optically reading document information; conveying rollers 10 and 10 provided upstream and downstream of the contact sensor 9 in the sheet conveying direction; It is composed of rollers 11 and the like,
The document set on the document setting table 6 is fed to the separation and conveyance roller 8 by the sheet feeding roller 7, and is conveyed by the separation and conveyance roller 8 toward the conveyance rollers 10 and 10 one by one. The transport rollers 10 move the original on the reading surface of the contact sensor 9, and the contact sensor 9 reads the document information photoelectrically and electrically. The document after the reading is completed is discharged to the outside by the transport rollers 10 and 10.

[0004] The image forming unit 3 includes an image forming unit U for a known electrostatic image forming process centered on the photoreceptor 12,
A registration roller 13 that sends the recording paper P fed from one of the paper feeding cassette 4 and the paper feeding unit 5 to the photoconductor 12 at a timing, and a recording paper P that receives a toner image transferred from the photoconductor 12. The image forming apparatus includes a fixing roller 14 for receiving the image and fixing the image.

[0005] The paper feed cassette 4 includes a cassette case 15.
And a paper feed roller 17 in which the bottom plate 16 whose end 16 a is provided to be able to swing up and down in the cassette case 15 and the upper surface of the recording paper P pushed up by the end 16 a of the bottom plate 16
It is composed of

At the time of paper feeding in the paper feed cassette 4, the recording paper P stacked on the bottom plate 16 in the cassette case 15
The uppermost one is in contact with the lower surface of the paper feed roller 17 due to the upward pressing of the end 16a of the bottom plate 16, and the paper feed roller 17 is rotated by a drive system (not shown) so that the uppermost one is fed in order from the uppermost one. The paper is fed, fed to the registration roller 13 via the conveyance roller 18, and conveyed.

The paper feed unit 5 is provided at the lower part 2 of the case substrate 20.
0a is installed in the apparatus main body 1, and a paper feed roller 21 installed in a lower portion 20a of the case substrate 20 and another end 22a facing the paper feed roller 21 so that the one end 22a can swing up and down. A bottom plate 22 which is a recording paper stacking plate on which the portion 22b is supported, a support lever 24 whose one end is pivotally supported and is urged by a spring 23 below the paper feed roller 21; It is provided with a separation pad 25 which is provided and presses against the paper feed roller 21 by receiving the urging force of the spring 23.

At the time of paper feeding in the paper feeding unit 5, the recording paper P stacked on the bottom plate 22 is moved upward by one end portion 22a of the bottom plate 22 being pressed by the urging spring 26, thereby causing the recording paper P to move upward. The sheet Pa is in contact with the lower surface of the sheet feeding roller 21, and the uppermost recording sheet P is fed to the nip N between the sheet feeding roller 21 and the separation pad 25 by the rotation of the sheet feeding roller 21 by a drive system (not shown). Paper. Even if a plurality of sheets of recording paper are fed, the feeding roller 21
1 according to the relationship between the force set in the nip N portion between the sheet and the separation pad 25 and the relationship between the frictional force between the recording sheets P.
Only the recording paper is conveyed separately. Nip N
Is fed and conveyed to the registration roller 13 via the conveyance roller 27.

The paper separating and conveying mechanism comprising the paper feeding roller 21 and the separation pad 25 in the paper feeding unit 5 is a kind of the paper separating and conveying mechanism, and has a so-called corner claw which engages with a corner of the paper. Compared to the paper separation and transport mechanism, there is a restriction that the corner claws must be installed according to the paper width size, but it is advantageous in that separation and transport are performed regardless of the paper width size. .

[0010]

However, FIG.
In the configuration of the sheet feeding unit 5 shown in FIG. 1, for example, there is a problem as described below when feeding strongly stiff paper (postcard or the like). That is, when printing is performed on both sides of a sheet having a strong stiffness, the fixing roller 1 is used for image fixing when printing on one side.
The fixing heat is applied by 4 to easily curl the paper, and when printing on the other side, as shown in FIG. 11, the paper P in a curled state (this state is called lower curl) is fed. If the paper feed unit 5 is set on the bottom plate 22 of the apparatus unit 5 as it is, the paper feed unit 5 does not have a mechanism for suppressing the curl of the paper P. Therefore, when the paper is fed, as shown in FIG. When the part 22a moves upward,
Unlike the state in which the normal non-curled sheet is in contact with the lower surface of the sheet feeding roller 21, the lower upper end portion Pa of the lower curled sheet P is separated from the sheet feeding roller 21. Therefore, if the sheet feeding operation is performed as it is, the sheet is not fed to the predetermined nip N portion between the sheet feeding roller 21 and the separation pad 25, and a trouble occurs that the sheet is not normally fed.

Conventionally, the user removes the curl from the curled sheet P (to re-stiffen the sheet in a direction opposite to the curl direction so that the surface of the sheet becomes horizontal) in order to avoid the trouble. Is performed), and then set on the bottom plate 22.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a paper feeding device capable of properly feeding even curled paper without complicating the configuration. is there.

[0013]

In order to achieve the above object, according to the present invention, an end portion of a sheet stacking plate is lifted, and a sheet stacked on the sheet stacking plate is pressed against a sheet feeding roller. By the separation pad which presses the roller through the paper,
In a paper feeding device configured to be able to separate a plurality of papers one by one and convey the papers in a predetermined direction regardless of the paper width size, the paper loading plate near the paper feed roller and the paper loading plate are substantially arranged. At the upper limit position, a rib portion is provided in contact with the sheet surface substantially parallel to the sheet feeding direction. With this configuration, the lower curled sheet is curled by the rib portion and the sheet stacking plate during sheet feeding. Since the sheet is pressed and the leading edge is fed toward a predetermined nip position between the sheet feeding roller and the separation pad, an appropriate sheet feeding operation is always performed.

Further, according to the present invention, an end portion of a sheet stacking plate is lifted to press a sheet stacked on the sheet stacking plate against a sheet feed roller, and the separation pad is pressed against the sheet feed roller via the sheet. A sheet feeding device configured to be able to separate a plurality of sheets one by one regardless of the sheet width size and to convey the sheets in a predetermined direction; At a substantially upper limit position, a pressing member that elastically contacts the paper surface is provided.
The lower curled paper is always properly adjusted because the curl is pressed by the pressing member and the paper stacking plate at the time of paper feeding, and the leading end is fed toward a predetermined nip position between the paper feeding roller and the separation pad. The paper feeding operation is performed.

Further, according to the present invention, the pressing member includes a plate member made of a low friction material and a spring member for urging the plate member in the direction of the sheet stacking plate. When the paper is fed, the curl of the paper is pressed by the pressing member and the paper stacking plate, and the leading end is fed toward a predetermined nip position between the paper feed roller and the separation pad. Paper operation will be performed. Further, since the pressing member comes into contact with the paper with appropriate elasticity and frictional resistance, the paper surface is not damaged during paper feeding.

Further, according to the present invention, the sheet loaded on the sheet loading plate is raised by lifting the end of the sheet loading plate against a paper feed roller, and the separation pad is pressed against the paper feed roller via the sheet. Multiple sheets of paper 1 regardless of paper width size
In a sheet feeding device configured to be able to separate sheets one by one and convey the sheet in a predetermined direction, a leaf spring that contacts a sheet surface is provided above the sheet stacking plate near the sheet feeding roller and at a substantially upper limit position of sheet stacking. With this configuration, the lower curled sheet is pressed by the leaf spring and the sheet stacking plate at the time of sheet feeding, and the leading end is directed toward a predetermined nip position between the sheet feeding roller and the separation pad. Therefore, an appropriate sheet feeding operation is always performed. In addition, because the leaf spring contacts the paper with moderate elasticity,
There is no damage to the paper surface during paper feeding.

Further, according to the present invention, an end of the sheet stacking plate is lifted to press the sheet stacked on the sheet stacking plate against a sheet feed roller, and the separation pad is pressed against the sheet feed roller via the sheet. Multiple sheets of paper 1 regardless of paper width size
In a sheet feeding device configured to be able to be separated and transported in a predetermined direction one by one, the sheet surface is pressed by its own weight above the sheet stacking plate near the sheet feeding roller and at a substantially upper limit position of sheet stacking, In addition, a rotatable roller member is provided, and with this configuration, the lower curled sheet is curled by the roller member and the sheet stacking plate at the time of sheet feeding, and the leading end is formed by a sheet feeding roller, a separation pad, and the like. Is fed toward the predetermined nip position, so that an appropriate paper feeding operation is always performed. Further, since the roller member comes into contact with the paper with a constant load and an appropriate frictional resistance, the paper is fed smoothly and stably, and the paper surface is not damaged during the paper feeding.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Members corresponding to those described with reference to FIGS. 10, 11, and 12 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 1, FIG. 2, and FIG. 3 are views showing the configuration of a sheet feeding device for explaining a first embodiment of the present invention, in which a portion above a bottom plate 22, which is a sheet stacking plate, near a sheet feeding roller 21. The paper contact end surface 31a extends to the inner wall of the base case 30 provided on the case substrate 20 to a substantially upper limit position (indicated by a two-dot chain line L in the drawing) of the paper stack on the bottom plate 22; The contact end face 31a is in the paper feeding direction (arrow A direction)
A plurality of rib portions 31 that are substantially parallel to are provided side by side (one is shown in the front in the figure).

Then, as shown in FIG. 1, when the sheet P curled downward is set on the bottom plate 22, the sheet P is inserted between the bottom plate 22 and the rib portion 31. In the process of raising one end 22a of the bottom plate 22,
As shown in FIG. 2, the paper P is curled on the upper surface side by the paper contact end surface 31 a of the rib portion 31,
When further lifted by the bottom plate 22, as shown in FIG. 3, it is strongly pressed by the sheet contact end surface 31a and the bottom plate 22, curling is suppressed, and the state becomes almost horizontal with respect to the bottom plate 22, and the leading end (lower side) The upper end portion Pa is directed to a predetermined nip N position between the feed roller 21 and the separation pad 25. Therefore, when the paper feed roller 21 is driven to rotate, the leading end Pa of the paper P enters the nip N and a predetermined separation / conveyance operation is performed.

FIGS. 4, 5 and 6 are diagrams showing the configuration of a sheet feeding device for explaining a second embodiment of the present invention. The sheet feeding plate 21 is located above a bottom plate 22 near a sheet feeding roller 21. The paper contact end face 32a extends to the inner wall portion of the base case 30 provided on the case substrate 20 to a substantially upper limit position L of the paper stack on the bottom plate 22, and the paper contact end face 32
A plurality of leaf springs 32 each having a curved shape in which a is directed from the upstream to the downstream in the paper feeding direction A are arranged side by side (in the drawing, the front one is shown).

As shown in FIG. 4, when the lower curled sheet P is set on the bottom plate 22, the sheet P is inserted between the bottom plate 22 and the sheet contact end surface 32a of the leaf spring 32. In the process of raising one end 22a of the bottom plate 22 during paper feeding, as shown in FIG. As shown in FIG. 6, the paper is strongly pressed by the paper contact end surface 32a and the bottom plate 22, curl is suppressed, and the state is substantially horizontal with respect to the bottom plate 22, and the leading end Pa is set to the feed roller 2
1 and a predetermined nip N position between the separation pad 25. Therefore, when the paper feed roller 21 is rotationally driven, the leading end Pa of the paper P enters the nip N, and a predetermined separation and transport operation is performed.

During the paper feeding operation, the paper contact end surface 32a of the leaf spring 32 comes into contact with the surface of the paper P by an appropriate elastic force, so that the printing surface is not damaged by stripes or the like. Further, the sheet contact end surface 32a is formed in a curved shape whose end portion is directed from upstream to downstream in the sheet feeding direction A, and can contact the sheet P and escape upward in the sheet feeding direction when the sheet P is set. Therefore, there is no possibility of causing damage such as rubbing marks on the leading edge of the sheet during setting.

It is also conceivable to install a pressing member which makes elastic contact with the sheet instead of the leaf spring 32 without changing the above-mentioned conditions for installing the leaf spring 32. For example, at least the surface side which comes into contact with the sheet does not exhibit large frictional resistance. A pressing member including a paper contact plate member made of a friction material and a torsion spring for urging the paper contact plate member toward the bottom plate 22 may be provided. The action of the pressing member on the curled sheet is the same as that of the leaf spring 32, suppressing the curl, enabling appropriate sheet feeding, and without damaging the sheet P.

FIGS. 7, 8 and 9 are views showing the configuration of a sheet feeding device for explaining a third embodiment of the present invention, in which a portion above a bottom plate 22 which is a sheet stacking plate near a sheet feeding roller 21. An arm 33 having one end swingably supported on the inner wall of the base case 30 provided on the case substrate 20;
At the other end of the arm 33, a roller member 35 composed of a paper contact roller 34 rotatably supported is provided.
The roller member 35 is made of a low-friction material that does not exhibit a large frictional resistance at least on the surface of the arm member 33.
The arm body 33 hangs down in the direction of the bottom plate 22 due to its own weight.
The paper contact surface of the paper contact roller 34 is positioned at a substantially upper limit position L of the paper loading on the bottom plate 22 via the. A plurality of the roller members 35 having the above-described configuration are arranged side by side so that the longitudinal direction of the arm body 33 extends from the upstream to the downstream in the paper feeding direction A (in FIG. There).

As shown in FIG. 7, when the lower curled sheet P is set on the bottom plate 22, the sheet P is inserted between the bottom plate 22 and the sheet contact roller 34, and During the process of raising the one end 22a of the bottom plate 22, the curled upper surface of the sheet P is pressed by the sheet contact roller 34 under the weight of the arm 33, as shown in FIG. 22, the paper contact roller 34 and the bottom plate 2 are lifted as shown in FIG.
2, the curl is suppressed, the state is substantially horizontal with respect to the bottom plate 22, and the leading end Pa is directed to a predetermined nip N position between the feed roller 21 and the separation pad 25. Therefore, when the paper feed roller 21 is driven to rotate, the leading end Pa of the paper P enters the nip N and a predetermined separation / conveyance operation is performed.

During the paper feeding operation, the paper contact roller 34
Since the surface of the sheet P always comes into contact with the arm body 33 under its own weight with a constant load, stable and smooth sheet feeding with a constant transport load is performed. Further, the paper contact roller 34 is supported by the arm body 33 and can abut on the paper P and escape upward in the paper feeding direction when the paper P is set. There is nothing to cause.

[0028]

As described above, according to the paper feeder of the present invention, the curl is suppressed by the rib, the pressing member, the leaf spring, the roller member and the paper stacking plate when the curled paper is fed. Since the leading edge of the sheet can be reliably sent to a predetermined nip position between the sheet feeding roller and the separation pad, a good sheet feeding operation is always performed, and the reliability of sheet feeding is improved.

Further, since the pressing member or the leaf spring can be brought into contact with the paper with appropriate elasticity and frictional resistance, the paper surface is not damaged during paper feeding.

Further, since the roller member can be brought into contact with the paper with a constant load and an appropriate frictional resistance, the paper can be fed smoothly and stably, and the surface of the paper may be damaged during the paper feeding. Does not occur.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a sheet feeding device for describing a first embodiment of the present invention;

FIG. 2 is a configuration diagram illustrating a sheet feeding device for describing a first embodiment of the present invention;

FIG. 3 is a configuration diagram illustrating a sheet feeding device portion for describing a first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a sheet feeding device for explaining a second embodiment of the present invention;

FIG. 5 is a configuration diagram showing a sheet feeding device for explaining a second embodiment of the present invention;

FIG. 6 is a configuration diagram showing a sheet feeding device portion for describing a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a sheet feeding device for explaining a third embodiment of the present invention;

FIG. 8 is a configuration diagram showing a sheet feeding device portion for describing a third embodiment of the present invention.

FIG. 9 is a configuration diagram showing a sheet feeding device portion for describing a third embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a facsimile apparatus for explaining a conventional sheet feeding apparatus.

FIG. 11 is a diagram for explaining a problem when a curled sheet is fed in a conventional sheet feeding apparatus.

FIG. 12 is a diagram for explaining a problem when a curled sheet is fed in a conventional sheet feeding apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Case board 21 Feed roller 22 Bottom plate 22a One end of bottom plate 25 Separation pad 30 Base case 31 Rib 31a Paper contact end surface of rib 32 Plate spring 32a Paper contact end surface of plate spring 33 Arm body 34 Roller for paper contact 35 Roller Member N Nip between paper feed roller and separation pad P Paper L Maximum loading position

Claims (5)

[Claims] An end portion of the sheet stacking plate is lifted to press a sheet stacked on the sheet stacking plate against a sheet feed roller, and a separation pad is pressed against the sheet feed roller via the sheet.
In a paper feeding device configured to be able to separate a plurality of papers one by one and convey the papers in a predetermined direction regardless of the paper width size, the paper loading plate near the paper feed roller and the paper loading plate are substantially arranged. A sheet feeding device, wherein a rib portion is provided at an upper limit position to contact a sheet surface substantially parallel to a sheet feeding direction. 2. A separation pad which presses a sheet loaded on a sheet stacking plate by a sheet feeding roller by raising an end of the sheet stacking plate and presses the sheet stacking roller with the sheet via a sheet.
In a paper feeding device configured to be capable of separating a plurality of papers one by one and transporting the papers in a predetermined direction regardless of the paper width size, the paper loading plate near the paper feed roller and the paper stacking A sheet feeding device, wherein a pressing member elastically contacting a sheet surface is provided at an upper limit position. 3. The pressing member includes a plate member made of a low-friction material at least on a side elastically in contact with a sheet surface, and a spring member for urging the plate member in the direction of the sheet stacking plate. 2. The paper feeder according to 2. 4. The sheet loading plate is lifted up to press the paper loaded on the paper loading plate against a paper feed roller, and a separation pad is pressed against the paper feed roller via the paper.
In a paper feeding device configured to be able to separate a plurality of papers one by one and convey the papers in a predetermined direction regardless of the paper width size, the paper loading plate near the paper feed roller and the paper loading plate are substantially arranged. A sheet feeding device, wherein a leaf spring that contacts a sheet surface is provided at an upper limit position. 5. A separation pad which raises an end portion of a sheet stacking plate and presses a sheet stacked on the sheet stacking plate against a sheet feeding roller, and presses the sheet stacking roller with a sheet via a sheet.
In a paper feeding device configured to be capable of separating a plurality of papers one by one and transporting the papers in a predetermined direction regardless of a paper width size, the paper feeding device is provided above the paper loading plate near the paper feeding roller and in a paper loading direction. A sheet feeding device characterized in that a roller member that presses a sheet surface by its own weight and that is rotatable is provided at a substantially upper limit position.