JP2009040576A - Paper sheet conveying device and paper sheet conveying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet conveying device which is unnecessary for repeating the treatment for every paper sheet by a process unit even when any double feed occurs, capable of shortening the treatment time, and saving the burden or the labor of a user, and excellent in convenience. <P>SOLUTION: The feeding operation of paper sheets to a conveying path 13 by a conveying-out unit 17 is performed after detecting that the feeding operation of the paper sheets to a process unit 5 is completed by a feed detection unit 43 for detecting the completion of the feeding operation of the paper sheets to the process unit 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a paper transport apparatus and a paper transport method for feeding paper to a process unit via a transport path. The sheet conveying apparatus and the sheet conveying method according to the present invention can be applied to, for example, a document conveying mechanism in a copying machine or a recording sheet conveying mechanism in a printer. The reading unit provided with the CCD or CIS of the original reading device, or the electrophotographic, ink jet, or thermal transfer recording unit in the image forming apparatus corresponds to the process unit in the present invention.

  Some electrophotographic copying machines include an automatic document feeder (ADF) that automatically sends a document on a document table, and sequentially copies the document supplied from the ADF onto a recording sheet. In such a copying machine, the documents set in a stack on the document tray of the ADF and transported one by one by the pickup roller are sent to the document placement table through a conveyance path provided in the apparatus main body. The image is read by the reading device and an image corresponding to the original is formed on the recording paper. The read original is discharged from the original placement table to the original discharge section on the ADF.

In the copying machine as described above, two or more original documents are overlapped and are simultaneously transported from the ADF into the transport path, so that the so-called “double feeding” may occur. When the double feed state occurs, the document is jammed in the transport path, and the subsequent document unloading operation or reading operation becomes impossible. There is also a possibility that a so-called “copy omission” may occur in which a document that is not copied is created.
Therefore, in Patent Document 1, the ADF is provided with detection means for detecting double feed, and when the detection means detects that the original has fallen into the double feed state, conveyance of the original is immediately stopped. .

JP-A-60-260032

  As described above, in the conventional copying machine, the reading operation is stopped as soon as a double feed is detected, so it is not known how much the reading operation by the reading device for the previously conveyed document has progressed. Assuming that a correct image is not obtained uniformly, all read images including the image of the document that has already been read are discarded. For this reason, it is necessary for the user to reset the original on the ADF and read the original again from the first page, which takes time to reset the original, or the trouble of performing the same original reading operation twice. There was a problem in terms of usability of the copier. In other words, processing by a process unit such as a reading device needs to be performed again from the beginning, and there is room for improvement in that respect.

  The present invention has been made to solve the above-described problems, and even when multiple feeding occurs, it is not necessary to repeatedly process all sheets by the process unit, and therefore, the processing time can be shortened. Another object of the present invention is to provide a sheet conveying apparatus and a sheet conveying method that are easy to use while reducing the burden and effort of the user.

The present invention is directed to a paper transport apparatus that feeds paper to a process unit via a transport path. The paper transport device has completed the operation of taking out the paper one by one from the paper set in a stack and feeding the paper toward the transport path, and the operation of feeding the paper to the process unit. A feed detection unit for detecting
Then, after the feeding detection unit detects that the sheet feeding operation to the process unit is completed, the sheet feeding operation by the carry-out unit is performed. .

  The feeding detection unit can be configured to perform a paper feeding operation by the carry-out unit after a predetermined time has elapsed after detecting that the trailing edge of the paper has passed the transport path.

  Specifically, the predetermined time is set to a time required until the paper is discharged to the paper discharge unit after the supply detection unit detects that the trailing edge of the paper has passed through the conveyance path. be able to.

  The first mode in which the paper feeding operation by the carry-out unit after the feeding detection unit detects that the paper feeding operation to the process unit is completed, and the feeding detection unit, A second mode in which a paper feeding operation is performed by the carry-out unit before it is detected that the paper feeding operation to the process unit has been completed, and the user can switch between the first mode and the second mode. It can be configured to be possible.

  Further, the paper transport method according to the present invention includes a step of sending the paper to the transport path by the carry-out unit, a feed detection step of detecting that the paper transported in the transport path is fed to the process unit, And a step of feeding the next sheet into the conveyance path by the carry-out section after the feeding detection step detects that the sheet has been fed to the process unit.

  The feeding detection unit can perform a sheet feeding operation by the unloading unit after a predetermined time has elapsed since it was detected that the trailing edge of the sheet has passed the transport path.

  Specifically, the predetermined time is set to a time required until the paper is discharged to the paper discharge unit after the supply detection unit detects that the trailing edge of the paper has passed through the conveyance path. be able to.

  In the paper transport device and the paper transport method according to the present invention, the paper detection unit detects that the paper feeding operation to the process unit (the previous paper) has been completed, and then the paper (after (Sheet paper) is sent out. Therefore, even when the subsequent sheet falls into the double feeding state, there is no preceding sheet before the process unit, and the preceding sheet has already been fed to the process unit. For this reason, the process by the process unit for the previous sheet can be surely executed to the end.

  According to this, for example, when the sheet conveying apparatus and the sheet conveying method according to the present invention are applied to the document conveying mechanism of the copying machine, at the time of occurrence of double feeding, the document existing in the conveying path before that time. Thus, the reading operation of the original by the reading device (process unit) can be executed to the end. Therefore, unlike the conventional embodiment in which the reading operation is stopped immediately when a conventional multi-feed is detected, the reading operation is interrupted in the middle of reading, and a manuscript image that must eventually be discarded does not occur. This means that it is possible to clearly distinguish between a document that has fallen into a double-feed state and a document that has been normally read before the double-feed state, and therefore, without destroying the image of the document that has been normally read. You can save it and use it effectively. In other words, since it is possible to execute a copying process without any problem on a normally read original image, it is not necessary to reset all originals to the ADF which is an automatic carry-out unit, or the first sheet Therefore, it is not necessary to perform a reading operation again from the original document, and it is possible to provide a copying machine that is easy to use with less burden on the user or trouble.

  Further, when the paper transport device and the paper transport method according to the present invention are applied to the recording paper transport mechanism of the printer, at the time of occurrence of multi-feed, for the recording paper existing in the transport path before that, The image forming operation by the image forming apparatus (process unit) can be executed until the end. Therefore, the image forming operation is interrupted, and recording paper on which an image is partially formed does not occur, and the user has to check the page on which the image forming operation has been completed, or the burden or time to redesign the print page. By reducing the number, it is possible to provide a printer that is easy to use.

  The feeding detection unit can perform the sheet feeding operation by the unloading unit after a predetermined time has elapsed since it was detected that the trailing edge of the sheet has passed the transport path. According to this, it is possible to secure a sufficient processing time by the process unit and to more reliably execute the process by the process unit to the end.

  More specifically, the predetermined time is set to a time required until the paper is discharged to the paper discharge unit after the supply detection unit detects that the rear end of the paper has passed through the conveyance path. Can do. According to this, after the previous paper is discharged to the paper discharge unit, the subsequent paper is sent out to the transport path. Does not exist. Therefore, it is possible to clearly distinguish the paper that has been processed by the process unit from the paper that has been double-fed and to prevent the both from being mixed.

  A first mode in which the paper feeding operation is performed by the carry-out unit after completion of the paper feeding operation to the process unit, and a second mode in which the paper feeding operation is performed by the carry-out unit before the completion of the paper feeding operation to the process unit. Mode, wherein the first mode and the second mode can be switched by the user, and the feeding timing by the carry-out unit is switched according to the number of sheets conveyed and the user's preference. Therefore, it is possible to improve the practical convenience of a multifunction machine equipped with the sheet conveying device according to the present invention.

  In other words, when the first mode is selected, after the operation of feeding the paper to the process unit is completed, the feeding operation by the next paper carry-out unit is performed. As a result, the image reading speed and the image forming speed are reduced. Inevitable to do. Therefore, as in the present invention, before the completion of the operation of feeding the paper to the process unit, there is provided a second mode in which a feeding operation by the next paper carry-out unit is performed. These first mode and second mode are set by the user. When the second mode is selected, the sheet feeding operation is sequentially performed regardless of the completion of the feeding operation to the process unit. Therefore, there is no problem of a decrease in image reading speed and image forming speed as in the first mode, and a more speedy image reading operation and the like can be realized.

  FIG. 1 to FIG. 3 show an embodiment in which the sheet conveying apparatus according to the present invention is applied to a document conveying mechanism of a copying machine. In FIG. 2, the copying machine 1 includes a paper feeding cassette 2, an image recording unit 3 for forming an image on a recording paper fed from the paper feeding cassette 2 through a recording paper feeding path, and the image And an image reading unit 4 disposed above the recording unit 3. The image recording unit 3 includes a photoconductor unit 5 and a toner cartridge 6 that supplies toner to the photoconductor unit 5 as main components. On the upper surface of the image reading unit 4, an operation panel 7 having various operation buttons and an automatic document conveying device (paper conveying device: hereinafter referred to as “ADF”) 9 are installed. The ADF 9 is assembled in the document pressing cover 10 of the image reading unit 4.

1, 2, and 3, the ADF 9 includes a U-shaped document conveyance path 13 (hereinafter referred to as “conveyance path”) from the upper document tray 11 to the lower document discharge unit 12. Then, the document placed on the document tray 11 is sent to the conveyance path 13 and a document image is formed by the reading device 15 (process unit).
As shown in FIGS. 1 and 3, the ADF 9 includes a carry-out unit 17 that takes out originals one by one from the original 16 set on the original tray 11 and feeds the originals toward the conveyance path 13, and the conveyance path 13. And a group of sensors for detecting the position of the document in the conveyance path 13.

  The carry-out unit 17 includes a pickup roller 19 and a pad 20 that is disposed below the pickup roller 19 and urges the document 16 upward. The roller 19 and the pad 20 cooperate to form a document tray. The documents are taken out one by one from 11 and sent out to the conveyance path 13.

The conveyance roller group is disposed at an upstream position of the conveyance path 13 and is a registration roller (starting roller) 21 that performs a conveyance operation in the downstream direction of the document sent from the unloading unit 17 into the conveyance path 13. The first to third feed rollers 22, 23, 24 provided downstream of the conveyance path 13 relative to 21 and a CIS (Contact) that performs the reading operation of the back side document
The image sensor includes a CIS roller 26 provided at a position opposed to the reading unit 25 and an exit roller 27 provided at the most downstream position and responsible for a document discharge operation to the document discharge unit 12. These rollers 19, 21, 22, 23, 24, and 27 are driven to rotate by receiving the driving force supplied from the ADF motor 33 through the power transmission systems 30, 31, and 32.

  A paper feed clutch 48 is provided in the middle of the power transmission system 30 reaching the pickup roller 19, and the rotational drive supplied from the ADF motor 33 to the pickup roller 19 by turning off the paper feed clutch 48. The power can be cut off. Further, a registration clutch 49 is provided in the middle of the power transmission system 31 reaching the registration roller 21, and the rotational drive supplied from the ADF motor 33 to the registration roller 21 by turning off the registration clutch 49. The power can be cut off.

The reading device 15 includes a platen glass 34 and a bottom frame 35 that supports the platen glass 34, and a CCD (Charge Coupled Device) reading that reads an original in an internal space formed by the platen glass 34 and the bottom frame 35. A unit 36 is provided. The CCD reading unit 36 includes a light source 37 that irradiates scanner light toward an original on the platen glass 34, a CCD image sensor 38 that reads an image by converting reflected light from the original into an electrical signal, and the like.
As shown in FIG. 3, the surface document reading position of the reading device 15 is provided at an intermediate portion between the second feed roller 23 and the third feed roller 24 in the conveyance path 13. That is, the second feed roller 23 is responsible for the operation of feeding the original document to the final reading device 15 and functions as a feed roller in the present invention.

  As shown in FIGS. 1 and 4, various sensors such as a DSS sensor 40, a DRS sensor 41, a WFS sensor 42, a DS2 sensor 43, and a DS3 sensor 44 are provided in the transport path 13 in order from the upstream side. Further, the document tray is provided with a DS1 sensor 45 (see FIG. 4), and detects the size of the document placed on the tray. The DSS sensor 40 detects the trailing edge of the document, and the DRS sensor 41 detects the leading edge of the document and is used for resist timing control.

The WFS sensor (double feed detection unit) 42 detects the thickness of the document flowing in the conveyance path 13. Specifically, a pair of upper and lower rollers are arranged so as to sandwich the conveyance path 13, and the facing interval between these rollers is detected by the WFS sensor 42. Then, the detection value by the WFS sensor 42 is compared with a threshold value stored in the RAM 55 or the ROM 52, and when the detection value exceeds the threshold value, the document sent from the carry-out unit 17 into the conveyance path 13 is in a double feed state. It can be determined that it has fallen.
The DS2 sensor 43 detects the trailing edge of the document that has reached the document reading position. The DS3 sensor 44 detects the trailing edge of the document that has reached the CIS reading unit 25 in the duplex mode. The double feed detection by the WFS sensor 42 is executed only when the double feed detection mode is selected by operating the operation panel 7.

  As shown in FIG. 4, the image reading unit 4 is controlled by an image reading control unit 50 and a main body control unit 51 that controls the entire copying machine 1. The image reading control unit 50 controls the ADF 9, and based on detection signals from sensors such as the WFS sensor 42, the DS1 sensor 45, the DS2 sensor 43, the DS2 sensor 44, the DSS sensor 40, and the DRS sensor 41, It controls the registration clutch 49, the ADF motor 33, the paper feed clutch 48, the CCD reading unit 36, the CIS reading unit 25, and the like.

  The main body control unit 51 receives operation signals from various switches constituting the operation panel 7 and reads a control program stored in the ROM 52, and based on the control program, the image reading control unit 50, the CODEC 53, and the image recording Control unit 3 and the like. In addition to the RAM 55 and timer 57 as work areas, the main body control unit 51 is connected to an image memory 56 in which document images read by the CCD reading unit 36 and the CIS reading unit 25 are stored.

Next, a document reading operation using the ADF 9 will be described with reference to FIGS.
As shown in FIG. 5, first, when an on signal is received from the start button of the operation panel 7 in a state where the original is set on the original tray 11 (YES in S1), the control units 50 and 51 33 is turned on, and the rollers 19, 21, 22, 23, 24, and 27 are rotationally driven through the power transmission systems 30, 31, and 32. As a result, the first original is picked up by the pickup roller 19 (S2), and the original is sent out from the carry-out portion 17 to the conveyance path 13, where the registration roller 21 and the first to third feed rollers 22, 23,. 24, it is transported in the transport path 13 toward the downstream side. Whether or not a document is set on the document tray 11 is detected by DS1 (45). Until the start button of the operation panel 7 is turned on (NO in S1), the image reading unit 4 is in a standby state.

  Next, the control units 50 and 51 confirm whether or not the double feed detection mode (first mode) is selected (S3). When the double feed detection mode is not selected (second mode: NO in S3), the pickup roller 19 is operated with the detection signal from the DSS sensor 40 as the next document feed timing. Specifically, when the trailing edge of the document is detected by the DSS sensor 40 (S4), the elapsed time from the trailing edge detection is measured by the timer 57, and when the predetermined time has elapsed (YES in S5), the DS1 sensor ( Based on the detection signal from step 45), the presence or absence of the document on the document tray 11 is confirmed (S6). If there is a document (NO in S6), the next document is picked up and sent into the conveyance path 13 (S7), and the process returns to S4. If there is no document on the document tray 11 (YES in S6), the ADF motor 33 is driven for a predetermined time until the previously sent document reaches the document discharge unit 12, and the various rollers 21, 22, 23 are driven.・ Rotate 24 and 27 to finish.

  When the double feed detection mode is not selected, the double feed detection by the WFS sensor 42 is not performed even when the double feed occurs, so that each step (S4, S5, S6, and S7) is executed.

  When the double feed detection mode is selected (YES in FIG. 5, S3), as shown in FIG. 6, first, the single-sided copy mode for copying only the front side is selected, or both sides for copying the front and back sides are selected. It is confirmed whether the copy mode or the back side copy mode for copying only the back side is selected (S8). If the single-sided copy mode is selected (YES in S8), the pickup roller 19 is operated with the detection signal from the DS2 sensor 43 as the next document feed timing. Specifically, when the trailing edge of the document is detected by the DS2 sensor 43 (S9), the elapsed time from the trailing edge detection is measured by the timer 57 (S10), and when a predetermined time has elapsed (YES in S10), Based on the detection signal from the DS1 sensor 45, the presence or absence of a document on the document tray 11 is confirmed (S11). Here, the time from when the trailing edge is detected by the DS2 sensor 43 until the document reaches the document discharge unit 12 is defined as “predetermined time”.

  If there is a document on the document tray 11 (NO in S11), the next document is picked up and sent out into the transport path 13 (S12), and the process returns to S9. If there is no document on the document tray 11 (YES in S11), the ADF motor 33 is driven for a predetermined time until the previously sent document reaches the document discharge unit 12, and the various rollers 21, 22, and 23 are driven.・ Rotate 24 and 27 to finish.

  When the duplex copy mode or the reverse copy mode for copying only the reverse side is selected (NO in S8), the pickup roller 19 is operated with the detection signal from the DS3 sensor 44 as the next document feed timing. Specifically, when the trailing edge of the document is detected by the DS3 sensor 44 (YES in S13), the elapsed time from the trailing edge detection is counted by the timer 57 (S14), and when a predetermined time has elapsed (in S14). YES), based on the detection signal from the DS1 sensor (45), the presence or absence of a document on the document tray 11 is confirmed (S15). Here, the time from when the trailing edge is detected by the DS3 sensor 44 until the document reaches the document discharge unit 12 is defined as a “predetermined time”.

  If there is a document on the document tray 11 (NO in S15), the next document is picked up and sent out into the transport path 13 (S16), and the process returns to S13. If there is no document on the document tray 11 (YES in S15), the ADF motor 33 is driven for a predetermined time until the previously sent document reaches the document discharge unit 12, and the various rollers 21, 22, and 23 are driven.・ Rotate 24 and 27 to finish.

  When the double feed detection mode is selected (YES in S3), when the WFS sensor 42 detects that the double feed state has occurred, the ADF motor 33 is immediately stopped and all the rollers are driven to rotate. Stop.

  When the document passes through the conveyance path 13, a document image is formed by the reading device 15 such as the CIS reading unit 25 or the CCD reading unit 36. This document image is stored in the image memory 56 and is recorded (copied) on a recording sheet by the image recording unit 3 after the reading operation is completed or in parallel with the reading operation.

  As described above, even when a double feed state occurs, the reading operation can be executed to the end of the previous document. That is, as described above with reference to FIG. 6, after a predetermined time elapses after the trailing edge of the document is detected by the DS2 sensor 43 or the DS3 sensor 44 until the previous document reaches the document discharge unit 12, A sending operation is performed on the conveyance path 13 for the next document. For this reason, even when the double feed state occurs, the previous document reaches the document discharge unit 12 and the reading operation by the reading device 15 is completed.

  As described above, in this embodiment, after the trailing edge is detected by the DS2 sensor 43 or the DS3 sensor 44, the next document feeding operation by the pickup roller 19 is performed. According to this, even when the next sheet falls into the double feed state, there is no preceding document before the reading position by the CCD reading unit 36 or the reading position by the CIS reading unit 25, and the previous document has already been read. The reading operation has been completed. For this reason, the reading operation by the reading device 15 for the previous document can be surely executed to the end.

  Therefore, according to the present embodiment, an image of a document that is normally read can be stored without being discarded and can be used effectively. In other words, since it is possible to execute the copying process without any problem on a normally read document image, it is not necessary to reset all the documents in the ADF 9 which is an automatic carry-out unit, or the first sheet Therefore, it is not necessary to perform a reading operation again from the original document, and it is possible to provide a copying machine that is easy to use with less burden on the user or trouble.

  In the above embodiment, the paper conveying apparatus according to the present invention is applied to the original conveying mechanism of the copying machine 1, but it can also be applied to a recording paper conveying mechanism of the image recording unit 3 as shown in FIG. . In this case, the pickup roller of the paper feed cassette 2 corresponds to the carry-out portion of the present invention, and the photosensitive unit 5 corresponds to the process unit of the present invention.

  A double feed detection unit 62 is provided at an upstream position of the transport path 61 from the paper feed cassette 2 to the paper discharge unit 60, and the recording paper fed from the paper feed cassette 2 by the double feed detection unit 62 falls into a double feed state. Is detected. Further, sensors 63 and 64 for detecting the completion of the operation of supplying the recording paper to the photosensitive unit 5 are provided at the upstream position and the downstream position of the upstream position of the photosensitive unit 5.

  According to the copying machine shown in FIG. 7, the image forming operation by the photosensitive unit 5 can be executed to the end of the recording paper existing in the transport path 61 before the occurrence of double feeding. Therefore, the image forming operation is interrupted, and there is no recording paper on which an image is partially formed, and the user has to check the page on which the image forming operation has been completed, and the burden and trouble of respecifying the print page. By reducing the number, it is possible to provide a copying machine with excellent usability.

  In the above embodiment, as a specific example of the double feed detection unit 42 (WFS sensor), a method of detecting based on the thickness of the document passing through the conveyance path 13 is described, but the present invention is not limited to this, and other than that. This method can also be adopted. For example, a light receiving element and a light projecting element may be arranged with the conveyance path 13 interposed therebetween, and it may be detected that a double feed state has occurred based on a change in the amount of received light when the document passes. Further, the location of the WFS sensor 42 is not limited to the location in the illustrated example.

  In the above embodiment, the state in which the double feed detection mode is turned on is the first mode, and the state in which the double feed detection mode is turned off is the second mode. However, the present invention is not limited to this. In short, in the second mode, the paper feeding operation by the carry-out unit 17 is performed before the DS2 sensor or the DS3 sensor detects that the paper feeding operation to the process units 5 and 15 is completed. It only has to be.

1 is a system conceptual diagram of an ADF to which a sheet conveying apparatus and a sheet conveying method according to the present invention are applied. 1 is an overall view of a copying machine to which a sheet conveying apparatus and a sheet conveying method according to the present invention are applied. It is a schematic block diagram of an image reading part. It is a block block diagram of an image reading part. It is a flowchart for demonstrating image reading operation | movement. It is a flowchart for demonstrating the operation | movement at the time of double feed detection mode. 1 is a schematic configuration diagram of an image forming apparatus to which a paper transport device and a paper transport method according to the present invention are applied.

Explanation of symbols

5 Process unit (photosensitive unit)
13 Transport path 15 Process unit (reading device)
17 Unloading part 43 Feeding detection part (DS2 sensor)
44 Feed detection unit (DS3 sensor)

Claims (7)

A paper transport device for feeding paper to a process unit via a transport path,
A carry-out unit that takes out the sheets one by one from the sheets set in a stack, and sends the sheets toward the conveyance path;
A paper feed detection unit for detecting that the paper feed operation to the process unit is completed,
The paper transporting apparatus is configured such that the paper feeding operation by the carry-out unit is performed after the feeding detection unit detects that the paper feeding operation to the process unit is completed. apparatus.   The sheet feeding operation is performed by the unloading unit after a predetermined time has elapsed after the feeding detection unit detects that the trailing edge of the sheet has passed the transport path. 1. The sheet conveying apparatus according to 1.   The predetermined time is set to a time required for the paper to be discharged to the paper discharge unit after the feeding detection unit detects that the trailing edge of the paper has passed the transport path. 2. The paper conveying apparatus according to 2. A first mode in which a paper feeding operation by the carry-out unit is performed after the feeding detection unit detects that a paper feeding operation to the process unit has been completed;
A second mode for performing a paper feeding operation by the carry-out unit before the feeding detection unit detects that the paper feeding operation to the process unit is completed,
4. The sheet conveying device according to claim 1, wherein the first mode and the second mode can be switched by a user. 5. A step of feeding the paper to the transport path by the carry-out unit;
A feed detection step for detecting that the paper transported in the transport path is fed to the process unit;
And a step of feeding the next sheet into the conveyance path by the carry-out unit after the feeding detection step detects that the sheet has been fed to the process unit.   6. The sheet conveying method according to claim 5, wherein the sheet feeding operation by the unloading unit is performed after a predetermined time has elapsed after the feeding detection unit detects that the trailing edge of the sheet has passed the conveying path.   The predetermined time is set to a time required for the paper to be discharged to the paper discharge unit after the feeding detection unit detects that the trailing edge of the paper has passed the transport path. 6. The paper conveying method according to 6.

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