JPH0899728A - Automatic document feeder and image forming apparatus including the same - Google Patents

Abstract

(57) [Summary] [Purpose] Since the document table 5 has a notch 5i for exposing the second feed roller 36, the notch 5i
Dust such as dust will enter. The second manually-fed original at the end of the original placing table in the feeding roller direction is conveyed to the original placing table. [Structure] The document table 5 includes a roller shutter 5a,
And a roller shutter moving device 61. The roller shutter moving device 61 has a support shaft 5b, a torsion spring 5c, a tension spring 5d, a slider 5e, a slider guide 5f, and a stopper 5g. It has a link 34a which is urged clockwise by a spring 34c and is rotatable around a support shaft 34b. The other end of the link 34a is configured to come into contact with the protrusion of the slider 5e.

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 which can be applied to an image forming apparatus such as a copying machine or a laser beam printer, and an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, as in FIGS. 2 and 3 showing an automatic document feeder of the present invention, an original P is automatically placed in a reading section on a platen glass 3 which is arranged in an image forming apparatus such as a copying machine. In the automatic document feeder for feeding the document to the document stacking table, the document stacking table 5 is located at the elevated position, the document P is conveyed to the endless belt 20, and then the belt is reversed to discharge it to the document stacking table 5. It is known that the document placing table 5 is located at the lowered position, conveys the document P to the endless belt 20, rotates in one direction through the reading position, and discharges to the document placing table 5. ing. Further, as shown in FIG. 7, the document placing table 5 has a pair of notches 5i at the ends of the closed path in the conveying direction, and when the document placing table 5 descends to take the closed path, the document placing table 5 moves to the second path. The circular portion of the feed roller (paper feed roller) 36 is exposed from the document table 5. Then, the second delivery roller 3
The rotation of 6 causes the lowest document P of the document stack placed on the document table 5 to be conveyed.

[0003]

However, in the above-mentioned conventional example, since the document placing table 5 has the notch 5i for exposing the second feeding roller 36, dust such as dust is caused from the notch 5i. Will enter. for that reason,
This may cause a jam at the time of feeding the paper or cause a malfunction of the automatic document feeder 2.

Therefore, the present invention provides an automatic document feeder in which roller shutters are provided at a pair of cutouts at the ends of the document table in the closed path direction, and an image forming apparatus using the same. The purpose is.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an original placing table on which an original can be placed and an original are separately supplied, and the original is further supplied. A document feeding unit that conveys the document to a reading position and discharges it onto the document placing table; and a paper feed roller that feeds the document on the document placing table toward the supply / separation unit of the document feeding unit. In an automatic document feeder including: a document placing table, an elevating unit that raises and lowers the document placing table to an ascending position and a descending position; and the document placing table is rotatably supported by the document placing table and is substantially flush with the document placing table. And a shutter moving unit that rotates the roller shutter so that the paper feed roller is exposed when the document placing table is in a lowered position. When removing the originals on the original platen, Configured to obtain knob the document is rotated against the roller shutter to the urging force, in the automatic document feeder, characterized in that.

Further, it is preferable that protrusions are formed on the upper surface of the roller shutter at intervals so that fingers can be inserted therein.

Further, the original document conveying means conveys an original document on the platen to the reading position and an original document on the original document table to the endless belt, and the endless belt to the reading position. After the conveyance, the belt is reversed and the switchback path for discharging onto the original placing table and the original on the original placing table are conveyed to the endless belt, and the endless belt is
A closed path that rotates in one direction via the reading position and discharges onto the document placing table, and when the document placing table is in a raised position, the document is switched back from one end thereof. Can be supplied to the supply / separation part of the path,
Further, when the document table is in the lowered position, the document is supplied from the other end to the supply / separation part of the closed path, and the roller shutter is provided on the other end side of the document table. Good.

The present invention further comprises an automatic document feeder,
Image forming means for reading the original at the reading position on the platen and forming an image with the read image information;
The same applies to an image forming apparatus including sheet material feeding means for feeding sheet materials one by one, transferring the image formed on the image forming means to the sheet material, and discharging the sheet material. .

[0009]

According to the above construction, when the document table 5 is in the raised position and the document P is conveyed through the switchback path, the notch of the document table provided at the end portion in the closed path direction is cut. The roller shutter covers the original placing table substantially flush with the original placing table. On the other hand, when the document table 5 is in the lowered position and takes the closed path, the shutter moving means rotates the roller shutter so that the paper feed roller is exposed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic construction 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 copying machine includes a platen glass 3 as a document reading section, 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 arranged above the platen glass 3.

A sheet feeding unit 909 stores a sheet S and is detachably attached to the apparatus main body 900, a cassette 910, a deck 913 arranged on a pedestal 912, and a feeding roller for feeding the sheet S to the image forming unit 902. 911. The image forming unit 902 is provided with 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. At the downstream side of the image forming unit 902, the conveying device 92
0, a fixing device 904, a discharge roller 905, and the like.

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

When a paper feed signal is output from the control device 930 provided in the apparatus main body 900, the cassette 910,
The sheet S is fed from the 911 or the deck 913.
On the other hand, the light that is applied from the light source 907 to the document P placed on the platen glass 3 and reflected therefrom is applied to the photosensitive drum 914 via the lens 908. Photosensitive drum 914
Is previously charged by the primary charging device 919, an electrostatic latent image is formed by irradiation of light, and then a toner image is formed by the developing device 915.

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

Then, the separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the fixing device 9
By 04, the unfixed toner image is permanently fixed on the sheet S. The sheet material S having the toner image fixed thereon is discharged by the discharge roller 90.
5 is discharged from the apparatus main body 900.

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

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

In FIG. 1, a pair of side guides 7 are slidably mounted on the document mounting table 5 to regulate the position of the plurality of documents P placed in the width direction and to align the whole. It is supported. The recycle lever 10 placed on the document P is a member that distinguishes the unfed document P from the document P that has been fed and ejected onto the document table 5 after being fed. Reference numeral 6 denotes a shutter that receives and aligns the leading edge of the document P, and retracts below the document table 5 at the time of sheet feeding. The document table 5 is rotatable about the support shaft 4 between an inclined position shown in FIG. 2 and a horizontal position shown in FIG. 3. At the position shown in FIG. It is configured to be fed from the lowermost side by the rotation of the feeding roller 9.

On the downstream side of the first feeding roller 9, there is provided a first separating section consisting of a conveying roller 11 rotating in the document feeding direction and a separating belt 12 rotating in the document returning direction. The separating section separates and conveys the originals P sent by the first sending roller 9 one by one.
A first paper feed roller pair consisting of a large roller 13 and a paper feed roller 15 in contact with the large roller 13 is disposed downstream of the first separation unit, and the first separation unit and the first paper feed roller pair are provided. The first transport path 16 formed by the pair of paper feed rollers is configured.

Above the platen glass 3, a document conveying means F ₁ is arranged. The document conveying means F ₁ has an endless belt 20, a driving roller 17, and a driven roller 19. An endless belt 20, which is wound around a driving roller 17 and a driven roller 19 and is capable of rotating in the forward and reverse directions, is disposed in contact with the platen glass 3. The forward rotation of the endless belt 20 causes the document P to be transferred at a predetermined timing. It is conveyed onto the platen glass 3. Then, the document image stopped at the reading position is fixedly read by scanning the light source 907 in the direction of the arrow.

After the reading is completed, the document P is conveyed to the flapper 25 via the conveyance path outside the large roller 13 by the reverse rotation of the endless belt 20. The flapper 25 reverses and guides the original P to the platen glass 3 when reading both sides of the original P, and guides the original P to the discharge roller pair 29 via the sheet discharge path 26 when reading on 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 pair of discharge rollers 29 is placed on the unfed document P on the document mounting table 5 and distinguished by the recycle lever 10 (switchback path).

The original document transporting means F ₁ also has a first separating section and the like.

When the document placing table 5 is at the position shown in FIG. 3, the document P has the trailing edge side first and the second conveying path 4
It is adapted to be conveyed to the platen glass 3 via 5.

Also on the rear end side of the document P, a half-moon-shaped second feed roller 36 for feeding the document P placed on the document placement fifth from the lowest one by one downstream, and the document P 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 that presses the document P against the second delivery roller 36, a transport roller 40 that rotates in the document feeding direction, a separation belt 41 that rotates in the document returning direction, a drive roller 17, a driven roller 19, an endless belt Have twenty. When the original P placed on the original placing table 5 is sent to the downstream side by the second sending roller 36, the original P is formed into the second sheet including the conveying roller 40 and the separation belt 41.
The separating section separates the sheets one by one. A second transport path 45 for transporting the separated document P to the platen glass 3 serving as a reading unit is provided on the downstream side of the second separation unit including the transport roller 40 and the separation belt 41. The second transport path 45 has a pair of transport rollers 43,
A relay roller 46 and a paper feed roller pair 47 are provided respectively.

A document P is placed 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 original P is arranged.

The original P separated by the second separating section
Is conveyed onto the platen glass 3 by the driven roller 19 via the second conveyance path 45 and the movement guide member 50. The original P conveyed on the platen glass 3 passes through the fixed light source 907, is scanned, and then is conveyed to the discharge path 26 through the outside of the large roller 13, and is discharged to the original setting table by the discharge roller pair 29. 5 is placed.

By the way, in the present embodiment, the document table 5 is rotatable about the support shaft 4 between the inclined position shown in FIG. 2 and the horizontal position shown in FIG. Mutual movement between the skew position and the horizontal position shown in FIG. 3 is performed by an elevating drive device (elevating means) G that vertically moves the document table 5.

As shown in FIGS. 2 and 3, the lift drive device includes a drive source (not shown) such as a motor, a connecting shaft 33 connected to the drive source such as a motor (not shown), and a connecting shaft 33. Of the frame 31 fixed to the document table 5 and having a driving member 35 fixed to both ends of the driving 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) integrated with the frame 31, and a support shaft 4 serving as a support shaft on which the support member (not shown) is rotatable.
It is composed of a compression spring (not shown) that urges 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 counterclockwise direction, the connecting shaft 33, the drive member 35, and the drive pin 35a provided on the drive member 35 also rotate in the counterclockwise direction. . Then, the frame 31 and the document placing table 5 are raised about the support shaft 4 by the urging force of a compression spring (not shown), and the document placing table 5 takes an oblique position,
It is configured to form a switchback path.

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

Here, as shown in FIG. 4, the document table 5
Is a roller shutter 5a rotatably attached to the front end of the document placing table 5, and a roller shutter moving device 6
1 (shutter moving means). The roller shutter moving device 61 includes a torsion spring 5c provided on a support shaft 5b of the roller shutter 5a and biased upward.
And a tension spring 5d that biases the roller shutter 5a downward and that has a slightly smaller biasing force than the torsion spring 5c.
And the slider 5 connected to the other end of the tension spring 5d
e and the 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, and further on the right end in the drawing of the tray base 34 provided below the frame 31.
It has a link 34a that is urged clockwise by a torsion spring 34c and is rotatable around a support shaft 34b.
The other end of the link 34a is configured to come into contact with the protrusion of the slider 5e.

With this structure, as the document table 5 descends about the support shaft 4, the link 34a rotates counterclockwise against the urging force of the torsion spring 34c.
When the slider 5e is pushed down and the roller shutter 5a is pulled downward so that the document placing table 5 takes a horizontal position to form a closed path, the roller shutter 5a is positioned vertically downward with respect to the document placing table 5.

Then, the circular portion of the second feeding roller (paper feeding roller) 36 is exposed from an opening 5h (see FIG. 6) formed by the roller shutter 5a being positioned vertically below the document table 5. The original document P placed on the original document table 5 is fed from below.

Further, when the document P on the document placing table 5 is taken out, the document P can be picked by rotating below the document placing surface against the biasing force of the torsion spring 5c.

Further, as shown in FIG. 6, projections are formed on the upper surface of the roller shutter 5a with a space for inserting fingers.

[0039]

As described above, according to the present invention,
Even when the document table is in the raised position and the switchback path is taken, dust or other dust may get into the notches provided on the document table to expose the paper feed roller when the closed path is taken. Therefore, there is no occurrence of a jam at the time of paper feeding and a failure in the automatic document feeder.

Further, when the roller shutter is pressed downward, the roller shutter rotates a little from the original placing table surface, so that the original placed on the original placing table can be easily picked.

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

[Brief description of drawings]

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

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

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

FIG. 4 is a vertical sectional view of a roller shutter and roller shutter moving means 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 placing table.

[Explanation of symbols]

P original 2 automatic original feeding device 3 platen glass 5 original placing table 5a roller shutter G elevating means (elevating device) 6 first shutter 7 side guides F ₁ and F ₂ original conveying means 9 first delivery roller 10 cycle lever 11 Conveyor Rollers 12 Separation Belts 13 Large Rollers 15 Paper Feed Rollers 16 First Conveyance Routes 17 Drive Rollers 19 Followed Rollers 20 Endless Belts 26 Discharge Routes 29 Discharge Rollers 36 Second Sending Rollers 40 Conveyor Rollers 41 Separation Belts 50 Movement Guides Member 61 Shutter moving means (roller shutter moving device)

Claims (4)

[Claims] 1. An original placing table on which an original can be placed, and original feeding means for feeding the original separately, feeding the original to a reading position, and discharging the original onto the original placing base. , The original on the original table is supplied by the original conveying means.
In an automatic document feeder including a paper feed roller that feeds toward a separation unit, an elevating unit that elevates and lowers the document placing table to an ascending position and a descending position, and rotatably to the document placing table. A roller shutter supported and biased so as to be substantially flush with the document placing table; and when the document placing table is in a lowered position, the roller shutter exposes the sheet feeding roller. And a shutter moving unit that rotates in a direction such that the roller shutter can be rotated against an urging force to pick up the original when the original on the original placing table is taken out. An automatic document feeder. 2. The automatic document feeder according to claim 1, wherein protrusions are formed on the upper surface of the roller shutter at intervals so that fingers can be inserted therein. 3. The document conveying means conveys a document to the reading position on a platen, and a document on the document mounting table to the endless belt, and moves the document to the reading position by the endless belt. After the conveyance, the belt is reversed to discharge the document on the document placing table, and the document on the document placing table is conveyed 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 placing table. When the document placing table is in a raised position, the document is fed from one end thereof to a supply / separation unit of the switchback path. When the original placing table is in the lowered position, the original is fed from the other end to the feeding / separating portion of the closed path, and 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. The automatic document feeder according to claim 1, wherein the original 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: forming means; and sheet material conveying means for feeding sheet materials one by one and transferring the image formed on the image forming means onto the sheet material and discharging the sheet material.