JP2005112515A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device assuring a high producibility in the fold-up mode and a stable transporting performance. <P>SOLUTION: The image forming device is equipped with a branching guide means at the upstream side of its fold-up part and a branch transport path furnished with a sheet rotating part, whereby it is possible to select in the fold-up mode whether the paper sheet is introduced directly to the fold-up part or to be introduced upon rotating 90 degrees in the sheet rotating part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus having a folding unit that performs a folding process after forming an image on a sheet.

  Post-processing devices that perform folding processing are widely used as accessory devices for copiers and printers. The folding section of such post-processing devices is required to be small and a series of operations following image formation. In order to perform the folding process as a part of the process, the folding process is generally performed by providing a crease perpendicular to the conveyance direction provided in the conveyance path of the sheet on which the image is formed.

  Therefore, in the folding mode, the orientation of the sheet on which the image is formed and conveyed is limited to a certain orientation due to the fold. In many cases, a folding process for making a crease parallel to the short side of the sheet is performed. In the folding process mode, the sheet is conveyed so that the conveying direction is the long side of the sheet, and image formation is performed.

  However, since the productivity is reduced in the image formation in which the long side is the transport direction, there is a proposal to rotate the sheet 90 ° before the folding process in order to improve the productivity (Patent Document 1). ).

In addition to Patent Document 1, for example, Patent Documents 2 to 5 disclose techniques for rotating the paper orientation by 90 °. As can be seen from these Patent Literatures, the paper orientation is rotated by 90 °. However, a considerable space is required, and the conveyance path becomes complicated. On the contrary, problems such as reduction in productivity and occurrence of conveyance failure occur.
JP-A-57-112852 JP-A-5-301659 JP 2001-180846 A JP 2001-328751 A JP 2002-234636 A

  An object of the present invention is to solve the above-described problem in a post-processing apparatus that rotates a sheet by 90 ° in a stage before folding processing.

The object is achieved by the following invention.
(1)
In an image forming apparatus including an image forming unit that forms an image on a sheet, a post-processing device that includes a folding unit that performs a folding process on the image-formed sheet, and a control unit.
The post-processing apparatus has a sheet rotating unit and a branch guide unit for rotating the sheet by 90 °,
The control unit conveys the sheet sent from the image forming unit to the post-processing apparatus directly to the folding unit and folds the sheet or guides the sheet to the sheet rotating unit and rotates the sheet by 90 °. An image forming apparatus, wherein the folding unit, the sheet rotating unit, and the branch guide unit are controlled so as to be conveyed to a folding unit and folded.
(2)
(1) characterized in that the paper rotation unit is provided in a branch conveyance path branched substantially perpendicularly to a conveyance path for conveying the paper from the paper receiving unit of the post-processing apparatus to the folding unit. The image forming apparatus described.
(3)
The control means performs conveyance and image formation with a paper conveyance direction as a short side for a sheet of a predetermined size or less, and rotates the sheet by 90 degrees by the sheet rotation unit in the folding mode. The image forming apparatus according to (1) or (2), wherein the image forming apparatus performs a folding process.

  According to the invention of any one of claims 1 to 3, productivity can be improved in the folding mode by conveying a sheet and forming an image so that the conveyance direction becomes a short side, and the conveyance direction is long. It is also possible to form images by conveying the paper so that it is on the side, and the folding process can be performed without going through the paper rotation section, so the conveyance in the post-processing device is stable, and the productivity in forming a small number of images Will improve.

  According to the second aspect of the present invention, an increase in size due to the installation of the sheet rotating portion is avoided, and a small image forming apparatus is realized.

  FIG. 1 is an overall view of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus includes an image forming apparatus main body A that forms an image on a sheet P by an electrophotographic method, and a post-processing apparatus B that performs a folding process on the sheet P on which the image is formed.

  The image forming apparatus main body A includes an image reading unit 101, an image forming unit 102, and paper storage units 103 and 104.

  The post-processing apparatus B includes a sheet rotating unit 200 and a folding unit 300 that rotate the sheet by 90 °.

  The image forming apparatus has a folding mode in which folding processing is performed on a sheet on which an image has been formed. In an image forming mode other than the folding mode, the image forming apparatus is based on image data generated by the image reading unit 101 or image data received by the communication interface 107. The image forming unit 102 forms an image on the paper P supplied from the paper storage units 103 and 104, and sends the paper P to the post-processing apparatus B.

  In the post-processing apparatus B, the paper P received by the paper receiving unit 400 is transported along the straight transport path H1 by the transport rollers 401 and 403, the folding rollers 301 and 302, and the paper discharge roller 404 to the paper discharge tray 405. Eject paper.

  In the folding mode, an image is formed in the same manner as described above, and the sheet P received by the sheet receiving unit 400 is branched at a substantially right angle with respect to the substantially horizontal linear conveyance path H1, and the sheet P is conveyed downward. The sheet is guided to the transport path H2 by a switching gate 402 as branch guide means, rotated 90 ° by the sheet rotating section 200, and then folded in the folding section 300. The sheet discharge tray 405 is transported by the transport rollers 305 and 306 and the sheet discharge roller 404. Paper is discharged.

  In the folding mode, the paper P sent to the post-processing apparatus B is transported on the straight transport path H1 without being guided to the branch transport path H2, and the folding section 300 performs the folding process, and the folded paper P The paper is discharged onto the paper discharge tray 405 by the transport rollers 305 and 306 and the paper discharge roller 404.

  Regarding the control in the folding mode, when the paper P is sent to the branch conveyance path H2 and the folding process is performed after the paper rotation process, and when the folding process is performed by conveying the straight conveyance path H1 and introducing it directly into the folding unit 300. This will be explained later.

  The image reading unit 101 includes a document conveying device and an optical reading unit. The document conveying device includes a document feeding tray 111 on which a scanned document is placed, a document feeding unit 112 that feeds a document one by one, and a document reading position. It has a platen roller 113 that conveys the document, a reverse conveyance unit 114 that reverses the document, and a document discharge tray 115 that discharges the read document.

  The document placed on the document feed tray 111 is separated into one sheet, circulates around the platen roller 113, and image reading is performed at a reading position below the platen roller 113.

  In the single-sided reading, the original after reading is discharged to the paper discharge tray 115. In the double-sided reading, the original after reading is reversed by the reverse conveyance unit 114 and then supplied to the platen roller 113 again. The paper is discharged after the back side scanning is performed.

  The image reading is performed not only on the document conveyed by the document conveying device but also on the document placed on the document table 116.

  The optical reading unit includes a scanning unit 117 composed of a lamp and a mirror for illuminating a document, a scanning unit 118 composed of two mirrors, an imaging lens 119, and an image sensor 120 composed of a line CCD.

  In the mode of reading the conveyed document, the optical element of the optical reading unit is read at a fixed position.

  In the mode of reading a document on the document table 116, scanning is performed by moving the scanning units 117 and 118 along the document table 116.

  The image forming unit 102 forms an image on the paper P by an electrophotographic method based on the image data generated by the image reading unit 101 or the image data acquired through the communication interface 107. The photoconductor 122, the charging device 123, an exposure device 124, a development device 125, a transfer device 126, a separation device 127, a cleaning device 128, and a fixing device 129. A toner image is formed on the photoconductor 122 by charging, exposure, and development, and the transfer device 126 The toner image is transferred to the paper P and fixed by the fixing device 129.

  The image forming unit 102 has a double-sided image forming function. In double-sided image formation, the sheet P on which the image has been formed and fixed on the front side is guided downward by the switching gate 137, and the reverse conveyance unit 131 passes through the back surface branch path 131. After reversing the front and back at 138, the paper is fed to the registration roller 136 and conveyed to the transfer position by the registration roller 136, whereby an image is formed on the back surface.

  By performing the above-described processing on the paper P supplied from the paper supply unit 103 and 104, an image is formed on one side or both sides. The sheet P on which the image is formed is discharged from the discharge port 106 to the post-processing apparatus B by the discharge roller 137.

  FIG. 2 is a cross-sectional view of the paper rotation unit 200 of the post-processing apparatus B, and FIG. The sheet rotation unit 200 is configured as a unit, is provided in a branch conveyance path H2 that conveys the sheet P downward, and includes disk-shaped sheet holding members 201 and 202 and a stopper 205.

  The sheet holding member 201 is a disk having a plane holding portion as shown in FIG. 3A which is a front view thereof and FIG. 3B which is a left side view thereof. As shown in FIG. 3C, which is a front view of the sheet holding member 202, and in FIG. 3D, which is a right side view thereof, the sheet holding member 202 is formed of a disk having a cross-shaped holding projection 203, and is indicated by a solid line in FIG. The holding position shown and the leading end of the holding ridge 203 are displaced to the open position shown by the dotted line away from the paper holding member 201. The sheet holding member 202 is made of rubber. In addition, names, such as a front view in FIG. 3, are based on FIG.

  The displacement as described above is performed by the renoid SL1, and when the paper holding member 202 is at the position of the solid line, the tip of the holding ridge 203 contacts the paper holding member 201 and holds the paper P. The sheet holding members 201 and 202 are also rotated 90 ° about the center of the disk by driving the motor M1.

  The stopper 205 is displaced between an operating position indicated by a solid line and a retracted position indicated by a dotted line, and this displacement is performed by a solenoid SL2.

  The sheet rotating unit 200 is moved up and down by the motor M2, and is set at a position corresponding to the size of the sheet P to be processed. The position of the paper rotation unit 200 is set so that the center of the disk constituting the paper holding members 201 and 202 is the center of the paper P of each size.

  Reference numerals 210 and 211 are guides for guiding the paper P, and form a branch conveyance path H2.

  In the initial state, the solenoids SL1 to SL3 are off, the paper holding member 202 is in the position indicated by the dotted line, and the paper holding members 201 and 202 form a gap through which the paper P passes. Moreover, the stoppers 205 and 206 are in the positions of solid lines.

  FIG. 4 is a timing chart of the operation of each unit in the sheet rotating unit 200. The operation timing of the sheet rotation unit 200 is set using a sheet leading edge detection signal of a sensor PS (shown in FIG. 2) provided at the entrance of the sheet rotation unit 200 as a reference signal.

  A predetermined time after the sensor PS detects the leading edge of the paper, the solenoid SL1 is activated to set the paper holding members 201 and 202 to the positions indicated by the solid lines in FIG. This operation of the solenoid SL1 is set to a time immediately after the leading edge of the sheet reaches the stopper 205.

  Accordingly, the paper holding members 201 and 202 hold the paper P stopped by hitting the stopper 205.

  Next, the solenoid SL2 is activated and the stopper 205 is retracted to the position indicated by the dotted line. In a state where the paper P becomes free by this retraction, the motor M1 is operated to rotate the paper holding members 201 and 202 by 90 °. As a result, the paper P held by the paper holding members 201 and 202 rotates 90 °.

  Next, the solenoid SL1 stops, and the paper holding members 201 and 202 are displaced to the positions indicated by the dotted lines in FIG. 2 to release the paper.

  The released paper falls and reaches the stopper 206.

  Next, the solenoid SL3 is actuated to retract the stopper 206, and the sheet S falls onto the transport roller 207 and is transported by the transport roller 7 to the folding unit 300 that is the next processing unit.

  Next, the folding unit 300 will be described with reference to FIG.

  The main part of the folding unit 300 includes folding roller pairs 301 and 302 and a nip roller 303.

  In the process of introducing the paper P into the folding unit 300, the folding rollers 301 and 302 convey the paper in the left direction in the figure. For example, when the paper is folded in half at the center of the paper, after the folding rollers 301 and 302 stop when the center of the paper P (the center in the transport direction) reaches the middle of the folding rollers 301 and 302, The folding roller 301 rotates so as to convey the paper in the left direction, while the folding roller 302 rotates so as to convey the paper in the right direction.

  By the conveyance in the opposite direction of the folding rollers 301 and 302, the sheet P is folded in the middle between the folding rollers 301 and 302, and the sheet P advances downward with the fold as the head. Note that the sheet P is accurately folded by the downwardly convex guide 304.

  The folded sheet P is nip-conveyed by the nip roller 303, is strongly folded, and is discharged from the discharge roller 404 to the discharge tray 405 through the transfer rollers 305 and 306.

  Next, the control in the folding mode will be described with reference to FIGS.

  FIG. 5 is a block diagram of the control system, and FIG. 6 is a control flowchart.

  In FIG. 5, the control means CR controls the paper feed unit PF to perform control so that the transport direction of the paper becomes a short side, and controls the image processing unit GS to control the paper that travels with the transport direction as the short side. The image is rotated so as to correspond to the above, the paper rotating unit 200 is controlled to rotate the paper on which the image is formed by 90 °, and the folding unit 300 is controlled to perform the folding process.

  FIG. 6 is a flowchart of control from image formation to post-processing. In the following description, with respect to the orientation of the paper and the image, the direction in which the paper conveyance direction is the short side is referred to as the vertical direction, and the direction in which the conveyance direction is the long side is referred to as the horizontal direction.

  In step F1, it is determined whether or not the sheet is A4 size or smaller. The paper size is set by the operator or obtained from the document size and the set magnification. In the case of printing, a paper size is specified in a print command from a personal computer. The A4 size in step F1 means a size irrelevant to the orientation of the paper, and includes portrait orientation and landscape orientation, that is, A4 having a short side in the transport direction and A4R having a long side.

  Actually, no in step F1 means, for example, a B4 size or an A3 size.

  If it is A4 size or smaller (F1 yes), in step F2, a vertically oriented sheet is selected.

  In step F3, it is determined whether or not the image is vertically oriented (F2). When the image is not oriented vertically (no in F3), the image processing unit GS performs image processing for rotating the image by 90 ° (F4). When the image is in portrait orientation (F3: yes), image rotation processing is not performed.

  As a result, all the images are unified vertically, and a vertically oriented image is formed on the vertically oriented paper.

  Next, image formation is performed (F5), and the sheet is sent to the post-processing apparatus B.

  Next, in step F6, it is determined whether or not the folding mode is set. When in the folding mode (yes in F6), the gate 402 is operated to guide the paper to the branch conveyance path H2 (F7), and the paper rotation unit 200 rotates the paper by 90 ° (F8) and folding. Processing (F9) is performed, the paper is discharged (F10), and the process ends.

  If it is not the folding mode (no in F6), the sheet is conveyed through the straight conveyance path H1, the paper discharge process is performed without rotating the paper (F10), and the process is terminated.

  When the paper is B4 size or A3 size, image formation is performed on the paper (F11), and it is determined whether or not the folding mode is selected (F12). If the determination in step F1 is no, the switching gate 402 is not switched, and the sheet P travels straight on the straight conveyance path H1 regardless of the folding mode and is introduced into the folding unit 300.

  In the folding mode, after performing the folding process (F13), if not in the folding mode, the sheet is discharged without performing the folding process (F14) and the process ends.

  FIG. 7 is a flowchart of another example of control from image formation to post-processing.

  In this example, step 1A for determining the number of image forming sheets in the job is inserted between step F1 and step F2.

  When the number of sheets on which an image is to be formed is equal to or greater than the predetermined number (F1A: yes), the same control as in FIG. 6 is performed.

  In this example, even when the paper size is A4 or less, if the number is less than a predetermined number, for example, less than 10, the sideways paper is conveyed, an image is formed, and the folding process is performed.

  That is, when the number is less than 10 (no in F1A), the landscape paper is selected (F2A), the images are unified in the landscape orientation (F3A, F4A), and image formation is performed. For the paper on which the image is formed, the processing from step F11 is performed.

  This control prevents the productivity from decreasing due to the time required for the sheet rotation process in the image forming process for a small number of sheets.

1 is an overall configuration diagram of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows a paper rotation part. It is a figure which shows a paper holding member. 5 is a timing chart of the operation of each unit in the paper rotation unit 200. It is a block diagram of a control system in an embodiment of the present invention. It is a flowchart of control in an embodiment of the invention. It is a flowchart of the other example of control in embodiment of this invention.

Explanation of symbols

A Image forming apparatus main body B Post-processing apparatus 200 Paper rotation part 300 Folding part 402 Switching gate CR control means H1 Straight conveyance path H2 Branch conveyance path

Claims (3)

In an image forming apparatus including an image forming unit that forms an image on a sheet, a post-processing device that includes a folding unit that performs a folding process on the image-formed sheet, and a control unit.
The post-processing apparatus has a sheet rotating unit and a branch guide unit for rotating the sheet by 90 °,
The control unit conveys the sheet sent from the image forming unit to the post-processing apparatus directly to the folding unit and folds the sheet or guides the sheet to the sheet rotating unit and rotates the sheet by 90 °. An image forming apparatus, wherein the folding unit, the sheet rotating unit, and the branch guide unit are controlled so as to be conveyed to a folding unit and folded. The paper rotation unit is provided in a branch conveyance path that branches substantially at right angles to a conveyance path that conveys a sheet from a sheet receiving unit of the post-processing apparatus to the folding unit. Image forming apparatus. The control means performs conveyance and image formation with a paper conveyance direction as a short side for a sheet of a predetermined size or less, and rotates the sheet by 90 degrees by the sheet rotation unit in the folding mode. The image forming apparatus according to claim 1, wherein folding processing is performed.

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