JP2000118827A - Paper conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper conveying device which prevents adequately the pulling back of papers exhausted on a paper exhaust board, in the reverse rotation time of an exhaust roller. SOLUTION: In this paper conveying device 20, plural flexible members 39 and 40 are provided in the condition having plural hanging down front end positions, as well as hanging down to the lower direction from the abutting position of an exhaust roller 29 and a pressure roller 35, at a document tray 30 side from the exhaust roller 29 to exhaust documents whose images are read in a document reading device, onto the document tray provided out of the device. As a result, even though numerous sheets of documents are loaded on the document tray 30 when the exhaust roller 29 is rotated in the reverse direction, the invasion of the documents to the abutting part of the exhaust roller 29 and the pressure roller 35 can be prevented securely by the flexible member pieces 39a, 39b, 40a, and 40b of the plural flexible members 39 and 40 having the different hanging down front end positions. The pulling back of the documents into the device by the exhaust roller 29 and the pressure roller 35 rotating reversely can be prevented securely, consequently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus, and more particularly, to a sheet conveying apparatus for appropriately preventing a sheet discharged onto a sheet discharge table from being pulled back when a discharge roller rotates in a reverse direction.

[0002]

2. Description of the Related Art In an image reading apparatus such as a facsimile apparatus or a copying apparatus or an image forming apparatus, a sheet on a sheet table is sent out by a pickup roller in a feed roller direction, and a feed roller and a separation member (for example, a separation roller, etc.) ) To separate the sheets one by one and transport them into the apparatus, and discharge the paper on which image reading or image formation has been performed in the apparatus by a discharge roller and a pressure roller onto a paper discharge table. I have. Then, the conventional paper transport device raises the pickup roller to a paper feedable position at which the paper can be fed out at the timing of feeding the paper on the paper mounting table in the direction of the feed roller, and feeds all the paper on the paper mounting table. When the paper and the discharge are completed, the pickup roller is lowered to the retreat position away from the paper feedable position.

[0003] A paper transport device includes a pickup roller, a feed roller, and a discharge roller as one driving source (for example,
Drive motor) to rotate the drive source forward to raise the pickup roller to a position where paper can be fed and to convey the paper. Also, by rotating the drive source in reverse, the pickup roller is rotated. It has been lowered to the standby position.

However, when the driving source is rotated in the reverse direction, the discharge rollers are also rotated in the reverse direction, and the paper discharged on the paper discharge table is pulled back into the apparatus.
When an electromagnetic clutch is provided to rotate the drive source in the reverse direction, the discharge roller and the drive source are separated by the electromagnetic clutch to prevent the discharge roller from rotating in the reverse direction and pulling back the sheet.

[0005] If the discharge roller is prevented from rotating in the reverse direction by using an electromagnetic clutch or the like, the cost of the sheet transport device, and eventually the image reading device and the image forming device, is increased, and the size of the device is increased.

In view of this, the present applicant has previously proposed a paper feeder which prevents the paper discharged to the paper discharge tray from being pulled back into the apparatus without providing an electromagnetic clutch or the like (Japanese Patent Application Laid-Open No. HEI 9-163568). No. 9-12196). As shown in FIGS. 5 and 6, the paper feed device is provided with a discharge roller 3 for discharging the paper 1 onto a paper discharge table 2 and a pressure roller 4 in contact with each other. The electromagnetic clutch that separates the drive motor and the discharge roller 3 during the reverse rotation has been removed, and the discharge roller 3 and the pressure roller 4 are located downstream of the discharge roller 3 and the pressure roller 4 in the sheet conveyance direction. The thin film 5 is disposed so as to hang downward. Although a plurality of the thin film films 5 are provided, all the thin film films 5 are formed to have the same length, and the hanging lower end position is the same position. In the paper feeding device, since the electromagnetic clutch is removed, when the drive motor is rotated in reverse to lower the pickup roller (not shown) from the paper possible position to the retracted position, the discharge roller 3 is also reversely rotated by the reverse rotation of the drive motor. Rotates,
The thin film 5 prevents the paper 1 discharged onto the paper discharge table 2 from being pulled back into the apparatus by the reverse rotation of the discharge roller 3 and the pressure roller 4 when the discharge roller 3 rotates in the reverse direction.

[0007] In FIGS. 5 and 6, the paper feeding device includes a transport roller 6 that transports the sheet 1 to the discharge roller 3,
A pressure roller 7 is provided in contact with the transport roller 6, and a reading unit (not shown) for reading an image of the sheet 1 is provided between the transport roller 6 and the discharge roller 3. The sheet feeding device includes a lower guide plate 8 and an upper guide plate 9.
The paper 1 is conveyed while being guided, and is ejected by the kicking member 10 fixed to the rotating shaft 3 a of the discharge roller 3 while the paper 1 is kicked onto the paper discharge table 2. Further, the paper feeder is provided with a static elimination brush 11 on a portion of the upper guide plate 9 facing the paper discharge table 2 to remove the electric charge on the paper 1 and improve the discharge performance of the paper 1. Let me.

[0008]

However, in the above-mentioned paper feeder, the discharge roller 3 in which the sheet 1 discharged onto the sheet discharge table 2 rotates reversely by the thin film 5 when the discharge roller 3 rotates reversely. However, as shown in FIG. 6, since all the thin film films 5 are formed to have the same length and are disposed so that their lower end positions are the same. When a large number of sheets 1 are discharged onto the sheet discharge table 2 and the upper end surfaces of the large number of sheets 1 placed above the hanging lower end position of the thin film 5 come up, all the thin films 5 Is in a state where the lower end of the paper has run on the upper surface of the uppermost sheet 1 and the discharge rollers 3
When is rotated in the reverse direction, the uppermost sheet 1 may be pulled back to the contact portion between the discharge roller 3 and the pressure roller 4 and may not be properly prevented from being pulled back into the apparatus.

In view of the above, the first aspect of the present invention is to dispose a sheet on which an image has been formed or an image has been read in the apparatus on a sheet discharge table side with respect to a discharge roller for discharging the sheet onto a sheet discharge table provided outside the apparatus. , While hanging downward from the contact position between the discharge roller and a driven roller that contacts the discharge roller,
By arranging a plurality of flexible members in a state in which the plurality of hanging tip positions are present, when the discharge roller is rotated in the reverse direction, a large number of sheets are placed on the sheet discharge table. However, the plurality of flexible members having different hanging tip positions reliably prevent the paper from entering the abutting portion between the discharge roller and the driven roller, and the discharge roller and the driven roller, which rotate the paper in the reverse direction, make it possible to prevent the paper from moving inside the apparatus. It is an object of the present invention to provide a sheet transporting device that can reliably prevent the sheet from being pulled back to the original.

[0010]

According to a first aspect of the present invention, there is provided a sheet transport device provided in a predetermined device for forming an image or reading an image, and feeds a plurality of sheets placed on a sheet placing table. A pickup roller, a feed roller that separates the sheets sent out by the pickup roller in contact with a separation member one by one, and transports the separated sheet into the apparatus, and an image forming or image forming apparatus in the apparatus that contacts a driven roller. A discharge roller that discharges the read sheet onto a paper discharge table disposed outside the apparatus, and a drive source that rotationally drives the pickup roller, the feed roller, and the discharge roller in forward and reverse directions. And picking up the paper on the paper mounting table by the pickup roller in accordance with the rotation of each roller in the normal rotation direction and the reverse rotation direction by the drive source. And a pickup roller moving mechanism for moving the paper feed position between the paper feed position and the retractable position away from the paper feed position in the roller direction. A plurality of flexible members that hang down below a contact position between the discharge roller and the driven roller, and the plurality of flexible members have a plurality of hang-down tip positions. The above-mentioned object is achieved by being disposed in a state where it exists.

According to the above construction, the paper on which the image formed or image read in the apparatus is discharged onto the paper discharge table provided outside the apparatus is closer to the paper discharge table, and the discharge roller is Since a plurality of flexible members are arranged in a state in which a plurality of the drooping tip positions are present and a plurality of flexible members are provided in a state in which the plurality of flexible members hang down below a contact position with a driven roller abutting on the discharge roller, Even when a large number of papers are placed on the paper discharge table when rotated in the reverse direction, the papers may be brought into contact with the discharge roller and the driven roller by a plurality of flexible members having different hanging tip positions. Intrusion can be reliably prevented, and the paper can be reliably prevented from being pulled back into the apparatus by the reverse rotation of the discharge roller and the driven roller.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 4 are views showing an embodiment of a sheet conveying apparatus according to the present invention. FIG. 1 is a view showing a sheet conveying apparatus 20 to which an embodiment of the sheet conveying apparatus according to the present invention is applied. It is a principal part side sectional view.

In FIG. 1, a paper conveying device 20 is applied to a document reading device such as a facsimile device, and a lower guide plate 21 is provided in a main body housing 20a of the document reading device as shown in FIG. A document conveying path 23 is defined by the upper guide plate 22. Lower guide plate 21 on the upstream side of the document conveying path 23 in the document conveying direction (rightward direction in FIG. 1).
Is a document placing table (sheet placing table) 24 on which a plurality of documents (sheets) 25 (see FIG. 4) are placed.

The paper transporting device 20 includes a document transporting path 23
A pickup roller 26, a feed roller 27, a transport roller 28, and a discharge roller 29 for sending out the document 25 on the document table 24 are sequentially disposed from upstream to downstream in the document transport direction. A document tray (sheet discharge table) 30 (see FIG. 4) is attached to the outer surface of the main body housing 20a on the 29 side. Usually, the document tray 30 is inclined with its leading end positioned higher than the discharge roller 29 in order to prevent the document 25 discharged onto the document tray 30 by the discharge roller 29 from dropping. It is arranged.

The pickup roller 26, the feed roller 27, the transport roller 28, and the discharge roller 29 are driven to rotate in the forward and reverse directions by a drive motor (not shown) as one drive source, and are driven to rotate in the forward direction. As a result, the original 25 is driven to rotate in a direction of transporting the original 25 from the original placing table 24 toward the original tray 30.

The upper guide plate 22 above the pickup roller 26 is provided with a pressing member 31 that comes into contact with the pickup roller 26.
When the drive motor rotates in the forward direction, the document 25 on the document table 24 is moved to a feedable position where the document 25 is sent out in the direction of the feed roller 27 by contacting the pressing member 31, and the drive motor rotates in the reverse direction. Is rotatably attached to a pickup roller moving mechanism (not shown) that moves to a retreat position separated from a sheet feedable position downward by rotating in the direction.

The feed roller 27 has an upper guide plate 22
The separation roller (separation member) 32 attached to the sheet is in contact with a predetermined pressure, and the feed roller 27 separates the document 25 sent out by the pickup roller 26 together with the separation roller 32 one by one. Transport in the direction.

A pressure roller 33 attached to the upper guide plate 22 is in contact with the transport roller 28, and the transport roller 28 transports the document 25 transported from the feed roller 27 toward the discharge roller 29. .

As shown in FIG. 2, a document reading sensor 34 is provided between the transport roller 28 and the discharge roller 29. The document reading sensor 34 includes, for example, a light source, a contact glass, and a photoelectric conversion device. 2. Description of the Related Art A contact-type image sensor having an element or the like is used. Document reading sensor 3
Reference numeral 4 reads an image of the document 25 conveyed to the discharge roller 29 by the conveyance roller 28 at a predetermined resolution.

A pressure roller 35 attached to the upper guide plate 22 is in contact with the discharge roller 29, and the discharge roller 29 is transported by the transport roller 28 and the original 25 whose image is read by the original reading sensor 34. Is discharged onto the document tray 30.

As shown in FIG. 3, the discharge roller 29 is fixed to a rotating shaft 29a.
It is rotatably supported by a slide bearing 36 attached to the lower guide plate 21 and a bearing (not shown), and is rotationally driven in a forward rotation direction and a reverse rotation direction by a drive motor via a gear mechanism (not shown). A pair of kicking members 37 are attached to the rotating shaft 29a. The kicking members 37 push the rear end of the document 25 discharged onto the document tray 30 by the discharge rollers 29, and place the document 25 on the document tray 30. Discharge while kicking.

As shown in FIG. 3, on the downstream side of the pressure roller 35 of the upper guide plate 22, a neutralization brush 38 is arranged side by side in the width direction of the original 25, and
5 and a pair of flexible members 39 sandwiching the discharge roller 29,
40 is disposed by a method such as bonding with its tip hanging downward (toward the discharge roller 29). Note that FIG.
In FIG. 7, a dashed line attached to the tip of the charge elimination brush 38 omits the state in which the charge elimination brush 38 is disposed along the dashed line, and the flexible member 39, The hatching attached to the upper guide plate 22 of 40 indicates a portion (adhesion portion) of the flexible members 39, 40 attached to the upper guide plate 22.

The pair of flexible members 39 and 40 have two flexible member pieces 39 in the horizontal direction (the width direction of the document 25) in a portion below a portion attached to the upper guide plate 22.
a, 39b and flexible member pieces 40a, 40b, and the flexible member piece 39a and the flexible member piece 40a
The flexible member piece 39b and the flexible member piece 40b are formed longer than the flexible member piece 40b, and the distal end position of the flexible member piece 39a and the flexible member piece 40a that is suspended below the flexible member piece 39b is flexible. It is disposed in a state that it is located below a tip position of the sex member 40b that hangs down. All of the flexible member pieces 39a, 39b, 40a, and 40b have their leading end positions hanging down below the pressing roller 35 and the discharging roller 2.
9 is disposed below the position where the contact member 9 contacts.

Each of the flexible members 39, 40 has its flexible member piece 39a, 39b, 40a, 40b positioned such that its tip is lower than the contact portion between the pressure roller 35 and the discharge roller 29. The document 25 discharged onto the document tray 30 by the discharge roller 29 and the pressure roller 35 is pressed against the discharge roller 29 when the discharge roller 29 is rotated in the reverse direction. This prevents the discharge roller 29, which enters the contact portion with the roller 35 and rotates in the reverse rotation direction, from being pulled back into the main body housing 20a. As the flexible members 39 and 40, for example, mylar or the like is used.

Next, the operation of the present embodiment will be described. When reading the original 25, when the original 25 is placed on the original placing table 24 and a reading instruction is given on an operation display unit (not shown), the control unit (not shown) causes the drive motor to rotate the drive motor in the normal rotation direction. By driving, the pickup roller 26, the feed roller 27, the transport roller 28, and the discharge roller 29 are driven to rotate in the normal rotation direction.

When the drive motor is driven to rotate in the normal direction, the pickup roller 26 is moved upward by a pickup roller moving mechanism (not shown) from a lower retreat position away from the press member 31 and contacts the press member 31. The lowermost document 25 among the plurality of documents 25 placed on the document table 24
Is sent out toward the feed roller 27.

The feed roller 27 separates the original 25 sent out by the pickup roller 26 from the separation roller 32.
And is separated one by one and transported to the transport roller 28,
The transport roller 28 transports the transported document 25 to the document reading sensor 34 in cooperation with the pressure roller 33. The document reading sensor 34 reads an image of the document 25 being conveyed at a predetermined resolution, and the document 25 that has passed the document reading sensor 34 is conveyed to the discharge roller 29.

The discharge roller 29 is used to transport the original 2
5 is discharged onto the document tray 30 together with the pressure roller 35. At this time, the rotation shaft 29a of the discharge roller 29
Since the kicking member 37 is attached, the original 25
Is discharged onto the document tray 30 with its rear end kicked off by the kicking member 37.

The document 25 is conveyed sequentially, and when the conveyance of all the documents 25 placed on the document table 24, the reading of the image, and the discharge to the document tray 30 are completed, the sheet conveying device 20 Drives the drive motor in the reverse direction to rotate the pickup roller 26, the feed roller 2
7. The transport roller 28 and the discharge roller 29 are rotated in the reverse rotation direction, and the pickup roller 26 is moved by the pickup roller moving mechanism to a retracted position below the holding member 31.

At this time, as described above, the discharge roller 29
Is also rotated in the reverse direction, and among the plurality of originals 25 discharged and placed on the original tray 30, the uppermost original 25
Is pulled back in the direction of the discharge roller 29 due to the inclination of the document tray 30 and tries to enter the contact portion between the discharge roller 29 and the pressure roller 35. The flexible member pieces 39 a, 39 b, 4, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, 4 b, and 14 d are positioned below the contact position between the discharge roller 29 and the pressure roller 35.
Since the flexible members 39 and 40 provided with the originals 0a and 40b are attached,
5, the discharge rollers 2 are provided by the flexible members 39 and 40.
It can be appropriately prevented from entering the contact portion between the pressure roller 9 and the pressure roller 35, and can be appropriately prevented from being pulled back into the main body housing 20a by the discharge roller 29 rotated in the reverse rotation direction.

In particular, even when the number of the originals 25 discharged and placed on the original tray 30 increases, the flexible members 39 and 40 have different downwardly depending tip positions, that is, different positions. , Flexible member pieces 39a, 39 having different lengths
b, 40a, and 40b, the longer flexible member pieces 39a and 40a, for example, can be mounted on the upper surface of the document 25 as shown in FIG. The original 25 does not ride on the upper surface of the original 25 and the original 25
The document 25 is reliably prevented from entering the contact portion of the main body 2 with the discharge roller 29 rotating in the reverse direction.
0a can be reliably prevented from being pulled back.

As described above, the paper transporting device 20 of the present embodiment uses the document 25 rather than the discharge roller 29 for discharging the document 25 read in the document reading device onto the document tray 30 provided outside the device. On the tray 30 side, the discharge roller 2
9 and the pressure roller 35 which abuts on the discharge roller 29, and hangs downward in a downward direction.
40 are arranged.

Therefore, when the discharge roller 29 is rotated in the reverse direction, a large number of originals 25 are placed on the original tray 30.
Are placed, the flexible member pieces 39a, 39b, 40 of the plurality of flexible members 39, 40 having different hanging tip positions.
The original 25 is ejected by the discharge roller 29 and the pressure roller 3 at a and b.
5 can be reliably prevented from entering the contact portion, and the document 25 can be reliably prevented from being pulled back into the apparatus by the reverse rotation of the discharge roller 29 and the pressure roller 35.

As described above, the invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in the above embodiment, a pair of flexible members 39 and 40 are provided, and the flexible members 39 and 40 are provided with flexible member pieces 39a and 3a having different lengths.
Although 9b, 40a, and 40b are formed, the flexible member is not limited to the above-described configuration.
A plurality of flexible members having different lengths may be provided, and the number of flexible members is not limited at all. Further, the length of the flexible member is not limited to two types, and can be set appropriately as long as it is two or more types.

Further, the method of making the position of the tip of the flexible member different is not limited to the method of making the lengths different from each other as in the above-described embodiment. The mounting may be performed by changing the mounting position, for example, the mounting position on the upper guide plate 22.

Further, in the above-described embodiment, the case where the paper conveying device is applied to the image reading device has been described. The present invention can be similarly applied to an image forming apparatus.

[0039]

According to the paper transport apparatus of the first aspect of the present invention, the paper on which an image has been formed or an image has been read in the apparatus is more discharged than the discharge roller which discharges the paper onto a paper discharge table provided outside the apparatus. On the discharge table side, while hanging downward from the contact position between the discharge roller and a driven roller that comes into contact with the discharge roller, in a state where there are a plurality of the hanging tip positions, the plurality of flexible members are When the discharge roller is rotated in the reverse direction, even if a large number of papers are placed on the paper discharge table, the papers can be suspended by the plurality of flexible members having different tip positions. It is possible to reliably prevent the discharge roller and the driven roller from entering the contact portion, and to reliably prevent the sheet from being pulled back into the apparatus by the discharge roller and the driven roller rotating in the reverse direction.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view of a main part of a paper transport device to which an embodiment of the paper transport device of the present invention is applied.

FIG. 2 is a perspective view of a main part of the paper transport device of FIG. 1 with an upper guide plate being opened;

FIG. 3 is an enlarged perspective view of a discharge roller and a pressure roller of FIG. 1;

FIG. 4 is a front sectional view of a discharge roller, a pressure roller, and a document tray of FIG. 1;

FIG. 5 is an enlarged perspective view of a discharge roller and a pressure roller of a conventional sheet feeding device.

FIG. 6 is a front sectional view of a discharge roller, a pressure roller, and a sheet discharge table portion of the conventional sheet feeding device of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 paper transport device 20 a body housing 21 lower guide plate 22 upper guide plate 23 document transport path 24 document placement table 25 document 26 pickup roller 27 feed roller 28 transport roller 29 discharge roller 29 a rotation axis 30 document tray 31 pressing member 32 separation roller 33 pressure roller 34 document reading sensor 35 pressure roller 36 sliding bearing 37 kicking member 38 static elimination brush 39, 40 flexible member 39a, 39b, 40a, 40b flexible member piece

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) LA16 LC22 LD10 5C062 AB32 AB35 AD06 BA00

Claims (1)

[Claims] A pickup roller provided in a predetermined device for forming an image or reading an image, and for sending out a plurality of sheets placed on a sheet placing table; 1
A feed roller that separates the sheets one by one and conveys them into the apparatus, and discharges the sheet on which an image has been formed or image read in the apparatus by contacting a driven roller onto a sheet discharge table disposed outside the apparatus. A discharge roller, a drive source that drives the pickup roller, the feed roller, and the discharge roller to rotate in the normal rotation direction and the reverse rotation direction, and the drive source rotates the respective rollers in the normal rotation direction and the reverse rotation direction. A sheet comprising: a pickup roller moving mechanism for moving a pickup roller to a sheet-supplyable position at which the sheet on the sheet-mounting table can be fed in the direction of the feed roller; In the transport device, the paper discharge table is closer to the sheet discharge table than the discharge roller, and is suspended downward from a contact position between the discharge roller and the driven roller. That a plurality of flexible members disposed, said plurality of flexible members, the sheet conveying apparatus characterized by the pendent tip position is disposed in a state where there exist a plurality.