JP3359162B2 - Automatic document feeder and image forming apparatus having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder applicable to an image forming apparatus such as a copying machine and a laser beam printer, and an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, similarly to FIGS. 2 and 3 showing an automatic document feeder according to the present invention, a document P is provided in an image forming apparatus such as a copying machine and the like. In the automatic document feeder, the document placing table 5 is located at the ascending position, transports the document P to the endless belt 20, and then reverses the belt and discharges it to the document placing table 5, There is known a document tray having a closed path in which the document table 5 is positioned at a lowered position, conveys the document P to the endless belt 20, rotates in one direction via a reading position, and discharges the document P to the document table 5. ing. As shown in FIG. 7, the document table 5 has a pair of notches 5i at the end in the closed path conveyance direction. When the document table 5 descends and takes the closed path, the second A circular portion of the feed roller (paper feed roller) 36 is exposed from the document table 5. Then, the second delivery roller 3
As the document 6 rotates, the lowest document P in the document bundle placed on the document table 5 is transported.

[0003]

However, in the above-mentioned conventional example, since the document table 5 has the notch 5i for exposing the second feed roller 36, the notch 5i is exposed to dust or the like. Will enter. for that reason,
This causes a jam when feeding the paper or causes a failure of the automatic document feeder 2.

SUMMARY OF THE INVENTION Accordingly, the present invention provides an automatic document feeder and an image forming apparatus using the same, in which a roller shutter is provided at each of a pair of notches at an end of the document table in a closed path direction. It is intended for.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances.
A document placement table on which a document can be placed, and a document separated and supplied one by one, further transporting the document to a reading position, and discharging the document onto the document placement table In an automatic document feeder, comprising: a conveying unit, and a paper feed roller that feeds the original on the original mounting table toward a supply / separation unit of the original conveying unit. and lifting means for lifting the raised position and the lowered position, it is rotatably supported on the document table, and the document
A roller shutter biased so as to be substantially flush with the mounting table, and a shutter moving means for rotating the roller shutter so that the paper feed roller is exposed when the document mounting table is at a lowered position. And on the original table.
When the original is taken out, the roller shutter is
The document is configured to be able to rotate and grip the original.
And an automatic document feeder.

[0006] Preferably, a projection is formed on the upper surface of the roller shutter at an interval where a finger can enter.

Further, the document conveying means conveys the document to the reading position on the platen, and conveys the document on the document mounting table to the endless belt. After the conveyance, the belt is reversed, and a switchback path for discharging the document onto the document table, and the document on the document table is conveyed to the endless belt.
A closed path that rotates in one direction via the reading position and discharges the document onto the document table, and when the document table is at the raised position, switches the document from one end thereof to the switchback. Supply to the supply / separation section of the path,
Further, when the document table is at the lowered position, the document is supplied from the other end to the supply / separation unit of the closed path, and the roller shutter is provided at the other end of the document table. Good.

The present invention provides an automatic document feeder,
Image forming means for reading the document at a reading position on the platen, and forming an image with the read image information;
The present invention is similarly applied to an image forming apparatus including sheet material feeding means for feeding a sheet material one by one, transferring an image formed in the image forming means to the sheet material, and discharging the sheet material. .

[0009]

According to the above arrangement, when the original placing table 5 is at the raised position and the original P is transported along the switchback path, the notch of the original placing table provided at the end in the closed path direction is removed. The roller shutter covers the document table almost flush with the document table. On the other hand, when the original placing table 5 is at the lowered position and takes a closed path, the roller shutter is rotated by the shutter moving means so that the paper feed roller is exposed.

[0010]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a copying machine as an example of an image forming apparatus to which the automatic document feeder according to the present invention can be applied.

The apparatus main body 900 of the copier includes a platen glass 3 as a document reading unit, a light source 907, and a lens 90.
8, a paper feeding unit 909, an image forming unit 902, and the like.
An automatic document feeder 2 is provided above the platen glass 3.

A sheet feeding unit 909 includes a cassette 910 that stores sheets S and is detachable from the apparatus main body 900, a deck 913 disposed on a pedestal 912, and a feeding roller that feeds the sheets S to the image forming unit 902. 911. The image forming unit 902 includes a cylindrical photosensitive drum 914, a developing device 915, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like. On the downstream side of the image forming unit 902, the transport device 92
0, a fixing device 904, a discharge roller 905, and the like.

The operation of the copying machine having the above configuration will be briefly described.

When a paper feed signal is output from a control device 930 provided in the apparatus main body 900, the cassette 910,
Sheet S is fed from 911 or deck 913.
On the other hand, light reflected from the light source 907 on the original P placed on the platen glass 3 is irradiated on the photosensitive drum 914 via the lens 908. Photosensitive drum 914
Are charged in advance by a primary charger 919, and are irradiated with light to form an electrostatic latent image, and then a developing device 915 forms a toner image.

The sheet material S fed from the paper feeding unit 909
The skew is corrected by the registration rollers 901, and the skew is sent to the image forming unit 902 at a further adjusted timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the fed sheet S by the transfer charger 916, and the transferred sheet S is charged to the opposite polarity to the transfer charger 916 by the separation charger 917. The photosensitive drum 91
4

Then, the separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and
04, the unfixed toner image is permanently fixed on the sheet S. The sheet material S on which the toner image has been fixed is discharged from a discharge roller 90
5 is discharged from the apparatus main body 900.

In this manner, the sheet material S fed from the paper feeding unit 909 is formed with an image and discharged.

FIG. 2 is a vertical sectional front view of the automatic document feeder 2.

Referring to FIG. 1, a pair of side guides 7 are slidably provided on a document table 5 to regulate the position of a plurality of documents P placed in the width direction and align the entire document P. Supported. The recycle lever 10 placed on the original P is a member that distinguishes between the original P that has not been fed and the fed original P that is discharged onto the original placing table 5 after feeding. Reference numeral 6 denotes a shutter that receives and aligns the leading end of the document P and retracts below the document table 5 during paper feeding. The document table 5 is rotatable around the support shaft 4 between an inclined position shown in FIG. 2 and a horizontal position shown in FIG. 3. In the position shown in FIG. And is fed from the lowermost side by the rotation of the feed roller 9.

Downstream of the first feed roller 9, there is provided a first separating portion including a conveying roller 11 rotating in a document feeding direction and a separation belt 12 rotating in a document returning direction. The separation unit separates and transports the documents P sent by the first sending roller 9 one by one.
Downstream of the first separation unit, a first paper supply roller pair including a large roller 13 and a paper supply roller 15 in contact with the large roller 13 is provided. A first transport path 16 formed by the pair of paper feed rollers is configured.

[0022] The platen glass 3 upward, the document conveying means F ₁ is disposed. The document conveying means F ₁ has an endless belt 20, a driving roller 17, and a driven roller 19. An endless belt 20 that is rotatable in forward and reverse directions wound around a driving roller 17 and a driven roller 19 is disposed in contact with the platen glass 3, and the forward rotation of the endless belt 20 causes the document P to be rotated at a predetermined timing. It is transported on the platen glass 3. The original image of the original P stopped at the reading position is fixedly read by scanning the light source 907 in the direction of the arrow.

The original P after reading is conveyed to the flapper 25 via the conveying path outside the large roller 13 by the reverse rotation of the endless belt 20. The flapper 25 reverses the document P when reading both sides of the document P and guides the document P to the platen glass 3, and guides the document P to the discharge roller pair 29 via the sheet discharge path 26 when reading one side.
Reference numeral 27 denotes a detection sensor that detects the document P passing through the discharge path 26. The document P discharged by the discharge roller pair 29 is placed on a document P that has not been fed on the document placing table 5 and is distinguished by the recycle lever 10 (switchback path).

Note that the document transport means F ₁ also has a first separation unit and the like.

When the document table 5 is at the position shown in FIG. 3, the document P
5 to the platen glass 3.

Also on the rear end side of the original P, a second half-roller roller 36 for feeding the originals P placed on the original placement fifth one by one from the lowermost position downstream, document conveying means F ₂ consisting of substantially the same configuration as the original convey means F ₁ described above disposed on the distal end side, i.e., the guide plate 3
7, a weight 39 for pressing the original P against the second feed roller 36, a transport roller 40 rotating in the original feeding direction, a separation belt 41 rotating in the returning direction of the original P, the driving roller 17, the driven roller 19, an endless belt 20. When the document P placed on the document placing table 5 is sent downstream by the second sending roller 36, the document P is transported by the second sending roller 40 and the separation belt 41.
Are separated one by one. A second transport path 45 that transports the separated document P to the platen glass 3 as a reading unit is provided downstream of the second separating unit including the transport roller 40 and the separation belt 41. The second transport path 45 includes a transport roller pair 43,
A relay roller 46 and a paper feed roller pair 47 are provided, respectively.

A document P is provided between the upper roller of the paper feed roller pair 47 and the second roller 19 of the endless belt 20.
To the platen glass 3 or the platen glass 3
A moving guide member 50 for guiding the upper document P is provided.

Document P separated by the second separation unit
Is transported onto the platen glass 3 by the driven roller 19 via the second transport path 45 and the movement guide member 50. The document P conveyed onto the platen glass 3 passes through the fixed light source 907 and is read and then conveyed to the discharge path 26 outside the large roller 13. 5.

In this embodiment, the document table 5 is rotatable around the support shaft 4 between the inclined position shown in FIG. 2 and the horizontal position shown in FIG. The reciprocal movement between the skew position and the horizontal position shown in FIG. 3 is performed by an elevating drive device (elevating means) G that moves the document table 5 up and down.

As shown in FIGS. 2 and 3, the lifting drive device includes a drive source (not shown) such as a motor, a connection shaft 33 connected to the drive source such as a motor (not shown), and a connection shaft 33. Frame 31 having a driving member 35 fixed to both ends of the document member 35 and a bent piece 31a pressed by a driving pin 35a provided at a free end of the driving member 35.
A support member (not shown) integral with the frame 31, a support shaft 4 serving as a support shaft on which the support member (not shown) is rotatable,
A compression spring (not shown) formed by urging the frame 31 upward.

FIG. 2 is a longitudinal sectional view of the automatic document feeder 2 having a switchback path.

When a driving source (not shown) such as a motor rotates in the direction opposite to the clock, the connecting shaft 33, the driving member 35, and the driving pin 35a provided on the driving member 35 also rotate in the direction opposite to the clock. . Then, the frame 31 and the document placing table 5 rise around the support shaft 4 by the urging force of a compression spring (not shown), and the document placing table 5 assumes a skew position.
It is configured to form a switchback path.

FIG. 3 is a longitudinal sectional view of an automatic document feeder having a closed path. When a driving source (not shown) such as a motor rotates clockwise, the connecting shaft 33, the driving member 35, and the driving pin 3 provided on the driving member 35 are rotated.
5a also rotates clockwise. Then, the frame 31 and the document table 5 descend around the support shaft 4, and the document table 5 takes a horizontal position to form a closed path.

Here, as shown in FIG.
A roller shutter 5a rotatably attached to the leading end of the document table 5;
1 (shutter moving means). The roller shutter moving device 61 includes a torsion spring 5c provided on the support shaft 5b of the roller shutter 5a and biasing upward.
And a tension spring 5d for urging the roller shutter 5a downward and having a slightly smaller urging force than the torsion spring 5c.
And a slider 5 connected to the other end of the tension spring 5d.
e and a slider guide 5 for guiding the slider 5e
f, and a stopper 5g for keeping the roller shutter 5a flush with the document table 5. Further, a tray base 34 provided below the frame 31 at the right end of the drawing,
It has a link 34a urged clockwise by a torsion spring 34c and rotatable about a support shaft 34b.
The other end of the link 34a is configured to abut on the protrusion of the slider 5e.

With this structure, as the document table 5 is lowered around the support shaft 4, the link 34a rotates in the opposite direction to the clock, against the urging force of the torsion spring 34c.
When the slider 5e is pressed down and the roller shutter 5a is pulled down, and the document table 5 takes a horizontal position and forms a closed path, the roller shutter 5a is positioned vertically downward with respect to the document table 5.

The circular portion of the second feed roller (paper feed roller) 36 is exposed from the opening 5i (see FIG. 7) formed by the roller shutter 5a being positioned vertically below the document table 5 . Then, the original P placed on the original placing table 5 is fed from below.

Further, when the document P on the document table 5 is taken out, the document P is rotated below the document mounting surface against the urging force of the torsion spring 5c so that the document P can be picked.

Further, as shown in FIG. 6, projections 5h are provided on the upper surface of the roller shutter 5a with an interval at which a finger can enter.
Is formed.

[0039]

As described above, according to the present invention,
Even when the document table is in the raised position and takes the switchback path, dust or other dust may enter the notch provided on the document table to expose the paper feed roller when taking the closed path. Therefore, no jam occurs at the time of paper feeding, and no trouble occurs in the automatic document feeder.

Further, when the roller shutter is pressed downward, the roller is rotated from the surface of the document table, so that the document placed on the document table can be easily picked.

Further, since the projections are provided on the upper surface of the roller shutter at intervals so that fingers can enter, it is easy to take out the original placed on the original placing table.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an entire image forming apparatus according to the present invention.

FIG. 2 is a vertical sectional front view of the automatic document feeder (switchback path) according to the present invention.

FIG. 3 is a vertical sectional front view of the automatic document feeder (closed path) according to the present invention.

FIG. 4 is a longitudinal sectional view of a roller shutter and a roller shutter moving unit according to the present invention.

FIG. 5 is a cross-sectional view of the roller shutter according to the present invention.

FIG. 6 is a plan view of a document placing table according to the present invention.

FIG. 7 is a plan view of a conventional document table.

[Explanation of symbols]

P document 2 automatic document feeder 3 platen glass 5 document table 5a roller shutter G lifting means (lifting device) 6 first shutter 7 side guide F _1, F ₂ document conveying means 9 first feed roller 10 cycles lever DESCRIPTION OF SYMBOLS 11 Conveyance roller 12 Separation belt 13 Large roller 15 Paper feed roller 16 1st conveyance path 17 Drive roller 19 Follower roller 20 Endless belt 26 Ejection path 29 Ejection roller pair 36 2nd sending-out roller 40 Conveyance roller 41 Separation belt 50 Movement guide Member 61 Shutter moving means (roller shutter moving device)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-152068 (JP, A) JP-A-57-173653 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 1/00-3/68

Claims (4)

(57) [Claims] An original placing table on which an original can be placed; and a plurality of originals separated and supplied one by one.
Document transported to the document placement table and discharged onto the document table.
Feeding means, and feeding the original on the original placing table to the original feeding means.
An automatic document feeder, comprising: a paper feed roller that feeds the paper toward the separation unit;
Lowering means, rotatably supported by the document table,And placing the original
So that it is almost flush with the platformEnergized roller shutter
When the document table is at the lowered position,
The shutter is rotated so that the paper feed roller is exposed.
Tta moving means,, When taking out the original on the original platen,
So that the document can be gripped by rotating the document against its urging force.
Configured in  An automatic document feeder, characterized in that: 2. The automatic document feeder according to claim 1, wherein a projection is formed on an upper surface of the roller shutter with an interval for a finger to enter. 3. The endless belt for conveying an original to the reading position on a platen, the endless belt for conveying the original on the original placing table, and the endless belt moving to the reading position with the endless belt. After transporting, the belt is reversed, and a switchback path for discharging the document onto the document table, and the document on the document table is transported to the endless belt, and the endless belt is passed through the reading position. A closed path that rotates in one direction and discharges the document onto the document table.When the document table is in the raised position, the document is supplied from one end to the supply / separation unit of the switchback path. When the document placing table is at the lowered position, the document is supplied from the other end to a supply / separation unit of the closed path. Rashatta and formed by providing the other end of the document table, a document automatic feeding device according to claim 1 or 2, wherein. 4. An automatic document feeder according to claim 1, wherein the document is read at a reading position on the platen, and an image is formed based on the read image information. An image forming apparatus comprising: a forming unit; and a sheet conveying unit that feeds sheet materials one by one, and transfers and discharges an image formed by the image forming unit to the sheet material.