JPS6283936A - Both sides copying method - Google Patents

Abstract

PURPOSE:To enable automatic both sides copying of desired number of sheets by performing rear face copying of a perfect copy paper finished of front face copying and placed in an intermediate tray upon jamming during rear face copying of a document then performing both sides copying by the number of sheets missed through jamming. CONSTITUTION:Plural sensors S1-S5 are arranged along a feed path in a copying machine. Upon jamming during rear face copying, CPU is informed of the jamming position by a sensor to know the number of missed sheets. Upon depressing of a copy start button after removing the jammed copy papers, the copy papers finished of single face copying in the intermediate tray 44 are fed sequentially then entirely rear face copied and discharged. CPU will decide whether it will match with the number of sheets considering the jammed ones on the basis of a signal from a paper discharge sensor 51 and enter into copying operation corresponding with jammed sheets upon matching. Since the copy papers corresponding with jammed ones can be supplemented automatically, troublesome manual operation is not required.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a double-sided copying method that automatically makes a desired number of copies even if the copy paper jams while copying the back side of a double-sided original. Regarding.

(Prior Art) In many conventional copying machines, when copying multiple originals, the user places the originals one by one on the original table and replaces them, but when the number of originals to be copied increases, the user has to change the originals while standing. The work is quite difficult. Recently, an automatic document feeder has been developed and put into practical use, which automatically feeds multiple documents one by one to the document table and copies them when multiple documents are stacked in a predetermined position. There is.

By the way, there are many so-called double-sided originals that have content that you want to copy on both sides, and an automatic document feeder that can be used for such double-sided originals is also being considered. The feeding device first copies the front side of the document, then reverses the document, copies the back side, and discharges the document.The front and back sides of the document are copied in the same manner one after another, and the documents are sequentially discharged.

By the way, when copying double-sided originals in a copying machine that uses this type of document reversing automatic document feeder, the copy paper may jam (so-called jam) inside the copying machine while copying the back side. If this happens, take care of the jam by removing the copy paper that caused the paper jam, then continue copying for the remaining number of copies as desired, and finally copy the original again to make copies of the remaining number of copies due to the jam. The document is returned to the document placement plate-H manually. This work is very troublesome.

(Objects and Structure of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to facilitate the processing of copying the missing copy paper when a paper jam occurs while copying the back side of a double-sided original. To achieve this purpose, when a jam occurs while copying the back side of an original, the back side of the original is copied on all the copy sheets that have been copied on the front side in the intermediate tray, and the remaining copy paper that is insufficient due to the jam is automatically copied. The original is reversed by the original feeding device, and the front side is first copied, and then the original is reversed again to copy the back side.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 shows a schematic diagram of an electrophotographic copying machine that performs double-sided copying using the double-sided copying method according to the present invention. This is the main body of the copying machine.

The automatic document feeder A stacks the documents and li! A document placement plate 1 to be placed, a feed roller 2 that feeds out only the topmost document, a feed belt 4 that feeds the fed document in cooperation with a double feed prevention roller 3, and a document feeding path. A document feeding roller 5 arranged along the main body, a conveyor belt 6 that conveys the fed document to a fixed position on the glass document table of the copying machine main body, a document reversing guide 7, and a document reversing guide. 7
Three sets of conveyance rollers 8a, 8b are arranged along.

8C, and a pressure roller 6a along the conveyor belt 6.
, 6b, and 6c are arranged. This conveyor belt 6 is driven by a drive roller 6d, and is switched between a forward rotation direction indicated by a solid line arrow and a reverse rotation direction indicated by a broken line arrow between it and a driven roller 6e. A stone bar 9 is provided near one end of the conveyor belt 6 to stop the conveyed document at a fixed position on the glass document table. Electromagnetically driven. A first document feeding path from the document placement plate l to a fixed position on the glass document table and a second document feeding path along the document reversing guide 7.
The document feeding path is a common path in a portion C, and a document detection sensor consisting of a light emitting element 10a and a light receiving element 10b for detecting passage of a document is provided on this common path C. Reference numeral 11 denotes an original ejection roller that ejects the exposed original, 12 an original ejection tray that stores the ejected original, and 13 an original ejection sensor that detects that the original has been ejected.

In this document reversing type automatic document feeder, a feed roller 2, a double feed prevention roller 3, a feed belt 4, a document feed roller 5, a driving roller 6d of the conveyor belt 6, and a document reversing guide 7 are arranged. Conveyance rollers 8a, 8b, 8c
are configured to be driven by a common document feeding motor via clutches and gears, but among these, the rotation direction of the drive roller 6d changes when the rotation direction of the motor is changed, but the other The roller is rotated in one direction through a reversing mechanism regardless of the rotational direction of the motor.

On the other hand, the copying machine main body B for double-sided copying utilizes a conventionally known electrophotographic process, and is provided below the document reversing type automatic document feeding device A described above.

20 is a paper feed cassette for storing copy sheets P in a stacked manner; 21;
22 is a paper feed belt, 23 is a paper feed guide plate, 24 is a paper feed roller,
26 is a rotating drum having a photoreceptor 26a on its surface, and a charger 27, a developing device 28, a transfer device 29,
A separator 30 and a cleaning device 31 are sequentially arranged.

On the other hand, a glass original platen 32 is provided on the top surface of the copying machine body, and a glass original table 32 is placed on a fixed position to expose the original to be copied.Below it is an illumination lamp 33 for exposing the original, and A movable mirror 34, 35, a fixed mirror 36, and a lens 37 are arranged to guide the reflected light onto the photoreceptor 26a.

38 is a conveyor belt that conveys the copy paper separated from the rotating drum 26 after transfer to a fixing position; 39 is a fixing device; 40
2 is a switching mechanism that switches the path of the copy paper fixed by the fixing device 39 to the ejection path a or the reversing path, and includes two sets of transport rollers 40a and 40b, a switching member 40c that rotates in the direction of the arrow around point E, and It consists of 41 is a guide plate that guides the copy paper after single-sided copying towards the intermediate tray; 42 is a conveyance roller; 43 is a reversing belt that reverses the copy paper; 43a is a drive roller that drives the reversing belt 43;
Reference numeral 43b indicates a driven roller; 44 indicates an intermediate tray in which the single-sided copy paper that has been reversed by the reversing belt 43 is temporarily stored; and 45, the copy sheet moves up and down in synchronization with the copying operation using point F as a fulcrum, and is stored in the intermediate tray 44. 46 is a paper feed roller that moves up and down in synchronization with the copying operation and feeds the top sheet of copy paper stored in the intermediate tray 44; 47 is a paper feed belt; 48 is a conveyance roller;
9 is a paper feed guide.

Note that 50 is a paper ejection tray that stores the copy paper ejected by switching the switching mechanism 40, and 51 is a paper ejection tray that is arranged near the copy paper ejection port of the copying machine main body B and detects the ejection of recording paper. A sensor 52 is an intermediate tray sensor that is disposed near the conveyor belt 43 and detects the trailing edge of the copy sheet that has completed single-sided copying and is stored in the intermediate tray 44.

FIG. 2 is a block diagram of a document feeding control circuit for double-sided copying according to the present invention.

In the figure, 60 is a copy start button that is turned on when copying starts, 61 is a double-sided copy button that is turned on when copying a double-sided original, 62 is a copy number setting button consisting of a numeric keypad for setting the number of copies you want to make, and 10 is a first button. A document detection sensor consisting of the light-emitting element 10a and the light-receiving element 10b shown in the figure, 51 the paper discharge sensor that also appeared in FIG. 1, 52 the intermediate tray sensor, 63 the states of the copy start button 60 and the double-sided copy button 61 , a memory that temporarily stores the number of copies set by the number of copies setting button 62, the output state of the paper ejection sensor 51, etc. 64 is a memory that is copying the front side or the back side of the original based on the data stored in the memory 63. 65 is a drive circuit that drives the document feed motor 66, and as described above, this document feed motor 66 has a clutch and a gear. It is configured to drive various rollers and the drive roller 6d of the conveyor belt 6 through the drive roller.

In addition, a copy start button 60, a double-sided copy button 61, a copy number setting button 62, a paper ejection sensor 51, a memory 63, and a
Both the PU 64 and the drive circuit 65 are provided on the copying machine main body side, and the CPU 64 controls both the original feeding sequence of the automatic document feeding device and the electrophotographic process sequence within the copying machine main body. .

Next, a double-sided copying operation according to the present invention will be explained. Note that the following explanation is limited to the case where a double-sided original is copied onto both sides of copy paper.

First, to explain the normal duplex copying operation, place multiple double-sided originals that you want to copy on the document placement plate 1, stacking them in page order with the odd-numbered pages facing up, and press the duplex copy button 61 (duplex copy mode ) and set the desired number of copies using the number of copies setting button 62 (if the desired number of copies is 1)
(No setting is necessary if it is At this time, it is confirmed by the ON state of the internal 61 of the CPU 64 that it is the mode for reversing copying of a double-sided original, and then when the copy start button 60 is turned on, the original feeding motor 66 rotates forward and the automatic original feeding device The roller rotates. As a result, the document placement plate l
The uppermost document is sent out by a sending roller 2, and is fed by a feeding belt 4 and a feeding roller 5, and then sent to a conveying belt 6. The leading edge of the document emits light while the document is being fed, and the document detection sensor 1 consists of light receiving elements 10a and 10b.
When the light passes through the 0 position, the output of the light receiving element 10b rises. The stopper 9 is actuated to project in synchronization with the rising edge of the output signal of the document detection sensor IO, and when a set time tl by a timer set in the CPU 64 has elapsed from this rising edge, the A document feeding motor 66 is stopped. .

At this time, the leading edge of the original contacts the stopper 9 and is set in a fixed position on the glass original table 32 (at this time, the front side of the original (odd page side) is facing downward), and the subsequent electrophotographic process begins. do.

That is, the copying machine main body side enters the preparation state for the electrophotographic process, the rotating drum 26, the developing sleeve 28a, and the heating roller 39a of the fixing device 39 rotate, and the conveyor belt 38
As soon as the roller 39a starts moving, the heater of the heating roller 39a is energized.

After a predetermined period of time, a series of electrophotographic processes begins, starting with exposure of the document by the optical scanning system.

The visible image thus formed on the photoreceptor 26a is transferred to the copy paper P fed from the paper feeder 20 and fixed by the fixing device 39. Slightly prior to this, the switching member 40c is operated by a switching means (not shown) using a solenoid or the like.
is switched in the direction of the solid arrow around point E, so
After the fixing, the single-sided copy paper passes through a reversing path and is led to a guide plate 41 by a conveying roller 40a, and is further conveyed by a conveying roller 42 and placed on a reversing belt 43. The copy paper conveyed by the reversing belt 43 is temporarily stored in the intermediate tray 44 after being reversed. Similar single-sided copying is performed on the number of copy sheets set by the copy number setting button 62, and all copies are made on the intermediate tray 44.
is stored in. A single-sided copy sheet stored in the intermediate tray 44 is detected by the intermediate tray sensor 52 immediately before being stored.

The CPU 54 counts the output signal from the intermediate tray sensor 52, and when the count value matches the number of copies set by the copy number setting button 62 (this number is stored in the memory 63), the front side of the original is copied. It is determined that the mode has ended, and the motor reverse rotation signal CC is sent to the drive circuit 65.
Outputs W. As a result, the document feed motor 66 rotates in the reverse direction, and the document, which had been in the normal position, is conveyed by the conveyor belt 6 in the opposite direction (in the direction of the dashed arrow) to the direction of the document when being fed, and guided to the reversing section. The original is transported through the original reversing guide 7 by the transport roller 8a.
, 8b, and 8c in the direction of the arrow. CPU64
The elapsed time is measured by the timer set in the
When the set time t2 has elapsed, a motor forward rotation signal CW is output in place of the motor reverse rotation signal CCW that had been output until then.
Thereby, the motor 66 is switched to normal rotation. At this time, the leading edge of the original that has been reversed by the reversing section has reached the common path C, and as it progresses further, the leading edge of the original passes the position of the original detection sensor lO, reaches the transport belt 6, and is moved by the transport belt 6. The document continues to be transported toward a fixed position for exposure on the glass document table 32.

As in the case of setting the front side of the original described above, the original feeding motor 66 stops when the time t1 set by the timer has passed from the rise of the output of the original detection sensor 10. At this time, the document is stopped by the stopper 9 and remains at a fixed position on the glass document table 32, with the back side of the document facing downward.

Thereafter, a series of electrophotographic processes are performed on the back side of this document. That is, the back side of the document is exposed by the optical scanning system, and an electrostatic latent image of the back side is formed on the photoreceptor 26a, and developed by the developing device 28.

On the other hand, copy sheets with single-sided copies stored in the intermediate tray 44 are fed from the uppermost one by a paper feed roller 46 in synchronization with the timing of the electrophotographic process, and are fed by a paper feed belt 47.

The single-sided copy paper is transported along a guide plate 49 by a transport roller 48 or the like to a transfer position, where the visible image of the back side of the document formed on the rotating drum 26 is transferred.

In this way, the copy paper on which both sides have been copied is conveyed to the fixing position by the conveyor belt 38, where it is fixed by the fixing device 39. At this time, the switching member 40C of the switching mechanism 40 is switched in the direction of the broken line arrow, so the conveyance roller 40a
The copy paper conveyed by 40b and 40b passes through the discharge path a, is discharged from the paper discharge port of the main body of the copying machine, and is stored in the paper discharge tray 50. At this time, the paper ejection sensor 51 detects the ejection of the copy paper.

The optical scanning system exposes the back side of the document at a predetermined timing, and the intermediate tray 44 is exposed in synchronization with the copying operation.
Copy paper with one side copied is fed from the machine, and the back side of each copy paper is copied. When the last copy sheet stored in the intermediate tray 44 is fed, the reverse side is copied, and the sheet is ejected, the CPU 64 sets the count value obtained by counting the output from the paper ejection sensor 51 using the copy number setting button 62. Since the number of sheets matches the number of sheets, it is determined that double-sided copying has been completed, and a motor reverse rotation signal CCW is output to the drive circuit 65. As a result, the original feed motor 66 rotates in reverse, and the copied original is guided to the reversing section where it is reversed, and then ejected by switching forward rotation of the original feed motor 66 and waits for an output from the ejection sensor 13. The next original is fed.

The above is a normal double-sided copying operation. Next, the operation when a jam occurs during backside copying according to the present invention will be explained with reference to the flowchart of FIG.

Inside the copying machine main body B, a plurality of sensors are provided along the copy paper feeding path. The ones shown by the diagonally shaded squares S1 to S55 in FIG. A sensor S is provided at the separation head to detect how tightly the copy paper is wrapped around the drum 26. , the sensor S3 provided near the entrance to the fixing device 39, the already mentioned paper ejection sensors 51 and 52,
These include a sensor S4 provided midway on the guide plate 41 on the downstream side of the switching mechanism 40, and a sensor S5 provided on the exit side of the intermediate tray 44. A copy paper jam is detected by one of these sensors.

Now, as described above, the CPU 64 of the copying machine determines whether or not it is in the back side copy mode of the original based on the match between the count value output from the intermediate tray sensor 52 and the number of copies set by the number of copies setting button 62 (F -1), if a jam occurs while copying the back side (F-2), a jam occurrence warning will be displayed on the operation panel on the top of the copier main body, and the CPU 64 will check which sensor detected the jam. It is possible to determine the position of the jam occurrence, and from the position of occurrence, it is possible to know the number of copies that are insufficient due to the occurrence of the jam (F-3) (In high-speed machines, multiple copies are made at the same time to increase the copying speed. Paper is in various stages of the electrophotographic process within the copier body, and a jam can cause all of this copy paper to be wasted).

When the copying start button 60 is pressed again after removing the jammed copy paper, the copy papers remaining in the intermediate tray 44 that have already been copied on one side are fed one after another, and all of them are copied on the back side as described above. The sheets are then ejected in sequence.

The CPU 64 determines whether or not the count value obtained by counting the output from the paper ejection sensor 51 matches the number of sheets that is less than the set desired number of sheets by the amount of the shortage due to the jam.F-4
), if they match, it is determined that the reverse side copying mode has ended and the copying operation for the missing part begins.

That is, at the end of the back copy mode, the CPU 64 outputs a motor reversal signal CCW, the document feed motor 66 is reversed, the document on the glass document table 32 is guided to the reversing section by the conveyor belt 6, and the document feeder motor 66 is guided to the reversing section by the conveyor belt 6, and the document feeder motor 66 is guided to the reversing section by the conveyor belt 6, and the conveyor rollers 8a, 8b , 8c (F-5). At the stage when the reversal of the document is almost completed, the CPU 64 stops the motor reverse rotation signal CCW and outputs the motor forward rotation signal CW. As a result, the document feeding motor 66 switches to normal rotation, and the moving direction of the conveyor belt 6 also switches to the direction of the solid arrow.0 Time t1 elapses after the leading edge of the reversed document passes the position 10 of the document detection sensor. When the time period elapses, the forward rotation signal CW from the CPU 64 stops, and the document feeding motor 66 stops. At this time, the original is set in a fixed position on the glass original table 32 with the front side facing down (F
-6). After that, the copying operation for the front side of this document starts (F-7).This operation is the same as the operation in the normal front side copying mode described above, so the explanation will be omitted, but copying was determined in step (F-3). Repeated for the number of sheets missing due to jam. The copy sheets for which front side copying has been completed for this number of sheets (F-8) are temporarily stored in the intermediate tray 44. CP when the intermediate tray sensor 52 detects that the last missing copy sheet has entered the intermediate tray 44.
A motor reversal signal CCW is output from U64, and the document feed motor 66 is reversed. The subsequent document reversal operation is the same as in the normal double-sided copy mode described above (F-9).
After the original is reversed, when the original is set on the glass original platen 32 with the back side facing down (F-1o), the back side copy mode is started. A series of electrophotographic processing is performed on the back side of the original, and copying is performed on the back side of the copy paper with the front side copied stored in the intermediate tray 44 (F-11).
).

In this way, when double-sided copying is completed for the missing copy paper due to the jam (F-12), when the ejection of the last copy paper is detected by the paper ejection sensor 51, the motor reversal signal CCW is output from the CPU 64. Glass manuscript table 32
The upper document is led to the reversing section by the conveyor belt 6, where it is re-inverted (F-13), passes over the glass document table 32 again, and is discharged (F-14).

In this duplex copying mode in which a double-sided original is copied onto both sides of copy paper, if a jam occurs while copying the back side of the original, the original is automatically reversed and double-sided copying is performed to compensate for the shortage due to the jam.

In the above embodiment, when a jam occurs while copying the back side of a document, the first copying process of copying the back side of the document is performed first on all the copy sheets on which the front side has been copied in the intermediate tray, and then the paper is shortened due to the jam. In response to the shortage of copy paper, a second copying process is performed in which the original is reversed and the front side is copied first, and then the original is reversed again and the back side is copied.
In the present invention, on the contrary, the second copying process may be performed first, and then the first copying process may be performed. However, when the intermediate tray enters the paper feeding mode, not only one copy but several copies are made. Since there are many cases where paper gets caught in the paper feed roller, it is better to eject the copy paper with the front side copied remaining in the intermediate tray as soon as possible to reduce trouble, and also to reduce the number of copies that have been copied on both the front and back sides as quickly as possible. It is preferable to perform the first copying process first and then perform the second copying process because it is more convenient for subsequent operations to know and calculate the shortfall.

In the above embodiment, the document reversing section is provided on the opposite side of the document ejection side across the glass document table, but the present invention is not limited to this, and it goes without saying that it may be provided on the document ejection side. Further, the document reversing means is not limited to the one in which the document is reversed while being conveyed by the reversing roller in the reversing guide as illustrated, but may be of a so-called switchback type.

(Effects of the Invention) As described above, the present invention provides a double-sided copying method in which double-sided copying is performed from a double-sided original using an automatic document feeder having a document reversing means, in which a jam occurs while copying the back side of the original. In this case, the first copying process involves copying the back side of the original on all the copy sheets in the intermediate tray that have already been copied on the front side, and the automatic document feeder reverses the original and copies the front side first to cover the missing copy paper due to a jam. Since the second copying process of copying, then re-inverting the original and copying the back side is performed, the desired number of copies is automatically made without the troublesome work of manually setting originals to make up for the shortage due to a jam. A double-sided copy is obtained.

[Brief explanation of drawings]

1 is a schematic diagram of an electrophotographic copying machine that performs double-sided copying by the double-sided copying method according to the present invention; FIG. 2 is a block diagram of a document reversal control circuit of the electrophotographic copying machine shown in FIG. 1;
FIG. 3 is a flowchart of copying operations after a jam occurs. l... Original placement plate, 6... Conveyance belt, 7... Original reversing guide, 9... Stopper, 13... Original discharge sensor, 20... Paper feed cassette, 26... Rotating drum, 40... switching mechanism, 44... intermediate tray, 6
6... Original feed motor special: 1 Applicant Roku Konishi Photo Industry Co., Ltd. Agent
Patent Attorney Hiroshi SuzukiFigure 2Figure 3

Claims (2)

[Claims] (1) In a duplex copying method that uses an automatic document feeder with a document reversing function to make double-sided copies from a double-sided original, if a jam occurs while copying the back side of the original, all copies of the front side in the intermediate tray will be copied. Regarding paper, the first copying process involves copying the back side of the original, and for the lack of copy paper due to a jam, the automatic document feeder reverses the original and first copies the front side, then flips the original again and copies the back side. and a second copying process. (2) The double-sided copying method according to claim 1, wherein the second copying process is performed subsequent to the first copying process.