JP2002333797A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the continuity of a series of image forming processing in the case of detecting the doubly feeding of paper and also to reuse the paper related to the doubly feeding. SOLUTION: This image forming device is equipped with a paper supply unit 30 feeding the paper P one by one, a paper carrying part 40 carrying the fed paper P to a specified carrying path, an image forming part 90 forming an image on the carried paper P, a doubly feeding detecting sensor S2 provided on the carrying path and detecting the doubly feeding of the paper P, and a controller for controlling the paper carrying part 40 and the image forming part 90 at least based on doubly feeding detection information. When the doubly feeding of the paper P is detected, the controller controls the paper carrying part 40 so that the paper P related to the doubly feeding may be ejected in a state where the image is not formed yet, and also holds image data scheduled to be formed as the image on the paper P and then performs control so that the image may be formed on the paper P fed from the paper supply unit 30 based on the image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method suitable for a copying machine, a multifunction machine, a printer, a facsimile, etc. having a copying function using an electrophotographic system.

[0002]

2. Description of the Related Art Conventionally, a plurality of types of sheet-feeding recording sheets (hereinafter, simply referred to as sheets) of different sizes such as A4 size (vertical), A4 size (horizontal), B5 size, B4 size and the like are stored. An image forming apparatus such as a copying machine, a multifunction peripheral, a printer, and a facsimile equipped with a paper cassette is often used.

In recent years, a post-processing device is connected to the main body of the device as an optional device, and a copier or a multi-function device having a function of folding a sheet after image formation during saddle stitching is often used. It has become. According to this type of image forming apparatus, the paper fed from the paper feed cassette may be undesirably double-fed.

[0004] Here, the double feeding means that two or more sheets are overlapped and fed out of a paper feed cassette, and the plurality of sheets are overlapped and conveyed to an image forming unit. Double feed is likely to occur when frictional force is applied to a sheet during a drying period or the like.

When the overlapped paper is conveyed to the image forming section, an original image may be formed across a plurality of papers, in which case all the multiply fed papers are wasted. Would. Usually, a misaligned image is often formed on the uppermost sheet, and the uppermost sheet is wasted. For this portion, the original image is reread and the image is formed.

[0006] Regarding the countermeasure against double feeding, a paper feeder with a transport return function is described in a patent document (JP-A-11-286345) which is a technical document. According to this paper feeder, the double feed detection sensor is provided near the exit of the paper feed cassette, and when the sensor detects the double feed, the paper conveyance is stopped, and the paper related to the double feed (hereinafter, the double feed Paper) is returned to the original position of the sheet cassette.
As a result, an image is not formed on the multi-fed sheet.

[0007] In addition, Japanese Patent Laid-Open Publication No. 11-245
No. 06) describes an image forming apparatus with a transport stop function. According to this image forming apparatus, the double feed detecting unit is provided near the transport roller of the paper feed cassette, and when the double feed detecting unit detects the double feed, the paper transport mechanism is stopped. When this double feed occurs, "double feed" is displayed on the display monitor of the operation unit or the like to inform the user. By treating the double feed as JAM, an image is not formed on the double feed.

[0008]

However, according to the conventional image forming apparatus having the function of preventing double feeding, there are the following problems. When the double feed of the paper is detected, the paper transport is stopped or the paper transport mechanism is stopped. Therefore,
An image forming process such as an exposure process, a development process, a transfer process, and a fixing process is interrupted, and it is difficult to maintain job continuity. Particularly, in an image forming apparatus that treats multifeed as JAM, downtime depending on removal of the multifeed occurs. Depending on the mounting position of the double feed detection sensor, a plurality of sensors may be required, or image data to be formed on the paper may be overwritten due to a delay in double feed detection timing. This causes a situation in which a document that is to be subjected to image formation on the multi-fed paper must be read again.

In view of the above, the present invention has been made to solve the above-mentioned problems. In the case where a double feed is detected for a sheet, the continuity of image forming processing can be ensured, and the sheet related to the double feed is provided. It is an object of the present invention to provide an image forming apparatus and an image forming method which can reuse the image forming apparatus.

[0010]

In order to solve the above-mentioned problems and to achieve the object, an image forming apparatus according to the present invention includes a sheet supply means for storing a plurality of sheets and feeding the sheets one by one. Conveying means for conveying the sheet fed from the sheet feeding means to a predetermined conveying path; image forming means for forming an image on the sheet conveyed by the conveying means; and an image forming means provided upstream of the image forming means. Detecting means for detecting the multi-feeding of the sheets, and at least a control device for controlling the conveying means and the image forming means based on the multi-feed detecting information obtained by the detecting means. Is detected, the transport unit is controlled so as to discharge the multi-fed paper without forming an image on the paper, and holds data on the image to be formed on the paper. , Then, it is characterized in that for controlling the image forming means to form an image on the basis of the data on a sheet fed from the sheet supply means.

According to the image forming apparatus of the present invention, when the sheets are fed one by one from the sheet feeding means containing a plurality of sheets, the sheets fed from the sheet feeding means are transported by the conveying means in a predetermined conveying path. Transported to If the detecting unit does not detect double feeding of the sheet, an image is formed on the sheet by the image forming unit.

Further, when the detecting means detects the double feed of the paper, the control device which has inputted the double feed detection information causes the conveying means to discharge the paper as it is without forming an image on the paper relating to the double feed. And control the image forming means so as to hold the data relating to the image to be formed on the paper and then form an image on the paper fed from the paper supply means based on the data. It is made to do.

Therefore, a double feed exclusion in which the multi-feed paper is discharged to a specific discharge tray other than the designated discharge tray or a paper feed unit without forming an image on the multi-feed paper is excluded. Continuous image control can be performed. That is, when a double feed of paper is detected, an image forming process that forms a blank image can be inserted, so that the continuity of the series of image forming processes can be ensured.

The image forming method according to the present invention detects a double feed of sheets fed one by one from a predetermined paper storage position, and when the double feed of the sheets is detected, an image is formed on the sheet related to the double feed. The paper is discharged as it is without forming the paper, the data related to the image to be formed on the paper is held, and then the image is formed on the paper fed from the paper storage position based on the data. It is assumed that.

According to the image forming method of the present invention, the multi-feed paper is not formed on the multi-feed paper, and the multi-feed paper is transferred to a specific discharge tray other than the designated discharge tray or a paper feed unit. Double feed exclusion continuous image control such as discharging paper can be executed. Therefore, when a double feed of sheets is detected, an image forming job that forms a blank image can be inserted, so that the continuity of the series of image forming jobs can be ensured. Thus, downtime such as stoppage of the image forming job can be eliminated. In addition, since the sheet in which no image is formed before the image formation can be discharged, the waste of the sheet can be eliminated.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus and an image forming method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating a configuration example of an image forming apparatus 100 as an embodiment according to the invention. In this embodiment, a control device is provided for executing a multi-feed elimination continuous image forming control with respect to the multi-feed of the paper, and when the multi-feed of the paper is detected in the transport path on the upstream side of the image forming means, the multi-feed is performed. The sheet is discharged as it is before image formation, and data relating to an image that should have been formed on the sheet is retained. Next, an image is formed on a sheet fed from a sheet supply unit based on the data. Is formed, so that the continuity of the series of image forming processes can be ensured, and the paper related to the multi-feed can be reused.

The image forming apparatus 100 shown in FIG. 1 performs double feed detection before forming an image on a sheet P, and executes image forming control based on the double feed detection. It is suitable to be applied to a copier, a multifunction peripheral, a printer, a facsimile, etc. having a copying function. The image forming apparatus 100 includes a paper feed unit 30, a paper transport unit 40, a document transport unit 70, an image reading unit 80, and an image forming unit 90.

A manual paper feed unit 35 is provided on the right side of the image forming apparatus main body. Further, the image forming apparatus 100
In some cases, an optional post-processing device 200 or a large-capacity sheet feeding device 300 may be connected for use. This double feed is as defined in the conventional example.

The image forming apparatus 100 is provided with paper feed units 30, 31, and 32, etc., which are examples of paper supply means.
It is made to feed out one by one. Paper feed units 30, 3
Paper feed cassettes are provided in 1 and 32, A4 size (vertical)
And sheets of A4 size (horizontal), B5 size and the like are set.

Above (at the downstream side of) the paper feed unit 30, a paper transport section 40 is provided as an example of a transport means, and the paper P fed out of the paper feed unit 30 based on a paper transport start signal SS4 is supplied to a predetermined location. Transport route. The control unit 16 supplies the sheet transport start signal SS4.

The paper transport section 40 has a registration roller 28. The registration roller 28 is provided at a demarcation point that separates the first paper feed and the second paper feed in the paper P transport process. The registration roller 28 is provided to synchronize the transfer start timing in the second sheet feeding with the transfer start timing in the image forming unit 90.

An image forming unit 90, which is an example of an image forming unit, is provided above the conveying path, and forms an image on a sheet P conveyed by the sheet conveying unit 40 by an electrophotographic method. A double feed detection sensor S2, which is an example of a detecting unit, is provided below the image forming unit 90 and on the sheet transport unit 40 downstream of the registration rollers.
Prior to image formation, double feed of paper P is detected.

The double feed detection sensor S2 outputs, for example, a high level (hereinafter referred to as "H" level) double detection signal SD2 to the control device 16 when double feed is detected. If there is no double feed, low level (hereinafter referred to as "L" level)
Is output. An ultrasonic or optical double feed detection sensor S2 is used as the double feed detection sensor S2. The ultrasonic system has high detection accuracy, and the optical system can be configured at low cost.

In this example, when the paper feed unit 30 has a paper feed cassette or when an external large-capacity paper feed device 300 is used in addition to the paper feed unit 30, the double feed detection sensor S2 On the upstream side before image formation, the sheet P is disposed on a common transport path of the sheet P fed from the sheet feeding unit 30 or the like or the large capacity sheet feeding apparatus 300.

This common transport path is on the upstream side of the registration roller 28 and near the lower portion of the developing device 21. The reason why the double feed detection sensor S2 is arranged on the common transport path is that the optical sensor or the like only needs to be provided at one place, and it is not necessary to provide it at several places. Cost can be reduced.

In the document feeder 70, a document D is separated one by one from a bundle of documents placed on the document tray 1 by a document feeder 2 composed of a feed roller, a separation / transport roller and a registration roller. Transported by the drum 3,
The image is read under the transport drum 3. The document D from which the image has been read is discharged to the document discharge tray 4. The document sensor S1 is provided on the document conveying path immediately before the image reading position, and detects the leading edge and the trailing edge of the document D.

The image reading section 80 illuminates the original D moving below the transport drum 3 with the illumination light source 10 and picks up the reflected light from the original D by an optical system including a mirror 11 and a lens 12 and an image formed by a line CCD. Scanning reading is performed by projecting onto the element 13. The image information converted into an electric signal by the image sensor 13 is converted into digital image information and stored in an image memory or the like. The image reading section 80 starts reading an image based on a document leading edge detection signal SD1 from the document sensor S1.

The image forming section 90 is provided with the exposure device 22, and emits a laser diode based on digital image information (hereinafter, referred to as image data DIN) created by the image reading section 80. Has an optical system for guiding the light beam onto the photoreceptor 20.
The image forming unit 90 is provided with a drum-shaped photoconductor 20 and an image forming process unit 21 in addition to the exposure device 22, forms an electrostatic latent image on the photoconductor 20, and forms a toner image by a development process. The transfer process transfers the toner image to the paper P.

That is, in the image forming section 90, the photosensitive member 20 is rotated by the image forming start signal SS3, and the sheet P fed out from the sheet feeding unit 30 or the like is fed by the registration roller 28 at a proper timing. . The toner image formed by the image forming process unit 21 on the rotating photoconductor 20 is transferred onto the paper P. In the image forming process section 21, cleaning of toner remaining after transfer is performed.

A fixing device 23 is provided downstream of the photoreceptor 20 so as to fix the toner image on the paper P. A switching guide 33 is provided downstream of the fixing device 23, and switches between discharging the sheet P subjected to the fixing process as it is or leading the sheet P to the reversing unit or the backside image forming sheet supply unit 36. The back side image forming paper supply unit 36 is provided on the paper supply unit 30. In addition, switching guide 3
A discharge roller 34 and a discharge tray 41 for normal use are provided on the downstream side of 3.

A post-processing device 200 is configured to be detachably attached downstream of the image forming apparatus 100. Post-processing such as saddle stitching and / or center folding of the sheet P after image formation is performed. It is made to do. When the post-processing device 200 is connected to the image forming device 100, the sheet P subjected to the fixing process by the fixing device 23 is directly conveyed to the post-processing device 200, or, The switching guide 33 selects whether the sheet is conveyed or the sheet is conveyed to the back-side image forming sheet feeding section 36.
The post-processing apparatus 200 is provided with a normal discharge tray 51 for storing the post-processed paper P. In addition to the tray 51, a discharge tray 5 for exclusively storing the multi-feed paper P is provided.
2 are provided.

FIG. 2 is a block diagram showing a configuration example of a control system of the image forming apparatus 100. Image forming apparatus 1 shown in FIG.
The control system 16 is provided with a control device 16, which includes a document sensor S1, a double feed detection sensor S2, an operation unit 15, a writing control unit 17, an image memory 18, a sheet transport unit 40, and a document transport unit. 70, an image reading unit 80, an image forming unit 90, and a post-processing device 200 are connected.

In the control unit 16, at least the sheet transport unit 40 is provided based on the double feed detection information (hereinafter also referred to as double feed detection signal SD2) obtained by the double feed detection sensor S2.
And the image forming unit 90. In this control system, when the multi-feed of the paper P is detected, the paper transport unit 40 is controlled by the control device 16 so as to discharge the paper P related to the multi-feed without forming an image.

At the same time, the control device 16
The image forming unit 90 controls the image forming unit 90 so as to hold the image data DIN which is to be formed in the next time, and to form an image on the sheet P fed out from the sheet feeding unit 30 based on the data DIN. (Hereinafter, this is referred to as double feed exclusion continuous image formation control.)

The control unit 16 controls the paper transport unit 40 so that the paper P related to the multi-feed is discharged to a specific discharge tray 52 other than the specified discharge tray 51 or the like or is circulated to the paper feed unit 30 or the like.
To be controlled. In this re-feeding process, the sheet may be returned to the original position of the sheet feeding unit 30 in the opposite direction to the normal conveyance direction.
The paper may be passed (passed) through the transfer / fixing system and returned to the original position from the rear of the sheet feeding unit 30 using the reversing path below the fixing system. This is for reusing the multi-fed paper P.

The control unit 16 has a counter, and counts the number of times of image formation. For example,
When the one-sided mode is set, +1 is added each time an image is formed on one sheet. When the duplex mode is set, +1 is added when the front side of the sheet P is formed, and +1 is set when the back side of the sheet P is formed.

In this example, when the number of times of image formation is counted for the sheet P, and when the multi-feed of the sheet P is detected, the control device 16 counts the number of image formation times for the sheet P related to the multi-feed. To be excluded from. That is, +1 addition is not performed in the counter. In this way, there is no need to give the user any disadvantage in charging for the copy count.

The operation unit 15 is provided on the front upper surface of the main body of the apparatus, is constituted by a touch panel with a liquid crystal display function, and is an interface for interacting with an operator in setting a single-sided mode, a double-sided mode, a post-processing mode and the like. Function as The paper size is also set. Operation unit 1
5 outputs the operation information D1 related to the mode to the control device 16.

As the control device 16, a CPU (Central Processing Unit) not shown, a RAM for storing image data DIN, a ROM for storing a control program, and the like are used. When, for example, the post-processing mode is selected and designated by the operation unit 15 to the control device 16, the operation information D1 thereof is input.

The control device 16 executes control information D for executing a shift mode, a staple mode, a center folding mode, an inter-sheet mode or the like in accordance with the operation information D1.
2 is temporarily stored in a RAM (not shown) in the control device 16. The control information D2 is used for controlling when the sheet P on which the image is formed is folded in two or a cover is attached to the sheet P.

The original document sensor S1 is provided immediately before the image reading position on the original conveying path, and detects the position of the original D.
A document detection signal SD1 is output to the control device 16. The image reading section 80 stores the image data DIN obtained by reading the document D in the image memory 18. The writing control unit 17 controls writing of the image data DIN read from the image memory 18 to the image forming unit 90. This is to hold the image data DIN to be formed on the paper P when the double feed is detected.

The above-described control unit 16 controls the document transport unit 70, the image reading unit 80, the image forming unit 90, and the entire post-processing unit 200 in addition to the multi-feed elimination continuous image forming control. The document feed start signal SS1 is output to the document feeder 70 based on the information D1 or the document detection signal SD1 is output.
To output the document reading start signal SS2 to the image reading unit 80, and then output the image forming start signal SS3 to the image forming unit 90 based on the
The control information D2 is output to

Next, an operation example of the image forming apparatus 100 in the image forming method according to the present invention will be described. FIGS. 3 and 4 are flowcharts illustrating processing examples (parts 1 and 2) in the image forming apparatus 100. In this embodiment, the multi-feed of the paper P fed out one by one from the predetermined paper storage position is detected, and when the multi-feed of the paper P is detected,
The sheet P is discharged as it is without forming an image on the sheet P related to the double feeding. Then, it is assumed that the image data DIN to be formed on the paper P is held, and then an image is formed on the paper P fed from the paper storage position based on the data. The double feed detection sensor S2 is located at the same point serving as a common transport path for the three paper feed cassettes and capable of detecting double feed. Of course, the original D is placed on the original plate 1 in advance.

Based on this, the user sets the image forming conditions using the operation unit 15 in step A1 of the flowchart shown in FIG. As for the image forming conditions, a one-sided mode or a two-sided mode, a post-processing mode, a sheet size, and the like are set. By setting these modes, the controller 1
6 is determined. The mode setting data is set in a register in the control device 16, the image forming unit 90, and the like. When such various modes are set and the start button is pressed, a document image is read by the image reading unit 80 in step A2. The image data DIN is stored in the image memory 18 in step A3.

Thereafter, in step A4, the sheet transport section 40 starts the first sheet feeding. In the first paper feed, the paper P is fed out one by one from the paper feed unit 30 which is a paper storage position of a paper size set in advance. The paper P fed out from the paper supply unit 30 is transported by the paper transport unit 40 to a predetermined transport path.

The paper P conveyed to this conveyance path is timed by the registration rollers 28 in step A5, and the second paper feeding is started. Before forming an image in step A6 in parallel with step A4, the double feed detection sensor S
2, the double feed of the paper P is detected. Here, the double feed detection sensor S2 detects the double feed, and outputs a "H" level double detection signal S.
D2 is output to the control device 16. If there is no double feed, an "L" level double detection signal SD2 is output.

The controller 16 receiving the double detection signal SD2 determines in step A7 whether the double feed detection sensor S2 has detected double feed. Here, the double feed detection sensor S
2 outputs a double feed detection signal SD2 = “H” level to the control device 16, the control device 16 identifies the sheet P as “double feed present”. Although the actual image formation is stopped, a dummy image forming process for inserting the formation of a white image may be performed. At this time, the counter does not add +1.

In this dummy image forming process, SD2 =
With the “H” level as a trigger, the white image data DIN ′ is changed from the original image data DIN write control to the image forming unit 90.
Can be switched to the control for writing to. The image forming section 90 forms a virtual or actual white image based on the white image data DIN '.

Then, in step A8, the image data D to be formed on the sheet P
IN is held by the write control unit 17. Then, proceeding to step A9, the control device 16 controls the sheet transport unit 40 so as to discharge the sheet P related to the multi-feed without forming an image on the sheet P as it is. This is for reusing the paper P related to the double feed.

Thereafter, the process proceeds to step A22, where the control device 16 determines whether or not all the given jobs have been completed. If all jobs have not been completed, step A
Return to 4. In this example, not all jobs have been completed,
Returning to step A4, the sheet P is fed out of the sheet feeding unit 30 based on the next first sheet feeding, and the sheet P is second fed in step A5.

At this time, the double feed of the paper P is detected by the double feed detection sensor S2 in step A6. When the double feed detection signal SD2 = “L” level is output to the control device 16, “no double feed” is identified, so that the step A
The document image is formed on the sheet P by the image forming unit 90 in 10 to step P15. That is, step A10
Then, the first image data DIN is read from the image memory 18 by the writing control unit 17 and the image data DIN is written to the image forming unit 90.

Thereafter, the image formation start signal SS3 causes
As the photoconductor 20 rotates, in step A11, the photoconductor 20 is exposed by the image forming process unit 21 based on the image data DIN, and an electrostatic latent image is formed on the photoconductor (exposure process). Then, in step A12, the electrostatic latent image is developed on the photoconductor by the developing device 21 to form a toner image (developing process).

Thereafter, the process proceeds to step A13, where the toner image on the photoreceptor is transferred to the sheet P in the image forming section 90 (transfer processing). In the image forming process section 21, cleaning of toner remaining after transfer is performed.

The toner image transferred onto the sheet P is fixed by the fixing device 23 in step A14. Thereafter, in step A15, the counter in the control device 16 is incremented by one.

Thereafter, the process proceeds to step A16, where the control device 16 determines whether the single-sided mode or the double-sided mode is set. Here, the mode setting data set in the register or the like is determined, and if the duplex mode is set, the process proceeds to step A17.
At step 8, the back side image forming process is performed. In this backside image forming process, the backside image data DIN is written, exposure, development, and transfer processes are performed, and then a fixing process is performed.
I do. Thereafter, the process proceeds to step A19.

In step A19, the control device 16 determines whether the post-processing mode is set. Here, the post-processing mode mode set in the register or the like is determined, and if the post-processing mode is set, the process proceeds to step A20 to execute the post-processing. Thereafter, the process proceeds to step A21. When the post-processing mode is not set in step A19 and after the post-processing is executed in step A20, the process proceeds to step A21 to discharge the sheet.

As described above, according to the image forming apparatus 100 and the image forming method according to the embodiment of the present invention, the sheet P for multi-feed is designated without forming an image on the sheet P for multi-feed. Double feed exclusion continuation image formation control such as discharging paper to a specific paper discharge tray other than the paper discharge tray, paper feed cassette 30, or the like can be executed.

That is, when a double feed of the paper P is detected, control for forming a blank image can be inserted, so that the continuity of the series of image forming processing can be ensured. Therefore, downtime such as stoppage of an image forming job can be eliminated.

Further, in the image forming apparatus 100, the paper P related to the multi-feed is discharged to a specific discharge tray 52 or the like other than the designated discharge tray or is sent to the paper feed cassette 30. Can be separated. Confusion in the user is avoided. At the time of double feed detection, a sheet (blank sheet) P on which no image is formed before image formation can be discharged. Therefore, the paper P at the time of double feed detection can be reused, and waste of the paper P can be eliminated.

In the case where the duplex mode is set in the image forming apparatus 100 and the multi-feed of the paper P is detected, the paper P related to the multi-feed is transported along the same transport path as in the single-side mode. The paper is discharged. Therefore, it is possible to avoid occurrence of JAM caused by passing through a complicated double-sided mode transport path.

In the image forming apparatus 100, when the double-side mode or the single-side mode is set in advance, and the multi-feed of the paper P is detected, the multi-feed paper P is discharged as it is before the image formation. The paper is printed, and the duplex mode or the simplex mode is executed as it is. Therefore, it is not necessary to perform the special control of the multi-feed, and the continuous image forming control excluding the multi-feed can be executed by adding simple software.

In this image forming apparatus 100, when the post-processing mode is set, and when the multi-feed of the paper P is detected, the multi-feed paper P is discharged as it is before the image formation. The paper P is excluded from the post-processing mode. Therefore, when the post-processing mode is set, the sheet P when double feed is detected can be reused, and waste of the sheet P can be eliminated.

[0063]

As described above, according to the image forming apparatus of the present invention, there is provided a control device for controlling the conveying means and the image forming means based on the double feed detection information. When the feeding is detected, the conveyance unit is controlled so that the sheet related to the multi-feed is discharged without forming an image on the sheet, and the data related to the image to be formed on the sheet is held. Then, an image is formed on the paper fed from the paper supply means based on the data.

With this configuration, it is possible to execute the multi-feed exclusion continuous image forming control in which the sheets relating to the multi-feed are sent to a specific discharge tray other than the designated discharge tray, a paper feed unit, or the like. Therefore, when a double feed of paper is detected, an image forming process that forms a blank image can be inserted, so that the continuity of the series of image forming processes can be ensured. Thereby, downtime such as stoppage of the device can be eliminated. Further, since the sheet without the image formed thereon before the image formation can be discharged, the waste of the sheet can be eliminated.

According to the image forming method of the present invention, a double feed of sheets fed one by one from a predetermined paper storage position is detected, and when the double feed is detected, the sheet related to the double feed is detected. The sheet is discharged as it is without forming an image, data related to the image to be formed on this sheet is held, and an image is formed on the next fed sheet based on the data (multi-feeding). Paper exclusion continuous image formation control).

With this configuration, when a double feed of sheets is detected, an image forming job that forms a blank image can be inserted, so that continuity of the series of image forming jobs can be ensured. Thus, downtime such as stoppage of the image forming job can be eliminated. In addition, since the sheet in which no image is formed before the image formation can be discharged, the waste of the sheet can be eliminated. INDUSTRIAL APPLICABILITY The present invention is very suitable when applied to a copying machine, a multifunction peripheral, a printer, a facsimile, etc. having a copying function using an electrophotographic method.

[Brief description of the drawings]

FIG. 1 is an image forming apparatus 1 according to an embodiment of the invention.
It is a schematic diagram of a cross section showing a configuration example of 00.

FIG. 2 is a block diagram illustrating a configuration example of a control system of the image forming apparatus 100.

FIG. 3 is a flowchart illustrating a processing example (part 1) in the image forming apparatus 100;

FIG. 4 is a flowchart illustrating a processing example (part 2) in the image forming apparatus.

[Explanation of symbols]

 2 Document Feeding Unit 16 Control Device 20 Photoconductor 21 Image Forming Process Unit 22 Exposure Device 23 Fixing Device 30 Paper Feeding Unit (Paper Supplying Unit) 40 Paper Transporting Unit (Transporting Unit) 70 Document Transporting Unit 80 Image Reading Unit 90 Image Forming Unit (Image Forming Means) 100 Image Forming Apparatus 200 Post-Processing Apparatus S2 Double Feed Detection Sensor (Detecting Means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/00 H04N 1/00 108H 108 1/04 107B 1/04 107 G03G 21/00 392 (72) Invention Person Peng Yuba 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Hideo Yamane 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H027 DA47 DC10 DC16 DE01 DE02 DE10 ED17 ED19 EK03 EK10 EK14 FA13 FA24 FA27 FD08 ZA07 3F048 AA02 AA04 AA05 AB01 BA13 BB10 DA04 DC12 DC19 EA12 EB28 3F053 EA02 EA04 EA05 EC02 ED18 LA02 LA05 LA07 LB01 5C062 AA02 AA05 A07 A02 AA1A02 AA13A01

Claims (13)

[Claims] 1. A method for storing a plurality of sheets,
A sheet supply unit that feeds out one sheet at a time, a conveyance unit that conveys the sheet fed from the sheet supply unit to a predetermined conveyance path, an image forming unit that forms an image on the sheet conveyed by the conveyance unit, and the image A detecting unit provided upstream of the forming unit for detecting the double feed of the paper; and a control device for controlling the conveying unit and the image forming unit based on at least the double feed detection information obtained by the detecting unit. When the multi-feed of the paper is detected, the control device controls the transport unit so as to discharge the multi-feed paper without forming an image on the multi-feed paper and forms an image on the paper. Holds data related to the scheduled image,
Next, the image forming apparatus controls the image forming unit to form an image based on the data on the sheet fed from the sheet supply unit. 2. The control device according to claim 1, wherein the control unit controls the transport unit to discharge the paper related to the multi-feed to a specific discharge tray other than a designated discharge tray or to forward the paper to a paper feed unit. The image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein the controller is configured to count the number of times of image formation for the sheet, and when the multi-feed of the sheet is detected, the controller excludes the sheet related to the multi-feed from the counting process of the number of times of image formation. The image forming apparatus according to claim 1, wherein: 4. The apparatus according to claim 1, wherein the paper supply unit has a plurality of paper supply units, or the paper supply unit is an external large-capacity paper supply device. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is disposed on a common conveyance path of the sheet fed from the sheet feeding unit or the large-capacity sheet feeding device on an upstream side of the sheet feeding unit. 5. The image forming apparatus according to claim 1, wherein an ultrasonic sensor is used as the detection unit. 6. The image forming apparatus according to claim 1, wherein an optical sensor is used as the detection unit. 7. A multi-feed of sheets fed one by one from a predetermined paper storage position is detected, and when the multi-feed of the sheets is detected, an image is not formed on the sheet related to the multi-feed without change. Ejecting a sheet, holding data relating to an image to be formed on the sheet, and forming an image based on the data on a sheet next fed from the sheet storage position. . 8. The image forming method according to claim 7, wherein the double feeding of the sheet is detected before image formation. 9. The image forming method according to claim 7, wherein the sheet related to the multi-feed is discharged to a specific discharge tray other than a designated discharge tray or sent to a paper feed unit. 10. A method for counting the number of times of image formation for the sheet, wherein when a double feed of the sheet is detected, the sheet related to the double feed is excluded from the process of counting the number of times of image formation. The image forming method according to claim 7, wherein: 11. A single-sided mode for forming an image on one side of the sheet when a double-sided mode for forming an image on both sides of the sheet is set in advance and a double feed of the sheet is detected. The image forming method according to claim 7, wherein the sheet related to the multi-feed is ejected through the conveyance path. 12. When a double-sided mode for forming an image on both sides of the sheet or a single-sided mode for forming an image on one side of the sheet is set in advance, and the double feed of the sheet is detected, 8. The image forming method according to claim 7, wherein the sheet to be fed is ejected before image formation, and the double-sided mode or the single-sided mode is executed as it is. 13. When a post-processing mode for performing post-processing after forming an image on the sheet is set in advance, and when multi-feed of the sheet is detected, the sheet related to the multi-feed is image-formed. 8. The image forming method according to claim 7, wherein the sheet is discharged as it is without being processed, and the sheet is excluded from the post-processing mode.