JP3115559B2 - Stackless Duplex Continuous Copying Method for Copying Machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a stackless duplex continuous copying method in a copying machine.

[0002]

[Prior art]

A function of performing continuous double-sided copying without stacking copy sheets after performing single-sided copying in a circulating transport path for performing double-sided copying as a copying machine (hereinafter, referred to as a copying machine).
Stackless double-sided continuous copying function). In such a copying machine, when performing double-sided continuous copying, copy sheets are sequentially fed, and backside copying is sequentially performed on the fed copy sheets. When the copy sheet on which the back side copy is first performed reaches a predetermined position on the circulating conveyance path (hereinafter, referred to as a circulable number determination position), the number of copy sheets conveyed on the circulating conveyance path is increased by the circulating conveyance. It is determined that the maximum value of the number of copies that can be retained in the path (hereinafter referred to as a recyclable number) has been reached, and the feeding of new copy sheets is stopped.

[0004] Thereafter, the front side copy is sequentially performed on the copy paper on which the back side copy has been performed. Then, when the front side copy of the last sheet of the copy sheet currently being conveyed on the circulation conveyance path is completed, the sheet feeding is restarted and the same processing is performed.

[0005] The number of recyclable sheets varies depending on the copy size, copy mode, sheet feed stage, and the like. Therefore, the position for determining the number of recyclable sheets also changes depending on the copy size, copy mode, sheet feed stage, and the like. For this reason, a copy sheet detection sensor is provided at a plurality of predetermined circulable number determination positions in the circulating transport path. Then, based on the output of the copy sheet detection sensor provided at the recyclable sheet number discrimination position determined based on the copy size, the copy mode, the paper feed stage, etc., the copy sheet on which the back side copy is first performed can be circulated. It is determined whether or not the number has reached the number determination position.

Conventionally, there is a problem that a plurality of copy sheet detection sensors are required to determine whether the number of copy sheets conveyed on the circulation conveyance path has reached the circulable number. .

[0007]

According to the present invention, there is no need for a copy sheet detection sensor for determining whether or not the number of copy sheets conveyed on the circulating conveyance path has reached the circulable number. It is an object of the present invention to provide a stackless duplex continuous copying method in a copying machine.

[0008]

A stackless duplex continuous copying method in a copying machine according to the present invention is capable of circulating the number of copy sheets that can stay in a circulating transport path when performing stackless duplex continuous copying. First as the number of sheets
Step: If the remaining number of copies is larger than the circulable number of sheets, copy paper is sequentially fed by the circulable number of sheets, and the circulable number of copy sheets is moved from the copy paper carrying point in the circulating path to the circulating path. After the first step of copying each copy sheet sequentially loaded into the circulating transport path in the second step, and the final sheet of those copy sheets,
At a predetermined timing after passing through the carry-in point in the circulating transport path, a third step of restarting the sheet feeding operation to start the next double-sided continuous copying cycle is provided, and the first step is a unit. Copies per hour
Copy size and copy, with number as copy speed
Each combination of paper feeder positions where paper is fed
Is the first table that stores the copy speed for
The copy size and copy set by the user.
-Supports combinations of paper feeder positions where paper is fed.
Calculated copy speed as the first copy speed
Each combination of step, copy size and copy mode
The second copy speed is stored for each
From the table, the copy size set by the user
And the copy speed corresponding to the combination of copy modes
Determining the code as the second copy speed.
Slower of the first copy speed and the second copy speed
Copy speed as the third copy speed
Based on the desired step and the third copy speed
And a step of obtaining the number of recyclable sheets .

In the copy mode, there are few aggregation modes and a few
At least one type of aggregation mode is included.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a digital copying machine.

As is well known, the digital copying machine includes a document supply unit 1, a scanner unit 2, an image forming unit 3, a fixing unit 4, paper feed trays 5, 6, 7, 8, manual feed tray 9, A paper transport mechanism and the like are provided.

The document supply unit 1 includes an automatic document feeder (AD)
F). The scanner unit 2 includes an illumination lamp (not shown), an optical system, a CCD, a laser unit, and the like. The image forming unit 3 includes a photosensitive drum 31, a charger (not shown), a developing device (not shown), a transfer discharger 32, a separation discharger 33, a cleaning device (not shown), and a static eliminator (not shown). Etc. are provided.

The paper transport mechanism will be described. Paper feed rollers 51, 61, 71 for feeding copy paper for each paper feed tray 5, 6, 7, 8 and manual feed tray 9;
81, 91 and a pair of separating rollers 52, 62, 72, 82, 92 for preventing double feeding of fed copy sheets.
Is provided.

The copy paper fed from the lowermost (fourth) paper feed cassette 5 is fed to the first to sixth feed roller pairs 1.
The sheet is sent to the registration roller pair 17 via 1 to 16.
The copy sheet fed from the third-stage sheet feed cassette 6 is sent to the registration roller pair 17 via the second to sixth feed roller pairs 12 to 16. The copy paper fed from the second-stage paper feed cassette 7 is sent to a registration roller pair 17 via third to sixth feed roller pairs 13 to 16. Copy paper fed from the uppermost (first-stage) paper feed cassette 8 is fed to the fourth to sixth feed roller pairs 14 to
The sheet is sent to a pair of registration rollers 17 via the line 16. The copy sheet fed from the manual feed tray 9 is sent to a registration roller pair 17 via a sixth feed roller pair 16.

The copy paper sent to the registration roller pair 17 is transferred to the photosensitive drum 3 by the registration roller pair 17.
The toner image formed on the photosensitive drum 31 is transferred to the transfer position around the photosensitive drum 1, and is then separated from the photosensitive drum 31. The copy sheet peeled off from the photosensitive drum 31 is sent to the pair of fixing rollers 19 in the fixing unit 4 by the conveyor belt 18, and the toner image transferred to the copy sheet is fixed on the copy sheet.

In the two-sided continuous copying mode, the copy paper on which the transfer has been performed on the first one side (the copy paper on which the back side has been transferred) passes through the fixing roller pair 19 and is separated by the separation claw 101 into the seventh copy. Is sent to the direction changing unit 22 by the seventh feed roller pair 20 and the eighth feed roller pair 21. The copy sheet sent to the direction changing unit 22 is sent to the ninth feed roller pair 24 side by the forward roller 23, and the ninth to twelfth feed roller pairs 24, 25, 26, 27
The sheet is fed to the fifth feed roller pair 15.

The fifth and sixth feed roller pairs 1
The transfer to the transfer position around the photosensitive drum 31 is performed by the pair of registration rollers 5 and 16 and the registration roller 17, and the transfer to the next one side is performed. The copy paper on which the transfer to the next single side has been performed (the copy paper on which the surface transfer has been performed) passes through the fixing roller pair 19 and then is separated by the separation claw 101.
The sheet is sent to the discharge roller pair 102 and is discharged onto the discharge tray 103 by the discharge roller pair 102.

In this specification, the fifth and sixth feed roller pairs 15 and 16, the registration roller pair 17, the transport belt 18, the fixing roller pair 19, and the seventh feed roller pair 2
0, an eighth feed roller pair 21, a direction changing unit 22, a forward roller 23, and ninth to twelfth feed roller pairs 24, 2
The path through which the copy sheet is transported by 5, 26, and 27 will be referred to as a circulation transport path.

The copy paper carry-in point in the circulating transport path refers to a point at which the fed copy paper is carried into the circulating transport path, and the copy paper is fed from one of the paper feed trays 5, 6, 7, and 8. When paper is fed, the PA shown in FIG.
In the case where copy paper is fed from the manual feed tray 9, the position indicated by PB in FIG. 1 is indicated.

In this digital copying machine, in the double-sided continuous copying mode, when the copy start button is pressed, the copy size, the copy mode, and the position of the tray where the copy paper is fed (before the copy operation is started). The number of copies per minute (hereinafter referred to as
The copy speed is calculated, and based on the calculated copy speed, the number of copy sheets that can stay in the circulating transport path (hereinafter, referred to as a recyclable number) is determined.

When the designated number of copies (preset number) is larger than the number of recyclable sheets, the following control is performed. That is, the copy sheets are sequentially fed from the sheet feed tray (or the manual feed tray) by the number of circulable sheets, and are sequentially loaded into the circulating transport path from the copy sheet loading point in the circulating transport path. When the circulating number of copy sheets are conveyed into the circulating conveyance path, that is, when the last sheet of the fed circulating number of copy sheets is conveyed into the circulating conveyance path, the paper feeding operation is performed. Is stopped.

The timing for stopping the paper feeding operation is determined, for example, as follows. A point P between the fifth feed roller pair 15 and the sixth feed roller pair 16
B, a copy paper detector 2 downstream of the copy paper transport direction.
00 is provided. Then, based on the detection signal of the copy sheet detector 200, the number of copy sheets conveyed into the circulating conveyance path is counted up by a counter, and when the count value of the counter reaches the circulable number, the sheet feeding operation is performed. To stop.

The copy sheets of the recyclable number are carried in, the transfer and fixing (reverse copy) on the first side of all copy sheets are completed, and the last sheet of the copy sheets is copied on the circulating transport path. At a predetermined timing after the sheet has passed the paper carrying point, the paper feeding operation is restarted to start the next double-sided continuous copying cycle. At this time, if the number of remaining copies (the remaining number of copies) is larger than the recyclable number, the same control as described above is performed.

The timing for restarting the sheet feeding operation is determined, for example, as follows. That is, when the sheet feeding operation is stopped, the counter value of the counter is equal to the circulable number of sheets. Therefore, after the paper feeding operation is stopped, each time the copy paper detector 200 detects the rear end of the copy paper (in this case, the copy paper on which the back side copy is being performed), the counter of the counter is counted. Count down the value by one. Then, when the count value of the counter becomes 0, the sheet feeding operation is restarted.

If the feeding fails during the feeding of the circulable number of sheets and a non-feeding JAM occurs, a feeding operation (feed retry operation) is performed again after a predetermined time has elapsed. . When such a paper feed retry operation occurs, the copy speed (the number of copies per unit time) in the two-sided continuous copy cycle for the recyclable number of sheets decreases.

Therefore, in the two-sided continuous copying cycle corresponding to the circulable number of sheets, there is a possibility that the first calculated number of circulable number of copy sheets cannot stay in the circulating transport path. Then, in the two-sided copy cycle for the circulable number of sheets, the copy sheet that has been fed first and the back side has been copied and the copy sheet that has been fed thereafter overlap at the copy sheet carry-in point of the circulating transport path. And JAM may occur.

Therefore, when a non-feeding JAM occurs in a certain duplex continuous copying cycle, the feeding operation is stopped so that the feeding retry operation is not performed. And
After the first one-sided copy (reverse-side copy) of the copy sheets fed up to that point is completed, a predetermined one after the last sheet of the copy sheets has passed through the copy sheet carry-in point of the circulating transport path. The paper feeding operation is restarted at the timing of.

After the non-feeding JAM occurs and the feeding operation is stopped, the timing for restarting the feeding operation is determined, for example, as follows. That is, when a non-feeding JAM occurs, the counter value of the above counter is changed to a non-feeding JAM in the duplex copy cycle.
The value is equal to the number of copy sheets fed up to the time when the error occurs. Therefore, after the occurrence of the non-feeding JAM, the copy sheet detector 200 copies the copy sheet (in this case, the copy sheet on which the back side transfer is performed).
Every time the trailing edge of the counter is detected, the count value of the counter is counted down by one. Then, when the count value of the counter becomes 0, the sheet feeding operation is restarted.

FIG. 2 shows an example of a method for calculating the number of recyclable sheets.

First, the first copy speed A is obtained based on the paper feed stage and the copy size (step 1). That is, as shown in FIG. 3, the copy speed for each combination of the paper feed stage and the copy size is obtained in advance and stored in the storage device as the first copy speed table. Then, among the copy speeds in the first copy speed table, the copy speed corresponding to the combination of the copy size set by the user and the position of the tray (sheet feed tray) to which the copy sheet is fed is the first copy speed A. Is required.

Next, a second copy speed B is obtained based on the copy size and the copy mode (step 2). That is, as shown in FIG. 4, the copy speed for each combination of the copy size and the copy mode is obtained in advance and stored in the storage device as the second copy speed table. Then, of the copy speeds in the second copy speed table, the copy speed corresponding to the combination of the copy size and the copy mode set by the user is obtained as the second copy speed B.

In FIG. 4, the aggregation 2 in 1 is 2
This refers to a mode in which one document is copied onto one copy sheet. Aggregation 4 in 1 refers to a mode in which four documents are copied onto one copy sheet.

Next, the slower one of the first copy speed A and the second copy speed B is determined as the copy speed SPEED (step 3).

Based on the determined copy speed SPEED and the plurality of threshold values, the number of recyclable sheets DUP_CNT is obtained (step 4). Specifically, the recyclable number DUP_CNT is obtained based on the following Expression 1.

[0036]

(Equation 1)

[0037]

According to the present invention, there is no need for a copy sheet detection sensor for determining whether or not the number of copy sheets conveyed on the circulating conveyance path has reached the circulable number. And a stackless double-sided continuous copying method is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a digital copying machine.

FIG. 2 is a flowchart illustrating an example of a method for calculating the number of recyclable sheets.

FIG. 3 is a schematic diagram illustrating a first copy speed table in which a relationship between copy speeds for each combination of a paper feed stage and a copy size is stored.

FIG. 4 is a schematic diagram showing a second copy speed table in which a relationship between copy speed and copy speed for each combination of copy mode is stored.

[Explanation of symbols]

5, 6, 7, 8 paper feed cassette 9 manual feed tray 51, 61, 71, 81, 91 paper feed roller 52, 62, 72, 82, 92 separation roller pair 11-16, 20, 21, 24, 25, 26, 27 feed roller pair 17 registration roller pair 18 transport belt 19 fixing roller pair 23 forward roller

Continuation of the front page (56) References JP-A-2-110087 (JP, A) JP-A-4-81866 (JP, A) JP-A-4-338772 (JP, A) JP-A-64-55269 (JP) JP-A-2-196250 (JP, A) JP-A-2-14747 (JP, A) JP-A-63-300247 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) G03G 15/00 G03G 21/00 B65H 83/00-85/00

Claims (2)

(57) [Claims] When performing stackless two-sided continuous copying, the number of copy sheets that can stay in a circulating transport path is determined by:
First step for determining the number of recyclable sheets. If the remaining number of copies is larger than the number of recyclable sheets, copy paper is sequentially fed by the number of recyclable sheets, and the number of copy sheets of the number of recyclable sheets is copied in the circulating transport path. A second step of sequentially loading the copy paper into the circulating transport path from the paper loading point, and after completing the first one-sided copy of each copy paper sequentially loaded into the circulating transport path in the second step, A third step of restarting the sheet feeding operation at a predetermined timing after the last sheet has passed through the carry-in point in the circulating transport path to start the next double-sided continuous copying cycle .
In the first step , the number of copies per unit time is taken as the copy speed,
The paper size where the copy size and copy paper are fed
The copy speed for each combination of
From the remembered first table, set by the user
The paper size where the copy size and copy paper are fed
Copy speed corresponding to the combination of
-Each combination of step, copy size and copy mode required as speed
Is the second table storing the copy speed for this
The copy size and copy set by the user.
Copy speed corresponding to the combination of
The step of obtaining as 2 copy speeds, of the first copy speed and the second copy speed,
The slower copy speed is the third copy speed
And the third copy speed
Stackless sided continuous copying method characterized in that it comprises a step of obtaining the cyclable number of sheets Zui. 2. The copy mode includes a non-aggregation mode and a small copy mode.
Note that at least one aggregation mode is included.
The stackless duplex continuous copying method in a copying machine according to claim 1.