JPH08133588A - Circulating type document automatic feeding device - Google Patents

Abstract

PURPOSE: To prevent a paper feed failure and improve the reliability, in a circulating type document automatic feeding device for preventing the paper feed failure at recirculation of a document, by detecting the set abnormality of a paper discharge unit from the placed document. CONSTITUTION: This device has a document table 13 for setting a document bundle; a paper feed part 14 for separating and feeding the documents on the table 13; a carrying passage 15 for carrying a fed document (p) to an exposing position on a contact glass 12; and a paper discharge part 17 for returning the document carried out from the exposing position and reversed by a reversing part 15 onto the document table 13. Thus, it has a paper discharge unit 18 having the paper discharge part 17 and moved according to the document size; a document set sensor 24 for detecting the document top end on the table 13; a placed document rear end detecting sensor 48 arranged under the paper discharge unit 18 and moved together with it to detect the document rear end on the table 13; and a controller for prohibiting the above paper feeding operation when one of the sensors 24, 48 is non-detectable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circulating type automatic document feeder, and more particularly, to a device for preventing paper feeding failure during document recirculation.

[0002]

2. Description of the Related Art Conventionally, copy originals attached to a copy machine and placed on an original table are sent to an exposure position on a contact glass, and after the original image is exposed, the exposed originals are bundled on the original table. There is known a circulating type automatic document feeder for returning the document to the upper side, and by repeating this operation, it is possible to expose the document image at least once.

This type of automatic circulating document feeder is provided with a paper discharge section for returning the exposed document onto the document table after the document is placed on the document table with the leading edge of the document abutting against the stop claw. The paper discharge unit is manually moved in the paper feed direction of the original according to the original size, and is set at the position clicked during this movement.

[0004]

However, in such a conventional circulating type automatic document feeder, the paper discharge unit is set at a position more than a predetermined distance from the rear end of the document stack on the document table. As a result, the distance from the member that pushes out the document bundle provided in the paper discharge unit to the stop claw becomes longer than the document size, and the member cannot push the document stack to the stop claw. Therefore, there is a problem that the stacking state of the document bundle is not appropriate due to the defective stacking of the returned documents, and a sheet feeding failure such as double feeding or no feeding of the documents occurs at the next sheet feeding.

The member for pushing out the original stack is clicked when the paper discharge unit is moved to a position of about 10 mm ± 2 mm from the rear end of the original, but many kinds of original sizes are processed. Since it is general, there are multiple click positions. Therefore, the paper feed failure occurs due to carelessness such as a mistake in setting the paper discharge unit or forgetting this work itself. Further, there are some which display the set position of the paper discharge unit according to the size of the original placed on the original table, and this is also the same.

In order to solve this problem, the transport distance of the document transported in the apparatus corresponding to the set position of the paper discharge unit and the transport time for transporting the document are constant for each size of the document. By recognizing the transport distance of the document according to the set position and detecting and comparing the actual transport time, it is possible to detect the set abnormality of the discharge unit and stop the document feeding in one cycle. It was thought to be possible.

However, the document transfer time, which is an important factor in this method, varies depending on the type and thickness of the document even when the transfer distance is a fixed distance corresponding to the document size, and the slip amount of the roller and the like vary depending on the use environment. Since it is rarely constant, it is possible to detect an abnormal setting of the discharge unit when the transfer time is greatly different from the transfer distance, that is, when the operator forgets to move the discharge unit. However, it is not possible to detect a set abnormality such as when the movement of the paper discharge unit is insufficient. Therefore, it is not possible to reliably prevent defective paper feeding during document recirculation.
There is a problem of low reliability.

In view of this, the invention according to claim 1 prevents occurrence of a document feeding failure by detecting from the placed document that the paper discharge unit is not set at an appropriate position. The purpose is to improve reliability. Another object of the present invention is to maintain the usability by disposing the detection means outside the document transport path so as not to interfere with the placement and return of the document.

[0009]

To achieve the above object, the invention according to claim 1 separates a document table on which a plurality of documents can be stacked and a document placed on the document table one by one. And a paper feed unit for feeding the fed document to the processing position, and a paper discharge unit for returning the processed document delivered from the processing position onto the document table.
A paper discharge unit provided with the paper discharge unit and movable in the paper feed direction of the original according to the original size; and a front end detection means for detecting the front end in the paper feed direction of the original placed on the original table. In the circulating automatic document feeder, both the leading edge detecting means and the trailing edge detecting means that move together with the paper discharge unit to detect the trailing edge of the original on the original table in the sheet feeding direction detect the original. And a paper feed prohibiting means for prohibiting the paper feed operation when not detecting.

Further, the invention according to claim 2 is characterized in that the trailing edge detecting means is provided below the document placing surface of the document table.

[0011]

According to the first aspect of the present invention, the front end of the original on the original table in the paper feed direction is detected by the front end detection means, and the rear end is detected by the rear end detection means that moves together with the paper discharge unit. Then, when neither the leading edge detecting means nor the trailing edge detecting means detect the document, the paper feeding prohibiting means prohibits the paper feeding operation. Therefore, the setting abnormality of the paper discharge unit is detected, and the original is not fed at this time.

According to the second aspect of the invention, the trailing edge detecting means is disposed below the document placing surface of the document table.
Therefore, the trailing edge detection means is out of the route when the document is placed or returned, and does not come into contact with the document.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment attached to a copying machine of a circulating type automatic document feeder according to the present invention. First, the configuration will be described.

In FIGS. 1 and 2, 10 is a main body of the copying machine, 11 is a circulating type automatic document feeder (hereinafter, simply referred to as R) attached so as to cover the contact glass 12 of the main body 10 of the copying machine.
It is also called DF). RDF11 is a multiple document p
An original table 13 on which the (original stack P) can be placed, a paper feed section 14 for sending out the lowermost original p of the original stack P placed (set) on the original table 13 onto the contact glass 12, A transport unit 15 that loads and unloads the document p sent from the paper unit 14 onto the contact glass 12, a reversing unit 16 that reverses the document p that is unloaded by the transport unit 15, and a document p from the reversing unit 16 The sheet ejecting unit 17 for returning to the table 13 is provided, and the sheet ejecting unit 17 is manually moved in the sheet feeding direction according to the size of the document p to regulate the rear end position of the document stack P. It is provided in the paper discharge unit 18 including the fence 19. The RDF 11 sequentially sends the original p on the original table 13 to the exposure position (processing position) on the contact glass 12, and after the exposure of the main body 10 is completed, the original p is moved to the upper surface side of the original stack P on the original table 13. It is supposed to be returned, the main body
When the refeed signal from 10 is received, this operation is repeated to circulate the original p.

The paper feeding unit 14 has a pair of side fences 21 that are manually moved laterally with respect to the paper feeding direction of the original p, and has a notch portion and is rotated by a paper feeding signal of the original p from the main body 10. A plurality of calling rollers 22 for feeding the original p in the paper feeding direction and an original stopper 23 whose base portion is supported so that the leading end thereof can be swung are provided to feed the original p set on the original table 13. A side fence 21 controls the side in the paper direction and a document stopper 23 regulates the front end. The original stopper 23 is adapted to enable the feeding roller 22 to feed the original p (original bundle P) on the original table 13 by rotating the front end upward by a driving means (not shown). Further, after this, the leading end is lowered to make a circuit, and the original p returned from the rear is stopped at the leading end to correct the skew of the returned original p and the original p on the original table 13 is being fed. The original p and the returned original p are separated from each other.
The original p on the original table 13 is set by the calling roller 22.
A document set sensor 24 arranged near the document detecting sensor detects the leading edge thereof, and the completion of feeding the document stack p is detected by a partition document detecting sensor 25 arranged downstream of the document stopper 23 in the sheet feeding direction. Has become.

Further, the paper feed section 14 is driven by a conveyance guide 26 which extends in a curved manner from the vicinity of the document stopper 23 to one end of the contact glass 12 and a rubber roller arranged along the guide 26. Separation belt 27 and separation belt 27
A separation roller 28 that is in pressure contact with the separation belt 27; a pair of pull-out rollers 29 that pulls out the document p that has passed through the separation belt 27 and the separation roller 28 to the contact glass 12 side; and a registration sensor 30 that detects the leading and trailing ends of the document p. I have it. The paper feed unit 14 separates only the lowermost original p by the reverse rotation of the separation belt 27 with respect to the separation roller 28 that rotates in the paper feeding direction, and feeds it along the conveyance guide 26. p
Is pulled out by the pull-out roller 29 and fed onto the contact glass 12. Reference numeral 50 is a flexible sheet that presses the upper surface of the original p with a pressure of about its own weight.

The transport section 15 has an endless transport belt 32 wound around a pair of rollers 31 and capable of forward and reverse driving, and a plurality of pressure rollers 33 for pressing the transport belt 32 against the contact glass 12. The transport unit 15 carries in and stops the original p fed from the paper feeding unit 14 at a predetermined exposure position while the transport belt 32 presses it on the contact glass 12, and the exposed original p is placed on the contact glass 12. To the reversing unit 16. In addition, the reversing unit 16 includes a reversing guide 36 that curves upward from the contact glass 12 side, a reversing roller 37 that is provided along the circumference of the guide 36, and a reversing roller.
37 includes a pressure roller 38 for pressing the document p, and the reversing unit 16 holds the document p carried out from the transport unit 15 by the reversing roller 37 and the pressure roller 38 and guides it to the reversing guide 36. Flip along. Reference numeral 39 denotes a reversing document detection sensor that detects the leading edge or the trailing edge of the document p transported along the reversing guide 36, and 40a and 40b indicate the transport path of the reversed document p through the paper discharge unit 17 or the transport unit. It is a switching claw that switches to 15.

The paper discharge unit 17 is an intermediate belt 41 which conveys the document p wound around a pair of rollers and reversed by the reversing unit 16 toward the paper feeding unit 14, and a document on the document table 13 from the intermediate belt 75 side. A paper discharge guide 42 that forms a transfer path of the document p to the placement portion side, and a plurality of sets of paper discharge rollers 43 that are arranged along the paper discharge guide 42 and discharge the document p onto the document table 13. The paper ejection guide 42 and the paper ejection roller 43 are mounted on a paper ejection unit 18 which is movable on the original table 13 in the paper feeding direction of the original p (left and right in the drawing). The paper discharge unit 17 holds the document p reversed by the reversing unit 16 and conveyed by the intermediate belt 41 by the paper discharge rollers 43, discharges the document p onto the document table 13, and returns it for recirculation. In addition, the paper output unit 17 is provided with the document p.
When the paper discharge unit 18 is manually moved in the paper feeding direction after the paper is set to the position where it hits the document stopper 23,
When the lever 45 that moves while swinging on the rail 44 is clicked, the end fence 19 is positioned at a position separated from the rear end of the document stack P by L1 (10 mm ± 2 mm). In response to the above-mentioned paper feed signal, the push plate 46 provided near the end fence 19
The rear end of the original bundle P on the sheet 13 is moved so as to be pushed out to align the original bundle P. The push-out plate 46 may move the end fence 19 to align the document stack P.

Further, the paper discharge unit 17 is located below the document mounting surface of the document table 13 and the discharged document detection sensor 47 for detecting the front end or the rear end of the document p moved along the discharge guide 42. Is placed on the lower end side of the end fence 19 so as to be located at the position, and the placed document trailing edge detection sensor 48 that detects the trailing edge of the document p when it moves with the paper discharge unit 18 and is positioned at a position according to the document size. Equipped with these sensors 24, 2
The detection signals of 5, 30, 39, 47, etc. are taken in by a controller (not shown) together with other various sensor information. In this sensor group, the sensor 48 for detecting the trailing edge of the placed document
As shown in FIG. 2, the presence or absence of a document is detected obliquely from below and below the rear end of the document p on the document table 13, and can be detected even if the document p is curled. The long-distance type is used. Also,
Similarly, the document set sensor 24 also sets the document p on the document table 13.
The presence or absence of a document is detected obliquely from behind and below the leading edge.

The controller is composed of a CPU, a memory, an I / O circuit, etc., and in accordance with a control program stored in its internal memory in advance, based on a command signal from the copying machine main body 10 and various sensor information, the above-mentioned respective parts 14 to It controls the driving means and solenoids of the group of 17 rollers. Further, when both the document set sensor 24 and the placed document trailing edge detection sensor 48 do not detect the document p, this controller stops at least the driving of the paper feeding unit 14 and prohibits the paper feeding operation of the document p. It is like this. That is, this controller constitutes a paper feed prohibiting means, the document set sensor 24 constitutes a leading edge detecting means, and the placed document trailing edge detecting sensor 48 constitutes a trailing edge detecting means.

Next, the operation will be described. First, the document stack P is placed on the document table 13 while the leading end is abutted against the document stopper 23, and the side surface of the document stack P is regulated by the side fence 21. Position. This completes the document setting. When the start key (not shown) of the main body 10 is pressed, the paper feed signal is transmitted to the RDF 11.

When this paper feed signal is received, first, the controller confirms the detection signals of the document set sensor 24 and the placed document rear end detection sensor 48, and as shown by the solid line in FIG. When the rear end of the original p is not detected by the placed original rear end detection sensor 48 after the push-out plate 46 of the original P is separated from the set original P, the feeding of the original p is prohibited and a display not shown is shown. The means warns that the discharge unit 18 is set abnormally. Further, as shown by a broken line in FIG. 3, when the front and rear ends of the original p are detected by both the sensors 24 and 48 in the vicinity of the original stack P on which the pushing plate 46 is set, the paper discharge unit 18 It is determined that there is no set abnormality in (1) and the feeding operation of the document p is started.
Therefore, the original p discharged from the paper output unit 17 is stopped by the push-out plate 46 as shown in FIG.
It is possible to prevent the sheet 23 from being discharged to a position where it cannot be pushed out to the vicinity of the leading end of the sheet 23, and it is possible to prevent the circulation of the document p.

Here, in the case where the reversing unit 16 is provided with the reversing document detecting sensor 39 and the paper ejection unit 17 is provided with the paper ejection detecting sensor 47 as in the present embodiment, the set position of the paper ejection unit 18 is set. Since the distance L2 between them (the transfer distance of the document p) is determined in accordance with the above, the timing at which the document p passes is constant and varies depending on the size of the document. Therefore, when the position where the paper discharge unit 18 is set is displaced, the distance L2 is shortened and the detection timing is also shortened. (A setting error of the paper discharge unit 18 caused by an operator error is a large document. In most cases, the transfer time corresponding to the set position of the document p is compared with the actually detected transfer time so that the controller can recognize the set position of the paper discharge unit 18). By doing so, it is possible to detect the setting abnormality of the paper discharge unit 18 and stop the feeding of the document p in one cycle. However, the transfer time of the document p between the sensors 39 and 47 depends on the type and thickness of the document p even at a constant distance L2 between these sensors depending on the set position of the paper discharge unit 18.
Further, it is unlikely that the slip amount or the like of the roller fluctuates in the use environment and becomes constant. Therefore, when the actual transfer time is greatly different from the distance L2, that is, when the worker forgets to move the paper, the paper discharge unit 18 is generated.
Although it is possible to detect a set error in the
It is not possible to detect the set abnormality such as when the movement of 18 is insufficient. On the other hand, in this embodiment, together with the leading edge of the document p placed on the document table 13, the paper discharge unit
Since the setting abnormality of the paper discharge unit 18 is detected by detecting the trailing edge of the placed document trailing edge detection sensor 48 that moves with 18, the document p placed before the paper feeding operation is detected.
From this, it is possible to detect the setting abnormality of the paper discharge unit 18, and it is not affected by the slip of the rollers 36, 37, 43 and the like.

When the discharge unit 18 is set normally, the document stopper 23 is rotated upward to open the transport path of the document p, and the document stack P on the document table 13 is pushed out at the rear end. It is pushed out by the plate 46 and the calling roller 22
Is rotated and is sent to the separation belt 27 and the separation portion of the separation belt 27. Next, the originals p are separated and fed one by one from the bottom of the original stack P by the separating belt 27 and the separating belt 27, and are delivered to the pull-out roller 29 and the conveying belt 32 to reach the exposure position on the contact glass 12. After being brought in and stopped, it is exposed. During this exposure, the next original p
Registration sensor right before the conveyor belt 32 after the paper is separated and fed
It waits at the position where the tip is detected by 30. Therefore, the copy distance is shortened and the speed is increased by shortening the transfer distance of the next original p after the exposure.

After the exposure, the processed original p is carried out from the exposure position on the contact glass 12 by the conveyor belt 32, transferred to the reversing unit 16 and the paper ejecting unit 17, and ejected onto the original table 13. The sheets are printed and returned onto the document stack P. At this time, since the leading end of the document stopper 23 is lowered, the returned document p is urged against to correct the skew, and is separated from the fed document p on the document table 13. Therefore, when the feeding of the document p is completed,
The partition p is detected by the partition document detection sensor 25 because there is no document p on the downstream side of the leading end of the document stopper 23, and the sheet feeding operation is completed without making it impossible to determine the order of the documents p. When the original p is circulated, the original p is accurately circulated by restarting the feeding of the original p by the paper feed signal. Therefore, the reliability of RDF11 is high.

As described above, in this embodiment, in addition to detecting the leading edge of the original p on the original table 13, the trailing edge of the original p is detected by the mounted original trailing edge detection sensor 48 that moves together with the paper discharge unit 18. , The paper feed operation is prohibited when neither of the originals p is detected, so that there is an abnormality in the setting of the paper discharge unit 18 before the paper feed operation from the original p placed on the original table 13. It is not detected that the document p feeding operation is started. Therefore, it is possible to prevent the paper feed failure during the recirculation of the original p, the original p is not returned to the position where the paper feed failure occurs, and the reliability is improved.

Further, since the placed document rear end detection sensor 48 is disposed below the document placement surface of the document table 13, it is out of the transfer route of the document p and is not transferred when the document p is placed or returned. There is no contact. Therefore, the original p is not hindered from being placed or returned and the usability is not deteriorated. In the present embodiment, it is described that the paper feeding operation of the original p is prohibited unless the paper discharge unit 18 is set at the proper position according to the original size, but the original p is not circulated in only one copy. In this case, even if the paper discharge unit 18 is not in the proper position, there is no problem even if the paper feeding operation is executed. Therefore, it goes without saying that the paper feeding operation may not be prohibited in this setting.

In the present embodiment, an optical sensor is used as the detecting means for detecting the leading edge and the trailing edge of the original, but it goes without saying that a mechanical sensor may be used for detection.

[0029]

According to the first aspect of the invention, when neither the leading edge nor the trailing edge of a document on the document table cannot be detected, a setting abnormality of the paper discharge unit is detected and the document feeding operation is prohibited. Therefore, it is possible to reliably detect the setting abnormality of the paper discharge unit, and the document feeding operation is not started. Therefore, it is possible to prevent a paper feed failure when the originals are circulated, and a stacking failure of the returned originals does not occur. As a result, reliability is improved.

According to the second aspect of the invention, the means for detecting the trailing edge of the document is arranged outside the document transport path, so that the document placement and return is not hindered. Usability does not deteriorate.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment attached to a copying machine of a circulation type automatic document feeder according to the present invention, and is a front perspective view showing the entire configuration thereof.

FIG. 2 is a state diagram showing a state where the original is placed.

FIG. 3 is a plan view illustrating the function and effect thereof.

[Explanation of symbols]

 10 Copying machine main body 11 Circular automatic document feeder 12 Contact glass 13 Original table 14 Paper feed section 15 Feed section 16 Reversing section 17 Paper ejection section 18 Paper ejection unit 24 Original set sensor (leading edge detection means) 48 Rear edge of placed original Detection sensor (rear end detection means)

Claims (2)

[Claims] 1. An original table on which a plurality of originals can be stacked, a paper feed section for separating and feeding the originals placed on the original table one by one, and processing the fed originals. A transport unit that transports the document to the position, a paper discharge unit that returns the processed document that has been discharged from the processing position to the document table, and a paper discharge unit that can move in the document feed direction according to the document size. A circulating type automatic document feeder having a leading edge detection means for detecting the leading edge of the document placed on the document table in the sheet feeding direction. A trailing edge detection unit that detects the trailing edge of the document in the sheet feeding direction; and a sheet feeding prohibition unit that inhibits the sheet feeding operation when neither the leading edge detection unit nor the trailing edge detection unit detects the document. Circular manuscript automatic characterized by the provision Feeder. 2. A circulating automatic document feeder according to claim 1, wherein the trailing edge detecting means is arranged below a document placing surface of a document table.