JP3029476B2 - Document conveying device for electrophotographic apparatus and method thereof - 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 conveying apparatus and method for an electrophotographic apparatus such as a copying machine, a printer, and a facsimile apparatus, and more particularly, to a document conveying apparatus corresponding to a large-size sheet-through document and a computer paper document. The present invention relates to a document feeder and a method for an electrophotographic apparatus capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, a document feeder of an electrophotographic apparatus is provided with a sheet-through mode for feeding a document corresponding to a document size of A3 or more. In the sheet-through mode, the exposure means of the main body of the electrophotographic apparatus is stopped at a predetermined position, and an image is obtained by exposing the document at a precise speed while being conveyed.

Also, in such a document feeder of an electrophotographic apparatus, the above-mentioned sheet-through document discharge port is commonly used as a continuous computer paper document (hereinafter referred to as CF paper) paper feed port. There is. And this CF
A guide member for positioning the CF sheet in the width direction is provided at the sheet feed port to reliably feed the CF sheet without skew.

The guide member is attached to a carry-in guide plate which forms a carry-in path for CF paper so as to be slidable in a direction perpendicular to the paper carrying direction. When discharging the sheet-through document, the guide member is moved so as to retreat from the discharge path of the sheet-through document.

[0005]

As described above, in the conventional document feeder and method for an electrophotographic apparatus, a guide member provided at a paper feed port for CF paper discharges a sheet-through document. In the sheet-through mode, it is necessary to retract the guide member from the sheet-through original discharge path. However, when both the CF sheet and the sheet-through document are processed, if the guide member is not retreated, there is a problem that the sheet-through document is caught by the guide member and a paper jam (so-called jam) occurs.

Therefore, the invention according to the first aspect of the present invention is an electronic device capable of preventing the sheet-through document from being caught by the guide member of the CF sheet and causing a jam when the sheet-through document is ejected from the sheet feeding port of the CF sheet. It is an object of the present invention to provide a document conveying device for a photographic device. Claim 2
SUMMARY OF THE INVENTION It is an object of the present invention to provide a document feeder for an electrophotographic apparatus having a structure in which dust and the like hardly enter the apparatus while improving the durability of the guide member position detecting means.

Another object of the present invention is to provide a method of transporting a document in an electrophotographic apparatus capable of preventing a sheet-through document from being jammed by a guide member of a CF sheet and causing a jam. I have.

[0008]

According to the first aspect of the present invention,
In order to achieve the above object, a document feeding means for feeding a document to a platen, a document processing means for capturing image information of the document on the platen, and a document for sending a document from the platen after the document processing and discharging the document to the outside A document feeder for an electrophotographic apparatus, wherein the document feeder includes a paper feed port for holding and feeding a computer paper document by a guide member and a discharge port for discharging a sheet-through document. Guide member position detecting means for detecting the position of the guide member slidable in accordance with the size of the document, and the guide member being positioned within a discharge range of the sheet-through document based on the detection result of the guide member position detecting means. A sheet-through document discharge prohibiting unit for prohibiting a sheet-through document discharge process in a certain case.

According to a second aspect of the present invention, in order to achieve the above object, the guide member position detecting means slidably supports a position detecting magnet provided below the guide member and the guide member. And a magnetic sensing element that is disposed on the facing surface via a non-magnetic support member that detects the position of the position detecting magnet. According to a third aspect of the present invention, in order to achieve the above object, after a document is fed onto a platen and image information of the document is captured,
A document conveying method for an electrophotographic apparatus, in which a document is discharged out of the apparatus and a document feeding port for a computer paper document and a sheet discharging port for a sheet-through document are commonly used, a guide member for holding a computer paper document at the paper feeding port Is detected, and when the guide member is within the discharge range of the sheet-through document, the discharge processing of the sheet-through document is prohibited.

[0010]

According to the first aspect of the present invention having the above structure,
Guide member position detecting means detects the position of the guide member. When the detected position of the guide member is within the discharge range of the sheet-through document, the sheet-through document discharge processing is prohibited by the sheet-through processing prohibiting means.
As a result, when the sheet-through document is discharged, the document does not get caught on the guide member and no jam occurs, and the document can be transported safely and reliably.

Further, according to the second aspect of the present invention, the magnetic sensing element is provided so as to face a position detecting magnet provided below the guide member via a non-magnetic support member slidable. The position of the guide member is detected in a non-contact state. This improves the durability of the guide member position detecting means and can be formed without providing a gap in the sliding portion, so that it is possible to prevent problems due to entry of dust and the like into the machine.

Further, according to the third aspect of the present invention, when the guide member is within the discharge range of the sheet-through document, the processing of the sheet-through document is inhibited, so that the sheet-through document is discharged. In addition, it is possible to prevent a jam from being caused by being caught on the guide member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 to 8 are diagrams showing an embodiment of a document feeder for an electrophotographic apparatus and a method therefor according to any one of the first to third aspects of the present invention. FIG. 2 is a configuration diagram showing a copying machine as an electrophotographic apparatus to which the document feeder of the present embodiment is mounted. In the figure, a paper feeding unit 10 as a document feeding means is fixedly arranged on a copying machine main body 11, and feeds out a cut sheet document 13 set on a document table 12. Adjacent to the paper feed unit 10, a copier body 11 is provided with a contact glass 14 as a document mounting table. A transport unit 15 as a document transport unit that can be freely opened and closed with respect to the contact glass 14.
The cut sheet original on the contact glass 14
13 is conveyed. An exposure unit (scanner) 16 made of, for example, a halogen lamp is provided on the opposite side of the transport unit 15 with the contact glass 14 interposed therebetween. The transport unit 15 transports the cut sheet document 13 to a predetermined position on the contact glass 14. After that, the stopped cut sheet document 13 is exposed while moving.

In normal use, one or a plurality of cut sheet documents 13 are set on the document table 12 with the document surface facing down. After the setting is confirmed by the document set sensor 17, a copy start key (not shown) arranged on the copier is pressed, so that the cut sheet document 13 is moved by the recall roller 18 to the separation roller 19 and the separation blade 20. And is separated into individual sheets.
The separated cut sheet document 13 is pulled out by the pull-out roller 21.
And is sent to the transport unit 15. The sent cut sheet document 13 is transported by the endless transport belt 22.
It is sent to a predetermined position of the contact glass 14 and stops. After the stop, exposure is performed by the exposure means 16 on the copying machine main body side,
Thereafter, the sheet is again conveyed by the conveying belt 22 and is sent out from the contact glass 14.

The document non-reversal operation when the cut sheet document 13 is a single-sided document and the document reversal operation when the cut sheet document 13 is a double-sided document will be described with reference to FIG.
FIGS. 3A and 3B are diagrams showing an embodiment of the reversing unit of the document feeder shown in FIG. 2, wherein FIG. 3A shows the position of the claw at the time of non-reversing discharge, and FIG. Indicates the position of the nail.

In FIG. 3B, the document branched to the reversing path by the reversing switching claw 23 is conveyed by a reversing drive roller 27. The reversing driving roller 27 is in contact with a reversing driven roller 45 driven by the reversing roller 27. Then, in the nip portion where the reversing drive roller 27 and the reversing driven roller 45 are in contact,
The document branched to the reversing path by the reversing switching claw 23 is fed. At this time, in conjunction with the inversion switching claw 23, FIG.
As shown in (b), the reversing discharge claw 26 operates to guide the document toward the nip between the reversing driving roller 27 and the reversing driven roller 45 when the document is reversed. Also, when the reverse original is discharged by switchback, the reverse switching claw 23 and the reverse discharge claw 26
In conjunction with the position shown in FIG. 3A, the document fed backward from the nip is guided toward the discharge rollers 24.

The reverse discharge guide plate 29 temporarily stores documents to be reversed and discharged by switchback.
In front of the reverse discharge guide plate 29, that is, at the nip portion between the reverse drive roller 27 and the reverse driven roller 45, a reverse discharge switching claw is provided.
A reversing path is branched toward either the reversing discharge guide plate 29 or the contact glass 14 in accordance with the reversal discharge or reverse copy of the original.

In this embodiment having the above configuration, when the cut sheet document 13 is a one-sided document, the reversing switching claw 23 is located at the position indicated by the solid line in FIG.
13 is sent straight out to the document tray 25 by the discharge rollers 24. When the cut sheet document 13 is double-sided, the inversion switching claw 23 and the inversion ejection claw 26 are at the positions shown in FIG. It is guided by 28 and is conveyed again to a predetermined position of the contact glass 14 by the convey belt 22 which is conveyed backward. Then, after the back surface exposure, it is inverted and discharged again.

At the time of reverse discharge, the reverse switching claw 23 and the reverse discharge claw
The position of the reverse discharge switching claw 26 and the position of the reverse discharge switching claw 28 are shown in FIG. 3B (where the reverse discharge switching claw 28 is indicated by a dashed line), and the leading end of the document is guided by the reverse discharge guide plate 29.
When the trailing end of the document passes the reverse discharge sensor 30, the reverse drive roller 27 rotates in the reverse direction, and the discharge roller is switched back.
It is sent to 24 and inverted. In FIG. 3, 35 is a discharge sensor, 36 is a driven roller, and 37 in FIG. 2 is a presser mylar.

As described above, in this embodiment, the reversing path and the discharging path are branched by the reversing discharge pawl 26 which operates in conjunction with the reversing switching pawl 23, so that the rear end of the original at the time of the reverse discharge is reliably discharged. It can be sent to the road, and the transport reliability at the switchback branch can be improved. Also,
In the present embodiment, the reversing drive roller 27 and the reversing driven roller 45
A reverse discharge switching claw 28 is provided in the nip portion of
The reverse discharge switching claw 28 branches the reverse path toward either the reverse discharge guide plate 29 or the contact glass 14 in accordance with the reverse discharge or reverse copy of the document, so that the reverse copy original is conveyed to the contact glass 14, that is, conveyed. By shortening the transport distance when re-supplying to the belt 22, it is possible to shorten the reversal time of the back side copy original.

That is, in the present embodiment, the reversing drive roller 27 is provided at the center of the reversal conveyance path, and
The distance between 27 and the conveyor belt 22 can be set to about 1/2 of the maximum document length. This realizes a reversing conveyance path that is 以下 or less of the reversing conveyance path of the conventional machine shown in FIG. FIG.
In the reversing section of the conventional machine shown in FIG. 1, a reversing guide made of a mylar or the like corresponds to the reversing discharge claw 26 in the present embodiment.
There are 31. The reversing guide 31 is fixed, and is laid out so that the rear end of the document is directed toward the discharge path by the waist of the document after passing through the reversing guide 31. Further, the reversing conveyance path secures a maximum document length (for one sheet) centered on the turn roller 32 so that the leading end of the document does not reach the conveyance belt 22 at the time of reversal discharge. For this reason, the reverse conveyance path of the conventional machine is longer than that of the present embodiment. In FIG. 9, reference numeral 33 denotes a reverse drive roller, and reference numeral 34 denotes an intermediate transport roller.

As described above, in this embodiment, the reversing path is branched by the reversing discharge claw 26 interlocking with the reversing switching claw 23 so as to feed the original to the reversing path. The transport path for discharging the original from the reversing path can be reliably switched. Next, an original reading operation of an original moving / scanner fixing system, a so-called sheet through system, will be described. In the present embodiment, while conveying a sheet-through original, for example, an original of A3 or larger using the transport unit 15,
The document is read with the exposure means 16 fixed at a predetermined position. That is, the transport unit 15 shown in FIGS. 2 and 3 is provided with a sheet-through original feed unit 40, and the sheet-through original feed unit 40 feeds a sheet-through original to the transport belt 22 of the transport unit 15. I do. In the case of using a sheet-through document, one sheet-through document is turned upward and fed to the feed roller 42 along the document feed table 41. Infeed sensor 43
Detects the sheet-through document and the feed roller 42 is driven,
When it hits the entrance gate 44, the setting is completed. After the setting, the entry gate 44 is released to the state shown by the dashed line by pressing a copy start key (not shown), and is sent to the inversion driven roller 45 by the infeed roller 42, and the inversion discharge switching claw 28 in the solid line state
The cut sheet document 13 is transported in a direction opposite to the transport direction of the cut sheet document 13 by a transport belt 22 that is transported backward on the contact glass 14 while being guided.

Here, when the sheet-through original is conveyed, the exposure means (scanner) 16 on the copying machine main body 11 side is driven by the reversing driven roller.
In order to minimize the influence of the sheet 45 or the sheet-through discharge roller 46, the sheet is fixed to the vicinity of the center of the conveyance belt 22 in the document conveyance direction by the sheet-through document exposure control means 47. On the other hand, the sheet-through document is transported on the contact glass 14 by the transport belt 22 toward the paper feed unit 10. At this time, the sheet-through document is read by the exposure means (scanner) 16 arranged near the center of the transport belt 22 at a position where the document transport state is the best. Therefore, good image quality can be obtained, and reading accuracy of a sheet-through document can be improved.

In FIG. 2, a conveyor belt pressing roller 48 as a pressing member is provided at a position facing the scanner reading position where the exposure means 16 is fixedly arranged.
The contact pressure between the conveyor belt 22 and the contact glass 14 is increased by the conveyor belt pressing roller 48. For this reason, the stability of the document conveyance state is further improved, and the reading accuracy of the sheet-through document is further improved.

Since the original is conveyed in both directions, the reference scale 49 indicating the reference of the contact glass 14 is shown in FIG.
As shown in (1), when the sheet-through document is conveyed, the sheet retreats to a dashed line state, thereby enabling the sheet-through document to be fed back. The sheet-through document that has passed through the reference scale 49 is guided by the switching plate 50 in a dashed line state, sent to the sheet-through discharge roller 46, and discharged to the upper portion of the sheet feeding unit 10.

As described above, the exposing means 16 stops at a predetermined position while moving the sheet-through original fed to the transport belt 22 in the direction opposite to the transport direction of the cut sheet original by the transport belt 22. And the original image can be read. For this reason, the document transport device A
The DF can transport sheet-through documents,
It is possible to perform document exposure by sheet-through while utilizing the operability and transport reliability of the document transport device ADF. Further, there is no need to newly install a sheet-through original transport unit, which is advantageous in terms of operability and cost.

Here, the sheet-through discharge rollers shown in FIG.
46 is driven only in the sheet through discharge direction,
Driving force is input via an electromagnetic clutch as a discharge driving unit. For this reason, the sheet through discharge rollers 46
The drive is performed only at the time of sheet-through discharge, and the sheet-through document released from the conveying force of the conveying belt 22 can be discharged at a stable linear speed.

A gap formed between the transport section 15 and the paper feed section 10 is used as a sheet-through original discharge path. At least one or more sheet-through discharge rollers 46 are provided between the final end of the discharge passage and the final position where the conveyance force by the conveyance belt 22 is applied. At this time, it rotates in both forward and reverse directions.

As described above, the gap formed between the transport section 15 and the paper feeding section 10 is used as a sheet-through document discharge path, and the sheet-through discharge roller for discharging the sheet-through document.
By rotating the 46 in the discharge direction only when discharging the sheet-through document, it is possible to stably discharge the sheet-through document while following the existing apparatus configuration. In FIG. 4, a continuous computer paper document (hereinafter, referred to as CF paper) is carried in from the upper portion of the paper supply unit 10 with the discharge passage of the sheet-through document as a carry-in passage. The CF sheet is transported by the transport belt 22 in the same direction as the transport direction of the cut sheet document 13 and stopped.
It is also possible to read an original on a CF sheet by exposing the F sheet while moving the exposing means 16. According to the present embodiment, the CF paper is carried into the transport belt 22 from above the paper feed unit 10, and the CF paper is transported by the transport belt 22 one page at a time in the same direction as the transport direction of the cut sheet document 13. Then, the document is read by exposing it to light by exposure means. Therefore, while utilizing the operability and transport reliability of the document transport device ADF, the cut sheet,
It is possible to cope with various types of document conveyance such as a sheet-through document and CF paper, and it is possible to simplify a document passing path.

Next, the drive system of the transport section 15 will be described. As shown in FIG. 5, a transport belt is provided in the transport section drive system.
There are provided a conveyor belt motor 60 for driving the 22 and the sheet through discharge rollers 46 and the like, and a reversing motor 61 for driving the feeding rollers 42, the reversing driving rollers 27, and the discharging rollers 24. Conveyor belt 22 and sheet-through discharge roller 46
Is driven in the circumferential direction via a timing belt 62, an idler pulley 63, a timing belt 64 and the like. Conveyor belt
The belt 22 is wound around a belt driving roller 51 and a belt driven roller 52, and is driven to rotate in both directions. Further, the sheet-through discharge roller 46 is driven only in the discharge direction by a pulley 65 with an electromagnetic clutch as discharge driving means. Next, the feed roller 42 and the reversing drive roller 27 are driven by the two-tooth timing belt 68 after passing through the timing belt 66, the idler pulley 67, and the like. Furthermore, a timing belt 69 and a pulley 70 with a one-way clutch,
With the idler gear 71 and the idler gear 72, the discharge rollers 24 are driven only in the discharge direction regardless of the rotation direction of the reversing motor 61.

FIG. 6 is a schematic block diagram showing an embodiment of a document feeder of an electrophotographic apparatus.
1 shows the overall circuit configuration. As shown, ADF CPU
100 is provided with sheet-through document exposure control means 47. The CPU 100 is connected to a control device 102 on the copying machine main body side via a transmission / reception buffer 101, and transmits information by serial communication. The CPU 100 includes an input unit (input buffer) 103 to which a signal of each sensor is input.
A paper feed motor 104 for driving the paper feed unit 10, a transport belt motor 60, a reversing motor 61, and the like are driven. The driving of the three motors is controlled by each of the servo circuits 105 ac. Each servo circuit 105a
To c are a motor ON / OFF command from the CPU 100 and a command to control the motor speed (from the CPU 100 to the D
/ A converter 106) and a motor rotation direction command.
Each motor is operated according to 100 commands. Here, a pulse from an encoder 107 attached to the motor is used for controlling the speed of the motor in the servo circuits 105a to 105c. Also, this pulse information is
The CPU 100 mainly controls the position of the document based on the pulse information. A part of the pulse information is also used for detecting a motor abnormality.

The CPU 100 is connected to the analog port A
N1, AN2, and analog ports AN1, A
N2 is provided with variable resistors VR1 and VR2, respectively. This resistance value is set to a CPU with a resolution of, for example, 256 gradations.
Has supplied to 100. This information is used for adjusting the stop position of a document having a slight variation for each machine. For example, after a document passes through the registration sensor 57 of FIG.
Assuming that the number of stop pulses up to the document reference is 640, the value of VR1 may be changed so as to reach this number of pulses. On the software, for example, 600 pulses are fixed as 600
+ (Analog value of VR1) enables adjustment.

The CPU 100 has two servo circuits 10
5 Supply the same PLL control reference clock to b and c. The two servo circuits 105b and 105c respectively use the reference clock to control the conveyance belt motor 60 and the reversing motor 61.
Drive. Here, the PLL control is performed so that the document transport speed of the transport belt 22 driven by the transport belt motor 60 and the document transport speed of the inversion drive roller 27 driven by the inversion motor 61 become equal. That is, the reduction ratio of each motor and the diameter of each roller (for example, the diameter of the reverse drive roller 27 in FIG. The diameter of the belt drive roller 51 is selected.

As described above, in the present embodiment, the transport belt drive system for driving the transport belt 22 and the reversing drive rollers 27
There is no need to prepare different reference clocks for the feed drive system that drives the
Because the 60 and the reversing motor 61 can be controlled by PLL, it is not necessary to adjust each motor individually when adjusting the document feeding speed, and it is possible to adjust both motor speeds to the same speed by one adjustment. The adjustment work time can be shortened.

FIG. 1 is a block diagram showing one embodiment of the inlet for a CF sheet according to the first to third aspects of the present invention. The CF paper inlet 54 shown in FIGS.
As shown in (b), a CF positioning guide 84 for positioning the CF paper in the width direction (the direction of the arrow in FIG. 1B) is provided. The entrance 54 is also a discharge port for the sheet-through document 56.

The CF positioning guide 84 is slidably mounted on a CF carry-in guide plate 85 forming a CF paper carry-in passage, and moves so as to retreat from the discharge path when a sheet-through document is discharged. Is done. here,
As shown in FIG. 1B, a magnet 86 is attached to the lower part of the CF positioning guide 84. A magnetic sensing element 87 is attached below the CF carrying-in guide plate 85, and detects the magnetic force of the magnet 86 to detect the magnetic force.
The position of the F positioning guide 84 can be detected. Therefore, CF positioning guide in sheet through mode
If 84 is set to a position where it cannot prevent the discharge of sheet-through documents, the conveyance of sheet-through documents is permitted, but if the CF positioning guide 84 is at a position that prevents the discharge of sheet-through documents, the conveyance of sheet-through documents is prohibited. And inform the user with guidance. As a result, it is possible to prevent a jam of a sheet-through document due to a defective position setting of the CF positioning guide 84 at the time of sheet-through.

The magnet 86 is arranged in a non-contact manner with the magnetic sensing element 87 via a CF carry-in guide plate 85 which supports a CF positioning guide 84. For this reason, the guide member position detecting means of the present embodiment can be constructed in a sealed structure without providing an opening in the CF carrying-in guide plate 85, since there is no sliding friction and the durability is improved. Can be prevented from entering.

Hereinafter, the exposure operation of a sheet-through document (sheet-through mode) and the exposure operation of CF paper (CFF mode) will be described. Sheet-through mode This mode is used when copying an original of a size larger than the contact glass 14, for example, A2. When the sheet through mode is used, the mode is set by an input means (not shown) on the copying machine main body 11 side.
The mode setting will be described on the copying machine main body 11 side, but this mode may be entered when a sheet-through document is detected by the feed sensor 43 (see FIGS. 2 and 3) on the ADF side.

AD is set by mode setting from the copying machine body 11.
When the F side recognizes the sheet through mode, the feed sensor 43
, The reversing motor 61 is turned on for a certain period of time, and a sheet-through document is fed in such a manner as to come into contact with the entrance gate 44. Since the feed roller 42 is weakly in contact with the sheet-through document, the sheet-through document does not break even if it hits the entrance gate 44, and the skew (skew) of the sheet-through document is parallel to the entrance gate 44. Will be corrected. During this time, on the copying machine main body 11 side, the exposing unit 16 is moved to a substantially central position of the transport belt 22 as described above,
When the movement is completed, set the print switch to the green state,
Informs that copying is possible.

When the print switch is depressed in this state, the ADF first moves the entrance gate 44 to the position indicated by the broken line and then drives the reversing motor 61 in response to a command from the copier main body 11, and the sheet-through document is moved to the reversing registration sensor 80. Until it stops, and pause. When a sheet feed original feed command is received from the copier body 11 at a predetermined timing, A
The DF side drives the reversing motor 61 and the transport belt motor 60 at an accurate transport speed based on the reference clock frequency from the CPU 100 shown in FIG. 6, and starts transporting. This transfer speed can be changed by changing the reference clock frequency according to an instruction from the CPU 100. The magnification can be changed depending on the ratio of the conveyance speed of the sheet-through document and the speed of the image forming portion of the copying machine body 11. The sheet-through document is conveyed at a constant speed while exposing the contact glass 14 on the contact glass 14, and the reference scale 49 and the switching plate 50 are moved to the dashed line position. For this reason,
The sheet-through document is guided upward, and is discharged to the entrance 54 of the CF sheet, that is, to the upper part of the sheet feeding unit 10 via the sheet-through discharge roller 46.

As shown in FIG. 4, the entrance 54 of the CF paper and the upper surface of the paper supply unit 10 are substantially at the same height, and a sheet-through original can be discharged without bending. Also, since the document feed table 41 and the CF paper entrance 53 are almost at the same height, even if a sheet-through document is placed on the document feed table 41 to feed the sheet-through document, Can be placed almost on a flat surface, and the height of the top surface is made almost uniform, giving a neat appearance.

The operation in the case where several repeat copies are made from one sheet-through document will be described below. The first copy is the same as the above-mentioned operation, but the second operation is performed after the rear end of the sheet-through document has passed the exposure position in the first copy operation (this detection is performed by the reverse registration sensor 80 in FIG. 3).
Can be detected by counting the elapsed time or the number of pulses of the conveyor belt motor 60 after the rear end of the original has passed), the conveyor belt motor 60 and the reverse motor 61 Rotate in the transport direction. At the same time, the inversion switching claw 23 and the inversion ejection switching claw 28 are controlled so as to be at the positions indicated by the alternate long and short dash line. By reversing each operation system, the sheet-through document is picked up by the reversing switching claw 23,
It is driven by the driven roller 27 and the driven roller 45, and is guided to the reversing discharge guide plate 29 via the reversing discharge switching claw 28.

When the end surface of the sheet-through document passes through the sheet-through sensor 84, the reversing motor 61 performs the reversing operation again.
After a predetermined time (or after a predetermined pulse) from turning on the sheet through sensor 84, the operation is stopped. At this time, it is desirable that the distance from the end face position of the sheet-through document to the exposure position is equal to the distance between the document position stopped based on the reversal registration sensor 80 and the exposure position when the first copy is performed. As a result, it is possible to make the paper feed timings of the first and second and subsequent copying machines the same, which facilitates control. For the sake of explanation, the first original position and the second original position
The original position after the first time is controlled so as to be the same distance from the exposure position. However, if the structure is not possible, it is needless to say that the conveyance can be performed at a different timing. is there.

Next, after a predetermined timing, the copying machine body 11
When the document feed command is received from the ADF, the ADF controls the reversing motor 61 and the transport belt motor 60 as in the first sheet.
Starts the transport at an accurate transport speed based on the reference clock specified by. Thereafter, the same operation as that of the first sheet is performed, and this operation is repeated for the number of repeat sheets. After the completion of the copying of the number of copies, the sheet-through original is discharged from the entrance 54 of the CF sheet.

As shown in FIG. 1A, a sensor (hereinafter referred to as CF) for detecting the presence or absence of CF paper is provided at the entrance 54 of CF paper.
A paper detection sensor 81 and a sensor (hereinafter referred to as a CF paper hole detection sensor) 82 for detecting a hole in the CF paper are provided side by side. Note that the CF paper detection sensor 81 is used for detecting the discharge of a sheet-through document in the sheet-through mode.

Here, the CF paper hole detection sensor 82 provided at the CF paper entrance 54 is, as shown in FIG.
It is provided at a position 6.35 mm (1/4 inch) from the end face of the document of the CF paper 55. On the other hand, the CF paper detection sensor 81 is provided closer to the document center. As shown, the CF paper detection sensor 81 and the CF paper hole detection sensor 82
The document end surface of the sheet-through document 56 is set to pass almost at the center of the document. With such a sensor arrangement,
When repeat copying the sheet-through document 56, the skew of the document can be detected. That is, when normal conveyance is repeated, the CF paper detection sensor 81 is in the document detection state, and the CF paper hole detection sensor 82 is in the non-detection state. If the sheet-through document 56 is skewed for some reason, both sensors 81 and 82 are simultaneously turned ON or OFF. As a result, skew can be detected. In this embodiment, the skew detection width is (（) × (distance between sensors 81 and 82). Here, when the skew is equal to or larger than a predetermined skew, the repeat operation is stopped, and the sheet-through document 56 is discharged to the upper portion of the paper feeding unit 10. In addition, when such a configuration is implemented,
In the sheet-through mode and the other modes, the reference of the end of the document is different. However, by moving the lens system of the copying machine, the reference position in image formation is unified.

As shown in FIG. 4, the CF paper inlet 54 of this embodiment is commonly used as a sheet-through document discharge outlet. The entrance 54 is provided with the CF positioning guide 84 for positioning the CF paper in the width direction as described above. 1B, when a CF sheet (not shown) is placed at a predetermined position at the entrance, the CF positioning guide 84 slides in the direction of the arrow in accordance with the width of the CF sheet, and the CF sheet is moved from both sides. The paper is held so that it can be fed.

The position of the CF positioning guide 84 is determined by the magnetic force of the magnet 86 provided below the CF positioning guide 84.
It can be recognized by sensing with the magnetic sensing element 87 disposed facing through the. In this embodiment, as shown in FIG. 1B, since the magnetic sensing elements 87 are arranged at regular intervals, the position of the magnetic sensing element 87 that most strongly senses the magnetic force of the magnet 86 is determined by the CF positioning guide. 84 position.

Therefore, in the sheet through mode, it is automatically determined whether or not the position of the CF positioning guide 84 is within the discharge range of the sheet through document. If the position of the CF positioning guide 84 is within the discharge range, the discharge processing of the sheet-through document is prohibited. If the position is outside the discharge range, the sheet-through document is discharged as usual. Therefore, in this embodiment, even if the position setting of the CF positioning guide 84 is defective at the time of processing the sheet-through document, the occurrence of jam can be prevented beforehand, and it is durable, and it is difficult for dust and the like to enter the machine. It can be structured.

CFF mode This mode is used when copying CF paper.
Since the control itself in the CFF mode is already known, the details are omitted. The driving force is input to the sheet through discharge roller 46 provided in the CF paper carry-in path via the electromagnetic clutch so as to be driven only in the sheet through discharge direction as described above. For this reason, it is driven only at the time of sheet through discharge, and follows the moving direction of the CF paper at the time of loading and transporting the CF paper. As a result, both stable discharge of sheet through and loading of CF paper are achieved.

When copying the CF sheet, the transport unit 15 is opened, the side end of the CF sheet is positioned by the CF positioning guide 84, and the CF sheet is contacted along the CF loading guide plate 85. Set on glass 14.
As described above, when the CF sheet is set, the CF sheet is set so that the fold of the CF sheet matches the original reference. Next, by closing the transport unit 15, the CF document is set. The detection of the setting of CF paper is shown in FIG.
Is detected by the CF paper detection sensor 81 shown in FIG. When a print switch of a copying machine (not shown) is pressed, a CF paper feed command is output from the copying machine every time copying is completed.
Sent to F side. By the feed signal from the copier, A
The DF counts the holes of the CF sheet by the CF sheet hole detection sensor 82, and stops the CF sheet after counting one page. Then, the exposure unit is moved to perform an exposure operation, that is, a copy operation. The copied CF paper is discharged to a document tray 25 via a discharge roller 24. The end face of the CF sheet is pressed by the CF positioning guide 84 provided at the entrance of the CFF, thereby preventing skew.

In this embodiment, as can be seen from the above description, the transport direction is reversed between the sheet-through mode and the mode in which the normal cut sheet document 13 is transported from the document table 12. This is because during normal scan mode, AD
This is for shortening the document replacement time when a cut sheet document is fed at F. For example, as shown in FIG. 7A, when the document reference B is on the left side of the contact glass 14, the exposure unit of the main body scans from left to right as indicated by an arrow M, and stops the exposure unit of the main body. In the sheet through mode in which the exposure is performed, the document is conveyed from right to left as indicated by an arrow N. On the contrary, in FIG. 7B, when the document reference A is on the right side of the contact glass 14, the exposure unit scan direction of the main body is from right to left as indicated by an arrow M, and the document conveyance direction in the sheet-through mode is indicated by an arrow. Like N, it changes from left to right. Here, in the normal scan mode, the original is transported in the ADF in the same direction as the transport direction in the sheet-through mode (n direction in FIGS. 7A and 7B), and in the opposite direction (FIG. 7A). 7 (a) and (b) in the m direction), there is a difference in the conveyance span, and therefore, a difference occurs in the document replacement time. That is, the same direction n as the conveyance direction in the sheet-through mode (conveyance from the direction opposite to the document references A and B)
Therefore, when the cut sheet document is transported in the ADF mode, the document replacement time becomes longer. Here, the fact that there is a difference in document replacement time will be described using a specific simple model. The model is shown in FIG. The conveying speed of the cut sheet document 13 is 1500 mm / s, the distance from the registration sensor 57 to the document reference A is 110 mm, and the distance from the document reference A to the document reference B is 330 mm. FIG. 8B shows a time chart when the document size A4 is conveyed in the horizontal direction. The case where the document is stopped at the document reference A is indicated by a solid line, and the case where the document is stopped at the document reference B is indicated by a broken line. Conveyor belt motor
Assuming that the deceleration of 60 is performed linearly in 70 ms, (1) When the cut sheet document 13 conveyed in the m direction with the document reference A is stopped, the registration sensor 57 is turned off.
The time t ₁ from (the end of the original) to the stop of the original is (2) When stopping the cut sheet document 13 conveyed in the n direction on the basis of the document B, t ₂ is Thus, there is a difference in document replacement time of t ₂ −t ₁ = 80 ms. Therefore, in order to improve productivity, the cut sheet document 13 is transported in the m direction from the document reference A side in the normal scan mode, and the document in the sheet through mode is moved in the direction N opposite to the direction of the normal document transport. Transport is more advantageous.

[0053]

As described above, according to the document conveying apparatus of the electrophotographic apparatus according to the first aspect of the present invention, the guide member position detecting means detects the positioning of the guide member in the sheet through mode and performs the sheet through operation. By controlling the discharge processing of the sheet-through document by the document discharge prohibiting means, the jam of the sheet-through document does not occur, and the document can be reliably transported and processed.

According to the second aspect of the present invention, the position of the guide member is detected by the magnetic sensing element disposed opposite to the position detecting magnet below the guide member. Thus, the position can be detected with high durability in a non-contact manner, and dust and the like can be prevented from entering the inside of the machine as a sealed structure. According to a third aspect of the invention, there is provided an electrophotographic apparatus comprising:
By detecting the position of the guide member that holds the CF sheet and prohibiting the discharge processing of the sheet-through document when the guide member is within the discharge range of the sheet-through document, the sheet-through document without jamming can be reliably detected. Transport processing can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an original conveying apparatus and a method of an electrophotographic apparatus according to the first to third aspects of the present invention, wherein FIG. 1A shows a CF paper detection sensor and a CF paper hole detection. FIG. 3B shows the arrangement position of the sensors, and FIG. 3B shows a CF positioning guide at the entrance of the CF sheet.

FIG. 2 is a configuration diagram showing a copier as an electrophotographic apparatus to which the document feeder according to one embodiment of the present invention is attached.

FIGS. 3A and 3B are configuration diagrams showing an embodiment of a document feeder of the electrophotographic apparatus according to the present invention, wherein FIG. 3A shows a position of a claw at the time of non-reverse discharge, and FIG. The position of the nail at the time of inversion is shown.

FIG. 4 is an enlarged view showing a sheet-through document discharge section and a continuous computer paper document entrance section in FIG. 2;

FIG. 5 is a diagram illustrating a drive system of the document feeder.

FIG. 6 is a schematic block diagram illustrating the overall circuit configuration of the document feeder.

FIGS. 7A and 7B are diagrams showing a positional relationship between a document conveyance direction and a document reference, wherein FIG. 7A shows a document conveyance direction with respect to a document reference B, and FIG. Show.

FIGS. 8A and 8B are model diagrams showing a conveyance pattern due to a difference in setting of a document reference with respect to a document conveyance direction. FIG. 8A shows the positions of document references A and B, and FIG. is there.

FIG. 9 is a configuration diagram illustrating an example of a document reversing unit in a conventional document conveyance device.

[Explanation of symbols]

 84 CF positioning guide 85 CF loading guide plate 86 Magnet 87 Magnetic sensing element

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Shin Hidaka 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Limited (56) References JP-A-2-173772 (JP, A) JP JP-A-138078 (JP, A) JP-A-61-35466 (JP, A) JP-A-4-204460 (JP, A) JP-A-62-110934 (JP, U) JP-A-2-72444 (JP) , U) Japanese Utility Model 1-65231 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) G03G 15/00 107 B65H 29/52 H04N 1/04-1/203 G03B 27 / 62-27/64

Claims (3)

(57) [Claims] A document feeding means for feeding a document to a platen; a document processing means for taking in image information of the document on the platen; a document conveying means for sending a document from the platen after the document processing and discharging the document outside the machine; A document feeder of an electrophotographic apparatus in which a paper feed port for holding and feeding a computer paper document by a guide member and a discharge port for discharging a sheet-through document are commonly used. A guide member position detecting means for detecting a position of the guide member slidable according to the position of the guide member; and a guide member located within a discharge range of the sheet-through document based on a detection result of the guide member position detecting means. A document feeder for an electrophotographic apparatus, comprising: sheet-through document discharge prohibition means for prohibiting sheet-through document discharge processing. 2. The apparatus according to claim 1, wherein the guide member position detecting means is disposed on an opposing surface via a position detecting magnet provided below the guide member and a non-magnetic support member slidably supporting the guide member. 2. The document feeder for an electrophotographic apparatus according to claim 1, further comprising: a magnetic sensing element for detecting a position of the detection magnet. 3. A document is fed onto a platen, image information of the document is taken in, and then the document is discharged out of the apparatus. The paper feed port for computer paper and the discharge port for sheet-through document are commonly used. Detecting the position of a guide member for holding a computer paper original at the paper feed port, and performing a sheet-through original discharge process when the guide member is within the discharge range of the sheet-through original. A document conveying method for an electrophotographic apparatus, wherein the method is prohibited.