JP4447745B2 - Sheet conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying apparatus that conveys a sheet, and is applied to, for example, an image reading apparatus and an image forming apparatus such as an image scanner, a facsimile, a multifunction printer, and a copying machine.
[0002]
[Prior art]
FIG. 7 shows an example of a conventional representative apparatus for a document movement type image reading apparatus having a contact type sensor such as an image scanner, a facsimile, or a multifunction printer.
[0003]
The image reading apparatus 1 is installed on the upper part of the image forming apparatus 2.
[0004]
The image reading apparatus 1 includes a document feeding device including a document stacking tray 4, a pickup roller 5, and a separation pad 6.
[0005]
The document (sheet) 3 is set on the document stacking tray 4 with the image surface facing upward (face up), and is picked up by the pickup roller 5.
[0006]
A separation pad 6 formed of a member having a high coefficient of friction such as rubber or cork is pressed against and brought into pressure contact with the pickup roller 5 by a spring (not shown), and a plurality of sheets stacked on the document stacking tray 4 are pressed. When the original 3 is picked up, only the uppermost original 3 is separated and fed, and the original 3 is conveyed to the conveying roller 7 and the conveying roller 8.
[0007]
Thereafter, the document 3 changes its traveling direction along the substantially U-shaped conveyance path 12 and is conveyed to the image reading unit.
[0008]
The image reading unit includes a contact image sensor 9 which is a contact type sensor, and photoelectrically reads a document image of the document 3 being conveyed, in close contact with the contact image sensor 9.
[0009]
The original 3 from which the original image has been read is discharged by a paper discharge roller 13 and a paper discharge roller 14 onto a document discharge tray 15 disposed substantially parallel to the document stacking tray 4 with the image surface facing downward (face down). The
[0010]
[Problems to be solved by the invention]
However, in the case of the prior art as described above, the following problems have occurred.
[0011]
In the conventional image reading apparatus, as shown in FIG. 7, since a substantially U-shaped conveyance path is used as a conveyance path for conveying a document, for example, thick paper, photographs, etc. are thick and When handling a strong original, the guide wall surface of the substantially U-shaped conveyance path and the original are strongly rubbed to cause a large conveyance resistance, leading to a jam in which the original cannot be conveyed well and the conveyance of the original is delayed.
[0012]
Further, in the case of originals such as thick paper and photographs, the shape of the substantially U-shaped conveyance path may follow, and the original discharged outside the apparatus after image reading may be curled.
[0013]
Further, in originals such as thick paper and photographs, the guide wall of the substantially U-shaped conveyance path and the original are rubbed strongly, and the image surface of the original discharged outside the apparatus after image reading may be damaged. .
[0014]
Further, since originals such as thick paper and photographs require a large conveying force, the pressure contact force of the separation pad to the pickup roller is a load, and this original may not be picked up.
[0015]
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to provide a sheet conveying apparatus, an image reading apparatus, and a sheet conveying apparatus that can convey a strong sheet with a large thickness. And providing an image forming apparatus.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, in the sheet conveying apparatus of the present invention, a sheet stacking unit for stacking sheets, a pickup roller for feeding sheets from the sheet stacking unit, and the pickup in pressure contact with the pickup roller A separation member that separates the sheets fed by the roller into one sheet, a separation feeding means that separates and feeds the sheets stacked on the sheet stacking means one by one, and a sheet feeding from the separation feeding means In a sheet conveying apparatus provided with a linear conveying path for conveying a fed sheet and a curved conveying path connected downstream of the linear conveying path, the sheet conveyed through the linear conveying path is used as it is. with an open door to be opened to the upstream portion of the curved conveying path to discharge to the outside, in conjunction with opening and closing of the open door, and pressed to the pickup roller of the separating member, the Wherein said separating member closing the open door is pressed against to the pick-up roller, and cancels the pressure to the pickup roller of the separation member to the open time of the open door.
[0017]
A sheet stacking unit configured to stack sheets; a pickup roller that feeds a sheet from the sheet stacking unit; a separation member that presses against the pickup roller and separates the sheet fed by the pickup roller; A separation feeding unit that separates and feeds the sheets stacked on the sheet stacking unit one by one, a linear conveyance path that conveys the sheet fed from the separation feeding unit, and the linear shape In a sheet conveying apparatus having a curved conveying path connected downstream of the conveying path, the upstream portion of the curved conveying path is opened so that the sheet conveyed through the linear conveying path is discharged out of the apparatus as it is. An open door that enables the opening and closing of the open door and the pressure contact of the separation member to the pickup roller, the pressure contact force of the separation member to the pickup roller is: Characterized in that provided variably in accordance with the opening angle of the serial open door.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.
[0028]
(First embodiment)
The case where the sheet conveying apparatus of the present invention is applied to an image reading apparatus will be described with reference to FIGS.
[0029]
FIG. 1 is a schematic cross-sectional view showing an image reading apparatus according to the first embodiment.
[0030]
The image reading apparatus 1 is installed on the upper part of the image forming apparatus 2.
[0031]
The document 3 as a sheet is set on the document stacking tray 4 as a sheet stacking unit so that the image surface faces upward (face-up), and is picked up from the uppermost document 3 by a pickup roller 5 as a pickup roller.
[0032]
A separation pad 6 as a separation member formed of a member having a high coefficient of friction such as rubber or cork is disposed at a position opposite to the pickup roller 5 and is urged by the pickup roller 5 by a spring (not shown). Yes.
[0033]
The separation pad 6 separates the document 3 and feeds only the uppermost document 3 into the apparatus main body when a plurality of documents 3 are overlapped and fed (multiple feed) by the pickup roller 5.
[0034]
The document 3 conveyed into the apparatus main body is sent to the image reading unit by the conveyance roller 7 and the conveyance roller 8. In this image reading unit, the original 3 is photoelectrically read from the original image on the original 3 by a contact image sensor 9 as an image reading means.
[0035]
Thereafter, the paper is further conveyed by a face-up paper discharge roller 10 and a face-up paper discharge roller 11.
[0036]
Here, the conveyance path on which the conveyance roller 7, the conveyance roller 8, the contact image sensor 9, the face-up discharge roller 10, and the face-up discharge roller 11 are arranged is a linear conveyance path.
[0037]
Then, the document 3 is conveyed from the face-up discharge roller 10 and the face-up discharge roller 11 to a substantially U-shaped conveyance path 12 as a curved conveyance path connected downstream of the linear conveyance path, and is substantially U-shaped. The direction of travel is changed along the conveyance path 12, and the paper is sent to the paper discharge unit by the face-down paper discharge roller 13 and the face-down paper discharge roller 14.
[0038]
A document discharge tray 15 is disposed in the sheet discharge portion substantially parallel to the document stacking tray 4, and the document 3 is discharged face down (image down).
[0039]
Here, the image reading apparatus 1 is provided with a face-up door 16 as an open door that can open the upstream portion of the substantially U-shaped conveyance path 12.
[0040]
For this reason, for example, when handling a thick original 3 such as thick paper or a photograph, the face-up door 16 is opened. Then, the conveyance path through which the document 3 is conveyed is only a linear conveyance path to the face-up discharge roller 10 and the face-up discharge roller 11, and the document 3 obtained by photoelectrically reading the document image by the contact image sensor 9 is After passing through the face-up paper discharge roller 10 and the face-up paper discharge roller 11, the paper is discharged from the opening portion where the face-up door 16 is opened to the outside of the apparatus with the image surface facing upward (face-up) without changing the traveling direction.
[0041]
2 and 4 are sectional views of the vicinity of the pickup roller and the face-up door of the image reading apparatus according to the first embodiment, and FIGS. 3 and 5 are similarly bottom views.
[0042]
A separation pad 6 formed of a member having a high friction coefficient such as rubber or cork is urged against the pickup roller 5 by a spring or the like (not shown).
[0043]
As described above, the separation pad 6 separates the document 3 and feeds only the uppermost document 3 into the apparatus main body when a plurality of documents 3 are overlapped and fed (multiple feed) by the pickup roller 5. .
[0044]
However, when handling thick originals 3 such as thick papers and photographs and a strong paper, a larger conveying force is required as compared with the case of using normal papers. In the state of being in press contact with 5, the press contact force of the separation pad 6 to the pickup roller 5 may become a load and the document 3 may not be picked up.
[0045]
In order to prevent this, when handling a thick original 3 such as thick paper or a photograph, the pressure contact force of the separation pad 6 to the pickup roller 5 is released, and the original 3 is fed one by one. There is a need to.
[0046]
Therefore, in this embodiment, the opening / closing of the face-up door 16 and the pressure urging / releasing mechanism of the separation pad 6 (that is, the pressure contact of the separation pad 6) are interlocked.
[0047]
That is, the face-up door 16 is interlocked with the separation pad 6 through components such as the pressure release rod 17, the pressure release link 18, and the pressure release slider 19.
[0048]
For this reason, the user opens the face-up door 16 at the rear of the image reading apparatus when handling a thick original 3 such as thick paper or a photograph, which is thick.
[0049]
Then, as shown in FIGS. 4 and 5, the pressure release rod 17 is pulled, the pressure release link 18 rotates, and the pressure release slider 19 slides to apply the pressure contact force of the separation pad 6 to the pickup roller 5. It is configured to cancel.
[0050]
When normal paper is passed by face-down paper discharge, when the face-up door 16 is closed, the separation pad 6 is again urged against the pickup roller 5 and the separation pad 6 is pressed against the pickup roller 5. The
[0051]
As described above, the face-up door 16 that can open the upstream portion of the substantially U-shaped conveyance path 12 of the image reading apparatus 1 is provided, and the discharge destination is switched according to the thickness and the strength of the original 3. As a result, the image reading apparatus 1 can handle various documents 3.
[0052]
In particular, the thick and strong original 3 is opened by the face-up door 16 at the upstream portion of the substantially U-shaped conveyance path 12 and is discharged to the outside as it is conveyed through the linear conveyance path. be able to.
[0053]
For this reason, even if the thick and strong original 3 is conveyed, the guide wall of the conveyance path and the original 3 are strongly rubbed on the linear conveyance path, so that a large conveyance resistance does not occur. 3 is prevented from being jammed because the document 3 cannot be transported well. In addition, it is possible to prevent the original 3 from becoming the shape of the conveyance path and curling the original 3 discharged to the outside of the apparatus. Further, since the guide wall surface of the conveyance path and the document 3 are rubbed strongly, the document 3 discharged out of the apparatus is prevented from being damaged.
[0054]
On the other hand, when a normal document 3 is read, the document 3 is fed face-up and discharged face-down, so that even when a plurality of documents 3 are fed continuously, the order of the documents 3 overlaps. The document 3 can be discharged without changing the above.
[0055]
(Second Embodiment)
FIG. 6 shows a second embodiment. Here, only the characteristic part is shown, and since other configurations and operations are the same as those of the first embodiment, the same constituent parts are denoted by the same reference numerals, and the description thereof is omitted.
[0056]
In FIG. 6, the pressure contact force of the separation pad 6 to the pickup roller 5 is variable according to the opening angle of the face-up door 16.
[0057]
As a result, the user can change the opening angle of the face-up door 16 and change the pressure contact force of the separation pad 6 to the pickup roller 5, and the type of document 3 (the thickness of the document 3 and the strength of the strain). ), It is possible to set the optimum pressure contact force of the separation pad 6 to the pickup roller 5.
[0058]
Therefore, when the various documents 3 are discharged to the outside of the apparatus after the face-up door 16 is opened and conveyed through the linear conveyance path, the pressure contact force of the separation pad 6 to the pickup roller 5 is optimal according to the document 3. In this way, the separation and feeding performance can be stabilized, and a plurality of documents 3 can be set on the document stacking tray 4 and separated and fed.
[0059]
In the above embodiment, the image reading apparatus to which the sheet conveying apparatus of the present invention is applied has been described. However, the present invention is not limited to this, and the sheet conveying apparatus similarly forms an image on a sheet conveyed through a linear conveying path. It may be an apparatus for processing a sheet conveyed through a linear conveyance path, such as an image forming apparatus such as a facsimile, a multi-function printer, a copying machine or the like that forms an image by means (inkjet method, electrophotographic method, etc.).
[0060]
【The invention's effect】
As described above, the present invention is provided with an open door that allows the upstream portion of the curved conveyance path to be opened so that the sheet conveyed on the linear conveyance path can be directly discharged out of the apparatus. A thick and strong sheet can be discharged out of the apparatus as it is after being transported through the straight conveyance path by opening the upstream part of the curved conveyance path with an open door. Can be conveyed.
[0061]
For this reason, even when a thick and strong sheet is conveyed, the guide wall of the conveyance path and the sheet are strongly rubbed in the linear conveyance path, so that a large conveyance resistance does not occur. Can be prevented from jamming and the sheet conveyance is delayed. Further, it is possible to prevent the sheet from becoming the shape of the conveyance path and curling the sheet discharged out of the apparatus. Further, since the guide wall surface of the conveyance path and the sheet are rubbed strongly, it is possible to prevent the sheet discharged from the apparatus from being damaged.
[0062]
The opening / closing of the open door and the pressure contact of the separating member to the pickup roller are linked to bring the separating member into pressure contact with the pickup roller when the open door is closed and release the pressure contact of the separating member to the pickup roller when the open door is opened. Therefore, when the sheet having a large thickness and strong stiffness is discharged from the apparatus as it is after the upstream portion of the curved conveyance path is opened by the open door and the linear conveyance path is conveyed, Since the pressure contact with the pickup roller is released, the pressure contact force of the separation member against the pickup roller can be prevented from being a load, and a thick and strong sheet that requires a large conveying force is fed. can do.
[0063]
The opening and closing of the open door and the press contact of the separating member to the pickup roller are interlocked, and the press contact force of the separating member to the pickup roller is variably provided according to the opening angle of the open door, When the upstream part of the curved conveyance path is opened with an open door, and the sheet is conveyed out of the apparatus after being conveyed through the linear conveyance path, the separation member is pressed against the pickup roller depending on the thickness and strength of the sheet. Since the force is varied according to the opening angle of the open door, the sheet can be separated and fed by the pressing force of the separating member corresponding to the sheet to the pickup roller.
[0064]
A sheet conveying apparatus and an image reading unit that reads an image of a sheet conveyed through the linear conveying path of the sheet conveying apparatus, so that even if the sheet is thick and strong, the linear conveying path Can be read by the image reading means, the upstream portion of the curved conveyance path can be opened by the open door, and the sheet can be discharged out of the apparatus after being conveyed through the linear conveyance path.
[0065]
A sheet conveying device and an image forming unit that forms an image on a sheet conveyed through a linear conveying path of the sheet conveying device, so that even a thick and strong sheet can be conveyed linearly. An image can be formed by the image forming means when being transported on the path, the upstream portion of the curved transport path is opened by an open door, and the straight transport path can be discharged to the outside after being transported.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an image reading apparatus according to a first embodiment.
FIG. 2 is a cross-sectional view showing the vicinity of a pickup roller and the face-up door when the face-up door is closed in the image reading apparatus according to the first embodiment.
FIG. 3 is a bottom view showing the vicinity of the pickup roller and the face-up door when the face-up door is closed in the image reading apparatus according to the first embodiment.
FIG. 4 is a cross-sectional view showing the vicinity of the pickup roller and the face-up door when the face-up door of the image reading apparatus according to the first embodiment is opened.
FIG. 5 is a bottom view showing the vicinity of the pickup roller and the face-up door when the face-up door is opened in the image reading apparatus according to the first embodiment.
FIG. 6 is a schematic cross-sectional view showing an image reading apparatus according to a second embodiment.
FIG. 7 is a schematic cross-sectional view showing a conventional image reading apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Image forming apparatus 3 Document 4 Document stacking tray 5 Pickup roller 6 Separation pad 7 Transport roller 8 Transport roller 9 Contact image sensor 10 Face-up discharge roller 11 Face-up discharge roller 12 Approximate U-shaped transport path 13 Face-down delivery roller 14 Face-down delivery roller 15 Document delivery tray 16 Face-up door 17 Pressure release rod 18 Pressure release link 19 Pressure release slider

Claims (4)

Sheet stacking means for stacking sheets;
A pickup roller that feeds the sheet from the sheet stacking unit; and a separation member that presses the pickup roller and separates the sheet fed by the pickup roller into one sheet, and is stacked on the sheet stacking unit Separating and feeding means for separating and feeding the separated sheets one by one;
A linear conveyance path for conveying the sheet fed from the separation feeding means;
A curved conveyance path connected downstream of the linear conveyance path, and a sheet conveyance apparatus comprising:
An open door that allows the upstream portion of the curved conveyance path to be opened so that the sheet conveyed through the linear conveyance path is discharged out of the apparatus as it is ;
The opening / closing of the open door and the press contact of the separating member to the pickup roller are interlocked,
The sheet conveying device , wherein the separation member is pressed against the pickup roller when the open door is closed, and the pressure contact of the separation member against the pickup roller is released when the open door is opened . Sheet stacking means for stacking sheets;
A pickup roller that feeds the sheet from the sheet stacking unit; and a separation member that presses the pickup roller and separates the sheet fed by the pickup roller into one sheet, and is stacked on the sheet stacking unit Separating and feeding means for separating and feeding the separated sheets one by one;
A linear conveyance path for conveying the sheet fed from the separation feeding means;
A curved conveyance path connected downstream of the linear conveyance path, and a sheet conveyance apparatus comprising:
An open door that allows the upstream portion of the curved conveyance path to be opened so that the sheet conveyed through the linear conveyance path is discharged out of the apparatus as it is ;
The opening / closing of the open door and the press contact of the separating member to the pickup roller are interlocked,
The sheet conveying apparatus according to claim 1, wherein a pressure contact force of the separating member to the pickup roller is variably provided according to an opening angle of the opening door . The sheet conveying device according to claim 1 or 2 ,
An image reading apparatus comprising: an image reading unit that reads an image of a sheet conveyed through the linear conveyance path of the sheet conveying apparatus. The sheet conveying device according to claim 1 or 2 ,
An image forming apparatus comprising: an image forming unit configured to form an image on a sheet conveyed through the linear conveying path of the sheet conveying apparatus.

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