JPH02134651A - Image forming device - Google Patents

Abstract

PURPOSE:To make the best use of paper by containing overlapped sheets of paper in an intermediate containing means, instead of forming an image, in case the overlapped feed occurs. CONSTITUTION:An overlapped feed detecting means 8 checks whether the sheets of paper 3 are overlapped or not while they are carried into a developing and forming means 2 from a paper containing means 1 or the intermediate containing means 5, and detects the number of sheets. According to signals from the overlapped feed detecting means 8, an overlapped feed judging and commanding means 10 outputs signals indicating that an image is not formed on the paper 3 to an image forming means 2 and that the overlapped sheets of paper 3 are contained in the intermediate containing means to a driving means 7 for carrying when the sheets of paper are overlapped. At the same time, the means 10 outputs signals indicating that another paper 3 in the intermediate containing means 5 is carried to the image forming means 2 to the driving means 7 according to next copying commands from copy commanding means 11. Consequently, the overlapped sheets of paper 3 can be used effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus equipped with an intermediate tray for executing a double-sided copy mode or a composite copy mode.

[Prior Art] Conventionally, copying machines are known that have a double-sided copy mode in which images are copied on the front and back sides of a sheet of paper, and a composite copy mode in which separate original documents are copied and combined on one side of a sheet. This copying machine transports the paper carried out from an external paper cassette to the transfer unit, and stores the copied paper, on which the image has been copied, in an intermediate tray installed inside the copying machine, without ejecting it as it is. , and then transported to the transfer section again for double-sided copying or composite copying.

By the way, for example, when taking out paper from a paper cassette,
There are cases where a so-called multi-feed condition occurs, that is, a plurality of sheets are taken out in a stacked state.

A conventional copying machine is provided with a double-feed detection sensor on a paper conveyance path to detect such a double-feed state.

When a double feeding state is detected, the copy is copied in the transfer section and then stored in the intermediate tray. Then, the double feeding state is displayed externally. The user then sees the display, learns of the multifeed condition, opens the door of the copying machine, and removes the extra blank paper that has not been copied from among the sheets in the intermediate tray that are in the multifeed condition. are doing.

[Problem to be solved by the invention] However, the task of opening the door and removing the blank paper by the user is troublesome, and requires the same amount of effort as the task when a so-called paper jam occurs. There is a problem.

Also, if a double feed condition occurs when copying the front side during double-sided copying,
Due to the structure of the copying machine, extra blank paper is placed below the copied paper. Therefore, in order to remove the extra blank paper, first move the top copy of the paper in the intermediate tray to the outside, then remove the blank paper below it, and then move the copy paper again. It will be necessary to fit it into the intermediate tray. At this time, if the front and back or front and back of the copied paper to be stored again are incorrect, there is a risk that defective copies will be produced.

SUMMARY OF THE INVENTION In view of the problems of conventional copying machines, it is an object of the present invention to provide an image forming apparatus that does not require the user to perform troublesome work and that can effectively utilize blank paper.

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a paper storing means from which paper is normally taken out, an image forming means equipped with a photosensitive roller, a developing device, a transfer device, etc., and an intermediate paper storage means. an intermediate storage means for storing the copied paper, a discharge storage means for storing the ejected paper, a transport drive means for transporting the paper and the copied paper between the respective means, and upstream of the image forming means, Image formation comprising a double-feed detection flat stage that detects the double-feed state of sheets conveyed thereon, and a double-feed display means that displays the double-feed state based on the output signal of the double-feed detection means. In the apparatus, based on the output signal from the double feed detection means, a signal is output to the image forming means to prevent the image from being formed on the paper at the time of double feed, and to the conveyance driving means, Outputting a signal to store the multi-fed sheets in the intermediate storage means, and having the transport driving means transport the sheets in the intermediate storage means to the image forming means based on the next copy command from the copy command means. The image forming apparatus is characterized in that it includes double feeding state determination command means that outputs a signal indicating that the double feeding state is to be determined.

According to a second aspect of the present invention, in the first aspect of the present invention, the double-feed state judgment command means also calculates the number of double-feed sheets, and the double-feed state judgment command means is a means for calculating the number of double-feed sheets, and the double-feed state judgment command means is a means for calculating the number of double-feed sheets. a staying sheet number calculating means for calculating the number of sheets that can be stored by comparing the length of a predetermined path to return to the means and the size of the paper to be copied; (a) If the number of double-fed sheets exceeds the number of sheets that can be stored, the double-fed sheets carried into the intermediate storage means are sequentially ejected until the number of double-fed sheets becomes equal to or less than the number of sheets that can be stored. (b) when the number of double fed sheets is less than or equal to the number of retained sheets, the intermediate The multi-fed sheets carried into the storage means are sequentially transported to the image forming means, and a signal is output to the transport driving means to cause the sheets to be transported again to the intermediate storage means, and the image forming means is caused to form an image. An image forming apparatus characterized by comprising: staying sheet number comparison means for outputting a signal indicating the status of the image forming apparatus.

[Operations] The present invention provides that the double-feed state judgment command means outputs a signal to the image forming means not to form an image on the paper during electrical transmission based on the output signal from the double-feed detection means, A signal is outputted to the conveyance drive means to instruct the multi-feed paper to be stored in the intermediate storage means, and based on the next copy command from the copy command means, the paper is sent to the conveyance drive means to be stored in the intermediate storage means. outputs a signal to convey the sheet of paper to the image forming means.

Therefore, even if a double-fed state occurs, the user can effectively use the double-fed paper by issuing a copy command again, and can save the trouble of taking it out.

[Examples] The present invention will be described below based on drawings showing examples thereof.

FIG. 1 is a simplified sectional view of a copying machine in which the present invention is applied.

This copying machine has a document mounting table 24 on the top surface of its main body 21.
It is equipped with This original vI mounting table 24 is provided with a contact glass 22 on which the original B is placed. An optical system 26 having an exposure lamp 25 is provided below the contact glass 22 . A photosensitive drum 27 is disposed in the center of the main body 21 below the optical system 26. The photosensitive drum 27 rotates in the direction shown by arrow a in the figure, and a charger 28 and a developing device 29 are arranged upstream and downstream of the exposed portion, respectively. Further downstream of the developing device 29, a transfer device 210 is provided.

A paper storage means l storing paper 3 is attached to the side of the main body 21. The sheets 3 sequentially fed out from the sheet storage means 1 are sent to the transfer device 21O with timing controlled by the registration rollers 212.

The exposure lamp 25 of the optical system 26 is connected to the contact glass 22.
Exposure scanning is carried out below in the direction of the arrow mark, and the reflected light of the light emitted by the exposure lamp 25 is irradiated onto the exposed portion of the surface of the photosensitive drum 27 via the optical system 26.

As a result, a latent image is formed on the surface of the photosensitive drum 27, which has been charged in advance by the charger 28, and the developing device 28
9, and the toner image is further transferred onto the paper 3. A paper conveying belt 213 is provided downstream of the transfer device 210, and a fixing roller 214 is provided.
A guide member 216 is provided for guiding the intermediate storage means 5 to the intermediate storage means 5 as required. In double-sided copy mode,
The guide member 21B rotates from the illustrated state and guides the paper 3 toward the detour reversing path 217. Furthermore, the paper 3 is placed on the roller 2F.
Due to the action of B, it is made to advance within the conveyance guide 219,
The image is stored in the intermediate storage means 5 with the surface on which the image is fixed facing upward. Paper 3 stored in this intermediate storage means 5
When transferring an image to the back side of the paper 3, the paper 3 is sent to the conveyance guide 221 by the paper feed roller 220 and reversed so that the back side on which the image is not transferred is facing upward.
Furthermore, it is sent toward a transfer device 210 by registration rollers 212, and the image is transferred onto the back surface thereof. In this way, the paper 3 with images formed on both sides is moved by the guide member 2 in the illustrated state.
16, without being guided towards the reversal path 217.
It is discharged to the discharge storage means 4. Incidentally, an operation panel 224 is provided on the top surface of the copying machine main body 21 so that the user can issue various commands to the copying machine or know the status of the copying machine.

FIG. 2 is a block diagram showing an embodiment of an image forming apparatus according to the present invention. In the figure, the paper storage means 1 is provided outside the main body of the copying machine as described above, and is a means such as an external cassette for storing the paper 3. Image forming means 2
The photosensitive drum 27, the developing device 29, the transfer device 210
It is a means for forming an image by transferring a toner image onto the paper 3 fed from the paper storage means 1. As described above, the discharge storage means 4 stores the copied paper 3" or blank paper 3 discharged from the image forming means 2.
This is a means such as an ejection tray for storing the . Intermediate storage means 5
is a means such as an intermediate tray that intermediately stores the paper 3.3' discharged from the image forming means 2. These paper storage means 1, image forming means 2, discharge storage means 4, and intermediate storage means 5 are connected to the conveyance path 6. ．． It is communicated by 6b, 6i and 6d. The transport paths 6a, 6b,
6 6. is composed of the conveyance guy F' 219, 221, the conveyance belt 213, the guide member 216, and the like. The transport drive means 7 transports the paper 3, 3' along the transport path 6.
This means includes a registration roller 212, a roller 218, a roller 22o1, a motor, etc. for double feeding through the rollers 22o1 and 22o1. The double feed detection means 8 detects whether or not the sheets 3.3' are in a double feed state when the sheets 3.3' are carried from the paper storage means 3 or the intermediate storage means 5 to the development forming means 2. However, this is a means that can further detect the number of sheets. For example, if a light emitting device (LED) and a photo sensor are placed above and below the transport path, and paper 3.3' is fed in duplicate, the amount of light transmitted will decrease, and the amount of decrease will be related to the number of sheets fed in duplicate. Based on this, a device that detects the double feeding status and the number of sheets being transferred is used. Silicon fructose (SBC) or the like is used as such a photosensor. Double feed display means 9
is an operation panel 224 of the copying machine that notifies the user of the occurrence of a double feed condition in accordance with the output signal of the double feed detection means 8.
This is a display means such as a liquid crystal or an LED provided in the display. The copy command means 11 is a means for commanding copying, and is, for example, a print key provided on the operation panel 224 of a copying machine. .

The double feed state judgment command means 10 (a) sends a signal to the image forming means 2 not to form an image on the paper 3.3' during double feed, based on the output signal from the double feed detection means 8; (1)) Outputs a signal to the conveyance drive means 7 to store the multi-feed paper 3.3' in the intermediate storage means 5; (c)? Jf copy command means 1
This means outputs a signal to the conveyance driving means 7 to cause the sheet 3, 3' in the intermediate storage means δ to be conveyed to the image forming means 2 based on the next copying command from 1.

Furthermore, another embodiment of the present invention will be described.

The double-feed state judgment command means 10 is a means for also determining the number of double-feed sheets based on the output of the double-feed detection means 8.

The copy paper size setting means 12 sets the size of the paper to be copied, for example, A3. A means for setting A4, B5, B4, etc., for example, an operation panel 224 of a copying machine.
These include paper size setting keys provided on the top. The retained sheet number calculation means 13 is an intermediate storage means 5 of the image forming apparatus.
The length of a predetermined path from leaving the paper to returning to the intermediate storage means 5 is compared with the size of the paper to be copied (length in the conveying direction) set by the copy paper size setting means 12, and the paper can be stored therein. This is a means of calculating the number of sheets. The predetermined path is, for example, intermediate storage means 5→→conveyance guide 221→→registration roller 212→→transfer device 210→→conveyance bell) 21
3→→Fixing roller 214→→Guide member 216→→Detour reversal path 217→→Transport guide 219→→Intermediate storage means 5.

Based on the maximum number of sheets 3 that can stay simultaneously in this path, the number of sheets that can stay, including a margin, is calculated. The staying sheet number comparing means 14 compares the number of sheets that can be held, which is calculated by the staying sheet number calculation means 13, and the number of double-feed sheets output from the double-feeding state judgment command means 10, and (a) the number of double-feeding sheets is the number of sheets that can stay; When the number of multi-fed sheets exceeds the number of accumulated sheets, a signal is outputted to the transport drive means to sequentially discharge the multi-fed sheets carried into the intermediate storage means to the discharge storage means until the number of multi-fed sheets becomes equal to or less than the number of accumulated sheets, and A signal indicating that no image is to be formed is output to the image forming means, and (b) when the number of multi-fed sheets is less than the number of retained sheets, the multi-fed sheets 3.3 carried into the intermediate storage means 5 are
A signal is outputted to the transport drive means 7 to sequentially convey the images to the image forming means 2 and then again to the intermediate storage means 5, and a signal to cause the image forming means 2 to form an image is outputted. It is a means of outputting.

The above-mentioned double feeding state judgment command means lO5 staying sheet number calculation means 13
, the staying sheet number comparison means 14, etc. can also be realized using a microcomputer.

FIG. 3 is a flowchart showing the operation of the embodiment of the present invention. This operation is an operation in double-sided copy mode.

The paper size is set by the copy paper size setting means 12 (step Sl). At the same time, the transport direction is also set. Therefore, the length of the sheet 3 in the conveyance direction is determined.

Furthermore, the number of copies I desired to be copied is set (step S2). The copy command means 11 instructs copying (
Step S3). The number of copies ■ is stored in a variable P (step S4). The paper 3 is conveyed from the paper storage means 1 to the image forming means 2 (step S5). If the double feeding state is not detected by the double feeding detection means 8 (step S6), normal processing is performed.

That is, the number I of the copy set is subtracted by 1 (step S7), the front surface is copied by the image forming means 2 (step S8), and it is carried into the intermediate storage means 5 (step S9).
), the front side copying is repeated until the copy set number ■ becomes 0 (step 5lO).

When the front side copying is completed in this way, the paper 3'' on which the front side has been copied is sent from the intermediate storage means 5 to the image forming means 2 (step 5ll), and if there is no double feeding (step 5ill), it is stored. The value of the copy set number of the variable P is subtracted by 1 (step 512), and the image forming means 2 is caused to perform backside copying (step 513).

The paper 3' on which both sides have been copied is carried out to the ejection/storage means 4 (step 514). Then, when the back side copying of the number of sheets in the copy set is completed (step 515), the copying operation ends (step 516).

In addition, in step 5ill, if double feeding occurs, the number of sheets T of double feeding is memorized (step 5112), the destination of the ejection destination is memorized (step 5114) without image formation (step 5113), The stored value of the copy set number of variable P is subtracted by T (step 5l15), and the multi-feed paper 3 is directly ejected to the ejection/storage means 4 of the tray in which the forward light is stored (step 5l15).
step 8116). Then, when the variable P becomes 0, that is, when the reverse side copying of the number of sheets in the copy set is completed (step 515), the contents stored in the forward optical storage memory are displayed and the copying operation ends (step 516). Note that in step 5115, decrease! As for the number of copies made, the number of copies will be insufficient in the end, so copies will be made again later.

Next, in step S6, when the double feed detection means 8 detects a double feed state (step S6), the double feed state judgment command means 10 instructs the image forming means 2 to stop image formation (step 517), Memorize the number of double-feed sheets N (
Step 51B). Furthermore, the double feeding state judgment commanding means 10 outputs a signal to the conveying drive means 7 to cause the blank paper 3 to be carried into the intermediate storage means 5, and the carrying out means 7,
The paper 3 is carried into the intermediate storage means 5 (step 51
9). On the other hand, the retention sheet number calculating means 13 calculates the number of sheets that can be retained X from the paper size and the length of the predetermined path of the copying machine (step 520). Retained sheet number comparison means 1
4 compares the number of copies X with the number of multi-feed sheets N, and if N is less than If the number of sheets I is greater than or equal to N (step 522), all the double-fed blank sheets 3 are used, so the conveyance driving means 7
The blank paper 3 is transferred from the intermediate storage means 5 to the image forming means 2.
(Step 523). Then, if there is no double feeding, step 524), the image forming means 2 is made to perform front side copying (step 525),
Furthermore, the number N of double fed sheets is subtracted by 1 (step 526), and the number l of printed sheets is subtracted by 1 (step 527). and,
An instruction to store the paper 3 whose front side has been copied into the intermediate storage means 5 is output to the transport drive means 7 (step 528).

In this way, the double-feed blank sheets 3 are sequentially taken out from the intermediate storage means 5, the front side is copied, and the number of double-feed sheets N becomes 0 (step 529). If the copy set number I is not O, then , this time from the external paper storage means l.
Paper 3 is fed and front side copy is performed (step S30.
S5...). When the copy set number ■ is 0 (step 530), processing is performed as in the flow from step Sll described above. That is, from the intermediate storage means 5,
The sheet 3' on which the front side has already been copied is sent to the image forming means 2 (step 5ll), the value of the copy set number of the saved variable P is subtracted by 1 (step 512), and the back side is copied to the image forming means 2. (Step 5)
13).

The paper 3' on which both sides have been copied is carried out to the ejection/storage means 4 (step 514). When the back side copying of the number of sheets in the copy set is completed (step 515), the completion is displayed and the copying operation ends (step 816).

In addition, in step S24, if double feeding is detected during the process of unloading from the intermediate storage means 5, image formation is stopped (step S31), the number Y of double feeding is memorized (step 532), 2 Since this is a multi-feed, the destination of the multi-feed paper is memorized (step 533).
, the value obtained by subtracting the number Y from the number N of double fed sheets is the number N of double fed sheets.
Then, in step 534), the double-fed sheets 3 are directly discharged to the discharge storage means 4 (step 535).

Further, in step S22, if the number I of copy set sheets is smaller than the number N of multi-fed sheets, there will be a surplus of multi-fed sheets, and the excess paper will be ejected to the ejection/storage means 4. That is, if the paper is carried out from the intermediate storage means 5 (step 536), if double feeding has not occurred (step 5)
37), without performing image formation (step 838).
, store the discharge destination (Step 539), subtract 1 from the number of double-fed sheets (Step 540), and discharge the paper to the discharge storage means 4 (Step 541). Then, the number of multi-feed sheets is N.
is repeated until it becomes equal to the number of copies I (step 522).

Also, if double feeding occurs again in step S37 during this process, it is double feeding, so step S37
1 to step S35, the images are ejected without forming an image (steps S42, S43, and S35).
44. S45. S46).

Then, if the number of multi-fed sheets F (N is not 0, there are still some remaining, the process returns to step S22 and the above-mentioned operation is repeated (step 547). If the number of multi-fed sheets N is O, the process returns to step S5). , the above-mentioned operations will be performed thereafter.

Further, in step S21, if the number N of double-fed sheets is larger than the number of sheets that can be stored Since it is inconvenient that the sheet 3' on which the cover copy has been made is carried into the intermediate storage means 5, the following processing is performed.

That is, step 8 of carrying out the paper 3 from the intermediate storage means 5
48), if double feeding does not occur (step 549), without forming an image (step 550), memorize the ejection destination (step 551) and subtract l from the number N of double fed sheets (step 552), and eject and store. Discharge to means 4 (
step 553). Then, this operation is performed for the number of sheets that can be retained
Repeat until matches the number of multi-feed sheets (step 521)
.

Moreover, if double feeding occurs again at that time, since it is a double layer, it will be discharged in steps S54 to S358 in the same way as steps S31 to S35 described above, and the process will return to step S21 again.

[Effects of the Invention] As described above, the present invention has the following advantages:
Since the paper is stored in the intermediate storage means without forming an image, the paper can be used effectively and has the advantage that the user does not have to remove the paper.

Furthermore, since the present invention calculates the number of sheets that can be retained according to the paper size, the paper can be used effectively without any effort even in modes such as double-sided copying and composite copying.

[Brief explanation of the drawing]

FIG. 1 is a simplified sectional view showing an embodiment of the image forming apparatus of the present invention, FIG. 2 is a block diagram showing the embodiment, and FIG. 3 is a flowchart showing the operation of the embodiment. l... Paper storage means 2... Image forming means 3.3
'...Paper 4...Ejection storage means 5.Intermediate storage means 6a, 6b, 66. ...Conveyance path 7.
...Transport drive means 8...Double feed detection means lO
...Double feed status judgment command 13...Standing sheet number calculation means 14...Standing sheet number comparison means

Claims (2)

[Claims] (1) A paper storage means for taking out paper, an image forming means equipped with a photoreceptor, a developing device, etc., an intermediate storage means for storing paper and copied paper intermediately, and an ejector for storing ejected paper. a storage means, a conveyance drive means for conveying the paper and the copied paper between the respective means, and a double feed detection means for detecting a double feed state of the sheets conveyed thereupon upstream of the image forming means; In an image forming apparatus equipped with a double feed display means for displaying a double feed state based on an output signal from the double feed detection means, Sometimes, a signal is outputted to the image forming means not to form an image on the paper, and a signal is outputted to the conveyance drive means to store the multi-fed paper in the intermediate storage means, and the copying process is performed. The present invention further includes a multifeed state judgment command means for outputting a signal to the transport drive means to cause the paper in the intermediate storage means to be transported to the image forming means based on the next copying command from the command means. Features of the image forming device. (2) The multifeed state judgment command means also calculates the number of multifeed sheets, and calculates the length of a predetermined path from the intermediate storage means of the image forming apparatus to the return to the intermediate storage means, and the number of copies. A stacking sheet number calculation means that calculates the number of sheets that can be stored by comparing the size of the target paper, and a number of sheets that can be stored and the number of double fed sheets output from the double feeding state judgment command means, (a) When the number of sheets to be fed exceeds the number of sheets that can be stored, the transport drive sends a signal to the effect that the multi-fed sheets carried into the intermediate storage means are sequentially discharged to the discharge storage means until the number of multi-fed sheets becomes equal to or less than the number of sheets that can be stored. (b) When the number of multi-fed sheets is less than the number of retained sheets, the multi-fed sheets carried into the intermediate storage means are sequentially transferred to the intermediate storage means. Remaining sheet number comparison means for outputting a signal to the conveyance drive means to convey the sheets to the image forming means and then to convey them again to the intermediate storage means, and also output a signal to cause the image forming means to form images; The image forming apparatus according to claim 1, further comprising: .