JP2000211797A - Image forming device provided with slip sheet processing means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slip sheet processing means of an image forming device to output a booklet aligned in a desired direction after inserting the slip sheet formed with an image, capable of judging whether or not the set condition of the slip sheet to be prepared in a tray is appropriate taking into consideration a restriction where the post-processing such as the stapling is achieved in a combined manner or a condition to improve the paper feed performance from a slip sheet tray, excellent in operability for users, and less in operational mistakes. SOLUTION: The slip sheet set condition to a slip sheet tray is inputted using an LCD 13, a touch panel 14 and a key 16. When the staple mode of the face-down and the image rotation of 180 deg. is inputted and set, no desired processing result is obtained, and a CPU 10 prohibits the forming of an image. When no staple mode is set, originals are successively accumulated in an image rotation and accumulation control part 6 from the first page, the image of rotation of 0 deg. is formed in the reverse order from the final original, a transfer paper is discharged in a non-inverting manner to obtain the desired slip sheet processing result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus provided with an interleaving means, and more particularly, to a prepared top and bottom,
An image in which a desired booklet is output after interleaving by setting an instruction for the setting state or controlling the operation of the apparatus in accordance with the setting state when the interleaving sheet with the front and back is set on the tray. The present invention relates to a forming apparatus.

[0002]

2. Description of the Related Art Conventionally, interleaving is performed in an image forming apparatus such as a copying machine. Here, “insertion sheet” means special paper for plain paper to be printed, and is bound to plain paper to constitute one booklet (printed matter). In many cases, the cover of the booklet is used. Is used. Conventionally, what is actually performed as an interleaving process is to set some of a plurality of paper feed trays provided in the image forming apparatus as interleaving trays, and then set an operation mode of the apparatus to interleaving mode or Image formation (printing) in the set mode in a way that sets the cover mode
In the course of the processing, a slip sheet operation is performed as a part of the image forming process by using sheets from the slip sheet tray.

[0003] In other words, when an interleaving operation is performed during the above-described image forming process, it is not necessary to newly form an image on the paper used for the interleaving (for example, using a plain paper or using an image in another environment). However, some processing steps are performed during the image forming process. For example, when this is a fixing process, special paper is often used for the interleaving paper, so if the paper quality is changed by heating at the time of fixing or if an image is already formed in another environment, This causes a problem that the image quality is deteriorated. As described above, the above-described method is not a desirable method because the image forming processing apparatus performs unnecessary processing on the slip sheet. Therefore, as an alternative method, for example, in Japanese Patent Application Laid-Open No. Hei 5-24735, a slip sheet process is performed as post-processing of a recording (transfer) sheet that is output after finishing the image forming process so that the image forming process is not performed. There has been proposed an apparatus that performs an interleaving process.

[0004]

However, in the proposed image forming apparatus having a slip sheet processing function,
No consideration is given to the setting of the interleaving paper tray when the paper used as the interleaving paper has the top and bottom or the front and back. Properly setting the interleaf tray to output the unit of the printed matter (booklet) arranged in a desired direction after the interleaf, or improving the paper feeding performance from the interleaf tray (for example, paper feeding) This depends on whether the image forming surface comes to the contact surface of the rollers or not). In other words, when setting the interleaf in the interleaf tray, the prepared interleaf has already been image-formed, and there is a direction that can be used naturally. In order to apply it to the specified position of the slip sheet, it is necessary to turn the paper upside down after image rotation and transfer in the image forming process, and since it is restricted by such processing conditions, it is arranged in the desired orientation after the slip sheet. In order to output a booklet, a correct selection must be made as to the orientation of the slip sheet to be set on the tray.

In practice, it is necessary to select four orientations, top and bottom and front and back, in order to properly set the slip sheet when setting it on the tray. Conventionally, the user is required to determine whether the setting of the slip sheet on the slip sheet tray is appropriate or not. When setting the sheet on the tray, one of the four orientations, top and bottom, and front and back sides is used. Must be selected as an appropriate setting for the user, forcing the user to make troublesome decisions.

The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to insert a slip sheet using a sheet on which an image is formed in advance and insert each page after the slip sheet. Of the interleaving paper prepared on the tray to output a booklet aligned in a desired direction is determined by the combination of post-processing such as stapling and punching. An image forming apparatus is provided that includes a slip sheet processing unit that has good operability for the user and has few operation errors, in consideration of conditions for improving the paper feeding performance from a paper tray, and making the determination on the apparatus side. Is to do.

[0007]

According to the first aspect of the present invention, there is provided an image forming engine for forming an image on a sheet of paper, and a sheet discharging means for inverting / non-inverting and discharging a sheet on which an image has been formed in accordance with a selected operation mode. And an interleaf processing means for inserting interleaf paper supplied from the interleaf paper storage means into the discharge paper from the paper discharge means to perform interleaf paper. When setting a slip sheet in the storage means, there is provided guide display means for instructing the direction of the slip sheet to be set according to the discharge direction according to the operation mode selected by the sheet discharging means. The image forming apparatus is provided with means for displaying guidance on, for example, an operation panel, how to set a desired booklet after the slip sheet is inserted into the slip sheet tray. Operability is improved, Mistakes can be prevented.

According to a second aspect of the present invention, there is provided an image forming engine for forming images in directions different from each other by 180 ° on a sheet of paper in accordance with a selected operation mode, and inverting / non-inverting the direction of an image-formed sheet in accordance with the selected operation mode. Image forming apparatus comprising: a paper discharge means for inverting and discharging; and a paper processing means having a paper storage means and inserting a paper supplied from the paper storage means into a paper discharged from the paper discharge means to perform paper mixing. A slip sheet setting state input means for inputting a direction of the slip sheet when setting the slip sheet in the slip sheet storage means, wherein the operation is performed in accordance with the direction input by the slip sheet setting state input means. An image forming apparatus provided with interleaving processing means, wherein an orientation of an image formed by an image engine is selected, and an operation mode of reversal / non-reversal discharge is selected by the discharge means. Insertion paper storage means (insertion tray) An image is formed by selecting either 0 ° or 180 ° in the image forming engine in accordance with the interleaving paper set by the input means of the paper setting state (top and bottom, front and back), and inverted by the paper discharging process By setting an operation parameter for selecting “/ non-reversal”, an apparatus capable of performing appropriate interleaving with a simple operation is provided.

According to a third aspect of the present invention, there is provided an image forming engine for forming images in directions different from each other by 180 ° on a sheet of paper in accordance with a selected operation mode, and inverting / non-inverting the direction of an image-formed sheet in accordance with the selected operation mode. Sheet discharging means for inverting and discharging, sheet inserting means for inserting a sheet inserted from the sheet discharging means into the sheet discharged from the sheet discharging means and interleaving the sheet; And a post-processing means for performing post-processing such as staples and punches at specific positions of the material interleaved by the means, wherein the interleaving paper is set in the interleaving paper storage means. The orientation of the image formed by the image forming engine according to the orientation input by the interleaf set state input means when the post-processing means is not set. Reversing / non-reversing paper discharge by paper discharge means When an interleaving process is executed by selecting an operation mode, and when the post-processing unit is set and an input other than a direction in which an appropriate process can be executed is input to the interleaving set state input unit, Forming an image forming apparatus including interleaving processing means, wherein an image forming operation in the image forming engine is prohibited.
When the post-processing mode such as staple or punch is not selected or selected, the interleaving paper set by the input means of the orientation (top, front and back) of the paper set in the interleaving paper storage means (interleaf tray) is used. In addition, by automatically changing the copy operation parameters in the image forming process, a proper booklet can be obtained, a desired booklet can be obtained after the sheet insertion, and when selecting a post-processing mode such as staples and punches. By automatically changing the copy operation parameters in the image forming and discharging processes in accordance with the slip sheet set by the input means of the sheet setting state (top and bottom, front and back) of the slip sheet storage means (slip sheet tray). If the desired booklet cannot be obtained after the slip sheet is inserted, copying is prohibited to prevent erroneous copying.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the accompanying drawings. The image forming process, stapling, punching process and interleaving process according to the present invention will be described in order. FIG. 1 is a block diagram showing an outline of a control section of a digital copying machine as an embodiment of an image forming apparatus according to the present invention. The basic flow of image forming processing in this digital copying machine will be described with reference to FIG.
In the drawing, the arrows indicated by thick lines indicate image data lines.

First, an original image to be processed on a paper original set on a contact glass (not shown) is read by a CCD line sensor 1, and an obtained image signal is input to a reading control unit 2, where the A / D conversion is performed. And outputs it to the image processing unit 3 as image data. The image processing unit 3 performs various processes on the image data, and the processed image data flows to a write control unit 4 where it is output as an image write signal for driving an LD (laser diode) 5.
Laser writing is performed by scanning a photosensitive drum (not shown) with a light beam of the LD 5 driven by an image writing signal, and together with a charging process (not shown), an electrostatic latent image is formed on the drum.

The above operation is executed by the CPU 10 according to a program stored in the ROM 8. CPU
Reference numeral 10 denotes an address bus and a data bus, which are connected to the image processing units and control units of various input / output means as an interface with a user, that is, an LCD control unit 12 and an input / output port 15. As the input / output means, V
A RAM 11, an LCD control unit 12, an LCD 13, a touch panel 14, an input / output port 15, and a key sensor actuator 16 are provided. The RAM 9 is a work memory for executing a program. The ROM 8 stores language data (character font, text, bitmap data for icons) used for display on the operation unit, in addition to the programs. FIG. 2 shows an input / output operation panel used by the user. The CPU 10 controls the VR via the LCD control unit 13
The bit map developed in AM 11 is transferred to the LCD module and displayed on the liquid crystal display unit 22 composed of the LCD in FIG. The CPU 10 reads the language switching key 23 and the print key 24 shown in FIG.

Next, post-processing such as stapling and punching will be described. Here, the staple processing will be mainly described as the post-processing. In the post-processing apparatus according to the present embodiment, the staples are set to the rear end side in the sheet conveyance direction as an example.
The stapling method uses a method in which the stapling is performed in a top direction from the side of the discharged paper. Therefore, in the staple mode, an image is formed by rotating the image by 180 ° by image processing, and the transfer paper after the image formation is reversed by 180 ° in the transport direction and discharged. The transfer paper reversing mechanism (not shown) is located near the discharge section of the image forming apparatus. The orientation of the transfer paper handled in the above-described stapling will be described with reference to FIGS. 3A and 3B. FIG. 3A shows a discharge paper at 0 ° (no image rotation), and FIG. 3B shows an image transfer at 180 ° image rotation. Paper (C) reverses the paper in the transport direction and is discharged. The stapling process is performed on the right side of the transfer sheet which is inverted and discharged as shown in FIG. 3D (a portion shown as a staple side in FIG. 3).
Is applied to

The above-described operation is executed by the CPU 10 according to a program stored in the ROM 8. CPU
An address bus and a data bus are connected to control units of various input / output means serving as an interface with a user, that is, an LCD control unit 12 and an input / output port 15 to issue an operation instruction. The staple mode, punch mode, slip sheet (cover) mode, and the like are displayed on the liquid crystal display unit 22 (FIG. 2) on the operation panel, and keys are detected by the touch panel 14 arranged on the liquid crystal display unit 22. Input from the touch panel 14 is performed by the CPU 10 via the LCD control unit 12.
Sent to. Keys, sensors, and actuators 16 required for image formation are connected to the CPU 10 via an input / output port 15 and a driver (not shown).

In the above description, the processing for forming an image by rotating the image by 180 ° in the staple mode and the punch mode is performed. As a means for this, the image forming apparatus is provided with an image rotation / accumulation control unit 6. The image rotation / accumulation control unit 6
It has at least one page of image memory, and during a 180 ° image rotation operation, one page of read image (0 ° image) is temporarily stored in the image memory, and rotation is realized by changing the reading direction from the memory. Therefore, compared to the output of the 0 ° image data, the output of the image data to the writing control unit 4 is delayed by the accumulation time for one image page. Therefore, the first copy time decreases. In addition, a hard disk or the like is provided for electronic sorting, reverse copying of input pages, and the like, so that multiple page images can be stored.

Next, the slip sheet processing will be described. In this embodiment, an interleaving process is performed in combination with a staple process as a post process. In addition, since the slip sheet is a slip sheet insertion method that does not pass through the heat fixing unit of the image forming apparatus, a case in which an image-formed sheet (usually having a top and bottom and a front and back orientation) is used as the slip sheet to be used. Is exemplified. FIG. 4 shows a post-processing apparatus to which an interleaf tray and an insertion path are added. In FIG. 4, transfer paper discharged from an image forming apparatus (not shown) enters a post-processing apparatus through an entrance path 45, and in a staple mode, proceeds along a branch path 47 along a transport path 49 in the direction of the staple tray 43. When a part of the transfer paper is accumulated on the staple tray 43, it is stapled by the staple unit 44 and discharged to the shift tray 42. In the staple mode, the shift tray 42 does not shift.

On the other hand, when the mode is not the staple mode, the sheets are discharged to the shift tray one by one as they are via the entrance path 45, the branching section 47, and the through path 48. At this time,
If the shift sort mode is selected, the tray is shifted to the rear side or the front side in the figure at the timing when the final transfer sheet of the set is discharged. In this way, the stacked transfer papers are separated for each copy. The interleaving paper supplied from the interleaving tray 41 passes through the interleaving paper path 46, joins the transfer paper from the entrance path 45, and heads for the branch part 47. The punch unit (not shown) is preferably installed between the slip path 46 and the branching portion 47. This is because punching can be performed on both slip sheets and transfer paper output from the image forming apparatus. Punching is performed on one sheet of paper transported by passing the sheet. Here, a hole is formed on the basis of the trailing edge of the sheet. The shift tray descends as the stack amount increases, so that the height of the stacked transfer paper surface after ejection is kept constant. The upper surface of the paper discharge surface is detected by a sensor (not shown).

FIG. 5 shows how the slip sheet is processed and discharged to the shift tray 42 according to the direction (front and back) of the slip sheet set in the slip sheet tray 41 when the sheet is processed by the post-processing apparatus. And FIG. In both figures, .A. Is attached to the side of the image on the paper (the front side in the case of a two-sided image) to indicate the direction. FIG. 5 shows a case where the image is placed on the slip tray 41 with the image surface facing upward (face up). Direct path of the shift tray 42 (interleaf paper path 46 → branch 47 → through path 48)
However, the staple path (interleaf path 46 → conveyance path 49)
→ Even in the staple tray 43), the image is discharged to the shift tray 42 with the image surface facing downward (face down). FIG. 6 shows a case where the image is placed on the slip sheet tray 41 with the image surface facing downward (face down). The image is discharged upward (face-up) to the shift tray 42 regardless of whether it is a direct bribe or a staple path.

Further, when the orientation of the interleaf set on the interleaf tray 41 (top and bottom), that is, the orientation of the image formed on the paper surface (0 ° and its inverted 180 °) is taken into consideration. Is processed in any direction and the shift tray 42
FIG. 7 and FIG. FIG. 7 shows a case where the sheet is placed face-up on the slip sheet tray 41. Both 0 ° (A _{1 in} FIG. 7) and 180 ° (A _{2 in} FIG. 7) face down on the shift tray 42 as described in FIG. Since the paper itself cannot be rotated, the orientation of the image on the shift tray 42 is, of course, the same as the orientation on the slip sheet tray 41. FIG. 8 shows a case where the sheet is placed face down on the slip sheet tray. 0 ° (A _{3 in} FIG. 8), 180 ° (in FIG. 8,
A ₄ ) both face up on the shift tray 42 as shown in FIG. Here, the direction of the image on the shift tray 42 is the same as the direction on the slip sheet tray 41.

Next, an example of the slip sheet operation according to the present invention is shown and described. FIG. 9 shows an interleaf storage means (interleaf tray).
7 shows an example of an operation flow for performing an operation of guiding and displaying to a user about a slip sheet setting direction when setting a slip sheet. Note that the operation of this embodiment is executed in the above-described image forming apparatus and post-processing apparatus. The step numbers of the operation flow are given in parentheses in the description. This flow is started when the user selects an operation mode performed on the operation panel in FIG. It is determined whether the slip sheet mode has been selected as an operation result (S
91) When the slip sheet mode is selected, it is further confirmed whether the staple mode (S92) or the punch mode (S93) is selected.

When at least one of the staple mode and the punch mode is selected and set, the image on the operation panel is turned up and the top and bottom are rotated by 180 ° as shown in (A ₂ ) in FIG. Then, a guidance display to the effect that paper is set on the slip sheet tray 41 is displayed (S95).
When neither the staple mode nor the punch mode is set, as shown in (A ₁ ) in FIG. 7, the image on the operation panel is turned up, and without turning the top and bottom (0 °). 3.) A guidance display for setting a sheet on the slip sheet tray 41 is displayed (S94). When the operation flow of FIG. 9 is performed, although not shown in the flowchart, the image forming apparatus performs an operation of sequentially copying one page of the input document from the first page, reversely discharging the transfer sheet, and discharging the sheet to the post-processing apparatus. .

Next, another embodiment of the interleaving operation according to the present invention will be shown and described. In the above description, the operation to be applied to the method of prioritizing the selection of the interleaf, staple, and punch modes, and then setting the interleaf in the tray is performed. However, in this embodiment, the setting of the interleaf in the tray is prioritized. This is the operation to be performed. This operation will be described with reference to FIG. 10 showing the flow of the operation of this embodiment. This operation is started by the user selecting an operation mode performed on the operation panel in FIG. In this example, it is determined whether or not the slip sheet key has been turned on (S101). If it is determined that the slip sheet key has been turned on and the slip sheet mode has been selected, a screen asking about the sheet setting status of the slip sheet tray 41 is displayed on the operation unit. (S102). In this example, (A ₁ ) and (A ₂ ) in FIG. 7 showing an example of face-up and (A ₃ ) and (A ₄ ) in FIG. 8 showing an example of face-down can be selected. To be displayed. It is determined whether the direction of FIG. 7 (A ₁ ) and the front and back (ie, face-up 0 °) have been selected (S103), and if face-up 0 ° has been selected, the staple mode or the punch mode is set. Investigation (S108), if any of them is set, the start of image formation is prohibited (S109). here,
When the slip sheet mode, staple or punch mode is released, the prohibition is released and image formation is started (not shown). In addition, the setting of the staple mode or the punch mode is checked, and if neither is set, the image is formed by rotating the image by 0 ° and reversing the transfer sheet (S110).

If face-up 0 ° is not selected in the above flow, it is then determined whether the direction of FIG. 7 (A ₂ ) and the front and back (ie, face-up 180 °) have been selected (S104). When face-up 180 ° is selected, regardless of the setting of the stapling and punching modes, the rotation of 180 ° and the copying of the inverted transfer paper are performed (S
111). If the staple or punch mode is not set, the first copy time will be delayed, but the output will be correct (the top and bottom, front and back of each page will not be different) as a slip copy with the current slip tray. Can be

If face-up 180 ° is not selected in the above flow, it is then determined whether the direction of FIG. 8 (A ₃ ) and the front and back (ie, face-down 0 °) have been selected (S105). If face down 0 ° is selected, the setting of the staple mode or the punch mode is checked (S114). If either of them is set, the start of image formation is prohibited (S109). In addition, the setting of the staple mode or the punch mode is checked. If neither is set, the original is read in order from one page, and the image is sequentially stored. When the reading of the last original is completed, the page is moved in the direction of one page from the last original. An image having an image rotation of 0 ° is formed in the reverse order, and the transfer paper is discharged without being reversed (S
112). The image accumulation in this case is performed by the image rotation accumulation control unit 6 in FIG.

If face down 0 ° is not selected in the above flow, it is then determined whether the direction of FIG. 8 (A ₄ ) and the front and back (ie, face down 180 °) have been selected (S106). When face down 180 ° is selected, the setting of the staple mode or the punch mode is checked (S107), and if either is set,
The start of image formation is prohibited (S109). In addition, the setting of the staple mode or the punch mode is checked. If neither is set, the original is read in order from one page, and the image is sequentially stored. When the reading of the last original is completed, the page is moved in the direction of one page from the last original. An image having an image rotated by 180 ° is formed in the reverse order, and the transfer sheet is discharged without being inverted (S113). Also in this case, the image storage is performed by the image rotation / storage control unit 6 in FIG.

[0026]

According to the first aspect of the present invention, in the image forming apparatus in which the fixing-less interleaving processing means and the post-processing means are combined, when the interleaving processing mode is performed, the image is formed in advance and the top, bottom, front and back are formed. Even when the paper is used as an interleaf, the user can appropriately set the orientation state (top and bottom, front and back orientation) of the paper set in the interleaf tray which needs to be changed according to the operation mode of the paper ejection device. As described above, the occurrence of erroneous copying can be prevented, and a desired slip sheet operation can be performed.

According to the second aspect of the present invention, the image forming engine forms images in directions different from each other by 180 ° on the paper surface in accordance with the selected operation mode, and inverts the direction of the image-formed paper in accordance with the selected operation mode. In an image forming apparatus that combines a sheet discharging unit that discharges non-inverted paper and a fixing-less interleaving processing unit, when the interleaving mode is performed, a sheet in which an image has been formed in advance and has a top, bottom, and front and back is used as interleaving. Even if there is any orientation of 0 ° or 180 ° by the image forming engine in accordance with the interleaf set by the input means of the paper set state (top and bottom, front and back orientation) of the interleaf storage means (interleaf tray) To form an image, and automatically set and execute an operation parameter for selecting reversal / non-reversal in the paper discharging process, so that it is not necessary to re-set the interleaving paper each time, thereby improving operability, To allow the rice cake slip sheet operations.

According to the third aspect of the present invention, an image forming engine for forming images in directions different from each other by 180 ° on a sheet of paper in accordance with the selected operation mode, and reversing the direction of the image-formed paper in accordance with the selected operation mode. When an interleaving process mode is performed in an image forming apparatus that combines a non-reversing and non-reversing discharging unit, a fixing-less interleaving unit and a post-processing unit,
Even in the case where a sheet having an image formed in advance and having top, bottom, front and back is used as the slip sheet, the sheet is set by the input means of the sheet setting state (top, bottom, front and back) of the slip sheet storage means (interleaf tray). 0 ° or 1 with the imaging engine according to the slip sheet
An image is formed by selecting one of the orientations of 80 °, and the operation parameters for selecting reversal / non-reversal in the paper discharge process are automatically set and executed, so that the trouble of resetting the slip sheet can be omitted. The operability is improved, and desired interleaving operation and post-processing such as staples and punches after interleaving are enabled. Also, according to the current setting mode and how to set the slip sheet,
Even in the case where a miscopy occurs, the image forming operation is prohibited, so that the occurrence of the miscopy can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a control unit of a digital copying machine according to an embodiment of the present invention.

FIG. 2 shows an input / output operation panel of the digital copying machine shown in FIG.

FIG. 3 is an explanatory diagram of the direction of transfer paper handled for stapling.

FIG. 4 shows a post-processing apparatus to which an interleaf tray and an insertion path are added.

5 shows the orientation (face-up) of the slip sheet in the process of the post-processing device shown in FIG.

6 shows the orientation (face down) of the slip sheet in the process of the post-processing device shown in FIG.

FIG. 7 shows a state of a slip sheet set on the tray in a face-up state in a discharge tray.

FIG. 8 shows a state in which a slip sheet set in the tray face-down is in a discharge tray.

FIG. 9 shows an example of an operation flow for performing the slip sheet setting direction guiding operation.

FIG. 10 shows an example of an operation flow when priority is given to setting an interleaf sheet on a tray.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CCD, 2 ... Reading control part, 3 ... Image processing part, 4
... Write controller, 5 LD, 6 Image rotation / accumulation controller, 8 ROM, 9 RAM, 10 CPU, 11 V
RAM, 12 LCD control unit, 13 LCD, 14 touch panel, 15 input / output port, 16 key sensor actuator, 22 liquid crystal display unit, 23 language switching key, 24 print key.

Claims (3)

[Claims] An image forming engine for forming an image on a sheet of paper,
A sheet discharging means for inverting / non-inverting the image-formed paper in accordance with the selected operation mode and discharging the sheet, and inserting a sheet inserted from the sheet discharging means into the sheet discharged from the sheet discharging means; An interleaving processing means for performing interleaving, wherein when the interleaving paper is set in the interleaving paper storage means, the interleaving direction depends on the direction of paper discharge according to the operation mode selected by the paper discharging means. An image forming apparatus provided with a slip sheet processing means, which is provided with a guide display means for indicating a direction of a slip sheet to be set. 2. An image forming engine for forming images in directions different from each other by 180 ° on a sheet of paper in accordance with a selected operation mode, and inverting / non-inverting the direction of an image-formed sheet in accordance with the selected operation mode, and discharging the sheet. An image forming apparatus comprising: a paper discharge unit; and a paper processing unit that has a paper storage unit and inserts a paper supplied from the paper storage unit into a paper discharged from the paper discharge unit to perform the paper insertion. A slip sheet setting state input means for inputting an orientation of the slip sheet when setting the slip sheet in the slip sheet storage means; and forming the image by the image forming engine in accordance with the direction inputted by the slip sheet setting state input means. An image forming apparatus comprising an interleaving processing means, wherein an orientation of an image is selected and an operation mode of reversing / non-reversing discharging is selected in the discharging means. 3. An image forming engine for forming images in directions different from each other by 180 ° on a sheet of paper in accordance with a selected operation mode, and inverting / non-inverting the direction of an image-formed sheet in accordance with the selected operation mode, and discharging the paper. A sheet discharging means, a slip sheet storing means, a slip sheet processing means for inserting a slip sheet supplied from the sheet storing means into a sheet discharged from the sheet discharging means to perform slip sheets, and And a post-processing means for performing post-processing such as staples and punches at a specific position on the slip sheet. An interleaf sheet setting state input means, and when the post-processing means is not set, the direction of an image formed by the image forming engine and the reversal by the sheet discharging means according to the direction input by the interleaf sheet setting state input means. / The operation mode of non-reversed paper discharge When the post-processing means is set and the input other than the direction in which the proper processing can be executed is input to the interleaf sheet setting state input means, the operation is performed. An image forming apparatus comprising a slip sheet processing unit, wherein an image forming operation in an image engine is prohibited.