JPH10291662A - Sheet material feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce sheet interval and raise speed of continuous feeding, by forming a rotational shaft of a sheet material back end detecting sensor for detecting the back end of a sheet material coaxially with a rotational shaft of a sheet feeder roller. SOLUTION: A rotational shaft of a document's back end detecting sensor 24 is formed coaxially with a rotational shaft of a sheet feeder roller 7. A document pressing member 25 for restraining a document 3 on a document loading table 5 is also formed. Thus, because the document's back end detecting sensor 24 is coaxial with the sheet feeder roller 7, distance between a feeding position and a sheet material back end detecting position is decreased. Therefore, during continuous sheet feeding, distance between a document which is being fed and its next one can be decreased extremely, feeding cycle is shortened, and system speed is increased. By always restraining a document on the document loading table 5 with a document pressing member 25, adequate feeding operation without faults can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically feeding a document to an image reading apparatus such as a scanner, a copying machine and a facsimile, or a method for feeding printing paper to an image forming apparatus such as a printer, a copying machine and a facsimile. More specifically, the present invention relates to a sheet material feeding device configured to separate sheet materials by a reverse roller.

[0002]

2. Description of the Related Art A conventional automatic sheet feeding apparatus (hereinafter referred to as ADF) for automatically feeding an original to an image reading apparatus will be described with reference to FIG. I will explain it. FIG. 3 is a sectional view showing a schematic configuration of a conventional sheet material feeding apparatus.

As shown in FIG. 3, an ADF 1 is placed on an original reading device 2, and includes an original tray 4, an original loading table 5 located downstream of a feed end of the original tray 4, and an original detection unit. A sensor 6, a paper feed roller 7 adjacent to the feed end of the document tray 4, a reverse roller 8 corresponding to the paper feed roller 7, and a document trailing end detection sensor provided downstream of the paper feed roller 7 9 and a transport roller 11 provided on a transport path 10 on the downstream side of the paper feed roller 7.
And a transport guide roller 1 corresponding to the transport roller 11
2, the transport roller 11 and the transport guide roller 12
The document leading / end detecting sensor 13 provided on the downstream side, the transport path 14 on the downstream side thereof, the contact glass 15 and the document flip-up section 16 provided on the transport path 14, and the transport path 17 on the downstream side A document ejection sensor 18 provided in the conveyance path 17, a conveyance guide roller 19, paper ejection rollers 20 and 21 provided near the end of the conveyance path 17, and a paper ejection tray 22. I have.

Here, a plurality of originals 3 are placed on the original tray 4. The document loading table 5 is raised so that the document 3 on the document tray 4 is brought into contact with the paper feed roller 7 when a paper feeding operation command is issued, and is lowered to an initial state after the paper feeding operation is completed.

The paper feed roller 7 transmits or releases the drive by a drive transmission switching means (not shown) such as an electromagnetic clutch. During the paper feed operation, the paper feed roller 7 is driven to rotate in the direction of arrow A in the figure. When the document 3 is conveyed by the conveyance roller 11 and the conveyance guide roller 12, the transmission of the drive by the drive control member described above is released, and only the frictional force with the document 3 moves in the direction of arrow A in the same manner as described above. Driven rotation,
When the trailing edge of the document further passes, the document rotates in the direction of arrow B due to the frictional force with the reverse roller 8.

The drive of the reverse roller 8 is transmitted by a drive control member (not shown) such as a one-way clutch. When two or more documents 3 are provided in the gap between the reverse roller 8 and the paper feed roller 7, a plurality of documents are fed. In order to prevent a phenomenon called double feed, which is called paper, the document rotates in the direction of arrow C in the figure and feeds the original 3 to be conveyed a plurality of times in the direction opposite to the conveying direction. When only one of the upper surfaces of the document 3 remains in the gap, the document 3 is rotated in the direction of arrow D by the frictional force with the document 3 conveyed by the paper feed roller 7. Further, as described above, after the drive transmission of the paper feed roller 7 is released and the document 3 has passed, the document is rotated again in the direction of arrow C.

The document trailing edge detection sensor 9 detects the trailing edge position of the document 3 that has been fed and conveyed. The transport guide rollers 12 and 19 are in pressure contact with the transport roller 11 by an elastic member (not shown) or the like.
The document 3 that has been fed and conveyed by the paper feed roller 7 due to the pinching force with the document 1 is conveyed further downstream in the conveying direction.

The document leading / ending sensor 13 detects the leading edge and the trailing edge of the document at the position indicated by the arrow E in FIG. The document discharge sensor 18 is provided immediately before the discharge rollers 20 and 21 that guide the document 3 onto a discharge tray 22 from which the document 3 is discharged, and detects positional information of the document 3 in the discharge unit.

The operation of the ADF 1 configured as described above will be described below. First, when the ADF 1 receives a start command sent from the image reading device 2, the document tray 4
When the original 3 placed above is raised to a position where the original 3 comes into contact with the paper feed roller 7 by the original loading table 5, only the uppermost sheet of the original 3 is fed into the transport path 10 by the paper feed roller 7 and the reverse roller 8. After being drawn in and passing through the transport path 14 by the transport roller 11 and the transport guide roller 12, the contact glass 15
It is conveyed while contacting. At this time, the image information of the document 3 is sequentially captured by a reading unit (not shown) in the image reading device 2 at a location indicated by an arrow F. Further, when the leading end of the document 3 is conveyed while being in contact with the document flip-up section 16 provided in the image reading device 2, the document 3 is drawn into the conveyance path 17 in the ADF 1 again, and is conveyed by the conveyance roller 11 and the conveyance guide. The sheet is received by the rollers 19 and is discharged onto the sheet discharge tray 22 by the sheet discharge rollers 20 and 21. Regarding the reading of the next original, it is determined that the preparation for receiving the next original is complete by obtaining the timing at which the rear end of the original 3 passes through the position indicated by the arrow G in the figure by the original trailing edge detection sensor 9. The instruction may be a command to start a document feeding operation.

[0010]

However, in order to shorten the time for continuously obtaining image information of a plurality of documents,
This can be achieved by shortening the interval between the original to be read and the next original. However, in the conventional ADF, the sheet feeding operation of the next original is started after the trailing end of the original is detected, and the interval between the originals is reduced. Must be at least the distance between the paper feed position and the document trailing edge detection position, which has been a problem with regard to the speeding up of continuous conveyance of a plurality of documents.

Regarding document separation by use of the reverse roller 8, when the document being transported is separated from the paper feed roller 7 and the reverse roller 8 and the paper feed roller 7 starts to rotate in the reverse direction to the transport direction, the paper feed roller When the original 7 comes in contact with the original 3 on the original loading table 5, the original 3 on the original loading table 5 is moved in a direction opposite to the transport direction, and the original to be fed at the time of feeding the next original There is a problem that the paper feed roller 3 and the paper feed roller 7 do not come into contact with each other, causing a paper feed error.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. In continuous feeding of a sheet material using a reverse roller system for separating the sheet material, the speed of the continuous feeding can be increased by reducing the sheet interval. It is another object of the present invention to provide a sheet feeding apparatus capable of performing a stable sheet feeding operation.

[0013]

In order to solve the above-mentioned problems, a sheet material feeding device according to the present invention comprises a sheet feeding roller for feeding and conveying a sheet material, and transmission or release of drive to the sheet feeding roller. A drive transmission switching unit, a reverse roller pressed by an elastic member to the sheet feeding roller to separate sheet materials one by one, and a reverse roller positioned downstream in a sheet material conveying direction in sheet material conveyance by the sheet feeding roller; A sheet material feeding device having a conveyance roller for conveying a sheet material conveyed by a sheet feeding roller further downstream, and a sheet material rear end detection sensor for detecting a rear end of the sheet material Is configured coaxially with the rotation axis of the sheet feeding roller, and the distance between the sheet feeding position and the sheet material rear end detection position is shortened.

According to the present invention, in the continuous feeding of the sheet material using the reverse roller method for separating the sheet material, it is possible to reduce the sheet interval and to obtain a high speed continuous feeding. Is obtained.

[0015]

According to the first aspect of the present invention, there is provided a paper feed roller for feeding and conveying a sheet material, a drive transmission switching means for transmitting or canceling a drive to the paper feed roller, A reverse roller that is pressed by a resilient member to a sheet feeding roller and separates sheet materials one by one; and a reverse roller that is positioned downstream in the sheet material conveying direction in sheet conveyance by the sheet feeding roller and is conveyed by the sheet feeding roller. A sheet material feeding device having a conveying roller for conveying the sheet material further downstream, wherein a rotation axis of a sheet material rear end detection sensor for detecting a rear end of the sheet material is connected to a sheet feeding roller. Constructed on the same axis as the rotation axis, shortening the distance between the sheet feeding position and the sheet material trailing edge detection position.Reduced sheet spacing for continuous sheet feeding using the reverse roller method for sheet material separation. To obtain the speed of the continuous feed has the effect that it becomes possible.

According to a second aspect of the present invention, there is provided a paper feed roller for feeding and conveying a sheet material, paper feed roller control means for controlling the driving of the paper feed roller, and an elastic member provided to the paper feed roller. A reverse roller that is pressed by the sheet roller to separate the sheet material one by one; and a sheet roller that is located downstream in the sheet material transport direction in the sheet material transport by the sheet feed roller, and further downstream of the sheet material that is transported by the sheet feed roller. A conveying roller for conveying the sheet material, a sheet material loading table for loading the sheet material and supplying the sheet material to the sheet feeding roller, and raising and lowering the sheet material of the sheet material loading table to feed the sheet material to the sheet feeding section. Claims 1. A sheet feeder having a sheet stacking platform elevating means for separating and contacting a roller, wherein the sheet restraining unit includes a member having a high coefficient of friction for constantly pressing a sheet on the sheet stacking table. Obtained by a structure having a member with respect to continuous feeding of the sheet material using the reverse roller type sheet material separating, it has the effect that a stable sheet feeding operation can be performed.

An embodiment of a sheet feeding apparatus according to the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing a schematic configuration of a sheet material feeding device according to Embodiment 1 of the present invention, and FIG. 2 shows a sheet material separating operation in the sheet material feeding device. It is a partial sectional view. In the above ADF, FIG.
The same reference numerals are given to the same components as those of the conventional ADF shown in FIG. In addition, conventional ADF
The description of the same operation as described above is omitted.

The ADF 23 according to the first embodiment shown in FIG.
However, the point different from the conventional ADF 1 is that the original trailing edge detection sensor 9 disposed immediately after the paper feed roller 7 installed in the conventional example is eliminated, and the original is coaxial with the rotation axis of the paper feed roller 7. The difference lies in that the rotation axis of the rear end detection sensor 24 is configured, and that the document holding member 25 for controlling the document 3 on the document loading table 5 is configured. As shown in FIG. 2, the rotation angle of the document trailing edge detection sensor 24 is regulated by an elastic member such as a spring 26.
Reference numeral 4 denotes a position where the light receiving portion of the photo sensor 27 is normally cut off.

The operation for separating the sheet material and detecting the rear end position of the sheet material according to the first embodiment will be described below in detail with reference to FIG.

First, as shown in FIG.
Rises, the original 3 comes in contact with the paper feed roller 7, and the reverse roller 8 suppresses the double feed of the original 3 to separate the original into one sheet.
Paper feed roller 7 is in the direction of arrow A, and reverse roller 8 is in the direction of arrow D.
When the sheet feeding operation is performed by rotating in the direction, the document trailing edge detection sensor 24 is at a position where the light receiving portion of the photo sensor 27 is shut off.

FIG. 2B shows a state in which the original 3 is transported by the transport rollers 11 and the transport guide rollers 12, and the drive transmission of the paper feed roller 7 is released.
At this time, the rotation of the paper feed roller 7 is in the direction of the arrow A as in FIG. 2A, and the position of the document trailing edge detection sensor 24 is also shown in FIG.
(A) It has not changed. Also, in this state, after the rear end of the original 3 has passed through the paper feed roller 7, the original loading tray 5 is moved so that the original 28 remaining on the original loading tray 5 does not come into contact with the paper feed roller 7. Has begun descent. However, when the timing of this lowering is delayed, the original 28 remaining on the original loading table 5 comes into contact with the paper feed roller 7, and the original 28 is moved in the direction opposite to the original transport direction, and the next paper feed There is a risk that a paper feed error may occur at the timing. Therefore, here, the document 28 on the document loading table 5 is always pressed by the document holding member 25 having a member having a high friction coefficient so that the document 28 does not move from the initially set position. Need to be kept.

FIG. 2C shows the moment when the rear end of the document 3 is separated from the paper feed roller 7 and the reverse roller 8, and from this time on, the paper feed roller 7 and the reverse roller 8 are shown.
Means that the original 3 is the transport roller 11 and the transport guide roller 1
2 is released, and the reverse roller 8 is moved in the direction of arrow C by the sheet feeding roller 7.
Is rotated in the direction of arrow B by the driving force of the reverse roller 8. At this moment, the document trailing edge detection sensor 24 starts to rotate in the direction of arrow H in the figure, and the light receiving portion of the photo sensor 27 is opened. At this timing, a state in which the next document can be fed is detected.

Next, in FIG. 2D, the document trailing edge detection sensor 24 is located in a fully open state with respect to the photo sensor 27, and a series of sheet feeding operations is completed to prepare for feeding the next document. Indicates a state in which is ready.

As described above, since the document trailing edge detection sensor 24 is provided coaxially with the paper feed roller 7, the distance between the sheet feeding position and the sheet material trailing edge detecting position is reduced, and the continuous In this case, the paper feeding cycle can be shortened by minimizing the interval between the original document being fed and conveyed and the next original document, and it is possible to cope with an increase in the speed of the system. Further, since the original 28 on the original loading table 5 is always suppressed by the original pressing member 25, it is possible to obtain an accurate paper feeding operation without a paper feeding mistake or the like.

[0026]

As is clear from the above description, according to the present invention, in the sheet feeding apparatus, the rotation axis of the sheet material rear end detection sensor is provided coaxially with the rotation axis of the sheet feeding roller.
Since the distance between the sheet feeding position and the sheet material trailing edge detection position is shortened, the sheet feeding cycle can be shortened, and the speed of the apparatus itself can be increased.

Further, according to the present invention, the sheet material on the sheet material loading table is always pressed by the sheet holding member formed of a member having a high coefficient of friction in the sheet material feeding device. Even if the response is taken, a stable paper feeding operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a sheet material feeding device according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing a sheet material separating operation in the sheet material feeding device.

FIG. 3 is a sectional view showing a schematic configuration of a conventional sheet material feeding apparatus.

[Explanation of symbols]

 2 Document Scanner 3 Document 4 Document Tray 5 Document Loading Table 6 Document Detection Sensor 7 Feed Roller 8 Reverse Roller 10 Transport Path 11 Transport Roller 12 Transport Guide Roller 13 Document Lead / Terminal Detection Sensor 14 Transport Path 15 Contact Glass 16 Document Bounce Raising unit 17 Conveyance path 18 Document discharge sensor 19 Conveyance guide roller 20 Discharge roller 21 Discharge roller 22 Discharge tray 23 Automatic document feeder 24 Document rear end detection sensor 25 Document suppressing member 26 Spring 27 Photo sensor

Claims (2)

[Claims] A feed roller that feeds and conveys a sheet material; a drive transmission switching unit that transmits or cancels a drive to the feed roller; and a sheet material pressed by the elastic member against the feed roller. A reverse roller that separates the sheet material by a feed roller, and a transport roller that is positioned downstream in the sheet material transport direction in the sheet material transport by the paper feed roller and transports the sheet material transported by the paper feed roller further downstream. And a rotation axis of a sheet material rear end detection sensor for detecting a rear end of the sheet material is coaxial with a rotation axis of a sheet feeding roller, and the sheet feeding position and the sheet A sheet material feeding device wherein a distance from a material trailing edge detection position is shortened. 2. A paper feed roller for feeding and transporting a sheet material, paper feed roller control means for controlling driving of the paper feed roller,
The sheet material is pressed against the paper feed roller by an elastic
A reverse roller for separating sheets one by one, and a transport for transporting the sheet material transported by the paper feed roller further downstream, which is located on the downstream side in the sheet material transport direction in the sheet material transport by the paper feed roller. A roller, a sheet material loading table on which the sheet material is placed and the sheet material is supplied to the sheet feeding roller, and a sheet material of the sheet material loading table is moved up and down, and the sheet material is separated from and connected to the sheet feeding roller. A sheet feeding apparatus having a sheet stacking table elevating means, comprising a sheet holding member formed of a member having a high coefficient of friction that constantly presses a sheet material on the sheet stacking table. Sheet material feeding device.