JP3330738B2 - Automatic document feeder and transport method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder and a method for reading and exposing a plurality of document bundles automatically and continuously, and more particularly, to a method for exposing a previous document during exposure. The present invention relates to an automatic document feeder and a transfer method capable of feeding the next document to an exposure position and reliably discharging the exposed document one by one.

[0002]

2. Description of the Related Art Various types of automatic document feeders have been conventionally used as an automatic document feeder that feeds a document from a paper feed side, conveys and positions the document on a contact glass of a copying machine, discharges the document after reading and exposing. As a general one, after the originals separated one by one in the paper feeding unit are transported and positioned at the exposure position on the contact glass, during the exposure of the previous original, the next original is transported to immediately before the exposure position, When the exposure of the next document is completed, the next document is transported and positioned at an exposure position on the contact glass at a rapid conveyance speed.

Further, as a known technique relating to the automatic document feeder, for example, JP-A-4-101943, JP-A-4-144885, JP-A-5-27507 and the like can be mentioned.

Japanese Patent Application Laid-Open No. 4-101943 discloses a "document feeding device" for feeding a document fed at a pressing position of a pressing roller for pressing a belt for feeding a sheet-shaped document onto a document reading surface. It moves to the downstream side in the feeding direction in accordance with the reduction of the dimension along the direction, thereby shortening the copying time of a plurality of documents.

[0005] Further, the "document automatic circulating feeder" disclosed in Japanese Patent Application Laid-Open No. 4-144885 discloses a method of exposing a plurality of original bundles by placing a gate claw immediately after the last original of the first original bundle is exposed. After feeding the second set of documents separated from the mounting table, the gate claw is brought into contact with the document bundle, and when the last document of the first set is discharged, the gate claw is moved from above the document stack. The remaining originals are conveyed to the sheet feeding position while being separated from each other, and the first and second sets of originals are separated by a gate claw to shorten the copying time of the plurality of sets of originals.

The "document automatic feeder" disclosed in Japanese Patent Application Laid-Open No. 5-27507 has a first transport belt and a second transport belt which are arranged side by side so as to cover a document table. Are fed side by side like a single document.

In order to increase the productivity (CPM) of the copying machine, it is necessary to shorten the time required to replace the original in accordance with the exposure interval of the original. In the case of the above-described general document feeder, a structure is employed in which the next document stands by at a position before exposure while the previous document is being exposed. The document must be transported at a transport speed that is about two to three times the speed of the original. Therefore, power consumption,
There is a problem that noise is increased and durability is reduced. In addition, all of the above-mentioned known techniques have an effect of increasing the copying speed, but all of them solve the above-mentioned problem because the next original does not overlap the previous original during the exposure of the previous original. is not.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and can send a document at a low speed within the conventional document replacement time, thereby reducing power consumption, noise and improving durability. It is an object of the present invention to provide an automatic document feeder capable of reliably separating and discharging a previous document and a next document.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a document table on which a plurality of stacks of originals are mounted, and an abutment or separation on the leading end of the original stack. A document separating plate that engages and restricts the progress of the document bundle in the paper feeding direction, separation means for the document bundle to be fed, a contact glass for exposure, and a gap through which at least two documents can be inserted; A document feeder disposed opposite to the contact glass, a pair of pressing rollers disposed downstream of the document feeder in the sheet discharging direction and pressed against the contact glass, and an upstream side of the document feeder; A pull-out roller disposed to feed the document into the gap, and a discharge roller disposed downstream of the document feeder to feed the exposed document to the discharge side, wherein Located upstream The distance b between the first pressing roller and the pull-out roller is formed to be slightly shorter than the length L of the document, and the second pressing roller disposed downstream of the pressing roller in the transport direction is under exposure. Of the next document, which is disposed downstream near the leading end of the original document, and the preceding original document is fed into the gap during the exposure and has its leading end at a distance a 'upstream from the position of the second pressing roller. The first pressing roller is disposed on the downstream side in the vicinity of the leading end, and the distance a ′ is set to be at least larger than the distance a from the leading end of the preceding original being exposed to the paper discharge roller. It constitutes a transport device.

More specifically, the document transport means is a transport belt, and the document transport means has a pressure plate for pressing the document toward the contact glass, wherein the document partition plate, the pull-out roller, and the discharge roller A document set sensor for detecting the position of the document, a registration sensor, and a paper ejection sensor are arranged in the vicinity, and the document is set at the exposure position by being brought into contact with the document mounted on the contact glass in the vicinity of the contact glass. The original document scale is arranged.

In the automatic document feeder, a document set sensor detects the leading edge of a document bundle, then advances the document bundle in the paper feeding direction, and separates only the preceding document by a separating unit. The separated original is sent into the gap between the contact glass and the original conveying means by the pull-out roller and the original conveying means, and the original is exposed and positioned by the original scale by the original scale. It is fed into the gap by a pull-out roller, and based on the detection of the registration sensor, stops the leading end position of the next document near the upstream side of the first pressing roller, and activates the pull-out roller and the automatic conveyance unit when the exposure of the previous document is completed. The first original and the next original are simultaneously sent out in the sheet discharging direction while being pressed by the first and / or second pressing rollers, and the previous document is sent out by the sheet discharging rollers. Draft performed set continued exposure the next document to a predetermined exposure position while discharging the, is characterized in that to complete the exposure of the original bundle repeated successively the same operation.

[0012]

The bundle of a plurality of documents mounted on the document table is first positioned at the leading end by a document partition plate and detected by a document set sensor. The document separating plate is opened by this detection signal, and the document bundle is sent by the sheet feeding means, but is separated one by one by the separating means. First, the first document is sent to the contact glass by the pull-out roller and the document conveying means and is moved to the exposure position. Set. While the previous document is being exposed, the next document is sent to the contact glass by the pull-out roller and overlaps the previous document. In this case, the preceding document is pressed toward the contact glass by a pressing roller disposed downstream of the document conveying means, but the leading edge of the next document is close to the first pressing roller upstream of the pressing roller. It is sent only to.

On the other hand, the leading end of the exposed original is set at a position slightly advanced from the second pressing roller downstream of the pressing roller. When the exposure of the previous document is completed, the previous document and the next document are simultaneously moved in the discharge direction by the pull-out roller and the document conveying means, and the previous document is discharged by the discharge roller and the next document is exposed at the exposure position. Is set to A registration sensor and a paper discharge sensor located near the pull-out roller and the paper discharge roller detect the positions of the previous document and the next document, respectively, and are necessary for the pull-out roller and the control units such as the document conveying means and the paper discharge roller. Output a detection signal.

The distance b between the pull-out roller and the first pressing roller, the distance a 'between the leading end of the previous document and the discharge roller, and the distance a between the leading end of the next document and the second pressing roller are Each of them is formed in a predetermined size to ensure the reliability of the separated sheet discharge and the speed of the sheet discharge speed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are sectional structural views for explaining the outline structure of the present embodiment and the sheet feeding and discharging operations with time, and FIG. 7 is a partial sectional view of another embodiment of the document conveying means. FIG. 8 is a flowchart for explaining the operation of the present embodiment.

First, the overall structure of the automatic document feeder 1 of this embodiment will be described with reference to FIG. First, for the sake of explanation, in this embodiment, the number of originals is three, the first original is referred to as a first original 2, the next original is a second original 2a, and the next original is a third original 2. Original 2b. Automatic document feeder 1
The document table 4 is roughly divided into a document table 4 inclined obliquely upward from the apparatus main body 3, and a document partition plate 5 stored in the apparatus main body 3.
The document feed roller 6, the separation roller 7, the separation belt 8, the pull-out roller 9, the conveyance belt 10, which is one of the document conveyance means, the contact glass 11, the document scale 12, the paper discharge rollers 13, 14, and the like.

An original partition plate 5 and a pull-out roller 9
And a document set sensor 15 near the paper discharge roller 13.
And a registration sensor 16 and a paper discharge sensor 17 are provided and connected to a control unit (not shown). Guides 18 and 19 for guiding a document are formed between the separation roller 7 and the pull-out roller 9 and between the paper discharge rollers 13 and 14. In addition, a gap 20 is formed between the transport belt 10 and the contact glass 11 so that at least two documents can intervene.

First original 2 and second and third originals 2
Although a and 2b are superimposed on the original table 4, they naturally move toward the original partition plate 5 due to their own weight and the inclination of the original table 4.

The document partition plate 5 is rotatably supported about a rotating shaft 21 pivotally supported by the apparatus main body 3 side. A pressure roller 22 is pivotally mounted on one end and a first roller is mounted on the other end. A partition plate 23 that regulates passage of the original 2 and the like is provided integrally. The first document 2 and the like are sandwiched between the document retrieving roller 6 and the pressure roller 22 and are sent out in the sheet feeding direction by the operation of a sheet feeding motor (not shown).

The separation roller 7 is composed of a roller which rotates in the same direction as the document retrieving roller 6 when the document is fed, and the separation belt 8 is engaged with the separation roller 7 at an angle and rotates in the opposite direction. The first document 2 and the like sent to the separation roller 7 are separated one by one by the separation roller 7 and the separation belt 8 and sent to the guide 18 side. The document set sensor 15 detects that the first document 2 or the like has come to the position of the document partition plate 5.

The pull-out roller 9 is for holding the first document 2 and the like sent to the guide 18 and sending it to the conveyor belt 10 side. The front end position and the rear end position of one original 2 are detected, and necessary detection signals are sent to the control unit side.

The transport belt 10 is formed by stretching an endless belt 26 between a front end roller 24 and a rear end roller 25, and includes a first pressing roller 27, a second pressing roller 28, and guide rollers 29, which are pressing rollers. 30 is disposed in contact with the endless belt 26. The first and second pressing rollers 27 and 28 are engaged with pressing means (not shown) so as to press the endless belt 26 against the contact glass 11.

The contact glass 11 is made of flat transparent glass, and a reading exposure device (not shown) is provided below the contact glass. The reading and exposure of the original is performed by mounting the first original 2 and the like on the contact glass 11.

The original scale 12 is a contact glass 11
A scale for exposing and positioning the first original 2 and the like mounted thereon. The first original 2 and the like are positioned by being pressed against the front end of the original scale 12 by the movement of the transport belt 10 at the rear end. Is done.

The paper discharge roller 13 is exposed and
The first document 2 and the like sent out of the printer 19 are nipped and sent to the guide 19 side, and the discharge roller 14 discharges the first document 2 and the like from inside the guide 19 to the outside of the apparatus main body 3.

Next, referring to FIG.
The positional relationship between the second pressing rollers 27 and 28, the pull-out roller 9, and the paper discharge roller 13 will be described. Assuming that the length of the original such as the first original 2 in the paper feeding direction is L, the distance b between the pull-out roller 9 and the first pressing roller disposed on the upstream side of the transport belt 10 is b <L. In a relationship. That is, as shown in FIG. 4, the leading end of the second original 2a is the first original 2a.
If it is slightly upstream of the pressing roller 27, the rear end thereof is again held by the pull-out roller 9 by a sufficient length.

On the other hand, as shown in FIG. 4, when the first original 2 is set at the normal exposure position, the leading end of the first original advances to a position slightly protruding from the second pressing roller 28. In this state, the leading end of the second document 2a is set at a position slightly upstream of the first pressing roller 27 as described later. From the leading end of the second document 2a to the second pressing roller 2
If the distance from the leading end of the first document 2 protruding from the second pressing roller 28 to the paper discharge roller 13 is a, the distance to a 8 will be a '> a. And the first and second pressing rollers 27 and 28 are disposed. As a result, at the moment when the first document 2 is nipped by the discharge roller 13, the second document 2 a is
8 is not pressed. Therefore, the separation of the original in the paper discharging process is performed reliably.

Next, the operation of feeding and discharging a document by the automatic document feeder 1 of the present embodiment will be described with reference to the flowcharts of FIGS. 1 to 6 and FIG. As shown in FIG. 1, the first to third originals 2, 2a, 2b are stacked and mounted on the original table 4 (step 100). In this case, the partition plate 23 of the document partition plate 5 regulates the leading end of the first document 2 (step 101).

The document set sensor 15 detects that the first document 2 has reached the position of the document partition plate 5, ie, the position of the document retrieving roller 6 (step 102). The document separating plate 5 is rotated as shown in FIG. 2 by this detection signal (step 103), and the first document 2 and the like are sandwiched between the document retrieving roller 6 and the pressure roller 22 and the operation of the unillustrated sheet feeding means is performed. To start paper feeding (step 104).

When the first document 2 reaches the separation roller 7, the first document 2 is sent out along the groove of the separation roller 7, but the second document 2a and the like rotate in the opposite direction in contact with the separation roller 7. It is separated by the separation belt 8 (step 105). The leading end of the sent first original 2 is pinched by the pull-out roller 9 (step 106), and the registration sensor 16
Detects the leading edge of the first document 2 (step 107).

In this state, the sheet feeding means operates in the direction opposite to the sheet feeding direction so as not to feed the second document 2a. When the registration sensor 16 detects the leading end of the first document 2, the transport belt 10 is operated.
08), the first document 2 enters the gap 20 and is fed to a predetermined position on the contact glass 11 by the pulse count of the encoder of the transport belt drive motor (step 109). In this state, as shown in FIG.
is sent to the position of the pull-out roller 9 (step 1).
10), the third document 2b is separated by the separation belt 8 or the like (step 111).

When the registration sensor 16 detects the rear end of the first document 2 (step 112), the transport belt 10 stops, moves in the opposite direction, and retreats the first document 2 on the contact glass 11, and thereafter The end is brought into contact with the original scale 12, and the first original is read and set at the exposure position (step 113). FIG. 3 shows the positional relationship between the first, second, and third originals 2, 2a, and 2b in that state.

Next, reading and exposure of the first original 2 are performed (step 114), and at the same time, the pull-out roller 9 is operated to send out the second original 2a to the position shown in FIG.
(Step 115). That is,
The first original 2 is set at a regular exposure position where the leading end of the first original 2 protrudes from the second pressing roller 28, and is pressed against the contact glass 11 by the first and second pressing rollers 27 and 28, and the second original 2 a Is fed to the upstream side of the first pressing roller 27.

Next, when the exposure of the first document is completed, the pull-out roller 9 and the transport belt 10 are operated, the first document 2 is sent to the paper discharge roller 13 side, and the second document 2a is The document is sent to the second pressing roller 28 through the pressing roller 27, and at the same time, the third document 2b is also sent to the pull-out roller 9 side (step 116).

As described above, the first original 2 is fed while being pressed by the first pressing roller 27 and the second pressing roller 28 to the position where the first original 2 is held by the paper discharging roller 13. The second document 2a is only pressed by the first pressing roller 27 only. Therefore, the first document 2 and the second document 2a are surely separated in this state.

As shown in FIG. 5, the first document 2 is discharged by the discharge roller 13 (step 117), and at the same time, the second document 2 is discharged.
The original 2a is sent onto the contact glass 11 (step 118), and the third original 2b is sent to the position of the pull-out roller 9 (step 119).

The paper discharge sensor 17 detects the leading edge of the first document 2 (step 120), and the discharge of the first document 2 starts (step 121). At the same time, as shown in FIG. 6, the second original 2a is set at the normal reading exposure position (step 122), and the third original 2b is fed to a position where it overlaps with the second original 2a (step 123). Subsequently, the discharge of the first document 2 is completed (step 124).
Thereafter, by repeating the same operation, the second and third originals 2a and 2b are sequentially exposed and discharged.

FIG. 7 shows a conveying belt 10 as a document conveying means.
Instead of the pressure plate 31 and the first and second transport rollers 32,
An example using No. 33 will be shown. The pressure plate 31 is arranged so as to cover the contact glass 11 with the gap 20 interposed therebetween, and has a function of pressing the first document 2 or the like inserted into the gap 20 by an unillustrated means toward the contact glass 11 with an appropriate pressure. .

The first and second transport rollers 32,
Reference numeral 33 has the same function as the first and second pressing rollers 27 and 28, and is arranged in the same positional relation as these. First document 2 sent into gap 20
The sheet is pressed by the first and second transport rollers 32 and 33 while being pressed by the pressure plate 31, and is sent to the sheet discharge side. By appropriately setting the pressing force by the pressure plate 31, the transport motor can send out the first document 2 or the like with a low load, and the structure is simpler and less expensive than that using the transport belt 10. Can be done.

In the above description, only the first to third originals 2, 2a and 2b have been described as originals, but the same applies to a large number of originals. In this transport method, the size of the document is specified. However, in the case of a document of another size, the present embodiment is not applied as it is. Therefore, switching of the control unit is performed as performed by the conventional transport method.

[0041]

According to the present invention, the following remarkable effects are obtained. 1) The next original can be fed onto the contact glass during the exposure of the previous original, so that the time required to replace the original is shortened and the feeding efficiency is improved. 2) When the document replacement time is kept constant, paper feeding can be performed at a lower speed than in the conventional transport system. Therefore, power consumption and noise can be reduced, and durability can be improved. 3) Since a structure in which the next original is fed while the previous original is pressed by a pressing roller or the like is adopted, the pages of the original on the contact glass are not disturbed at all. That is,
Exposure and discharge are performed after being surely separated. 4) After the previous document has been sent to the paper discharge side, the next document that has been superimposed is set at a proper position, so that reliable separation is performed. 5) Since the detection sensors are arranged at the respective locations, reliable sheet feeding, conveyance, and sheet discharging are performed. 6) When a pressure plate is used as the document conveying means, the load on the contact glass is reduced, the size of the conveying motor is reduced, the structure is simplified, and the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall structure of an embodiment of the present invention and explaining a sheet feeding operation thereof.

FIG. 2 is a cross-sectional view illustrating a state in which a first document is fed in the embodiment.

FIG. 3 is a cross-sectional view illustrating a setting of an exposure position of a first document and a feeding state of a next document in the embodiment.

FIG. 4 is a cross-sectional view illustrating a state where the first and second originals are overlapped in the embodiment.

FIG. 5 is a cross-sectional view showing a state in which a first original is discharged, a second original is set to an exposure position, and a third original is fed in the embodiment.

FIG. 6 illustrates the discharge of a first document and a second accompanying the discharge according to the present exemplary embodiment.
FIG. 9 is a cross-sectional view showing a state of feeding and transporting a third document.

FIG. 7 is a partial cross-sectional view showing a document conveying means using a pressure plate and a conveying roller used in place of the conveying belt of the document conveying means in FIGS. 1 to 6;

FIG. 8 is a flowchart for explaining an operation from sheet feeding to sheet discharging according to the present embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 automatic document feeder 2 first document 2 a second document 2 b third document 3 device body 4 document table 5 document partition plate 6 document recall roller 7 separation roller 8 separation belt 9 pullout roller 10 transport belt 11 contact glass 12 Document scale 13 Discharge roller 14 Discharge roller 15 Document set sensor 16 Registration sensor 17 Discharge sensor 18 Guide 19 Guide 20 Gap 21 Rotary shaft 22 Pressure roller 23 Partition plate 24 Front end roller 25 Rear end roller 26 Endless belt 27 First Pressing roller 28 second pressing roller 29 guide roller 30 guide roller 31 pressure plate 32 transport roller 33 transport roller

Continuation of front page (56) References JP-A-4-101942 (JP, A) JP-A-5-43103 (JP, A) JP-A-5-24720 (JP, A) JP-A-2-64581 (JP) JP-A-4-32444 (JP, A) JP-A-5-139573 (JP, A) JP-A-3-256949 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB G03G 15/00 G03B 27/58-27/64 B65H 5/00-5/38 B65H 29/00-29/68

Claims (6)

(57) [Claims] An original table on which a plurality of original bundles to be stacked is mounted, and an original separating plate which abuts or separates from the leading end of the original bundle so as to be able to freely contact with and separate from the original bundle, thereby restricting the advance of the original bundle in the sheet feeding direction. When,
Separation means for separating a bundle of documents to be fed, document conveyance means arranged opposite to the contact glass via a contact glass for exposure and at least two documents, and a gap capable of inserting at least two documents, and the document conveyance means A pair of pressing rollers disposed downstream of the sheet discharging direction and pressed against the contact glass side; a pull-out roller disposed upstream of the document conveying means for feeding a document into the gap; A discharge roller disposed downstream of the means for feeding the exposed document to the discharge side, between the first pressing roller and the pull-out roller disposed upstream of the pressing roller in the conveying direction. Is formed slightly shorter than the document length L, and a second pressing roller disposed downstream of the pressing roller in the transport direction is near the leading end of the document being exposed and tip Ri is disposed upstream, during said exposure <br/> light of the previous document to overlie the preceding document pullout
A roller is fed into the gap by the roller and has a leading edge at a distance a 'upstream from the position of the second pressing roller, and has a leading end near the leading end of the next original and downstream of the leading end with the first pressing force. An automatic document feeder, wherein a roller is disposed, and the distance a 'is formed to be at least larger than a distance a from a leading end of a previous document being exposed to the discharge roller. 2. The automatic document feeder according to claim 1, wherein said document feed means is a transfer belt. 3. The automatic document feeder according to claim 1, wherein said document feeder has a pressure plate for pressing the document toward the contact glass. 4. The automatic document feeder according to claim 1, wherein a document set sensor, a registration sensor, and a sheet discharge sensor for detecting a position of the document are arranged near the document partition plate, the pull-out roller, and the sheet discharge roller. 5. An automatic document feeder according to claim 1, wherein a document scale is provided near said contact glass for abuttingly engaging a document mounted on said contact glass and setting said document at an exposure position. apparatus. 6. A document set sensor detects the leading edge of a document bundle, advances the document bundle in the paper feeding direction, separates only the preceding document by a separating means, and separates the separated document by a pull-out roller and a document. fed into the gap between the contact glass and the document conveying means by the conveying means, and exposure was exposed positioning of the previous document by the document scale, on the destination of the document by the pull-out roller the following document continued during the exposure
And a first pressing roller and a second pressing unit disposed on the downstream side in the paper discharging direction in the document conveying unit based on the detection of the registration sensor. The roller is stopped near the upstream side of the first pressing roller.
And / or simultaneously sending the previous document and the next document in the sheet discharging direction while pressing the second document with the second pressing roller, and setting the next document at a predetermined exposure position while discharging the previous document with the sheet discharging roller. An automatic document feeding method, comprising: performing exposure and repeating the same operation sequentially to complete exposure of a document bundle.