JPS6027265A - Device for forming image on both faces - Google Patents

Abstract

PURPOSE:To make image forming procedures efficient and to make compensation and interruption for jam possible by controlling switching of carrying to an image forming means in accordance with the image forming mode to a transfer material in the device provided with various mechanisms. CONSTITUTION:In an automatic double-face copying machine 1, the image of an original on an original platen 19 is transferred onto the transfer material and is formed on the surface of this material and is fixed. Thereafter, the transfer material is distributed and guided to one of the path, where an image is formed on the reverse face, and the path, where the transfer material is ejected to the outside of the machine, by a switching guide 39. The image is formed on the reverse face of the transfer material which is guided to the path where images are formed on both faces, and the transfer material is not stored in an intermediate tray 9 but is carried toward a pair of rollers 34 directly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a double-sided image forming apparatus that forms images on both sides of a transfer material.

(Prior Art) Recent image forming apparatuses have increasingly automated their operations, and devices equipped with an automatic duplexing mechanism, an automatic transfer material binding mechanism, an automatic transfer material distribution mechanism, an automatic document feeding mechanism, etc. have been developed. .

(Objective) A first object of the present invention is to provide a double-sided image forming apparatus that is capable of realizing the most efficient image forming procedure among apparatuses that have the above-mentioned various mechanisms.

A second object of the present invention is to realize a simple compensation procedure for a jam that occurs during image formation on the second side of a transfer sheet on which an image has been formed on the M1 side, which has been considered a serious problem in the past. An object of the present invention is to provide a patented image forming apparatus characterized by the following.

A third object of the present invention is to eliminate interruptions to the double-sided image forming operation during double-sided image formation, which was previously impossible.
It is an object of the present invention to provide a double-sided image forming apparatus that has the following functions.

For this purpose, the double-sided image forming apparatus of the present invention includes a first Ja feed switching means for switching between discharging the transfer material after passing through the image forming means to the outside of the machine or conveying it toward the intermediate tray; Whether the material to be rolled guided by the switching means and transported toward the intermediate tray is transported directly into the intermediate tray, or whether the material to be rolled is reversed in its transport direction and transported toward the image forming point. The present invention is provided with a second conveyance switching means for switching between the two conveyance switching means, and a control stage for controlling the operation of both of these conveyance switching means, thereby achieving the above object.

(Example) The image forming system in which the present invention will be described in detail below with reference to the drawings is well known, so the description will be omitted.

As shown in the figure, the double-sided image forming apparatus in this embodiment includes an automatic double-sided copying machine 1, an automatic document circulation feeder (hereinafter referred to as R
2. Automatic distribution device (hereinafter referred to as sorter)
3 and an automatic stitching device (hereinafter referred to as a stapler) 4.

In the automatic double-sided copying machine 1, an image forming section (transfer section) 5 consisting of processes around the photoreceptor 1O1, an original scanning projection section 6, and a fixing section 7 that fixes the image on the transfer material are used to transfer the original on the original table 19J-. An image corresponding to the image is formed on the transfer material. The transfer material on which the image is to be transferred is sent out from the transfer material cassette 28 or 28 in the transfer material loading/discharging section 8 by the paper feed roller 30 or 31, and after being synchronized with the image on the photoreceptor by the registration roller 32. , an image is formed on its surface (first surface) in the image forming section 5. The transfer material on which image formation has been completed is transferred to the photoreceptor 10
After being separated from the surface of the sheet and being conveyed by a conveyor belt 35, it is guided by a guide 36 and reaches the fixing section 7. The image formed in the fixing section 7 is transferred to a switching guide 39 via a pair of conveying rollers 38 . The transfer material is further transferred to its back side (second side) by this switching guide 39.
The electric power is guided to either a path for forming an image, that is, a path for forming a double-sided image, or a path for discharging the image to the outside of the machine.

The transfer material guided to the first path for double-sided image formation is conveyed by a pair of transport rollers 41. Conveyor belt 42. The paper is stored in the intermediate tray 9 by a pair of transport rollers 43 and 44 . The transfer materials stored in the intermediate tray 9 are separated and sent out one by one from the bottom side by the roller 45, and the transfer materials are separated and sent out one by one from the bottom side by the roller 45.
and 34, it reaches the registration roller 32 again, and an image is formed on its second surface in the same manner as described above.

Here, after being conveyed by the belt 42, the transfer material is further conveyed toward the intermediate tray 9 by the pair of rollers 43 and 44. When the rear end of the transfer material is detected by the sensor 48, the pair of rollers 43 and 44 is By reversing it, it is possible to directly convey it toward the roller pair 34 without storing it in the intermediate tray 9. In this embodiment, by guiding the transfer material to one of the two transport paths mentioned above, it is possible to efficiently carry out operations such as the use of RDF shade, jam compensation, and interruption, which will be described below. . In addition,
The speeds of the conveyor belt 42 and roller pairs 43 and 44 do not need to match the speed of the main body, and by setting them earlier than the speed of the main body, the instant reversal described later can be effectively performed.

In the RDF 2, there are a table 50 on which originals are stacked with the younger pages facing -L, and a roller 51 that separates the originals stacked on this table 50 one by one from the bottom and sends them out. It has a pair of transport rollers 53 and a belt 54 for transporting the original, a sensor 55 for detecting the position of the original, a roller 56 for returning the original to the original stacking table 50, etc., and each part operates according to each operation mode described later.

In the sorter 3, the transfer material discharged from the copying machine 1 is conveyed to the tray 70 or transferred to a plurality of bins 1313.
Switching control is performed to determine whether to distribute to the distribution section consisting of (13B-1 to e13-n) or to pass through the sorter and convey to the stapler 4. Since the configuration of the sorter's distribution section and the like is well known, a description thereof will be omitted.

After the stapler 4 is ejected from the copying machine 1, the sorter 3
By binding the transfer material that has passed through the
11) Creates a child. The stapler 4 includes a loading table 7゛2 for temporarily storing transfer materials, a stabilizing device 73,
Rollers 74 and 75 that feed out the stable finished booklet
It has a stand 78 on which a stable finished booklet is loaded and placed.

FIG. 2 shows the operation panel in the system of FIG.

Here, 101 and 102 are transfer material selection buttons;
03 is a numeric keypad for setting the number of copies, 104 and 10
5 is a copy selection button, 10B and +07 are interrupt buttons, 108, 109 and 110 are discharge port designation buttons, and 111 and 112 are automatic document feeder selection buttons. Note that not all of the modes are set by pressing these buttons; for example, when the stapler is selected, the automatic document feeder may automatically specify the circulating document feed mode. Furthermore, when nothing is selected, a priority mode, for example, one-sided copy mode, may be automatically designated. Such automatic mode setting is necessary to simplify user operations.

In addition to the operation section, an appropriate display section for indicating the status of the apparatus is required, but since it is not directly related to the present invention, its explanation will be omitted.

Furthermore, the automatic document feed R mode corresponds to ■@ document feeding and one image formation, and the automatic document feed A mode corresponds to one document feeding and multiple image formations. say.

Further, in the above-described embodiment, a manual paper feeder and an automatic double-sided document feeder are not included, but these are omitted to make the explanation easier to understand, and the present invention excludes these functions. It's not something.

FIG. 3 shows the mode selection flow in the embodiment described above.

If double-sided copying is not selected, single-sided copying is automatically performed and mode O is set (procedure STI).

5T2). When double-sided copying is selected, automatic I
b! :11;:+If the feeding device is not selected, the user manually places the document on the document table. Such a selection is often made in the case of a bookbinding or the like in which the original cannot be loaded into an automatic document feeder. In this case, if the number of copies is not set, one copy is automatically specified and mode I is set (steps STI, ST3, ST4,
5T5). The flow for mode I is shown in FIG.

When the number of copies is set, the mode becomes ■ (hand 1).
1fflST1. ST3. ST4,5T13). The flow of mode ■ is shown in Figure 5. In this embodiment, the selection of Mode I and Mode ■ is determined by whether or not the number of copies is set. You can do it like this.

Next, when the automatic document feeder is selected, the automatic document feeder R mode is selected, and the number of copies is small, the mode becomes ■ (step j order STI, Sr
1, Sr1, Sr1.5TI3), if there are many, it becomes attraction mode (step STI, ST3.ST?, ST8,
5TIO). The number of copies a at which this mode is switched differs depending on the machine configuration, but a detailed explanation will be given later (1st θ
(see figure). The flow of mode (2) is shown in FIG. 6, and the flow of mode (2) is shown in FIG.

If automatic document feed mode A is selected, it becomes mode V (hand 111R9TI, ST3.ST?, 5TII).
, The flow of mode ■ is shown in Figure 11. In this embodiment, as a selection method between R mode and A mode, when a stapler or tray is selected, R mode is given priority, and when a sorter is selected, A mode is given priority. It is set to be. Of course, modes other than this selection are also possible; for example, it is also possible to select the stapler and then select the A mode.

FIG. 4 shows the operation flow of mode I.

In this case, the operator performs double-sided copying by copying one page at a time starting from the last page. In the figure,
In step 5T41, when the copy button is pressed, the first side is copied, that is, the transfer material is fed from the transfer material loading/discharging unit 8, and an image is formed on the first surface thereof. Further, the switching guide 39 is turned on (solid line position in FIG. 1) (hand mr+5T42). The transfer material whose first side has been copied is conveyed by the belt 42 and rollers 43 and 44, and when the rear end passes the sensor 48, the roller 43-
．． 44 rotates in the opposite direction. As a result, the transfer material is again generally fed in the direction of the registration rollers 32 (step 5T43). When the old copy reaches the detection position of the sensor 33 and the copy button is pressed or the document cover is opened or closed after copying the first side (steps 5T44 and S'r45),
Copying is performed on the second side (back side) of this inverted transfer material. In this case, the switching guide 38 is turned off (dotted line position 11 in FIG. 1) (step 5T48). As a result, double-sided
The transfer material that has been processed is discharged to the outside of the copying machine 1.

By repeating this operation, small plates with the same page order are created, and stapling is performed if necessary.

Here, in a conventional double-sided copying machine of this type, mode I
As an alternative method for double-sided copying, instead of reversing the transfer material as described above, there is a method in which the single-sided copied transfer material is stored in an intermediate tray and then re-fed. This method has the problem that it takes a lot of time to store and refeed the paper, resulting in a slow copying speed. Another method is to first copy all the pages that will become the first side, such as even-numbered pages, and load them on an intermediate tray, and then copy all the pages that will become the second side, such as odd-numbered pages, all at once. There is. According to this method, if the manuscript is bound, the number of times the manuscript must be turned is increased, and if it is a single-sided sheet manuscript, it is necessary to extract every other page, which takes time to copy. Furthermore, if double feeding or jam occurs on the first side or in a product after copying the first side, there is a problem that recovery processing is difficult.

This problem is solved by mode (2) of the present embodiment described above. That is, the transfer material is not stored in the intermediate tray but is reversed and starts the copying operation to the 21st m tray, so that the copying speed can be increased. Further, since the originals can be replaced in order starting from the last page, it is also convenient from the viewpoint of operability. Furthermore, even in the case of 11th feed or jam, the corresponding page can be immediately known, making it easy to deal with it. In addition, the reversing operation of the transfer material in this embodiment is performed for the transfer material being conveyed.
I: Since the interval between
Compared to the conventional method of continuously reversing the copied transfer material, the mechanism can be built inside the cylinder, and the reliability is high. Further, according to this embodiment, as shown in FIG. 1, the path for switch-packing the transfer material is also used as the path for storing the transfer material in the intermediate tray, so that the following advantages can be obtained.

(1) It is possible to reduce the number of paths, simplifying the machine and facilitating jam handling.

(2) Even if the transfer material is long, place the tip of the material on the intermediate tray 1.
- Since it can be put out at -, there is no need for special space for switchbacks.

FIG. 5 shows the operation flow of mode (2).

Since this is a general double-sided copying mode, its explanation will be briefly described. The number of copies per copy is set (Step 5)
T51), when the copy button is pressed (step 5T52)
, the transfer material is fed from the transfer material loading/discharging section 8 and the first
A side copy is made and placed on the intermediate tray 9 11 (step 5)
T53). The above operation is repeated until the set number of sheets is reached (Step 5T54). Then, when the original is replaced and the copy button is pressed (Step 5T55), the transfer material is fed from the intermediate tray 9 and copying is performed on the second side (Step 5T54). 5T51
(,). By repeating this operation, the required number of double-sided copies can be made.

FIG. 6 shows the operation flow of mode (2).

Mode (2) repeats almost the same operation as the above-mentioned mode (2), and is adapted to the automatic document feeder 2. When performing double-sided copying, if the number of pages in the original is odd, one transfer material will not be copied on one side.
will occur. The flow shown in FIG. 6 includes a step of counting the number of original sheets. Of course, it is necessary to count the number of original pages even if automatic document feeding is not used, and in that case the operator must know the number of original sheets. Possible methods for counting the number of originals using the automatic document feeder 2 include a method in which the operator inputs whether the number is all or an even number, and a method in which the number of sheets is counted by feeding the original only once. It will be done.

- As an example, a case where the manuscript has an odd number of pages, for example 7 pages, will be explained. First, copy the final 7th page of the manuscript onto transfer material,
Turn off the switching guide 39 and output 1 directly (step ST81)
~5T67). Next, take out the 6th page of the manuscript and put it on the WS.
Make a one-sided copy, turn on the switching guide, and turn the belt 42
．． The rollers 43 and 44 transfer the transfer material IIi! send

Next, when the rear end of the transfer material is detected by the sensor 48, the rollers 43 and 44 are reversed to reverse the transfer material.

If this transfer material has reached the detection position of the sensor 33 and the next original is set, the second side is copied onto the reversed transfer material, the J-IJ conversion guide is turned off, and the document is removed from the machine. Discharge (procedures STE!8 to ST?13). This operation is carried out until the document goes through one cycle (step ST7?). If the number of copies is plural, the process returns to the operation for the seventh page and repeats the above-mentioned operation (step 5T78).

If the original has an even number of pages, for example, 6 pages, the above operation can be performed directly from the 6th page.

FIG. 7 shows a time chart of the operation in mode (2). In the figure, the process starts after the counting of the number of original sheets has been completed, and the process starts when the number of pages is an even number (from step 5T88 in FIG. 6). When the first copy of the original is sent out and reaches a fixed position, the optical system starts scanning. When the optical system reaches the position □, the registration roller 33 is turned on, and an image corresponding to the original is transferred onto the transfer material. Note that the transfer material in this case is sent out by turning on the paper feed roller 3o or 31 in advance. Since the switching guide 38 (first switching means) is turned on, the transfer material on which the image has been transferred is conveyed to the belt 42 side after being fixed, and further conveyed by rollers 43 and 44. sensor 48
When the transfer material is turned on and then turned off again, the rollers 43 and 44 rotate in the opposite direction (Fig. 7, conveyance switching means). When the transfer material reaches the sensor 33, the optical system starts scanning, and when the optical system passes the fixed position, The registration roller 32 is turned on, and the transfer material is conveyed to the transfer section 5 again to perform second side copying. At this time, since the first switching means is off, the transfer material is discharged outside the machine.

In this mode, let Eo be the time for exchanging the original, ts be the scanning time of the optical system, and tp be the time it takes for the material to be reversed and reach the sensor 33 after the end of scanning the optical system.
The time TI required to copy m pages of manuscript from the start of the figure to nta+7 is as follows. Here, t is the time during which the last sheet of paper is discharged from the machine after completion of scanning by the optical system (where m is an even number and to>tp).

Figure 8 shows the operation flow in mode (2).

The copying operation in this mode is well known; first, the first side of the transfer material is continuously copied, the transfer material that has been copied on one side is loaded in the intermediate tray 9, and then the second side is copied. Copying is performed continuously on the transfer material fed from the intermediate tray 9, but from the second round onwards, the first side copying and the second side copying are performed alternately to improve the efficiency of copying. It is. The steps up to step 5T8B in Figure 8 are the same as in Figure 6, and then the first side of the original (even numbered pages) is copied until the original is 1.
Repeat until the cycle is completed (steps 5T89 to 5T94). When the original has gone through one cycle, if there are an odd number of originals, the last page is not copied qj, the next 1st side original is copied and stored in the intermediate tray, and the next 2nd side original is copied from the intermediate tray. (Steps 5T95 to 5T105). This operation is repeated until the original has gone through one cycle (hand ++it ST 106). After the first round of originals, if the number of originals is an odd number, copy the last page and eject directly (step 5T10?, 57120 to 5TI25)
). Next, copying of the first side and the second side is repeated. This operation is repeated until the required number of first side copies is reached.

When the required number of copies is reached, if the manuscript has an odd number of sheets, the last page is copied and then the rice is taken out directly, and then the second page (double-sided copying is made by repeating only the copying) (Steps 5T108~ 5TIII). The f stage for detecting the first round of the document is indicated by the reference numeral 57 in FIG.

Here, when performing the above-mentioned operation with the copying machine shown in FIG. 1, there is a problem of overlapping when the transfer materials pass each other between the rollers 43 and 44, but according to the time chart shown in FIG. 9 described below, It is confirmed that no jamming occurs when the two pass each other.

The time chart I in Figure Q'59 is f
D4 e' This shows the case of 7 original sheets, and the start point is after the counting of the number of original sheets is completed.

ε1) Figure 9 (A) it Steps 5T89 to 5T8 in Figure 8
6, in this flow, only the first side is copied, and no bending or twisting of the transfer section occurs. Figure 9 CB) is the 8th
Step ST8 in the diagram? ~5T105, and by feeding the transfer material for second-side copying from the intermediate tray 9 in advance, it is possible to prevent the transfer material from being Φ: that is conveyed toward the intermediate tray 9, and the registration By making the length of the conveyance path between the I-roller 32 and the sensor 48 longer than the maximum dimension of the transfer material used, it is possible to reliably prevent the transfer materials from overlapping. This relationship will be explained in more detail with reference to FIG. 9(B). When the transfer material for copying the first side is sent out from the delivery section 8, this transfer material is sent to the belt 42 side after being transferred and fixed because the first switching guide is turned on. At this time, until the rear end of the transfer material sent out from the intermediate tray 9 passes the sensor 48, the roller 43
, 44 rotate so as to convey this transfer material upward in FIG. Figure 9C
As can be seen from B), after the transfer material from the intermediate tray 9 passes the sensor 48, the transfer material for the first side copy enters the sensor 48, and no overlap of the transfer materials occurs. Note that in steps 5T109 to 5T118 in the fp6B diagram, only the second side is copied, and no overlapping of transfer materials occurs.

In the above mode ■, the time required to make n copies of an m-page manuscript from the same starting point as shown in Figure 7 is Ty = n 6 m(ts+t, )+mt(,'L
t ■.

Here, to = 1.8sec, ts = 1se
c, tp=2.5sec.

At t = 2 sec, the number of originals is 6 (m = 6), and ■
When the copying time T is calculated using the equations and equations 0 and n on the horizontal axis, it becomes as shown in FIG. 1O, and it can be seen that mode 2 is faster up to n=3. If the number of manuscripts is not 6,
From the calculations, it can be seen that n=3 is a branching point. In addition, the number of sheets at this branch point will differ depending on the case of another machine distribution u1; and the speed of document exchange of I'lDF, etc., and the number of sheets a suitable for each machine will be used in mode It would be better if you could switch ①.

Note that the above embodiment has been described only for the case of single-sided originals, but even in the case of automatic document feeding that is capable of handling double-sided originals, there are two modes: a mode in which the transfer material is immediately reversed and both sides A mode may be considered in which the first side is successively transferred, and then the second side is successively transferred. In this case, the branching point changes depending on the number of copies, the number of original sheets, and the position and method of reversing the original during 1f1 dynamic original feeding. In any case, by applying the present invention, an optimal copy operation can be selected.

FIG. 11 shows the operation flow of mode V. Mode ■ is almost the same as mode ■, and differs from mode ■ in the first mode.
The part that determines whether or not the second side original has been set after the first side original has been ejected (hand j1 "l5T137,1
38) and the part that determines whether or not the first side original is set after carrying out the second side original (step 5T141 → 142 → 133 → 134), and finally the original goes through one round and ends (step 5T141).

Next, an explanation will be given of the operation when a jam occurs during the second +(i copying) in mode π and mode ■.

In conventional copying machines, where it is impossible to immediately reverse the transfer material and convey it to the transfer section as in this example, it is necessary to copy both sides of the area where the jam occurred first. However, it is impossible to implement it. In other words, in a copying section that sends out transfer materials stacked on an intermediate tray from the bottom to make double-sided copies, it is necessary to insert the transfer material for a single-sided copy of the portion where the jam occurred into the bottom of the intermediate tray. However, such work is difficult to implement. For this reason, conventionally, the copying operation must be started after all the transfer material in the intermediate tray has been removed, which is time consuming and results in a waste of one material. However, in an apparatus capable of immediately reversing the transfer material as in the present invention, after copying the page in the jammed area, the flow corresponding to copying onto the transfer material in the intermediate tray 9 is continued. This allows for efficient handling of jams.

Next, the interrupt mode will be explained.

In this case as well, the conventional device I'' cannot immediately reverse the transfer material.
In t, no interrupts other than single-sided interrupts were possible during double-sided copying. Similarly, double-sided interrupts were not possible even in devices that had a manual feed function. However, by adopting the configuration of the present invention, it is possible to make both the interruption during double-sided copying and the interrupt during manual double-sided copying, although one copy at a time, ijf-enabled.

(Effects) According to the present invention, the discharge path to the intermediate tray that temporarily stores the transfer material that has been copied on one side and the conveyance path that transports the transfer material that has been copied on one side to the transfer unit is partially shared. In addition, a switchback means is configured to convey the transfer material that has already been copied on one side to the immediate transfer section without storing it in the intermediate tray, so it is possible to obtain the highest copying speed for each mode, and also to prevent the occurrence of jams. It becomes possible to perform quick recovery processing for the data, and furthermore, it becomes possible to interrupt during double-sided copying.

[Brief explanation of the drawing]

FIG. 1 is an internal configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the operation panel of the device shown in FIG. 1, FIG. 3 is a flowchart showing mode settings in the device shown in FIG. 1, and FIG. Figures 5, 6, 8, and 11 are flowcharts showing the operation of the device in Figure 1 in each mode, Figures 7, 9 (A), and 9 (A), respectively. B) is a time chart showing the operation of apparatus 1/1 shown in FIG. 1, and FIG. 10 is a diagram showing the relationship between copying section φQ and copying time. 1...Copying machine, 2...Automatic original circulation feeder, 3...Automatic distribution device, 4...Automatic binding device, 5...Image forming section, -6... Original scanning projection section , 7...Fixing section, 8...Transfer material loading/unloading section, 9...Intermediate tray, 1O...Photoconductor, 13...Document stand, 28.29...Cassette, 30.31 ...Paper feed roller, 32...Registration roller. 33... Sensor, 34... Roller, 35... Conveyor belt, 36... Guide, 38... Roller pair, 39... Switching guide, 41... Roller pair, 42... Belt, 43.44...Roller pair, 45, 46...Roller, 47...Roller, 48...Sensor, 50...Document loading table, 51...Roller. 53...Roller pair, 54...Bell I, 55...Sensor, 56...Roller, 57...Sensor. Figure 4 Figure 5 Figure 10 Figure 0 123.4 Ikkumaki n (Miyako) -363-

Claims (1)

[Scope of Claims] An image forming means that forms an image on a transfer material, and a storage T stage that temporarily stores the transfer material on which an image has been formed on one side. a first conveyance switching means for switching whether to discharge the transfer material on which the image has been formed by the image forming means to the outside of the machine or to convey it toward the storage means; Should the transfer material conveyed by Mj be stored in the storage means as it is, or should the conveyance direction of the transfer material be reversed and transported to the image forming means with the trailing end as the beginning without storing it in the Mj storage means? of,! , I, and a control means for controlling the operations of the first and second conveyance switching means according to the image forming mode on the transfer material. .