Image forming apparatus, information processing apparatus

Abstract

To provide an image formation apparatus which can prevent sheet passage failure in the automatic two-sided printing in advance even when a portion of a recording material is cut out.SOLUTION: An image formation apparatus comprises: an image formation control unit 104 which forms an image on a perforation sheet applied with perforation processing; an operation panel 50 which receives input of recording material information about the perforation sheet formed with the image by the image formation control unit 104 and information on whether or not the automatic two-sided printing is performed on the perforation sheet; and a CPU circuit unit 101 which performs alarm display on the operation panel 50 without performing sheet passage of the perforation sheet when the automatic two-sided printing is instructed on the basis of the information input by the operation panel 50 and it is determined that there is a cut-out portion on the perforation sheet.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, such as a copying machine, a facsimile machine, a printer, or a multifunction machine, that has an automatic double-sided printing function for automatically printing on both sides of a recording material. [Background technology]

[0002] When an electrophotographic image forming apparatus prints (forms an image) on both sides of a sheet-like recording material, it flips the printing side of the recording material with an image formed on one side and forms an image on the other side. At this time, the recording material is switched back in a reversing section in the image forming apparatus to reverse the printing side. The function of automatically reversing the printing side of the recording material in the image forming apparatus to perform double-sided printing in this way is called an automatic double-sided printing function.

[0003] Image forming devices that perform automatic double-sided printing may not be able to automatically perform double-sided printing depending on the characteristics of the recording material. For example, automatic double-sided printing is difficult for "recording materials that are too short in the conveying direction" or "recording materials with high rigidity" that cannot pass through the conveying section (circulating conveying section) for the switchback. When automatic double-sided printing is performed with recording materials with such characteristics, there is a possibility that paper passing problems will occur in the circulating conveying section. For this reason, a technology has been disclosed that determines whether or not the recording material is usable for automatic double-sided printing before the recording material reaches the circulating conveying section, and does not perform automatic double-sided printing on recording materials that are determined to be unusable for automatic double-sided printing.

[0004] Patent Document 1 discloses an image forming device that detects the length of the recording material in the transport direction using a built-in detection unit. This image forming device determines whether automatic double-sided printing is possible based on the detection result of the length of the recording material in the transport direction, and if not possible, issues an instruction to perform manual double-sided printing. Patent Document 2 discloses an image forming device that determines whether automatic double-sided printing is possible based on the paper type of the recording material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-181876 A [Patent Document 2] JP 2006-199022 A Summary of the Invention [Problem to be solved by the invention]

[0006] Electrophotographic image forming apparatuses are increasingly being used in the field of light printing such as POD (print on demand). For this reason, image forming apparatuses are required to meet various needs regarding image quality and recording materials. For example, image forming apparatuses are used to produce price tags, business cards, admission tickets, delivery notes, and the like. For this reason, image forming apparatuses are required to print on recording materials (e.g., perforated paper, label paper, etc.) that are perforated in advance and can be torn off at the perforations. There are many types of perforated paper available according to the number of divided sides of the recording material (e.g., 2-division, 4-division, 8-division, 9-division, EIAJ standard delivery note, etc.).

[0007] When a detachable recording material is used for automatic double-sided printing with part of the recording material having been detached after being used once, there is a possibility that a paper feed failure will occur in the circulation transport section. Figure 11 shows the paper feed state when part of the perforated paper has been detached. The perforated paper shown in Figure 11(a) has a basis weight of 80 [g / m 2 This is an A4 size (210 mm x 297 mm) recording material divided into nine pieces. One side of this perforated paper (the upper right side) has already been used and separated. Therefore, the length of this perforated paper in the transport direction is 297 mm at the point (X) where there are three sides in the transport direction, and 198 mm at the point (Y) where one side has been used.

[0008] Figure 11(b) shows the behavior of the recording material when the perforated paper (recording material) in Figure 11(a) is passed through with the cut-out portion at the leading edge. In Figure 11(b), the position of dashed line A, which is perpendicular to the transport direction, shows a cross section of the behavior of the recording material at the moment it passes a bent part on the transport path. The solid line in Figure 11(b) shows the attitude of the recording material at position X, where there is no cut-out in the transport direction, and the dashed line shows the attitude of the recording material at position Y, where there is a cut-out at the leading edge in the transport direction.

[0009] If the tip position of the cutout perpendicular to the transport direction is B, it can be seen that the postures of the recording material at BY (the intersection of B and Y), which is the tip of the cutout, and BX (the intersection of B and X), which has no cutout in the transport direction, do not match and are separated. This is because BX, which has no cutout in the forward direction, is affected by the displacement of the forward position AX (the intersection of A and X), whereas BY, which is the tip of the cutout, is not affected by the displacement of the forward position. As shown in Figure 11(b), if the posture of the tip of the cutout is significantly different from the posture of the part without the cutout, the tip of the cutout will cause paper feed failure on the transport path. In other words, if paper is fed with the cutout at the tip, paper feed failure may occur.

[0010] The length of the recording material in the transport direction that allows automatic double-sided printing is 150 [mm] or more, and the basis weight of the recording material that allows automatic double-sided printing is 200 [g / m 2 In the case of image forming apparatuses with a sheet width of 0.01 mm or less, conventionally, the perforated paper shown in Figure 11(a) has been judged to be capable of automatic double-sided printing. When performing automatic double-sided printing with the perforated paper shown in Figure 11(a), the first side can be fed through without any problems by using the side without the notch as the leading edge. However, when feeding the second side, the leading and trailing edges of the recording material are switched when the paper is switched back at the reversing section to turn it over, and the paper is fed through with the notched part as the leading edge. At this time, there is a possibility that paper feeding problems may occur.

[0011] In view of the above problems, a main object of the present invention is to provide an image forming apparatus that can prevent paper feed failure during automatic double-sided printing even if part of the recording material is cut off. [Means for solving the problem]

[0012] The image forming apparatus of the present invention includes an image forming means for forming an image on perforated paper that has been perforated, an input means for inputting recording material information relating to the perforated paper on which the image is formed by the image forming means and information on whether or not automatic double-sided printing is to be performed on the perforated paper, and the automatic double-sided printing is instructed based on the information input by the input means, and the perforated paper is printed on the perforated paper. The difference between the maximum width of the perforated paper in the width direction perpendicular to the conveying direction and the leading edge width, which is the length in the width direction at the leading edge of the perforated paper in the conveying direction, or the trailing edge width, which is the length in the width direction at the trailing edge of the perforated paper in the conveying direction, deviates by a predetermined difference or more. and a control means for displaying an alarm without passing the perforated paper if it is determined that the perforated paper has been passed through the perforated paper. The information processing device of the present invention is characterized in that it comprises an input means for inputting recording material information regarding the perforated paper on which an image is formed and information regarding whether automatic double-sided printing is to be performed on the perforated paper, and a control means for displaying an alarm without passing the perforated paper through when it is determined that the automatic double-sided printing is instructed based on the information input by the input means and that the difference between the longest width of the perforated paper in the width direction perpendicular to the conveying direction of the perforated paper and the leading edge width, which is the length in the width direction at the leading edge of the perforated paper in the conveying direction, or the trailing edge width, which is the length in the width direction at the trailing edge of the perforated paper in the conveying direction, deviates by more than a predetermined difference. Effect of the Invention

[0013] According to the present invention, it is possible to prevent paper feed failure during automatic double-sided printing even if a portion of the recording material has been cut off. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an image forming apparatus. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] 6 is a flowchart showing a process for inputting print information. [Diagram 5] FIG. 13 is a diagram showing an example of a print item setting screen. [Figure 6] 11 is a view showing an example of a recording material setting screen. [Figure 7] 6 is a flowchart showing a print setting process. [Figure 8] FIG. [Figure 9] 4(a) and (b) are diagrams illustrating the detection results of the transport sensor. [Figure 10] 6 is a flowchart showing a process for determining whether automatic double-sided printing is possible. [Figure 11] 13A and 13B are diagrams illustrating the state of paper passing when part of the perforated paper is torn off. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the present invention is applied. Therefore, unless otherwise specified, it is not intended to limit the scope of the present invention to only those.

[0016] (Configuration of Image Forming Apparatus) FIG. 1 is a diagram illustrating the configuration of an image forming apparatus. The image forming apparatus 1 forms an image on a recording material P by an electrophotographic method. To this end, the image forming apparatus 1 performs each process of forming an image on an image carrier, transferring the image from the image carrier to the recording material P, and fixing the image on the recording material P. The image forming apparatus 1 of this embodiment is a four-color full-color multifunction printer (color image forming apparatus) using an A4 size electrophotographic process. The "A4 size" here refers to one in which A4 size recording materials are fed vertically. Vertical feeding means that the recording material P is fed with its long side in the transport direction. The image forming apparatus 1 may be a monochrome multifunction printer or single function printer.

[0017] The image forming apparatus 1 includes a controller 100. The controller 100 comprehensively controls the operation of various components in the apparatus based on acquired printing information (image data, recording material information, etc.) to form (print) an image on a recording material P. The recording material P is a sheet-like material on which an image can be formed, such as plain paper, thick paper, overhead projector paper, coated paper, label paper, binder paper, tab paper, perforated paper, etc. Perforated paper is a recording material P that has been perforated into a sheet. The perforated paper is cut along the perforations.

[0018] The image forming apparatus 1 forms a multi-color image by overlapping four colors of developer (hereinafter referred to as "toner"): yellow (Y), magenta (M), cyan (C), and black (K). To this end, the image forming apparatus 1 is equipped with image forming units 10Y, 10M, 10C, and 10K that form toner images of the respective colors. The image forming units 10Y, 10M, 10C, and 10K for each color have the same basic configuration. To distinguish the colors, suffixes Y, M, C, and K are added to the reference symbols, but in the following description, the suffixes will be omitted when it is not necessary to distinguish between the colors.

[0019] The image forming section 10 has a rotating drum-type electrophotographic photosensitive member (hereinafter referred to as "photosensitive drum 11") as an image carrier on which an image is formed. A charger 12 and a developing unit 14 are provided around the photosensitive drum 11. The developing unit 14 has a toner storage chamber that stores toner of a corresponding color. A laser scanner unit 13 that exposes the photosensitive drum 11 to laser light is provided near the image forming section 10. A cassette 2 that stores a recording material P is provided below the laser scanner unit 13. A transfer unit 20 is provided above the image forming section 10.

[0020] The transfer unit 20 has an intermediate transfer belt 21, a drive roller 22 that drives the intermediate transfer belt 21 to rotate, and a tension roller 24. Inside the intermediate transfer belt 21, four primary transfer rollers 15 are arranged along the belt surface of the intermediate transfer belt 21. Each primary transfer roller 15 is arranged to face the photosensitive drum 11 of each image forming unit 10 via the intermediate transfer belt 21. The upper surface of the photosensitive drum 11 of each image forming unit 10 is in contact with the lower surface of the intermediate transfer belt 21 at the position of the primary transfer roller 15. This contact portion becomes the primary transfer portion. A secondary transfer roller 25 is provided on the outer side of the portion of the intermediate transfer belt 21 that is backed up by the drive roller 22. The intermediate transfer belt 21 is in contact with the secondary transfer roller 25, and this contact portion becomes the secondary transfer portion. An intermediate transfer belt cleaner 23 is provided on the outer side of the portion of the intermediate transfer belt 21 that is backed up by the tension roller 24.

[0021] The image forming apparatus 1 is provided with a conveying path 53 for conveying the recording material P stored in the cassette 2 upward. The conveying path 53 is provided with a feed roller 3, a separation roller pair 4, a registration roller pair 5, a secondary transfer roller 25, and a fixing device 30, in this order from the upstream side in the conveying direction of the recording material P. A conveying sensor 60 for detecting the conveyed recording material P is provided downstream of the registration roller pair 5. The conveying path 53 branches into a conveying path 63 and a conveying path 54 downstream of the fixing device 30. A fixing discharge sensor 17 for detecting the recording material P is provided between the fixing device 30 and the branch. A double-sided flapper 51 is provided at the branching position. A discharge roller pair 52 is provided on the conveying path 63. The recording material P conveyed to the conveying path 63 is discharged to the discharge tray 9 by the discharge roller pair 52.

[0022] A pair of reversing rollers 62 is provided on the transport path 54. When automatic double-sided printing is performed, the recording material P is transported to the transport path 54, and the transport direction is reversed by the pair of reversing rollers 62. The transport path 54 is provided with a double-sided transport path 56 in the direction in which the transport direction of the recording material P is reversed. The transport direction of the recording material P is reversed by the pair of reversing rollers 62 and the recording material P is transported to the double-sided transport path 56. A switching flapper 61 is provided at the branching position of the transport path 54 and the double-sided transport path 56. When the rear end of the recording material P passes the position of the switching flapper 61, the switching flapper 61 switches so that the recording material P is transported to the double-sided transport path 56 side.

[0023] The double-sided conveying path 56 is provided with a double-sided conveying roller pair 55 and a double-sided re-feed roller pair 57. The recording material P is conveyed to the conveying path 53 via the double-sided conveying path 56 by the double-sided conveying roller pair 55 and the double-sided re-feed roller pair 57. The double-sided conveying path 56 is configured to merge with the conveying path 53 midway. The conveying path 54, the double-sided conveying path 56, the reversing roller pair 62, the double-sided conveying roller pair 55, and the double-sided re-feed roller pair 57 form a circulating conveying section.

[0024] The image forming apparatus 1 is provided with an image reader 40 at its top. The image reader 40 has a function of reading an image of an original document with a reader scanner 43, which is an optical sensor, and converting the image into an image signal. The image reader 40 is equipped with an original document feed unit 41. The original document feed unit 41 feeds original documents set on an original document tray 42 with the side on which an image is printed facing up, one by one starting from the top page, to the reading position of the reader scanner 43.

[0025] The reader scanner 43 reads an original image from an original fed by the original feeding unit 41. The reader scanner 43 includes a light emitting unit (not shown) and an image sensor (not shown). The light emitting unit irradiates light onto an original. The image sensor receives the light irradiated onto the original from the light emitting unit by forming an image on an imaging surface, and converts the reflected light of the received original image into an image signal. The reader scanner 43 reads the original image line by line in the main scanning direction (direction perpendicular to the original conveying direction). The image reader 40 reads the image of the entire page by reading the original image line by line from the conveyed original. When reading an original without using the original feeding unit 41, the user lifts the original feeding unit 41 and places the original on the platen glass 45. In this case, the reader scanner 43 reads the original image while moving from left to right in FIG. 1.

[0026] An operation panel 50 is provided on the front surface of the housing of the image forming apparatus 1. The operation panel 50 is a user interface having an input interface and an output interface. The input interface includes various key buttons, a touch panel, etc. The output interface includes a display, a speaker, etc.

[0027] (controller) FIG. 2 is a diagram for explaining the configuration of the controller 100. The controller 100 is described focusing on the parts necessary for explaining the operation of this embodiment, and other parts known as image control are omitted. The controller 100 is electrically connected to and capable of communicating with an external information processing device such as a computer 200, an input device such as an image reader 40, and an operation panel 50. The controller 100 controls the operation of each component in the image forming apparatus 1 based on printing information (image data, recording material information, etc.) acquired from the computer 200 and the operation panel 50 to form an image on a recording material P. Note that, when performing a copy operation, for example, the controller 100 acquires image data from the image reader 40 and acquires recording material information, etc. from the operation panel 50.

[0028] The controller 100 includes a central processing unit (CPU) circuit section 101. The CPU circuit section 101 includes a calculation section such as a CPU, a read only memory (ROM) 102, and a random access memory (RAM) 103. The CPU circuit section 101 controls the operation of the image forming apparatus 1 by executing a computer program stored in the ROM 102. The RAM 103 provides a working area when the computer program is executed. The document feed control section 107, the image reader control section 106, the image signal control section 105, the image formation control section 104, the operation panel control section 108, and the recording material conveyance control section 110 are connected to the CPU circuit section 101. The image signal control section 105 is connected to an external I / F 109 that controls communication with the computer 200. The image reader control section 106 is connected to the image reader 40. The operation panel control section 108 is connected to the operation panel 50. The operations of the document feed control unit 107 , the image reader control unit 106 , the image signal control unit 105 , the image formation control unit 104 , the operation panel control unit 108 , and the recording material transport control unit 110 are controlled by the CPU circuit unit 101 .

[0029] The document feed control unit 107 controls the document feed operation and transport operation by the document feed unit 41. The image reader control unit 106 controls the operation of the reader scanner 43 and the conversion to an image signal. The image signal control unit 105 acquires the image signal generated by the reader scanner 43 via the image reader control unit 106 and performs image processing on the acquired image signal. Specifically, the image signal control unit 105 converts the image signal, which is an analog signal, into an image signal, which is a digital signal, and then performs image processing, converts the digital signal after image processing into an image information signal and outputs it to the image formation control unit 104. The image signal control unit 105 can also perform image processing on the image signal, which is a digital signal input from the computer 200 via the external I / F 109, and converts the digital signal after image processing into an image information signal and outputs it to the image formation control unit 104.

[0030] The image formation control unit 104 controls the operation of each component involved in the image forming operation based on an image information signal acquired from the image signal control unit 105. The operation of each component will be described in detail later. The recording material transport control unit 110 controls the transport of the recording material P. An image is formed on the recording material P by the operation control of each component by the image formation control unit 104 and the transport control of the recording material P by the recording material transport control unit 110.

[0031] The operation panel control unit 108 transmits and receives information between the operation panel 50 and the CPU circuit unit 101. The operation panel 50 transmits information input via an input interface to the CPU circuit unit 101. The operation panel 50 outputs information from an output interface under the control of the CPU circuit unit 101.

[0032] 3 is an explanatory diagram of the recording material transport control unit 110. The recording material transport control unit 110 includes a CPU circuit unit 151 separate from the controller 100. The CPU circuit unit 151 includes a ROM 152 and a RAM 153. The CPU circuit unit 151 controls the operation of each component involved in the transport of the recording material P by executing a computer program stored in the ROM 152. The RAM 153 provides a working area when the computer program is executed. FIG. 3 mainly shows the parts necessary for explaining the operation of this embodiment, and other parts already known as transport control are omitted. The recording material transport control unit 110 of this embodiment acquires the detection results of the transport sensor 60 and the fixing discharge sensor 17. The recording material transport control unit 110 of this embodiment also controls the operations of the double-sided flapper 51, the switching flapper 61, the reversing roller pair 62, the double-sided transport roller pair 55, and the double-sided re-feed roller pair 57.

[0033] The image forming operation by the image forming apparatus 1 having the above-mentioned configuration will be described with reference to FIGS.

[0034] The controller 100 starts an image forming operation when an instruction to execute image formation is received from the operation panel 50 or the computer 200. The CPU circuit unit 101 acquires an instruction to execute image formation from the operation panel 50 or the computer 200, and instructs the image formation control unit 104 to start image formation processing. When the image formation control unit 104 is instructed to start image formation processing from the CPU circuit unit 101, it starts to rotate the photosensitive drum 11 in the image forming unit 10 and the drive roller 22 in the transfer unit 20 at a predetermined speed. The photosensitive drum 11 rotates clockwise in the figure, and the drive roller 22 rotates the intermediate transfer belt 21 in a forward direction (counterclockwise in the figure) relative to the rotation direction of the photosensitive drum 11.

[0035] The image forming unit 10 starts forming an image (toner image) on the photosensitive drum 11. First, the image forming unit 10 uniformly charges the surface of the photosensitive drum 11 with a predetermined potential and polarity by the charger 12. The laser scanner unit 13 scans and exposes the charged surfaces of the corresponding photosensitive drums 11Y, 11M, 11C, and 11K with laser light modulated according to image information signals of the respective colors of yellow, magenta, cyan, and black. As a result, electrostatic latent images of the corresponding colors are formed on the photosensitive drums 11Y, 11M, 11C, and 11K. The developing unit 14 develops the electrostatic latent images by electrostatically attaching toner of the corresponding color to the electrostatic latent images, thereby forming a toner image on the photosensitive drum 11. A yellow toner image is formed on the photosensitive drum 11Y. A magenta toner image is formed on the photosensitive drum 11M. A cyan toner image is formed on the photosensitive drum 11C. A black toner image is formed on the photosensitive drum 11K.

[0036] The toner images of each color formed on the photosensitive drums 11Y, 11M, 11C, and 11K are transferred onto the intermediate transfer belt 21 in a superimposed manner. This is performed by applying a predetermined potential to the primary transfer roller 15 facing the photosensitive drum 11, and electrostatically transferring the toner image on the photosensitive drum 11 onto the intermediate transfer belt 21 at the primary transfer section. The toner images of each color are superimposed by adjusting the transfer timing of the toner images from the photosensitive drums 11Y, 11M, 11C, and 11K to the intermediate transfer belt 21 according to the intervals between the photosensitive drums 11Y, 11M, 11C, and 11K and the rotation speed of the intermediate transfer belt 21. The toner images of each color are superimposed to form a full-color toner image on the intermediate transfer belt 21. The intermediate transfer belt 21 is an image carrier that carries the transferred full-color toner image. The transferred toner image is transported to the secondary transfer section by the rotational drive of the drive roller 22. Incidentally, any toner remaining on the photosensitive drum 11 without being transferred onto the intermediate transfer belt 21 in the primary transfer portion is removed by a cleaning member (not shown).

[0037] The recording material conveyance control unit 110 feeds the recording material P from the cassette 2 in parallel with the toner image forming operation by the image formation control unit 104. When the feeding operation is started, the recording material P is separated one by one from the cassette 2 by the feeding roller 3 and the separation roller pair 4, fed to the conveying path 53, and conveyed to the registration roller pair 5. The registration roller pair 5 is not rotating at the timing when the recording material P is conveyed. Therefore, the leading edge of the recording material P collides with the nip part of the registration roller pair 5, and forms a loop on the leading edge side. This corrects the skew of the recording material P. The registration roller pair 5 starts rotating after the skew correction to convey the recording material P. At this time, the registration roller pair 5 synchronizes with the toner image on the intermediate transfer belt 21 according to the timing when the conveying sensor 60 detects the leading edge of the recording material P, and adjusts the timing of conveying the recording material P to the secondary transfer unit.

[0038] In the secondary transfer portion, the toner image on the intermediate transfer belt 21 is transferred onto the recording material P. This is performed by applying a secondary transfer bias of a polarity opposite to the charge polarity of the toner to the secondary transfer roller 25 at the timing when the toner image and the recording material P are transported to the secondary transfer portion. By applying the secondary transfer bias to the secondary transfer roller 25, the toner image is electrostatically transferred from the intermediate transfer belt 21 to the recording material P. In other words, the recording material P is nipped and transported in the secondary transfer portion, so that the toner image is transferred to one surface of the recording material P. The recording material P to which the toner image has been transferred is transported to a fixing device 30. Note that the toner remaining on the intermediate transfer belt 21 without being transferred onto the recording material P in the secondary transfer portion is removed by an intermediate transfer belt cleaner 23.

[0039] The toner image is fixed to the recording material P onto which the toner image has been transferred by heating and pressurizing the recording material P by the fixing device 30. The fixing device 30 is heated to a temperature required for toner fixing at the start of the image forming operation, and is controlled to maintain that temperature until the recording material P reaches the fixing device 30. The toner image on the recording material P is fixed by heating and pressurizing in a fixing nip portion (not shown) of the fixing device 30. When the recording material P is discharged outside the machine, it is conveyed to the discharge tray 9 via a pair of discharge rollers 52 by being sandwiched and conveyed in the fixing nip portion.

[0040] During automatic double-sided printing, the position of the double-sided flapper 51 is switched, and the recording material P is guided to the conveying path 54. The recording material P guided to the conveying path 54 is conveyed by the fixing device 30, and reaches the switching flapper 61, which is stopped at the position shown by the solid line in FIG. 1 due to its own weight. As the recording material P is further conveyed, it pushes up the switching flapper 61 and reaches the reversing roller pair 62, and its leading edge protrudes to the outside from the image forming apparatus 1. When the trailing edge of the recording material P passes through the switching flapper 61 and reaches the double-sided reversing position a predetermined distance upstream of the reversing roller pair 62, the switching flapper 61 returns to the position shown by the solid line in FIG. 1 due to its own weight. Here, the reversing roller pair 62 rotates in the reverse direction, and the recording material P is conveyed to the double-sided conveying path 56 along the upper surface of the switching flapper 61.

[0041] The recording material conveyance control unit 110 detects the rear end of the recording material P based on the detection result of the fixing and ejection sensor 17, and stops the forward rotation drive of the motor (not shown) that drives the reversing roller pair 62 based on the detection timing. The recording material conveyance control unit 110 rotates this motor forward and backward to drive the reversing roller pair 62, thereby conveying the recording material P from the conveyance path 54 to the double-sided conveyance path 56. The recording material P conveyed to the double-sided conveyance path 56 is conveyed to the registration roller pair 5. Thereafter, the recording material P is conveyed from the registration roller pair 5 to the secondary transfer unit, where an image is formed again. By passing through the double-sided conveyance path 56, the printing side of the recording material P on which the image has been formed is reversed. Therefore, when the image is formed again, an image is formed on the side of the recording material P on which the image has not been formed.

[0042] (Printing information) FIG. 4 is a flow chart showing the input process of print information to the image forming apparatus 1. As described above, the print information includes information necessary for forming an image on the recording material P, such as image data representing an image to be printed and recording material information. The recording material information is, for example, information on the type of recording material, the printing side, the number of copies to be printed, and the paper feeding method. Here, a print process in which a user prints an image created by an application or the like using the computer 200 will be described. In addition to the print process, a similar process is also possible for a copy process in which an image of an original is duplicated. The print information may also be input through the operation panel 50. In this case, the CPU circuit unit 101 creates the print information.

[0043] When a user requests printing of an image via an application, computer 200 issues a print request to a printer driver. The print request may be issued directly from the application to the printer driver, or may be issued to the printer driver via an interface provided by the application's operating system. The print request starts a print processing procedure by the printer driver.

[0044] The printer driver displays a screen (hereinafter referred to as the "print item setting screen") on the display of computer 200 to prompt the user to set the print items (S101). Print items that can be set on the print item setting screen include the type of recording material and the paper feeding method. Note that the print items specified here are items necessary for explaining this embodiment, and are not limited to these items. Once the setting of the print items is completed, the printer driver creates print information based on the set print items (S102). Computer 200 transmits the print information created by the printer driver to image forming apparatus 1 (S103).

[0045] When creating print information using the operation panel 50, a print item setting screen is displayed on the display of the operation panel 50. The user sets the print items by operating various key buttons or the touch panel of the operation panel 50 (S101). The CPU circuit unit 101, which has received input from the operation panel 50, creates print information based on the set print items (S102).

[0046] 5 is a diagram illustrating an example of a print item setting screen used in the process of S101. The print item setting screen 300 includes a print layout display 301, a "number of copies" text box 302, "pages" radio buttons 303 and 304, a "start" text box 305, and an "end" text box 306. The print item setting screen 300 includes a "original size" pull-down menu 307, an "output size" pull-down menu 308, a "color mode" pull-down menu 309, a "type of recording material" pull-down menu 310, and a "detailed settings" button 311. The print item setting screen 300 includes a "paper feed method" pull-down menu 312, a "single-sided / double-sided" pull-down menu 313, a "print" button 316, and a "cancel" button 317.

[0047] The following values ​​are set for each print item on the print item setting screen 300. The value entered in the "Number of copies" text box 302 is set as the number of copies to be output for the printed material. The values ​​selected or entered in the "Pages" radio buttons 303, 304, "From" text box 305, and "To" text box 306 are set as the print page range. When radio button 303 is selected, all pages created by the user are set as the print page range. When radio button 304 is selected, the values ​​entered in the "From" text box 305 and "To" text box 306 are set as the print page range.

[0048] The item selected in the "Original Size" pull-down menu 307 is set as the size of one page of image. In the "Original Size" pull-down menu 307, standard sizes such as "A4" and "LTR" can be selected. The item selected in the "Output Size" pull-down menu 308 is set as the size when the image is output. In the "Output Size" pull-down menu 308, "Same as Original Size" or standard sizes such as "A4" and "LTR" can be selected. The item selected in the "Color Mode" pull-down menu 309 is set as the color mode when printing. In the "Color Mode" pull-down menu 309, one of "Auto (Color / Black and White)", "Color", and "Black and White" can be selected.

[0049] An item selected in the "Type of recording material" pull-down menu 310 is set as the type of recording material on which an image is formed. For example, "plain paper," "thin paper," "cardboard," "high-quality paper," "glossy paper," "inkjet official postcard," "postcard," "glossy postcard," "glossy film," "photo card," and the like can be set as the recording material. In addition, for example, "T-shirt transfer paper," "back print film," "transparency film," "envelope," "label paper," "perforated paper," and the like can be set as the recording material. The "Detailed settings" button 311 is used when detailed settings of the recording material are required (for example, the number of divided sides of perforated paper, etc.). By pressing the "Detailed settings" button 311, a recording material setting screen described later is displayed on the display of the computer 200, and detailed settings of the recording material can be made.

[0050] An item selected in the "Paper Feeding Method" pull-down menu 312 is set as the paper feeding method for the recording material P in the image forming apparatus 1. In the "Paper Feeding Method" pull-down menu 312, "Automatic," "Cassette," and "Manual" can be set as the paper feeding method. An item selected in the "Single-Sided / Double-Sided" pull-down menu 313 sets the print side to be used when printing on the recording material. In the "Single-Sided / Double-Sided" pull-down menu 313, either "Single-Sided" (single-sided printing) or "Double-Sided" (double-sided printing) can be set.

[0051] The contents set on print item setting screen 300 are stored in the storage of computer 200 together with the image data. When "Print" button 316 on print item setting screen 300 is pressed, the printer driver creates print information based on the image data and the contents set on print item setting screen 300. The printer driver transmits the created print information to image forming apparatus 1 and closes print item setting screen 300. When "Cancel" button 317 is pressed, the printer driver closes print item setting screen 300 and ends the process.

[0052] When the operation panel 50 is used, the contents set on the print item setting screen 300 are stored in the RAM 103 of the CPU circuit unit 101. When the “Print” button 316 on the print item setting screen 300 is pressed, the CPU circuit unit 101 creates print information based on the image data and the contents set on the print item setting screen 300.

[0053] 6 is an example diagram of a recording material setting screen that is displayed when a "detailed settings" button 311 is pressed on the print item setting screen 300. When print information is created, the contents set on the recording material setting screen 350 are also included in the print information. The recording material may be set using the recording material setting screen 350, or, for example, automatically by the CPU circuit unit 101 based on the results of scanning by the image reader 40.

[0054] The recording material setting screen 350 includes a "recording material layout" field 351 and a "recording material type" pull-down menu 352. The recording material setting screen 350 includes "recording material size" radio buttons 353, 354, a "standard size" pull-down menu 355, a "length" text box 356 for non-standard sizes, and a "width" text box 357. The recording material setting screen 350 includes "margin with or without margin" radio buttons 358, 359, a "leading edge" text box 360, a "trailing edge" text box 361, a "left edge" text box 362, and a "right edge" text box 363. The recording material setting screen 350 includes a "number of divided faces" text box 364, "division pattern" radio buttons 365, 366, 367, a "length direction" text box 368 for same-size division, and a "width direction" text box 369. The recording material setting screen 350 includes a “Delivery note / label” text box 370 , “Used side” radio buttons 371 and 372 , a “Yes” text box 373 , an “OK” button 374 , and a “Cancel” button 375 .

[0055] The following values ​​are set for each setting item on recording material setting screen 350. The values ​​set for each item are reflected in "Recording material layout" field 351. The item selected in "Recording material type" pull-down menu 352 is reflected in "Recording material type" pull-down menu 310 in the print item setting screen 300 described above. The item selected in "Recording material type" pull-down menu 352 is set as the type of recording material on which an image is formed by image forming apparatus 1. In FIG. 6, "Perforated paper" is set for this item.

[0056] The item selected by the "Recording Material Size" radio buttons 353, 354 is set as the outer size of the recording material. When the "Standard Size" radio button 353 is selected, a standard size such as A4 or LTR can be selected by using the "Standard Size" pull-down menu 355. When the "Custom Size" radio button 354 is selected, the recording material size is set by inputting values ​​into the "Length" text box 356 and "Width" text box 357 for the custom size. The length of the recording material in the transport direction is input into the "Length" text box 356 for the custom size, and the length in the direction perpendicular to the transport direction is input into the "Width" text box 357. In FIG. 6, the standard size "A4" is selected.

[0057] The "Margins" radio buttons 358 and 359 are items for setting whether or not to provide margins on the recording material. When the "No" radio button 258 is selected, "0" is displayed in all of the "Leading edge" text box 360, "Trailing edge" text box 361, "Left edge" text box 362, and "Right edge" text box 363. When the "Yes" radio button 259 is selected, a predetermined value can be set in each of the "Leading edge" text box 360, "Trailing edge" text box 361, "Left edge" text box 362, and "Right edge" text box 363. In FIG. 6, the "No" radio button 358 is selected. Therefore, "0" is displayed in all of the "Leading edge" text box 360, "Trailing edge" text box 361, "Left edge" text box 362, and "Right edge" text box 363.

[0058] The "Number of divided surfaces" text box 364 is an item for setting the number of divided surfaces according to the perforation R. The "Number of divided surfaces" text box 364 is set to "1" by default, but the number of divisions of the recording material can be set by entering a number in the "Number of divided surfaces" text box 364. The "Split pattern" radio buttons 365, 366, 367 are items that can be selected when a number of "2" or more is entered in the "Number of divided surfaces" text box 364. The item selected with the radio buttons 365, 366, 367 sets the size of the division.

[0059] When the "same size division" radio button 365 is selected, it becomes possible to input values ​​in the "length direction" text box 368 and the "width direction" text box 369 for the same size division. The number of division faces in the conveying direction of the recording material is input in the "length direction" text box 368, and the number of division faces in the direction perpendicular to the conveying direction of the recording material is input in the "width direction" text box 369. This sets the overall division pattern of the recording material. When the "delivery note / label" radio button 366 is selected, it becomes possible to set the "delivery note / label" text box 370. The "delivery note / label" text box 370 can be set by selecting a preset size such as "EAIJ standard" or "D label". When the "other (customize: set on layout)" radio button 366 is selected, it becomes possible to freely set the position of the perforation R by moving the perforation R on the "recording material layout" field 351. In FIG. 6, the “Same size division” radio button 365 is selected, “3” is entered in the “Vertical” text box 367, and “3” is entered in the “Horizontal” text box 368, setting up the perforated paper to be divided into 9 equal-sized pieces.

[0060] The item selected by the "used sides" radio buttons 371 and 372 sets whether or not there are used (cut-out) sides of the recording material. When the "no" radio button 371 is selected, it is set that there are no used sides. When the "yes" radio button 372 is selected, the number of used sides can be set in the "yes" text box 373. Furthermore, when the "yes" radio button 372 is selected, the position of the used sides can be set in the "recording material layout" field 351. This setting method is performed by selecting the used print side on the recording material layout displayed in the "recording material layout" field 351. FIG. 6 illustrates an example in which the "yes" radio button 372 is selected and "1" is entered in the text box 373. The used side position is set to side 376 at the right rear end position.

[0061] By pressing the "OK" button 374 after setting each of the above items, the set recording material information is finalized and stored in the storage of the computer 200. Once stored, the printer driver closes the recording material setting screen 350. When the "Cancel" button 375 is pressed, the printer driver closes the recording material setting screen 350 and returns the display to the print item setting screen 300. In this case, the recording material setting items that have been set up to that point are discarded without being saved.

[0062] When using the operation panel 50, pressing the "OK" button 374 after setting each item will finalize the set recording material information and store it in the RAM 103 of the CPU circuit unit 101. Once stored, the CPU circuit unit 101 closes the recording material setting screen 350. When the "Cancel" button 375 is pressed, the CPU circuit unit 101 closes the recording material setting screen 350 and returns the display to the print item setting screen 300. In this case, the recording material setting items that have been set up to that point are discarded without being saved.

[0063] (Determining whether automatic double-sided printing is possible) 7 is a flowchart showing the print setting process including the determination of whether automatic double-sided printing is possible in this embodiment. This process is executed by the printer driver of the computer 200 or the CPU circuit unit 101 of the image forming apparatus 1. Here, the case where it is executed by the CPU circuit unit 101 will be described. This process is performed based on the recording material information included in the print information. This process is started at the timing when the user inputs the print setting items in the process of S101 in FIG. 4. In this example, perforated paper is used as the recording material P.

[0064] The CPU circuit unit 101 determines whether or not the recording material P has a used side (a cut-out portion) (S201). Specifically, the CPU circuit unit 101 makes this determination based on whether the "used side" radio button 371 or 372 on the recording material setting screen 350 in Fig. 6 has been selected. The CPU circuit unit 101 determines that a used side exists when radio button 372 has been selected, and determines that no used side exists when radio button 371 has been selected.

[0065] If a used side is present (S201: Y), the CPU circuit unit 101 calculates the width of the recording material P at each position in the recording material transport direction based on the information in the "recording material layout" field 351 in FIG. 6, which sets the position of the used side (S202). Here, the lengths of the leading edge, trailing edge, and longest part of the recording material in the transport direction are calculated. The widths at each position in the transport direction in the case of the "recording material layout" field 351 in FIG. 6 are as follows. In the "recording material layout" field 351, the leading edge when the paper is passed is at the top of the screen. Conveying direction position Length Tip width 210[mm] Rear end width 140[mm] Maximum width 210[mm]

[0066] The CPU circuit unit 101 determines the presence and size of a notch at each of the leading and trailing ends based on the calculated width at each position in the transport direction (S203). Specifically, the CPU circuit unit 101 compares the calculated leading or trailing end width with the maximum width and determines whether the difference between them is greater than a predetermined difference. In the above example, the leading width is equal to the maximum width, and the trailing width is 67% of the maximum width. Therefore, in this case, it is determined that there is no notch on the leading side, but a notch on the trailing side.

[0067] The reason why the presence or absence of a notch is determined based on the amount of deviation, rather than on whether the leading edge width or trailing edge width matches the maximum width, will be explained below. When paper is passed with the edge with the notch at the leading edge, there is a possibility that the leading edge of the notch may get caught on the transport path, causing paper passing problems. However, if the notch width is sufficiently small, the notch has little effect on the attitude of the recording material, making it possible for the paper to pass. For this reason, the presence or absence of a notch is determined based on the amount of deviation.

[0068] When the difference between the leading edge width or the trailing edge width and the maximum width is equal to or greater than a predetermined difference, there is a possibility that paper passing failure will occur during automatic double-sided printing, and when the difference between the leading edge width or the trailing edge width and the maximum width is less than the predetermined difference, it can be determined that paper passing is possible during automatic double-sided printing. The threshold value of the notch width for determining whether or not a recording material with a notch on the leading edge side can be passed varies depending on the shape of the conveying path. Therefore, depending on the shape of the conveying path, it may be determined that automatic double-sided printing is not possible for a recording material with even a small notch.

[0069] If there is a notch (S203: Yes), the CPU circuit unit 101 determines whether automatic double-sided printing is set (S204). The CPU circuit unit 101 makes this determination based on whether "single-sided" or "double-sided" is selected in the "single-sided / double-sided" pull-down menu 313 in Fig. 5. If "single-sided" is selected, automatic double-sided printing is not set, and if "double-sided" is selected, automatic double-sided printing is set.

[0070] If automatic double-sided printing is set (S204: Y), the CPU circuit unit 101 determines that there is a problem with the transportation of the recording material P and that the device cannot be used for automatic double-sided printing. In this case, the CPU circuit unit 101 displays an alarm on the operation panel 50 to inform the user that the recording material P cannot be fed and therefore cannot be used for automatic double-sided printing (S205). FIG. 8 is an example of an alarm display. The CPU circuit unit 101 ends the process when the "OK" button on the alarm display screen is pressed. Note that when this process is performed by the printer driver, the printer driver displays an alarm display screen on the display of the computer 200.

[0071] If the recording material does not have a used side (S201: N), if there is no notch (S203: No), or if automatic double-sided printing is not set (S204: N), the CPU circuit unit 101 determines that there is no problem with the conveyance of the recording material. In this case, the CPU circuit unit 101 determines whether the print setting is complete (S206). The CPU circuit unit 101 determines that the print setting is complete when either the "Print" button 316 or the "Cancel" button 317 on the print item setting screen 300 in FIG. 5 is selected (S206: Y). If neither the "Print" button 316 nor the "Cancel" button 317 is selected (S206: N), the CPU circuit unit 101 returns to the process of S201 and continues to monitor the setting of automatic double-sided printing for recording materials with shapes that do not support automatic double-sided printing.

[0072] The image forming apparatus 1 of this embodiment as described above judges whether automatic double-sided printing is possible for a recording material P with a part cut off. This makes it possible to prevent a paper feed failure of a recording material P with a part cut off. In the above explanation, an example is explained in which the judgment as to whether automatic double-sided printing is possible is made when the print information is created, but this judgment processing may be made when the CPU circuit unit 101 acquires the print information or when the image forming processing starts.

[0073] (Modification) In the above explanation, the availability of automatic double-sided printing is determined before the start of paper passing based on recording material information such as the shape of the recording material input by the user. If the shape of the recording material set by the user differs from the shape of the recording material that is actually passed through, or if the image forming device 1 does not assume recording material shapes other than rectangular, it is difficult to determine the availability of automatic double-sided printing based on the shape of the recording material. Here, a configuration is described that eliminates such difficulties by detecting the shape of the recording material within the main body of the image forming device 1 after paper passing begins, and determining the availability of automatic double-sided printing based on the shape of the recording material predicted based on the detection results.

[0074] In the image forming apparatus 1, a sensor is disposed on the conveying path to detect the shape of the recording material P. In FIG. 1, a conveying sensor 60 is disposed on the conveying path 53. Here, a case where the shape of the recording material P is detected based on the detection result of the conveying sensor 60 disposed near the registration roller pair 5 will be described, but the position is not limited to this as long as the sensor is disposed on the conveying path. For example, the shape of the recording material may be detected from the detection result of a sensor disposed downstream of the separation roller pair 4. The conveying sensor 60 is a flag sensor, and a plurality of sensors are disposed in a direction perpendicular to the conveying direction of the recording material P. The detection result of the conveying sensor 60 is transmitted to the CPU circuit unit 101 via the recording material conveying control unit 110. The CPU circuit unit 101 detects the shape of the recording material P based on the detection result of the conveying sensor 60.

[0075] Fig. 9 is an explanatory diagram of the detection result of the transport sensor 60. Fig. 9(a) shows the arrangement of three transport sensors (first to third transport sensors). Fig. 9(a) shows a state in which a recording material P having a notch is transported. Fig. 9(b) is an exemplary diagram showing the detection result of the recording material P having a notch by the transport sensor 60. Note that the number of transport sensors is not limited to this, and may be more than one.

[0076] The detection result of the conveying sensor 60 (hereinafter referred to as the "output signal value") is binary data. A signal output value of "1" means that the conveying sensor 60 is detecting the recording material P. A signal output value of "0" means that the conveying sensor 60 is not detecting the recording material P. The timing when the output signal value transitions from "0" to "1", that is, the timing when the sensor changes from a state where the recording material P is not detected to a state where it is detected, represents the leading edge of the recording material P. Conversely, the timing when the output signal value transitions from "1" to "0" represents the trailing edge of the recording material P.

[0077] In the example of FIG. 9(a), there is a used surface at the position of the first conveyance sensor. Therefore, as shown in FIG. 9(b), the timing at which the output signal value of the first conveyance sensor transitions from "1" to "0" is earlier than the timing at which the signal output values ​​of the second and third conveyance sensors B transition from "1" to "0". If the timing at which the output signal value transitions from "1" to "0" is the same for the first to third conveyance sensors, it is possible to determine that there is no notch at the trailing end. As there are conveyance sensors with different transition timings of the output signal value, it is possible to determine that the recording material has a notch at the trailing end.

[0078] 10 is a flowchart showing the process of determining whether automatic double-sided printing is possible using the conveyance sensor 60. This process is performed only when automatic double-sided printing is set when setting the print information. In this example, perforated paper is used as the recording material P.

[0079] The CPU circuit unit 101 determines whether or not any of the conveyance sensors (first to third conveyance sensors) has detected the recording material P (S301). The CPU circuit unit 101 determines whether or not the recording material P has been detected based on whether or not the output signal value of the conveyance sensor 60 has transitioned from "0" to "1."

[0080] When at least one of the first to third conveyance sensors detects the recording material P (S301: Y), the CPU circuit section 101 monitors the timing of detection of the trailing end of the recording material P (S302). The CPU circuit section 101 monitors the timing at which the output signal value of the conveyance sensor 60 transitions from "1" to "0". The CPU circuit section 101 temporarily stores in the RAM 103 the timing at which the output signal value transitions from "1" to "0" (the trailing end detection timing).

[0081] The CPU circuit unit 101 waits until all the transport sensors (first to third transport sensors) no longer detect the recording material P (S303: N). The CPU circuit unit 101 determines whether the recording material P is no longer detected based on whether the output signal value of the transport sensor 60 has transitioned from "1" to "0". When all the transport sensors (first to third transport sensors) no longer detect the recording material P (S303: Y), this means that the trailing edge of the recording material P has passed the detection position of the transport sensor 60. When the trailing edge of the recording material P has passed the detection position of the transport sensor 60, it becomes possible to predict the shape of the recording material P.

[0082] The CPU circuit unit 101 determines whether there is a difference in the detection timing of the trailing edge of the recording material P (S304). The CPU circuit unit 101 compares the trailing edge detection timing of each transport sensor (first to third transport sensors) stored in the RAM 103 and determines whether there is a difference. If there is no difference in the trailing edge detection timing (S304: N), the CPU circuit unit 101 continues automatic double-sided printing of the recording material P because there is no notch at the trailing edge of the recording material P and there is no possibility of paper feeding failure during automatic double-sided printing (S307).

[0083] If there is a difference in the timing of detecting the rear end (S304: Y), the CPU circuit unit 101 determines that there is a notch at the rear end of the recording material P and that there is a possibility of paper feed failure during automatic double-sided printing, and stops automatic double-sided printing of the recording material P (S305). In this case, the CPU circuit unit 101 discharges the recording material P with the printing on the front side outside the image forming apparatus 1. During normal automatic double-sided printing, when the rear end of the recording material P with the printing on the front side reaches the double-sided reversal position, the reversing roller pair 62 stops and then rotates in the opposite direction to reverse the conveying direction. However, if there is a possibility of paper feed failure of the recording material P, the reversing roller pair 62 does not rotate in the opposite direction during automatic double-sided paper feed, and the recording material P is discharged directly to the paper output tray 9.

[0084] The CPU circuit unit 101 displays an alarm on the operation panel 50 of the image forming apparatus 1 to inform the user that the recording material cannot be used for automatic double-sided printing (S306). The CPU circuit unit 101 ends the process when the "OK" button on the alarm display screen in FIG. 8 is pressed.

[0085] The conveying sensor 60 may be configured to use a line sensor in addition to arranging multiple flag sensors in a direction perpendicular to the conveying direction. The line sensor is arranged in a direction perpendicular to the conveying direction. When the line sensor is used, the accuracy of detecting the shape of the recording material P is improved. In the above description, the CPU circuit unit 101 determines whether or not the recording material can be used for automatic double-sided printing, but this determination may be made by the CPU circuit unit 151 of the recording material conveying control unit 110. In this case, the detection result of the conveying sensor 60 is not transmitted to the CPU circuit unit 101. The timing of detecting the trailing edge of the recording material P is stored in the RAM 153. When the CPU circuit unit 151 determines that there is a possibility of a paper feed failure during automatic double-sided printing, it notifies the CPU circuit unit 101 of that effect. The CPU circuit unit 101 displays an alarm in response to this notification.

[0086] The image forming apparatus 1 of this embodiment as described above judges whether automatic double-sided printing is possible for the recording material P in a partially cut state. This makes it possible to prevent a paper feed failure of the recording material P in a partially cut state.

[0087] As described above, regardless of whether the shape of the recording material P is set by the user or the shape of the recording material P that is actually passed through, the image forming apparatus 1 can prevent failure of the recording material P to pass through when a portion of it is cut off.

Claims

1. an image forming means for forming an image on perforated paper that has been perforated; an input means for inputting recording material information relating to perforated paper on which an image is formed by the image forming means and information as to whether or not automatic double-sided printing is to be performed on the perforated paper; and a control means for displaying an alarm without passing the perforated paper when it is determined that the automatic double-sided printing is instructed based on information input by the input means and the difference between the maximum width of the perforated paper in the width direction perpendicular to the conveying direction of the perforated paper and the leading edge width, which is the length in the width direction at the leading edge of the perforated paper in the conveying direction, or the trailing edge width, which is the length in the width direction at the trailing edge of the perforated paper in the conveying direction, deviates by a predetermined difference or more. Image forming device.

2. The position of the perforation of the perforated paper is input by the input means; The leading edge width or the trailing edge width is determined based on the position of the perforation input by the input means.

2. The image forming apparatus according to claim 1.

3. an input means for inputting recording material information relating to the perforated paper on which the image is to be formed and information as to whether or not automatic double-sided printing is to be performed on the perforated paper; and a control means for displaying an alarm without passing the perforated paper when it is determined that the automatic double-sided printing is instructed based on information input by the input means and the difference between the maximum width of the perforated paper in the width direction perpendicular to the conveying direction of the perforated paper and the leading edge width, which is the length in the width direction at the leading edge of the perforated paper in the conveying direction, or the trailing edge width, which is the length in the width direction at the trailing edge of the perforated paper in the conveying direction, deviates by a predetermined difference or more. Information processing device.

Images