JP3072117B2 - Automatic document feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder mounted on a copying machine.

[Conventional technology]

2. Description of the Related Art In an automatic document feeder for automatically feeding a copy original onto a contact glass of a copying machine, an apparatus for automatically discharging an exposed copy original from the contact glass is often used.

In a conventional automatic document feeder of this type, for example, a unit for pulling out one document from a document bundle placed on a document table and a unit for conveying the document onto a contact glass of a copying machine are simply provided. The drive is performed by one drive source, and the size of the apparatus is reduced by also using the drive source.
Therefore, the method of feeding a document in such an automatic document feeder is such that a bundle of documents stacked on a sheet feeding table is
The document is fed one by one sequentially from the bottom document to the exposure position on the contact glass, and one exposed document is sent to the paper discharge path simultaneously with the feeding operation of the next document, for example. That is, the exposed document stays downstream of the exposure position in an undischarged state, and is discharged when the next document is fed.

[Problems to be solved by the invention]

However, in such a conventional automatic document feeder, only one document can be fed in one document feeding operation, and the conveyance efficiency is poor due to a large interval between the fed documents. It has been difficult to increase the speed of the automatic document feeder.

On the other hand, for example, it is conceivable to shorten the feeding interval by changing the timing of feeding and discharging according to the size of the fed document, thereby increasing the speed of the automatic document feeding apparatus. When the final document is discharged, the document is continuously discharged together with the immediately preceding document, whereby the speed of the automatic document feeder can be increased.

However, even in this case, since the interval between the final document and the immediately preceding document is small, the previous document comes into contact with the final document at the time of ejection, and the final document buckles or enters under the previous document. The problem that it is easy remains.

[Object of the invention]

Therefore, according to the present invention, when the final document is discharged, the final document and the immediately preceding document are continuously discharged, and when the final document is smaller than a predetermined size, the immediately preceding document is discharged onto the document bundle. After a predetermined period of time, the final document is ejected, while speeding up the automatic document feeder.
The purpose is to ensure the operation of discharging a bundle of documents.

[Means for solving the problem]

According to the present invention, in order to achieve the above object, a document bundle including a plurality of documents stacked on a paper feed table is sequentially fed one by one to an exposure position on a contact glass, and the exposed document is exposed to the light. When the next document is located at the exposure position on the contact glass, the exposed document is also placed on the contact glass while the document is conveyed from the position in the discharge direction and the interval between the exposed document and the next document is An automatic document feeder that variably controls the timing of feeding the next document so as to have a predetermined value such that the document is positioned at a position in the discharge direction from the exposure position. The last original detecting means for detecting that the original is the last original of the bundle, and the last original detecting means detects that the original fed to the exposure position is the last original of the original bundle. When the final document is discharged, a control is performed to delay and discharge the final document for a predetermined time so that the interval between the document immediately before the final document and the final document is larger than the predetermined value. And means.

Further, according to the present invention, in order to achieve the above object, when the predetermined value is smaller than a predetermined size of the exposed document, the next document is located at the exposure position on the contact glass. When the exposed document is also a predetermined value such that it is located at a position in the discharge direction from the exposure position on the contact glass, and when the size of the exposed document is a predetermined size or more, When the next original is located at the exposure position on the contact glass, the exposed original has a predetermined value such that the conveyance on the contact glass has been completed, and the control unit controls the final original. When the size is equal to or larger than a predetermined size, when the last original detecting means detects that the original fed to the exposure position is the last original of the original bundle, the final original is detected. When discharging, it is characterized in performing control to discharge without delaying the predetermined time.

〔Example〕

 Hereinafter, the present invention will be described based on examples.

FIGS. 1 and 2 are diagrams showing an embodiment of an automatic document feeder embodying the present invention, and FIGS. 3 to 5 are flow charts showing a discharge related process of an example of the feeding method.

 First, the configuration will be described.

1 and 2, reference numeral 10 denotes a copying machine main body (not shown in detail), and reference numeral 11 denotes a contact glass 12 of the copying machine main body 10.
An automatic document feeder 11 is disposed so as to cover the upper portion. The automatic document feeder 11 includes a document feed table 21 for setting (placing) a document bundle including a plurality of documents, and a sheet feed table. A paper feed unit for sequentially feeding a bundle of documents set on the sheet 21 one by one, for example, sequentially feeding the bottom document onto the contact glass 12
22, a transport unit 23 for loading and unloading the original sent from the paper feed unit 22 onto and out of the contact glass 12, a reversing unit 24 for reversing the original discharged by the transport unit 23, and a document from the reversing unit 24. The apparatus includes a return unit 25 for returning a document bundle on the paper feed table 21 and a control unit 26 for controlling these units.

The paper feed table 21 is located at one end side (forward side in the transport direction) of the apparatus as shown in the figure, and a plurality of call rollers having a pair of side fences 31 and cutouts
32A and 32B are provided. The leading end of a document stopper 33 is lightly in contact with the upper surface of the document bundle placed on the sheet feeding table 21 by its own weight. Abutting at the leading end, the original bundle that is first set on the paper feed table 21 is separated from the discharged original bundle discharged above the original bundle by the return unit 25, and these originals are separated. Correct the skew. In addition, a document set sensor 34 is provided in front of the call rollers 32A and 32B.
The presence or absence of a document set on 21 is detected by this document set sensor 34. The stoppers 33 are each supported on a side plate (not shown) of the automatic document feeder 11 so as to be vertically swingable, and a controller 100 (described later) operates a solenoid (not shown) according to a start signal transmitted from the copying machine main body 10. At the time of operation (ON), the solenoid drives the stopper 33 upward, thereby enabling re-feeding of the inverted and discharged originals onto the original bundle on the paper feed table 21. A pressing plate 36 made of a flexible sheet (for example, Mylar) is provided on the near side of the document stopper 33 in the document conveying direction, and the pressing plate 36 is driven up and down by a solenoid 35 like the document stopper 33. Then, the upper surface of the document is pressed with a low pressure while bending while being lowered.

The paper feed section 22 is contact glass from near the stopper 33
12, a conveyance guide 41 which extends in a curved manner to one side end, an endless belt 42 arranged along the guide, and a separation roller 43 which has a built-in one-way clutch (not shown) and presses against the endless belt 42. And the endless belt
Pull-out rollers 44 and 45 for pulling out the original separated by the separation roller 43 to the contact glass 12 side, and the final original placed on the top of the original bundle by detecting the original in front of the original stopper 33. A document partition detection sensor 46 for detecting whether or not a document has been fed, a registration sensor 47 for detecting the leading edge and the trailing edge of the transported document, and a paper feeding motor 48. Here, the document partition detection sensor
Reference numeral 46 denotes a final document detecting means for detecting that a document fed to an exposure position described later is a final document.
The endless belt 42 and the separation roller 43 separate only the lowermost document and transport it to the pull-out rollers 44 and 45 due to a difference in speed between the two and a difference in friction coefficient with the document paper. The drive is disconnected by the clutch 49. When a registration sensor 47 provided at a discharge section from the paper feed section 22 to the transport section 23 detects the leading end of the document, the clutch 49 is turned off and the driving force to the separation roller 43 is cut off. The roller 45 of the pull-out rollers 44, 45 is a roller that is driven while being urged by the roller 44, and a rotary encoder (not shown) is connected to the roller 45. This rotary encoder and registration sensor
Reference numeral 47 denotes a size detecting means for detecting the size of the document.

The transport unit 23 includes an endless transport belt 53 wound around a pair of rollers 51 and 52, and a plurality of pressure rollers 54 for pressing a lower running portion of the transport belt 53 against the contact glass 12. The unit 23 carries the original from the paper feeding unit 22 into a predetermined exposure position on the contact glass 12 by the operation of the belt conveyance motor 55, and carries out the exposed original from the contact glass 12 to the reversing unit 24. . Here, the exposure position is, for example, a position where the rear end of the document substantially coincides with the left end side of the contact glass 12 in FIG. 1, and after the registration sensor 47 detects the rear end of the document, the pull-out roller 45
The endless transport belt 53 is driven to rotate reversely based on the count number of the encoder that detects the rotation of the belt.

The reversing unit 24 includes a reversing guide 61 that extends upwardly from the other end of the contact glass 12, a reversing roller 62 provided along the guide, and a pressure roller 63 that presses the reversing roller 62. A switching claw 64 displaceable between a solid line position and an imaginary line position on the downstream side of the reversing roller 62, a reversing sensor 65 for detecting a document in the reversing conveyance path, and a reversing motor for driving the reversing roller 62. 66. The reversing guide 61 can reverse the upper and lower surfaces of the document when the document moves (U-turn) along the internal reversing conveyance path.
The reversing roller 62 and the pressure roller 63 are driven by a single motor separately from the endless transport belt 53, and their rotation is controlled based on the detection information of the reversing sensor 65 and the like in conjunction with the operation of the endless transport belt 53. When the switching claw 64 is switched to the solid line position in the drawing, the switching claw 64 guides the exposed document (for example, one-sided document or both-sided exposed double-sided document) to the return portion 25 side, while In this case, the exposed document (for example, a single-sided exposed double-sided document) can be inverted and the inverted document can be sent to the contact glass 12 side.

The return unit 25 is connected to a paper discharge unit 71 movable on the paper feed table 21 in the document conveying direction and a rear side of the paper discharge unit 71 in the paper discharge direction, and expands and contracts as the paper discharge unit 71 moves. It has guide plates 72, 73, 74 constituting a guide portion, and an intermediate belt 75 for transporting the document discharged from the reversing portion 24 to the paper discharge unit 71, and the paper discharge unit 71 is moved from the intermediate belt 75 side. A guide 76 that forms a paper discharge path to the original placement portion side of the paper feed table 21, a plurality of sets of paper discharge rollers 77A and 77B provided along the guide 76, and paper discharge rollers 77A and 77B are driven. It has a paper discharge motor 78 and an outer cover 79.
When the document is set at a position where the document comes into contact with the document stopper 33, the return portion 25 is moved to a rear end position of the document by a moving means (not shown) and positioned.

Reference numeral 81 denotes a document pushing plate provided in the return portion 25. The document pushing plate 81 pushes the document toward the separation roller 43 simultaneously with the positioning of the return portion 25. Reference numeral 82 denotes a paper discharge sensor installed near the exit of the return unit 25, which detects a document returned from the return unit 25 and outputs paper discharge information. This paper discharge information is given to the controller 100 shown in FIG. 2 together with other various sensor information.

As shown in FIG. 2, the controller 100 includes a CPU 101, an I
/ O circuit 102, TTL 102, ROM 104, clock circuit 105, reset IC 106, input / output buffers 107, 108, 109, counter 11
0, motor control ICs 111 to 114, drivers 115 to 118, etc. (These individual components are known, and detailed description is omitted.)
In accordance with a control program stored in the ROM 104 in advance, the CPU 101 receives command signals from the copier body 10 and various sensors 3
4, 46, 65, 82, 91, 92, 93, based on the information from the motors 48, 55, 66, 78, the solenoid 35, the reversing solenoid 83 of the switching claw 64, and the pushing solenoid 84 of the pushing plate 81. And so on. That is, as described later, the CPU 101 detects that the original fed to the exposure position is the final original of the bundle of originals by the final original detector, and the final original is smaller than a predetermined size by the size detector. Is detected, the final document is discharged with a predetermined time delay,
If the original fed to the exposure position is detected by the final original detecting means to be the last original in the bundle of originals, and if the final original is detected by the size detecting means to be equal to or larger than a predetermined size, the final original is detected. Control means for controlling the discharge of the gas without delay for a predetermined time. In FIG. 2, reference numeral 95 denotes a separation motor for driving the separation roller 43;
Is a display LED.

Next, the document feeding method will be described together with the operation.

First, place the original stack with the image surface facing up beforehand so that the leading end of the original stack contacts the original stopper 33.
After being placed on the top 21 and guiding both sides of the bundle of documents by approaching the side fences 31 on both sides, the paper discharge unit 71 is moved to a position suitable for the document size. Next, when the copy start key of the copying machine body 10 is pressed, the controller
The respective drive systems are appropriately driven by 100, and the lowermost document of the document bundle set on the document feed table 21
The sheet is fed to the exposure position on the copying machine main body 10 by the transfer section 22 and the transport section 23. Further, the size of the fed document is detected by the size detecting means including the registration sensor 47 and the encoder, and the timing of feeding and discharging is variably controlled according to the size of the document based on the detection information.

Specifically, according to a control signal from the copying machine main body 10, the call rollers 32 A and 32 B that are in contact with the lower surface of the document bundle are driven, and the lowermost document of the document bundle is separated by the endless belt 42 and the separation roller 43. The lowermost sheet is separated and conveyed to the pull-out rollers 44 and 45 by the separation unit. At this time, the stopper 33 is swinging upward, and the document conveyed between the pull-out rollers 44 and 45 is
While being conveyed to the exposure position on the contact glass 12 by the pull-out rollers 44 and 45 and the conveying belt 53, the size is detected by the size detecting means. Then, based on the detection information of the size detecting means, the operations of the call rollers 32A and 32B and the sheet feeding unit 22 are controlled, and the document conveyance timing is controlled so that the interval between the conveyed documents is set to the minimum value in a predetermined range.
Therefore, the largest number of originals corresponding to the original size are sequentially fed onto the contact glass 12 per fixed time, and the speed can be increased.

Next, the original surface of the original at the exposure position is exposed by the scanning illumination operation of the copying machine body 10.

Next, the reversing unit 24 and the return unit 25 discharge the original onto the original bundle on the original feed table 21 while reversing the upper and lower (original) surfaces of the exposed original. That is, the original after the exposure is completed is transported by the endless transport belt 53 to the reversing section 24.
After being transported along the reversing roller 62 and the pressure roller 63 along the reversing guide 61, for example, the upper and lower surfaces are reversed, and then transported to the return section 25 in this reversed state. Next, the inverted document is guided by the intermediate plate 75 to the guide plate 72,
The document is conveyed along the guides 73 and 74, is discharged along guides 76 by the discharge rollers 77A and 77B, and is discharged onto the document bundle on the document feed table 21. Further, each document discharged onto the document bundle on the document feed table 21 is
, And are sequentially stacked on the original bundle in a state where the original stopper 33 separates from the original bundle before exposure.

On the other hand, in the present embodiment, the processing shown in FIGS. 3 to 5 is executed by the CPU 101 of the controller 100 in connection with the paper discharging operation.

In the paper discharging process shown in the flowchart of FIG.
First, in step P11, it is determined whether or not the discharge start flag of the CPU 101 is "1". If the determination result is Yes (start flag = 1), in step P12, whether or not the last flag of the CPU 101 is "1" In step P13, whether the count value of the last paper counter provided in the CPU 101 is "1" or not, and in step P14, based on the detection information of the size detecting means, whether the document size is smaller than a small size, for example, LTY (letter size landscape). Is determined. At this time, if the determination result is NO in any of Steps P12 to P14, a normal paper discharging operation is executed in Step 16.

When a plurality of documents in the document bundle are sequentially fed, exposed, and discharged, the document placed on the top of the document bundle starts to be fed, and finally follows the document fed to the exposure position side. And
The final document placed on the top of the document bundle is fed.
At this time, if the original size is small,
Two originals are placed on the original 12, and the succeeding original adjacent to the original placed at the exposure position (the original immediately preceding the final original) is the final original. In this case, after the exposure of the final document,
These two originals are successively returned on the original bundle, and at the time of this return, the discharging operation is stopped for a predetermined time after the previous original of the two sheets is discharged onto the original bundle, and then, Discharge the final manuscript.

Specifically, in the process shown in FIG.
If the determination result is Yes for any of 2 to P14, step P15
After waiting for a predetermined delay time, the sheet discharging operation in step P16 is executed. The predetermined delay time is a time set so that the original paper discharged onto the bundle of originals and the succeeding final original do not come into contact with each other and are reliably separated and discharged. Therefore, even when the interval between the final document and the immediately preceding document is small, the previous document comes into contact with the subsequent final document when the document is discharged onto the bundle of documents, and the final document buckles or the final document is It is prevented from getting underneath.

In the paper discharge check process shown in FIG. 4, first, it is determined whether or not the paper discharge passage flag of the CPU 101 is 1 in step P21, and according to the determination result, the discharge sensor 82 is turned on in step P22 or P24. Alternatively, the OFF state is checked, and if the discharge sensor 82 is ON, the discharge passage flag is set to "1" in step P23. If the paper discharge sensor 82 is turned off in step P24, it is determined in step P25 whether or not the timer value of the internal timer of the CPU 101 that measures the time after passing the document has reached a predetermined value. If so, the paper discharge motor 78 is stopped in step P26. Next, in step P27, the count value of the discharge command by the internal counter of the CPU 101 is decremented, and in step P28, the count value of the last paper is decremented. Then, Step P29
Is used to determine whether the discharge command count value is 1 or not.
If Yes, the discharge start flag is set to 1 in step P30.

In the last paper check process shown in FIG. 5, first, in step P31, it is determined whether or not paper supply is completed.
When the paper feeding operation is completed, it is determined in step P32 whether or not the last original detection unit including the original partition detection sensor 46 is ON. At this time, if there is no leading edge of the original before the original stopper 33 (the last original is fed) and the last original detecting means is OFF, the number of originals (conveyance After the number of documents in the passage is stored, the last flag is set to 1 in step P34.

Thus, in the present embodiment, the controller 100
When the final document is discharged, the final document and the immediately preceding document are continuously discharged when the final document is discharged, and when the final document is smaller than a predetermined size, the immediately preceding document is discharged onto the document bundle and then discharged. After a certain time, the last original is discharged, and if the last original is larger than a predetermined size, the last original is discharged onto the bundle of originals and the last original is discharged without delay for a predetermined time. Therefore, the speed of the automatic document feeder 11 is increased, and a document ejection error is prevented, and the operation of ejecting the document bundle is ensured.

〔effect〕

According to the present invention, at the time of discharging the final document, the final document and the immediately preceding document are continuously discharged, and depending on whether the final document is a predetermined size or less or a plurality of documents on the contact glass, By judging and controlling whether or not to delay the discharge operation, discharge is delayed for paper of a predetermined size or less to prevent a discharge error, and discharge of paper of a predetermined size or more is not delayed. The effect of preventing a decrease in productivity can be obtained. Therefore, the speed of the automatic document feeder can be increased, and the operation of discharging the document bundle can be ensured.

[Brief description of the drawings]

1 to 5 are views showing an embodiment of a document feeding method of the automatic document feeder according to the present invention. FIG. 1 is a side sectional view showing a schematic configuration of the automatic document feeder. FIG. 3 is a control block diagram, FIG. 3 is a flowchart showing the paper discharge processing, FIG. 4 is a flowchart showing the paper discharge check processing, and FIG. 5 is a flowchart showing the last paper check processing. 10: Copier body, 11: Automatic document feeder, 12: Contact glass, 21: Feeding table, 22: Feeding section, 23: Transport section, 24: Reversing section, 25: ... Return unit, 46 ... Document partition detection sensor (final document detection means), 47 ... Registration sensor (size detection means), 100 ... Controller, 101 ... CPU (Control means).

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-78052 (JP, A) JP-A-62-93166 (JP, A) JP-A-1-288542 (JP, A) JP-A 63-93 273853 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 107 G03G 21/00 370-500 G03G 21/14 B65H 29/12-29/24 B65H 29/32

Claims (2)

(57) [Claims] 1. A document bundle comprising a plurality of documents stacked on a sheet feeding table is sequentially fed one by one to an exposure position on a contact glass, and the exposed document is transported from the exposure position in a discharge direction. In addition, the interval between the exposed document and the next document, when the next document is located at the exposure position on the contact glass, the exposed document also in the discharge direction from the exposure position on the contact glass Wherein the original fed to the exposure position is the last original of the original bundle When the last document detecting unit detects that the document fed to the exposure position is the last document in the bundle of documents, the last document detecting unit detects the last document. When you out, 1 of the final document
An automatic document feeder comprising: control means for performing control to discharge the last document with a delay of a predetermined time so that the interval between the previous document and the last document is larger than the predetermined value. 2. The method according to claim 1, wherein the predetermined value is smaller than the size of the exposed document, and when the next document is located at the exposure position on the contact glass, the exposed document is also A predetermined value that is located at a position in the discharge direction from the exposure position on the contact glass, and when the size of the exposed document is equal to or larger than a predetermined size, the next document is placed on the contact glass. When located at the exposure position, the exposed document has a predetermined value such that the conveyance on the contact glass has been completed.If the size of the final document is equal to or larger than a predetermined size, When the last original detecting means detects that the original fed to the exposure position is the last original of the bundle of originals, when discharging the final original, the predetermined time 2. The automatic document feeder according to claim 1, wherein the automatic document feeder performs a control of discharging without delay.