JP2000191168A - Automatic document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic document feeder capable of setting a document curl presser member without doing damage to a document at the time of setting the copy. SOLUTION: A groove type guide part 23 is provided on a roof part 22 to press a document end part provided on a side fence 21 of a bottom plate 8, a head end of a first arm 32 of a document curl presser unit 30 is made to enter it, and it is made a working point of the document curl presser unit at the time of elevating the bottom plate 8. A spring 35 is provided between the first arm 32 and a second arm 33, and proper pressing force is given to it when a curl presser roller 31 makes contact with a document 7. A filler 24 is pushed up by a bundle of the documents 7, and when a document set sensor 10 detects the set of the documents 7, the bottom plate 8 rises. At this time, a position of the working point of the document curl presser unit 30 also rises, the curl presser roller 31 lowers on the bundle of the documents 7 around a fulcrum shaft 34 as its fulcrum, presses the copy 7 down and smoothens a curl.

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 for an image forming apparatus such as a copying machine, a facsimile, and a scanner.

[0002]

2. Description of the Related Art In an automatic document feeder for an image forming apparatus, the position reference of a document set in a means for storing a document or a bundle of documents, that is, in a sheet feed table or a sheet feed tray, is based on an image. In the case of the reference on the back side of the forming apparatus, unlike the case of the reference on the center, the page-calling roller of the document is not always located at the center of the document, and may be located closer to the center or closer to the document depending on the document size. When the original is called up, the original tries to rotate forward (hereinafter referred to as skew). When the original is called up, the original tries to skew forward. Usually, side fences are provided on the back side and the front side of the sheet feeding table.

However, when a document has a curl, the side fence often cannot suppress the skew.
Therefore, in order to achieve both the skew at the time of document reading and the curl holding by the side fence, an elastic pressing member for holding the curl is provided at the tip of the side fence as in the apparatus disclosed in, for example, JP-A-8-286433. Although there is an example, if such a configuration is adopted, a problem occurs in the setting property of the document.

Generally, when an original is set on a paper supply table or the like, the original or a bundle of originals is set on the paper supply table or paper supply tray, and then a side fence is slid to start a copy operation. Alternatively, the side fence is set to the width of the document, and then the document is inserted between the side fences. The former is considered to be normal from the viewpoint of ease of operation. In that case, if the side fence is provided with the elastic pressing member as described above,
When the side fence slides after the document is set, the elastic pressing member hits the side edge of the document or the document bundle, and there is a risk that the document may be scratched or torn.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeder capable of setting a document curl pressing member without damaging the document when setting the document.

In the above-described structure, the fixed elastic pressing member is always in a state of pressing the surface of the original, so that the image of the original may be peeled off and the stripe-shaped stain may be generated when the original is transported. However, there is a problem in that the pressing force of the elastic pressing member becomes a resistance to the document conveyance, and there is a possibility that the document is not fed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder capable of reducing the load at the time of document transport even if the pressing force on the document is the same, removing the image, and improving the stain resistance.

Further, a state may occur in which the original curl pressing member excessively presses the original surface due to variations in parts and variations in assembly. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an automatic document feeder capable of pressing a curled document with an appropriate pressure regardless of variations in parts and assembly.

[0009]

According to the first aspect of the present invention, there is provided an automatic document feeder for accommodating a document or a document bundle, a document curl pressing means, A document detecting means for detecting that a document or a document bundle is set in the storage means; and the document or the document for bringing the document or the top document of the document bundle stored in the storage means into contact with a calling member A document lifting member capable of lifting the bundle, a driving means for the document lifting member, a paper feeding appropriate position detecting means for detecting a paper feeding position of the document or the document bundle stored in the storage means, and a connection to the storage means Transmitting means for sequentially transmitting the stored originals or the original bundle from the storing means,
One end is connected to the sending means, the feeding means for feeding the original sent from the sending means to the image reading section, and an interlocking mechanism for interlocking the original curl holding means with the elevation of the original lifting member. And

According to a second aspect of the present invention, in order to achieve the above object, the document curl pressing means is a rotating member.

According to a third aspect of the present invention, in order to achieve the above object, the interlocking mechanism comprises a plurality of arm members, and an elastic member is interposed at a connecting portion of each arm member.

According to a fourth aspect of the present invention, in order to achieve the above object, the document lifting member has a guide means, and the guide means is provided at one end of one arm member of the arm member forming the interlocking mechanism. A portion guided by engagement is provided, and the one arm member is rotated by a change in the position of the guide means accompanying the elevation of the document lifting member, and the rotation is performed by another arm member forming the interlocking mechanism. And transmitting the document curl pressing means so as to rotate and approach the stored document or the uppermost document in the document bundle.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an automatic document feeder that can be an embodiment of the present invention and an image forming apparatus equipped with the same. An automatic document feeder (hereinafter referred to as DF) 1 is mounted on an image forming apparatus (hereinafter referred to as apparatus main body) 2. The apparatus main body 2 is provided with an exposure unit, and the first mirror 3
The original set on the contact glass 5 is read by the lamp 4 and the lamp 4. The first mirror 3 and the lamp 4 move and read an image.

The operation of conveying a document in the DF1 will be described. The originals 7 stacked in a bundle on the paper feed table 6 are lifted by an original lifting member (hereinafter referred to as a bottom plate) 8 and pressed against a call roller 9. When the bottom plate 8 is in a standby state (when the original 7 is not set), the sensor 10 detects a filler (not shown in FIG. 1) provided on the bottom plate 8 and stands by. The bottom plate 8 is moved up and down by a bottom plate up / down stepping motor (not shown), and while the bottom plate 8 is raised, the call roller 9 is rotated to feed the top original 7 to the separation unit.

The separating section includes a separating belt 11 and a separating roller 12.
In order to read image information, the original 7 separated into one sheet is transported to the contact glass 5. The document 7 during image reading is stopped so that the trailing edge thereof abuts the document scale 5a. When the original 7 is sequentially fed from the top sheet and the last sheet is fed, the bottom plate 8 descends and returns to the home position.

The call roller 9, the separation belt 11, the separation roller 12, the first transport roller 13, and the second transport roller 14
In each case, the transport belt 15 is driven by a paper stepping motor (not shown), and the transport belt 15 is driven by a transport stepping motor (not shown). Since the paper feeding stepping motor and the conveyance stepping motor can be driven independently of each other, it is necessary to discharge the original 7 on the contact glass 5 and then feed the next original. It is possible to arbitrarily change whether the originals are arranged or how much the interval between the arranged originals is set.

First transport roller 13 and second transport roller 1
A first paper feed sensor 16 and a second paper feed sensor 17 for jam detection and document length detection are provided in the vicinity of the downstream side in the document conveyance direction of No. 4 respectively. First paper feed sensor 16 and second paper feed sensor
The document length information detected by the paper feed sensor 17 is stored in the document length storage memory when the document 7 is conveyed onto the contact glass 5 for reading an image and stops. At this time, if the number of documents on the contact glass 5 is one, it is stored in the first storage memory, if it is two, it is stored in the second storage memory, and if it is three, it is stored in the third storage memory (the same applies hereinafter).

After the reading of the image is completed, the original 7 which has reached the paper discharge section is discharged to a paper discharge tray 19 by paper discharge rollers 18. Each time one ejection of the document 7 is completed, the contents of the second storage memory are stored in the first storage memory, and the contents of the third storage memory are stored in the second storage memory (the same applies hereinafter).
The discharge roller 18 is driven by a discharge stepping motor (not shown). By counting the pulses of the transport stepping motor while the document 7 is being transported to the paper discharge unit, the amount of document transport by the transport belt 15 can be known.

A paper discharge sensor 20 is provided in the paper discharge section.
Thus, the detection of the discharge jam and the discharge deceleration timing is performed. By counting the pulses of the discharge stepping motor after the leading end of the document 7 has passed the discharge sensor 20, the amount of document feed by the discharge roller 16 after passing the sensor can be known.

In the figure, reference numeral 9a denotes a paper feed proper position detecting sensor which can detect a paper feed proper position detecting filler (not shown) interlocked with the calling roller 9.

FIG. 2 is an enlarged sectional view showing the vicinity of the bottom plate 8 in one embodiment of the automatic document feeder according to the present invention, and FIG. 3 is a plan view. The bottom plate 8 has a side fence 21,
The side fence 21 is provided with a roof 22 for holding down the end of the document. The sheet feed table 6 side of the roof portion 22 is a groove-shaped guide portion 23 as shown in the figure. A filler 24 for detecting the setting of a document is rotatably attached to the front end of the side fence 21 in the sheet feeding direction.

In the figure, reference numeral 30 denotes a document curl pressing unit.
It includes a rotatable curl holding roller 31, a first arm 32, a second arm 33, a fulcrum shaft 34, and a spring 35. The tip of the first arm 32 is the side fence 2
It enters into a groove-shaped guide portion 23 provided on the roof portion 22 of the first and serves as an action point of the document curl pressing unit when the bottom plate 8 is moved up and down. The other end of the first arm 32 is rotatably attached to a fulcrum shaft 34 fixed to a side surface of the sheet feeding table 6. One end of the second arm 33 is also rotatably attached to the fulcrum shaft 34, and a spring 35 is provided between the first arm 32 and the second arm 33. This spring 35
Has one end on the first arm 32 and the other end on the second arm 3.
3, the two arms 32 and 33 are connected, and when the curl pressing roller 31 contacts the original 7, the original 7
It works to give the proper pressing force to suppress the curl. Note that the original curl press unit 30 is lifted during standby because the bottom plate 8 is lowered (FIG. 2).

In the illustrated embodiment, the original curl pressing unit 30 is installed on the original set reference surface side (in the illustrated example, at the rear side of the apparatus), and functions to hold down the rear curl of the original 7. . That is, as shown in FIG.
This corresponds to the fact that the call roller 9 is arranged at a position that precedes all the originals 7 in the back, so that the original curl pressing unit 30 needs to be installed only on the back side (the original set reference position side). Of course, in the case of the reference on the near side, it may be provided on the front side of the apparatus, contrary to the illustrated embodiment,
It may be provided on both the back and front sides.

When the bundle of originals 7 is set on the bottom plate 8,
The filler 24 is pushed up and detached from the document set sensor 10, and the document set sensor 10 detects the setting of the document 7. Then, the bottom plate 8 is driven by a bottom plate up / down stepping motor (not shown) to move up, and the uppermost one of the originals 7 is pressed against the call roller 9, and the sheet feed proper position detecting filler interlocked with the call roller 9 is removed. It rises until the appropriate paper feed position detection sensor 9a detects it.

As shown in FIG. 4, when the bottom plate 8 rises, the position of the action point of the original curl pressing unit 30 on the bottom plate 8 also rises, and the curl pressing roller 31 is supported by the fulcrum shaft 34 as a fulcrum. The original 7 is pressed down to correct the curl.

At this time, it is conceivable that the second arm 33 pivots downward about the fulcrum shaft 34 due to the weight of the curl holding roller 31, but the first arm 32 and the second arm 33 are, for example, shown in FIG. This can be prevented by providing a stopper 36 as shown in FIG.

[0027]

In the automatic document feeder according to the first aspect of the present invention, as described above, it is possible to automatically set the original curl pressing means on the original without damaging the original when setting the original. There is an effect that it becomes possible.

In the automatic document feeder according to the present invention, in addition to the above-mentioned common effects, the load on the entire machine is reduced by using the pressing portion as a rotating member, and the image of the document is prevented from being peeled and the document is prevented from being stained. There is an effect that it becomes possible to do.

In the automatic document feeder according to the third aspect, in addition to the above-mentioned common effects, there is an effect that an appropriate pressing force can be applied to the document even when there are variations in parts and assembly. is there.

In the automatic document feeder according to the fourth aspect, in addition to the above-mentioned common effect, the interlocking mechanism is guided by the guide means of the document lifting member, and the document curl pressing means can be reliably set on the document. There is an effect that it becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an automatic document feeder that can be an embodiment of the present invention and an image forming apparatus equipped with the same.

FIG. 2 is an enlarged sectional view of the vicinity of a bottom plate 8 in an embodiment of the automatic document feeder according to the present invention.

FIG. 3 is a plan view of the same.

FIG. 4 is a sectional view of the embodiment of FIGS. 2 and 3 during operation.

FIG. 5 is a perspective view of a modification of the embodiment of FIGS. 2 and 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 automatic document feeder (DF) 2 image forming device (apparatus main body) 3 first mirror 4 lamp 5 contact glass 6 feed table 7 document 8 document lifting member (bottom plate) 9 call roller 9 a paper feed proper position detection sensor 10 Sensor 11 Separation Belt 12 Separation Roller 13 First Transport Roller 14 Second Transport Roller 15 Transport Belt 16 First Feed Sensor 17 Second Feed Sensor 18 Discharge Roller 19 Discharge Tray 20 Discharge Sensor 21 Side Fence 22 Roof 23 Guide part 24 Filler 30 Original curl press unit 31 Curl press roller 32 First arm 33 Second arm 34 Support shaft 35 Spring 36 Stopper

Claims (4)

[Claims] 1. A document or document bundle storage means, a document curl pressing means, a document detection means for detecting that a document or document bundle has been set in the storage means, and a document or document stored in the storage means. An original lifting member capable of lifting the original or the original bundle in order to bring the uppermost original of the original bundle into contact with the calling member; a driving means for the original lifting member; and an original or original bundle accommodated in the accommodation means Paper feeding appropriate position detecting means for detecting the paper feeding position of the document, feeding means for sequentially feeding the stored originals or document bundles from the storing means connected to the storing means, and one end connected to the feeding means. A conveying unit for conveying the original sent from the sending unit to the image reading unit, and an interlocking mechanism for interlocking the original curl pressing unit with the elevation of the original lifting member. An automatic document feeder, comprising: 2. The automatic document feeder according to claim 1, wherein said document curl pressing means is a rotating member. 3. An interlocking mechanism comprising a plurality of arm members,
3. The automatic document feeder according to claim 1, wherein an elastic member is interposed between connecting portions of the arm members. 4. The document lifting member has a guide means, and a portion guided by engaging with the guide means is provided at one end of one arm member of the arm member forming the interlocking mechanism. The one arm member is rotated by a change in the position of the guide means accompanying elevation of the document, and the rotation is transmitted to the other arm member forming the interlocking mechanism. 4. The automatic document feeder according to claim 3, wherein the document is rotated toward and away from the uppermost document of the document bundle.