JP2006264869A - Image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image forming system capable of realizing various modes of paper folding without complicating and enlarging a device by combining a pleat forming function in a post-processing unit and a sheet conveying function in a both-sided unit. <P>SOLUTION: The image forming system comprises an image forming body unit 1 having a first conveyance path A for forming an image on a paper sheet, the post-processing unit 100 having a second conveyance path B for performing post processing such as forming a pleat on the paper sheet, and the both-sided unit 50 having a third conveyance path C for feeding the paper sheet switched back from the second conveyance path B again to the first conveyance path A. After forming the first pleat on the paper sheet fed via the first conveyance path A to the second conveyance path B, the system switches back the sheet, feeds it to the third conveyance path C, and feeds it via the first conveyance path A to the second conveyance path B to form the second pleat. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an image forming system, in particular, an image forming main body unit, a post-processing unit having a function of forming at least a crease on a sheet, and a duplex unit for forming an image on both sides of the sheet. The present invention relates to an image forming system.

  Image forming apparatuses such as copiers and printers are equipped with a duplex unit for duplex printing, and include post-processing means for sorting printed paper, forming punch holes, folding paper, and stapling. Units are often connected. Since these post-processing means are mounted in a limited space, it is difficult to satisfy all the various post-processing functions desired by the user.

  As a post-processing function, a paper folding function for folding paper into various forms and a stapling function for binding a bundle of paper are desired. In particular, a function for folding paper into a Z shape (Z folding) is required to be installed as a special function. Has been.

  Although the Z-folding function is disclosed in Patent Document 1, since processing is performed only in the post-processing unit, the paper positioning mechanism, the configuration of the folding roller, and the like are complicated, and a large conveyance path such as a dedicated transport path is provided. There is a problem that it becomes.

  On the other hand, regarding diversification of paper transport paths, Patent Document 2 discloses that images are formed on both sides of a paper using a paper reversing function in a post-processing unit.

Conventionally, the image forming main body unit has been provided with a duplex unit for inverting paper for duplex printing, and the conveyance path is diversified. However, conventionally, no consideration has been given to combining the duplex unit with the sheet processing function in the post-processing unit.
JP-A-8-301511 JP 2002-167098 A

  Accordingly, an object of the present invention is to combine the function of forming a crease in the paper in the post-processing unit with the function of conveying the paper in the duplex unit, thereby increasing the complexity and size of the paper folding in various modes. An object of the present invention is to provide an image forming system that can be realized without any problem.

  In order to achieve the above object, the present invention forms an image forming main unit having a first conveyance path for transferring an image onto a sheet, and forms at least a crease on the sheet fed from the first conveyance path. And a duplex unit having a third transport path for sending the paper switched back in the second transport path to the first transport path again. In the image forming system, after the first fold is formed on the paper sent to the second transport path through the first transport path, the paper is switched back and sent to the third transport path. The second crease is formed by feeding the second conveyance path through the second conveyance path.

  According to the image forming system of the present invention, it is possible to form a crease facing the first surface side and the second surface side of the sheet by using the third transport path of the duplex unit that reverses the sheet. It is possible to realize paper folding in various modes such as Z-folding, three-folding of paper, and four-folding. In addition, since the existing duplex unit is used, the apparatus is not complicated and large.

  In the image forming system according to the present invention, the paper folding function can be realized in the following modes. In the first mode, the sheet is sent to the second transport path via the first transport path without image formation to form the first fold, and the sheet is switched back and passed through the third transport path. An image is formed by sending it to one conveyance path, and a second fold is formed by sending the sheet to the second conveyance path. Thus, an image can be formed on one side of the paper, and a Z-folded or tri-folded print can be obtained.

  In the second mode, the paper is sent to the first transport path to form the second page image, the paper is sent to the second transport path to form the first fold, and the paper is switched back. Then, it passes through the third transport path to the first transport path to form the first page image, and the sheet is sent to the second transport path to form the second fold. Thus, images can be formed on both sides of the sheet in the order of pages, and a Z-folded or tri-folded print can be obtained.

  In the third mode, the paper is sent to the first transport path to form the second page image, the paper is sent to the second transport path, and then switched back to pass through the third transport path. To the second transport path to form the image of the first page, send the sheet to the second transport path, and then switch back to the second transport path via the third transport path and the first transport path. The sheet is fed to form a first fold, and further, the sheet is sent to the second conveyance path through the third conveyance path and the first conveyance path to form a second fold. Thus, images can be formed on both sides of the sheet in the order of pages, and a Z-folded or tri-folded print can be obtained. Further, in the third mode, since the first and second folds are formed after the images are formed on both sides of the paper, there is no possibility that the image quality is impaired.

  In the fourth mode, the paper is sent to the first transport path to form the second page image, the paper is sent to the second transport path to form the first fold, and the paper is switched back. Then, the first page image is formed via the third conveyance path and sent to the first conveyance path, and the sheet is sent to the second conveyance path to form the second and third folds. Thus, it is possible to obtain a four-folded print in which images are formed on both sides of the paper.

  Embodiments of an image forming system according to the present invention will be described below with reference to the accompanying drawings.

(Schematic configuration of image forming system, see FIG. 1)
The image forming system shown in FIG. 1 includes an image forming main unit 1 and a post-processing unit 100. The image forming main unit 1 is an electrophotographic color printer, and synthesizes four color images by a so-called tandem method. And a scanner 2 for reading a document image.

  The scanner 2 is a well-known scanner that reads an image of a document placed on a platen glass (not shown) with an image sensor such as a CCD element. The document image is converted into three primary colors of RGB (red, green, and blue) with the image sensor. It is decomposed and converted into an electrical signal. The image data is further converted into reproduction colors of YMCK (yellow, magenta, cyan, black).

  In the image forming main unit 1, a print head 10 that forms a YMCK image including a photosensitive drum 11, a laser scanning optical device 12, a developing device 13, and the like is juxtaposed directly below the intermediate transfer belt 15. In each print head 10, the laser scanning optical device 12 receives the transfer of the YMCK image data, forms a latent image on the photosensitive drum 11, and forms a toner image by the developing device 13. Such an electrophotographic process is well known and will not be described.

  In the lower part of the image forming main unit 1, a paper feeding cassette 20 that feeds stacked sheets one by one and a manual paper feeding unit 21 for feeding arbitrary paper are installed. Furthermore, a large-capacity automatic paper feeding unit (not shown) is provided at the lower stage of the paper feeding cassette 20.

  The toner images formed on the respective photosensitive drums 11 are sequentially primary-transferred onto the intermediate transfer belt 15 that is rotationally driven in the direction of the arrow a, and four color images are combined. On the other hand, the sheets are fed upward one by one, and the composite toner image is secondarily transferred from the intermediate transfer belt 15 by the secondary transfer unit 16. Thereafter, the sheet is conveyed to the fixing unit 25 where the toner image is heated and fixed, and is transferred from the discharge roller 29 to the post-processing unit 100. In this specification, a path along which the sheet is transported during the secondary transfer is referred to as a first transport path A.

  The post-processing unit 100 includes a punch unit 110 for punching paper, a paper folding unit 120 for folding paper, a staple unit 130 for binding the end of a paper bundle, and a sorter unit for storing / sorting paper. Further, the sorter unit 140 is provided with a staple unit 150 for binding the central portion of the sheet bundle.

  Further, the post-processing unit 100 is provided with rollers 101, 102, 103, 104, 105 and the like for conveying paper. In the present specification, a path for transporting the sheet to the paper folding unit 120 that forms a crease in the sheet is referred to as a second transport path B.

  A double-sided unit 50 is attached to the image forming main unit 1. The sheet once sent to the second transport path B is switched back and sent to the duplex unit 50, and is passed through the first transport path A again. In the present specification, a path for transporting paper in the duplex unit 50 is referred to as a third transport path C.

  The sheet is switched back from the second conveyance path B and passes through the third conveyance path C, so that the sheet is sent again to the first conveyance path A with the front and back reversed. Here, “switchback” means reverse conveyance in the conveyance path with the front and back in the conveyance direction reversed.

(Paper folding unit, see FIGS. 2 to 4)
Here, the configuration and operation of the paper folding unit 120 will be described. The paper folding unit 120 includes paper folding rollers 121 and 122 and an abutting member 123, and the rollers 121 and 122 and the abutting member 123 are driven by a motor 124. The conveyance rollers 101 and 102 located upstream in the paper conveyance direction b of the paper folding unit 120 are driven by a motor 161, and the conveyance rollers 103 and 104 located downstream are driven by a motor 162. Further, a sensor 107 for detecting the conveyed paper is installed between the rollers 101 and 102.

  In the paper folding unit 120, the paper is transported by the transport rollers 101, 102, 103, and 104 so that the crease position is set between the paper folding rollers 121 and 122 and directly below the abutting member 123. Let Then, the abutting member 123 is lowered and abutted against the paper, and the rollers 121 and 122 are rotated in the direction of winding the paper to form a crease in the paper. Thereafter, the abutting member 123 is returned upward, and the rollers 121 and 122 are reversed to return the paper to the original.

  Next, a procedure for controlling the folding position in the paper folding unit 120 will be described with reference to FIGS. First, if the folding mode is selected (YES in step S1), when the leading edge of the paper P is detected by the sensor 107 (YES in step S2), counting of the driving pulses of the transport motor 161 is started (step S3). ).

  Thereafter, when the trailing edge of the sheet P is detected by the sensor 107 (YES in step S4), the motors 161 and 162 are turned off to stop the conveyance of the sheet P (see step S5, FIG. 4A). Further, as shown in step S6, the length of the sheet P is calculated by stopping the count of the transport driving pulse and multiplying the count value by the transport amount per step. Based on the calculated sheet length, a fixed size (length in the conveyance direction) of the sheet P conveyed according to a predetermined threshold is determined.

  For example, if a crease is formed at the center of the paper P, the contact point (paper folding position) from the sensor 107 to the paper folding rollers 121 and 122 from a value Lz that is ½ of the length in the transport direction of the paper P. The backward conveyance length L1 is calculated by subtracting the length L2 until L1 is set as a timer value.

  Next, the motors 161 and 162 are reversely rotated to reversely convey the paper P (step S7), and when the rear end of the paper P is detected by the sensor 107 (step S8, see FIG. 4B), the L1 Is set (step S9). Thereafter, when the timer count ends (step S10), the motors 161 and 162 are turned off to stop the reverse conveyance (see step S11, FIG. 4C). Thus, the central portion of the paper P is set at the paper folding position.

  Thereafter, the motor 124 is driven to start the folding operation (see step S12, FIG. 4D). When the folding operation is completed (YES in step S13), the paper P is transported according to the paper folding mode shown below (see FIG. 4). Step S14).

  The size of the paper P may be controlled using a numerical value instructed from the image forming main unit 1 in advance. During reverse conveyance in which the paper P is positioned at the folding position, it is preferable to set the conveyance speed as low as possible to eliminate variations in detection by the sensor 107 and overrun of the paper P as much as possible.

  In addition to the central portion, the position where the crease is formed on the paper P includes a ¼ position, a ¾ position, and the like from the rear end as will be described later, and the value Lz is properly used according to the fold position. . That is, the backward conveyance length L1 is obtained by L1 = Lz−L2, where Lz is a distance from the rear end of the paper to the paper folding position, and L2 is a distance from the sensor 107 to the paper folding position.

  By the way, in the present embodiment, the end staple unit 130 aligns the paper with the stopper 131 (see FIG. 1) on the basis of the trailing edge. Even if the length of the sheet varies, a crease is formed at a certain position from the rear end of the sheet, and the finish is uniform.

(First paper folding mode, see FIG. 5)
The first paper folding mode will be described with reference to FIG. First, the paper P is sent to the second transport path B via the first transport path A without forming an image, and a first fold F1 is formed at the center of the paper P (see FIG. 5A).

  Next, the paper P is switched back and sent to the third transport path C (see FIG. 5B), and further sent to the first transport path A to form the first page image (see FIG. 5C). ). Thereafter, the sheet P is sent to the second transport path B, and a second fold F2 is formed at a position 3/4 from the rear end (see FIG. 5D).

  By repeating the above process for each paper P, an image can be formed on one side of the paper P to obtain a Z-folded print bundle, and the end of the paper P is bound by the staple unit 130. Thus, a print bundle shown in FIG. 5E is formed.

(Second paper folding mode, see FIG. 6)
The second paper folding mode will be described with reference to FIG. First, the paper P is sent to the first transport path A to form an image of the second page (see FIG. 6A), and further, the paper P is sent to the second transport path B to reach the central portion of the paper P. One fold line F1 is formed (see FIG. 6B).

  Next, the paper P is switched back and sent to the third transport path C (FIG. 6C), and further sent to the first transport path A to form the first page image (see FIG. 6D). . Thereafter, the sheet P is sent to the second transport path B, and a second fold F2 is formed at a position 3/4 from the rear end (see FIG. 6E).

  By repeating the above process for each sheet P, images can be formed in order of pages on both sides of the sheet P to obtain a Z-folded bundle of prints. By binding, a print bundle shown in FIG. 6F is formed.

(Third paper folding mode, see FIG. 7)
The third paper folding mode will be described with reference to FIG. First, the sheet P is sent to the first transport path A to form the image of the second page (see FIG. 7A), and then the sheet P is sent to the second transport path B and then switched back to the third page. It feeds into the conveyance path C (see FIG. 7B). Further, it is sent to the first transport path A to form the first page image (see FIG. 7C).

  Next, after the sheet P is sent to the second transport path B, it is switched back and sent to the third transport path C (see FIG. 7D). Further, the paper P is sent to the second transport path B through the first transport path A to form a first fold F1 at the center of the paper P (see FIG. 7E). Further, the sheet P is sent to the second transport path B through the third transport path C and the first transport path A, and a second fold F2 is formed at a position 3/4 from the rear end (see FIG. 7F). ).

  By repeating the above process for each paper P, it is possible to form a Z-folded print bundle by forming images in page order on both sides of the paper. Further, the end of the paper P is bound by the stapling unit 130 to form a print bundle shown in FIG.

  In the third paper folding mode, since the first and second folds F1 and F2 are formed after the images are formed on both sides of the paper P, the image quality is not impaired.

(Tri-fold mode, see Fig. 8)
The tri-fold mode will be described with reference to FIG. This tri-fold mode is a modification of the second paper fold mode, in which the folds F1 and F2 are formed at positions 1/3 from the leading edge and the trailing edge of the sheet, respectively.

  First, the paper P is sent to the first transport path A to form the image of the second page (see FIG. 8A), and further, the paper P is sent to the second transport path B and 1 from the rear end of the paper P. A first fold F1 is formed at the position of / 3 (see FIG. 8B). Next, the paper P is switched back and sent to the third transport path C (FIG. 8C), and further sent to the first transport path A to form the first page image (see FIG. 8D). . Thereafter, the sheet P is sent to the second transport path B, and a second fold F2 is formed at a position 1/3 from the rear end (see FIG. 8E).

  Thus, as shown in FIG. 8 (f), it is possible to form an image on both sides of the paper P and obtain a tri-folded print. If an image is formed only on one side of the paper P and is folded in three, the folds F1 and F2 are formed at 1/3 positions from the leading edge and the trailing edge of the paper P in the first paper folding mode. do it.

(Fourth paper folding mode, see FIG. 9)
The fourth paper folding mode will be described with reference to FIG. First, the paper P is sent to the first transport path A to form an image of the second page (see FIG. 9A), and further, the paper P is sent to the second transport path B and 1 from the rear end of the paper P. A first fold F1 is formed at the position of / 4 (see FIG. 9B).

  Next, the paper P is switched back and sent to the third transport path C (see FIG. 9C), and further sent to the first transport path A to form the first page image (see FIG. 9D). ). Thereafter, the sheet P is sent to the second transport path B to form a second fold F2 in the center (see FIG. 9E). Further, the sheet P is conveyed by 1/4 in the second conveying path B, and a third fold F3 is formed at a position 1/4 from the rear end (see FIG. 9F).

  As a result, as shown in FIG. 9G, it is possible to obtain a four-folded print in which images are formed on both sides of the paper P.

(Other examples)
The image forming system according to the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the gist thereof.

  In particular, the detailed configuration is arbitrary in various paper conveyance paths. Further, the image forming main unit may form a monochrome image, and the type of post-processing function installed in the post-processing unit is arbitrary except for the paper folding unit.

  In the above-described embodiment, the face-down discharge in which the sheet is discharged from the image forming main unit 1 with the image forming surface facing down has been described. On the other hand, in the case of face-up discharge, a printed matter similar to face-down discharge can be obtained by switching the print page order in reverse.

1 is a schematic configuration diagram illustrating an example of an image forming system according to the present invention. It is a schematic block diagram which shows a paper folding unit. It is a flowchart figure which shows the folding position control in a paper folding unit. It is explanatory drawing which shows the fold formation operation | movement in a paper folding unit. It is explanatory drawing which shows the 1st paper folding mode. It is explanatory drawing which shows 2nd paper folding mode. It is explanatory drawing which shows the 3rd paper folding mode. It is explanatory drawing which shows a trifold mode (modified example of a 2nd paper folding mode). It is explanatory drawing which shows 4th paper folding mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image formation main body unit 50 ... Duplex unit 100 ... Post-processing unit 120 ... Paper folding unit P ... Paper F1-F3 ... Crease A ... 1st conveyance path B ... 2nd conveyance path C ... 3rd conveyance path

Claims (8)

An image forming main unit having a first conveyance path for transferring an image onto a sheet, and a post-processing unit having a second conveyance path for forming at least a fold on the sheet sent from the first conveyance path And a duplex unit having a third conveyance path for sending the paper switched back in the second conveyance path to the first conveyance path again,
After the first fold is formed on the paper sent to the second transport path via the first transport path, the paper is switched back and sent to the third transport path, and further passed through the first transport path. Sending to the second transport path to form a second fold;
An image forming system.   The image forming system according to claim 1, wherein the sheet is Z-folded by the first fold line and the second fold line.   The image forming system according to claim 1, wherein the sheet is folded in three by the first fold line and the second fold line.   The image forming system according to claim 1, wherein the sheet is folded in four by forming a third fold in addition to the first fold and the second fold.   The sheet is sent to the second transport path through the first transport path without image formation to form the first fold, and the sheet is switched back and sent to the first transport path through the third transport path. 4. The image forming system according to claim 1, wherein the image is formed, and the sheet is sent to a second conveyance path to form a second fold. 5.   The paper is sent to the first transport path to form the second page image, the paper is sent to the second transport path to form the first fold, and the paper is switched back to the third transport path. 3 through the first transport path to form an image of the first page, and the sheet is transported to the second transport path to form a second fold. The image forming system according to claim 3.   The paper is sent to the first transport path to form the image of the second page, the paper is sent to the second transport path, then switched back, and sent to the first transport path via the third transport path. An image of the first page is formed, the sheet is sent to the second conveyance path, then switched back, and sent to the second conveyance path through the third conveyance path and the first conveyance path, and the first fold line is formed. And the second fold is formed by sending the sheet to the second conveyance path via the third conveyance path and the first conveyance path. The image forming system according to claim 3. The paper is sent to the first transport path to form the second page image, the paper is sent to the second transport path to form the first fold, and the paper is switched back to the third transport path. 2 through the first transport path to form an image of the first page, and the sheet is transported to the second transport path to form second and third folds. Item 5. The image forming system according to Item 4.

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