JP2012181529A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that controls the number of folds of a sheet by inputting a grain direction of the sheet from an operation display device to be added to sheet information on the sheet for forming a sheet bundle, thereby improving the folding quality of the sheet bundle and reducing bookbinding time.SOLUTION: The grain direction of a sheet on which an image is formed is input from an operation display device. A folding condition, such as one fold or two folds, is changed on the basis of a predetermined folding mode selection table, from the grain direction of the sheet, the number of sheets and basis weight, thereby improving the folding quality of the sheet bundle and reducing bookbinding time.

Description

  The present invention relates to an image forming apparatus equipped with a sheet processing apparatus having a finishing function for stacking sheets on which images are formed and folding the sheets.

  2. Description of the Related Art Conventional sheet processing apparatuses having a sheet folding function include, for example, a sheet storage unit, a pair of folding rollers, and a protruding plate as described in Patent Document 1. In such an apparatus, the center portion of the sheets stacked and stored in the sheet storage portion is bound first, and then the binding portion is pushed into the nip portion of the folding roller pair by a protruding plate to fold the sheet bundle in half. It is designed to be discharged outside the machine.

  Further, as described in Patent Document 2, even in the case of a large number of sheets, in order to perform sufficient folding processing, the folded portion of the sheet is changed to the nip portion of the pair of folding rollers according to the number of sheets. Some have a so-called two-fold folding mode that allows them to pass twice. Since the fold is strengthened by folding twice, it is possible to perform binding with good appearance without opening the sheet bundle after the folding process.

JP 04-333469 A JP 09-183567 A

  By the way, a sheet generally used in a copying machine, a printer, or the like is a so-called cut sheet, and in the sheet manufacturing process, a gap is formed along the blending direction of the sheet fibers. It is widely known that there is a close correlation between the direction of the gap and the ease of folding the sheet.

  20A and 20B are schematic diagrams showing the relationship between the sheet gap direction and the sheet crease direction. In the figure, W indicates the blending direction of the sheet fibers, that is, the gap direction. FIG. 20A shows a case where the sheet gap direction is orthogonal to the sheet crease direction, and FIG. 20B shows a case where the gap direction and the crease direction are parallel to each other.

  When the sheet gap direction is orthogonal to the sheet crease direction (FIG. 20 (a)), the restoring force of the sheet fiber acts in a direction to open the sheet, so that the sheet is difficult to crease, resulting in bookbinding. The quality will drop.

  On the other hand, when the sheet gap direction is parallel to the sheet crease direction (FIG. 20 (b)), the opening force of the sheet bundle is hardly affected by the sheet fiber, so the sheet is easy to crease, and the bookbinding quality. Goes up. For example, even for the same paper type (basis weight) and the same number of sheet bundles, if the relationship between the sheet crevice direction and the sheet crease direction is different, the ease of crease on the sheet will be different, and the appearance of the sheet bundle will be different. There will be a difference in binding quality.

  In the apparatus described in Patent Document 2, the folding mode is only switched between the first folding and the second folding according to the number of sheets. Therefore, even when the sheet gap direction is parallel to the crease direction and sufficient folding quality is obtained by one-folding, the double-folding mode is selected and bookbinding takes time. On the other hand, the sheet crease direction is orthogonal to the crease direction, and the fold once mode is selected according to the number of sheets even when fold twice is necessary to make a sufficient crease. The folding quality was insufficient.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to control the number of folding operations for folding a sheet based on information on the sheet crease direction with respect to the sheet crease direction, thereby improving the sheet fold quality and shortening the binding time. An object of the present invention is to provide an image forming apparatus provided with a processing device.

  The present invention has been made in view of the above-described circumstances, and includes an image forming unit that forms an image on a sheet, a sheet information input unit that inputs information on a sheet on which an image is formed, and a sheet on which an image is formed. An image forming apparatus comprising: a sheet processing apparatus that includes: a folding unit that performs a folding process on the sheet; and a control unit that controls the folding unit. Folding operation by the folding unit when the sheet gap direction is perpendicular to the sheet crease direction according to the gap direction information which is the blend direction of the sheet fibers of the sheet input from the sheet information input unit The number of times is controlled so as to be larger than the number of folding operations when the score direction of the sheet is parallel to the fold direction of the sheet.

  In the present invention, since the optimum bookbinding conditions are set based on the information on the sheet gap direction with respect to the sheet crease direction, it is possible to efficiently improve the bookbinding quality.

Main sectional view of an image forming apparatus to which a sheet processing apparatus according to the present invention is applicable FIG. 1 is a diagram of an apparatus for detecting a gap direction of a sheet according to the present invention Illustration of calibration curve for detection using terahertz waves Table of folding mode switching selection means according to the present invention Main sectional view of sheet processing apparatus according to the present invention Similarly, a front view showing the drive unit of the conveyance system of the sheet processing apparatus Similarly, the front view which shows the width alignment part of a sheet processing apparatus, and a sheet positioning member Similarly, a front view of a protruding unit portion and a folding roller portion of the sheet processing apparatus Similarly, a top view of the protruding unit portion and the folding roller portion of the sheet processing apparatus Similarly, the main dimensions of the sheet positioning part of the sheet processing device Similarly, a block diagram related to the control of the sheet processing apparatus Similarly, the main flowchart in the bookbinding mode of the sheet processing apparatus Similarly, a flowchart related to the basic operation of the sheet processing apparatus. Similarly, a flowchart related to the basic operation of the sheet processing apparatus. Similarly, a flowchart for controlling the switching solenoid. Similarly, flowchart in stack mode Similarly, a flowchart related to the control of the width adjusting mechanism. Similarly, a flowchart for controlling the folding operation of the bookbinding unit. Similarly, a flowchart relating to the control of the double folding operation. Schematic diagram showing the relationship between the crease direction and the sheet gap direction

Embodiments of the present invention will be described below with reference to the drawings.
First, an example of an image forming apparatus to which the sheet processing apparatus according to the present invention can be applied will be described with reference to FIG.

  As shown in FIG. 1, reference numeral 1000 denotes a digital copying machine as an image forming apparatus. The digital copying machine 1000 includes an image forming apparatus main body 1 and a finisher 2 (bookbinding apparatus) that is a sheet processing apparatus. The image forming apparatus main body 1 includes a printer unit 103, a reading unit 102 disposed on the upper surface of the printer unit 103, and a document feeding device 101 that sends a document to the reading unit 102.

  A reading unit 102 that reads an image of a document includes a scanner unit 904, mirrors 905 to 907, a lens 908, an image sensor 909, and the like. When reading the document D by the reading unit 102, first, the document D is set on the document tray 900 a of the document feeder 101. At this time, it is assumed that the document D is set with the surface on which the image is formed on the document tray 900a facing upward.

  Next, after the originals D set in this way are conveyed one by one from the top page in order to the left (in the direction of the arrow in the figure) by the original feeder 101, the original D is left on the platen glass 902 through a curved path. The paper is conveyed from the right direction to the right direction, and then discharged onto the paper discharge tray 912.

  Thus, when reading the image of the document being conveyed by the document feeder 101, the scanner unit 904 is held in a predetermined position, and the document D is placed on the scanner unit 904 from left to right. The document D is read.

  In this reading process, when passing through the platen glass 902, the document D is irradiated with light by the lamp 903 of the scanner unit 904, and the reflected light is applied to the image sensor 909 via the mirrors 905 to 907 and the lens 908. Try to guide. Note that the image data of the original read for each line by the image sensor 909 is sent to the exposure device 910.

  On the other hand, it is also possible to perform document reading processing by temporarily stopping the document D conveyed by the document feeder 101 on the platen glass 902 and moving the scanner unit 904 from left to right in this state. Further, when reading a document without using the document feeding device 101, the user lifts the document feeding device 101, sets the document on the platen glass 902, and then performs a document reading process. .

  Further, in the printer unit 103 that forms an image on a sheet, a sheet feeding unit 9002 that feeds the sheet P stored in the cassettes 914 and 915 and an image on the sheet P fed by the sheet feeding unit 9002. The image forming unit 9003 and the like are formed.

  Here, the image forming unit 9003 includes a photosensitive drum 911, a developing unit 913, a transfer charging unit 916, and the like, and laser light from the exposure device 910 is irradiated onto the photosensitive drum 911 during image formation. As a result, a latent image is formed on the photosensitive drum 911. The latent image is visualized as a toner image by the developing unit 913. A fixing unit 917, a discharge roller 104, and the like are disposed on the downstream side of the image forming unit 9003.

  Reference numeral 400 denotes an operation display device provided on the upper surface of the image forming apparatus main body 1. The operation display device 400 displays a plurality of keys for setting various functions related to image formation and information indicating a setting state. It has a display unit and the like.

Next, an image forming operation of the image forming apparatus main body 1 having such a configuration will be described.
First, as described above, the image data of the document D read by the image sensor 909 of the reading unit 102 is sent to the exposure apparatus 910 after being subjected to predetermined image processing. Thereafter, the exposure apparatus 910 outputs a laser beam corresponding to the image signal.

The laser light is irradiated onto the photosensitive drum 411 while being scanned by the polygon mirror 910a, whereby an electrostatic latent image corresponding to the scanned laser light is formed on the photosensitive drum 911. Next, the electrostatic latent image formed on the photosensitive drum 911 is developed by the developing unit 413 and visualized as a toner image.
On the other hand, the sheet P fed from any of the cassettes 914, 915, the manual sheet feeding unit 925, and the double-sided conveyance path 924 is detected by the gap detection sensor 300 as the gap direction detection device. The Although the details of the perforation detection sensor 300 will be described later, it is arranged downstream from the point where the paper feed paths from the paper feed stages 914, 915 and 925 merge. Thereafter, the toner image on the photosensitive drum 911 visualized in the transfer portion is transferred to the sheet P by being transferred to a transfer portion constituted by the photosensitive drum 911 and the transfer charger 916. The sheet P after the transfer is subjected to a fixing process by a fixing unit 917. Next, the sheet P thus subjected to the fixing process is discharged to the finisher 2 by the discharge roller 104.

  For example, when the sheet P is discharged from the image forming apparatus main body 1 with the surface on which the toner image is formed facing down (face down), the sheet P that has passed through the fixing unit 917 is once guided to the path 922 by the flapper 921. Like that. Thereafter, after the trailing edge of the sheet passes through the flapper 921, the sheet is switched back, conveyed to the discharge roller 104 by the flapper 921, and discharged from the image forming apparatus main body 1.

  As a result, the sheet P is discharged from the image forming apparatus main body 1 with the surface on which the toner image is formed facing downward. In addition, when image forming processing is performed in order from the first page by discharging the sheet P face down by such so-called reverse paper discharging, for example, when the image forming processing is performed using the document feeder 101. The page order can be aligned. Also, the page order can be made uniform when image forming processing is performed on image data from a computer.

  Further, when image formation is performed on a hard sheet P such as an OHP sheet conveyed from the manual sheet feeding unit 925, the surface on which the toner image is formed is faced upward without introducing the sheet P to the pass 922 (face The sheet is discharged from the image forming apparatus main body 1 by the discharge roller 104.

  Further, when image forming processing is performed on both sides of the sheet P, the sheet P is guided straight from the fixing unit 917 toward the discharge roller 104. Then, immediately after the trailing edge of the sheet P passes through the flapper 921, the sheet P is switched back so as to be guided from the path 922 to the duplex conveyance path 924 by the flapper 921.

  By the way, the sheet P discharged from the image forming apparatus main body 1 is then taken into a finisher 2 (bookbinding apparatus) which is a sheet processing apparatus that binds and folds a sheet on which an image has been formed. It has become.

FIG. 5 is a diagram of the sheet processing apparatus showing details of the features of the present invention.
Reference numeral 3 denotes an inlet flapper which switches between the bookbinding mode and the stack mode by turning on / off the inlet solenoid 3d (FIG. 6).

[Stack Mode]
Reference numeral 4 denotes a paper discharge path. A stacker discharge roller 5 and a stacker discharge roller 6 are disposed on the downstream side of the paper discharge path 4. Reference numeral 7 denotes a stacker tray on which the sheets discharged from the stacker discharge roller pairs 5 and 6 are stacked. When the stack mode is selected, the entrance flapper 3 is switched, and the sheet P discharged from the image forming apparatus main body 1 is conveyed to the paper discharge path 4.

[Bookbinding mode]
Reference numerals 11 and 12 denote guides, and reference numeral 13 denotes a conveying roller. A conveying roller 14 is disposed on the opposite surface. Reference numerals 15 and 16 are upper and lower switching flappers. As shown in FIG. 6, the upper and lower 15d and 16d on the switching flapper are turned on / off by an electrical signal, so that the two positions indicated by the one-dot chain line and the solid line shown in FIG. It is configured to take. 17a and 22a are half-moon shaped meniscus rollers, and elastic members 17d and 22d are arranged on the opposing surfaces and are urged by the half-moon rollers 17a and 22a, respectively.

  A stapler 18 has a plate-shaped staple and a drive motor. The stapler 18 is configured to be swingable about a rotation shaft 18a. Reference numeral 19 denotes an anvil, and the stapler 18 swings around the rotation shaft 18a to guide the tip of the U-shaped staple needle by the anvil 19 and to crush the end of the staple needle into a glass shape.

  Reference numerals 20 and 21 denote guides arranged on the downstream side of the stapler 18. Reference numerals 24a and 24b denote width adjusting members that are pressed from both sides of the sheet to align the sheets (FIG. 7). Reference numeral 23 denotes a sheet positioning member (sheet storage means) that receives the leading end of the sheet that has entered between the guides 20 and 21 and temporarily stores and stores the sheet. The sheet positioning member 23 is configured to be movable between the guides 20 and 21 in the direction of the arrow in the figure. A sheet leading end detection sensor 33 that detects the leading end of the sheet is disposed on the sheet positioning member 23.

  Reference numeral 25 denotes a protrusion unit, which is retracted outside the guide surfaces of the guides 12 and 21 before the sheet folding operation. Reference numerals 26 and 27 denote a pair of folding rollers (sheet conveying means) as folding means, which are pressed against each other. The sheet is pushed into the nip portion of the folding rollers 26 and 27 by the pushing unit 25 and conveyed while being folded in two.

  The folding rollers 26 and 27 can be rotated forward and backward, and at least one sheet is passed through the nip portion of the pair of folding rollers twice or a plurality of times depending on the sheet type (basis weight), the number of sheets, and the like. Multiple folding operations are possible. The folding rollers 26 and 27 are controlled by a control unit (FIG. 1) according to a first mode in which a sheet as a folding condition is folded once and a second mode in which the sheet is folded twice based on an output signal of the sheet number counting unit CNT1. 11). Based on the output signal of the folding operation mode selection means 223, the folding rollers 26 and 27 perform a folding operation either in the first folding mode or in the second folding mode. Controlled.

  Further, the sheet movement amount by the folding rollers 26 and 27 is measured by the sheet movement amount measuring unit 222. When the sheet is folded twice, the folding operation is controlled so that the sheet is transported in the opposite direction to the ejecting direction after being moved by a certain amount in the ejecting direction, and is transported again in the ejecting direction.

  Reference numeral 28 denotes a paper discharge guide for guiding the folded sheet bundle discharged from the folding rollers 26 and 27 between the nips of the folded sheet bundle discharging roller 30 and the roller 31. A paper discharge sensor 29 detects the leading edge and the trailing edge of the folded sheet bundle. Reference numeral 32 denotes a discharge tray on which folded sheet bundles are stacked.

[Width alignment mechanism]
The width adjusting mechanism will be described with reference to FIG.
Reference numerals 24a and 24b are width-adjusting members disposed in the front-rear direction, each having a wall surface that is parallel to the sheet conveyance direction and perpendicular to both sides of the sheet, forms a rack portion in the center portion, and has a pinion gear in each rack. 24c is engaged. Reference numeral 24d denotes a width adjusting motor constituted by a stepping motor, and a pinion gear 24c is fixed on the output shaft. Reference numeral 24e denotes a width-shifting HP sensor, which includes a photo interrupter. The width adjusting HP sensor 24e detects a flag formed in a part of the width adjusting member 24a when the width adjusting members 24a and 24b are retracted about 5 to 10 mm outside the maximum sheet width that can be aligned. It is arranged at the position to do.

[Sheet positioning drive mechanism]
The sheet positioning drive mechanism will be described with reference to FIGS.
A sheet positioning member 23 receives the leading edge of the sheet that has entered between the guides 20 and 21. A plurality of rollers 23 a are rotatably attached to both ends of the sheet positioning member 23, and slide in grooves formed in the frame 8. Racks are formed at both ends of the sheet positioning member 23, and the racks are engaged with two left and right pinion gears 23b. A shaft 23c is provided at the center of the pinion gear 23b and transmits driving to the left and right pinion gears. A sheet abutting gear 23d is fixed to one end of the shaft 23c.

  Reference numeral 61 denotes a sheet positioning motor, which is a stepping motor. A gear 62 is fixed on the output shaft of the sheet positioning motor 61 and is engaged with the stopper gear 23d.

  A flag is formed on a part of the sheet positioning member 23, and the sheet positioning HP sensor 63 detects when the sheet positioning member 23 reaches the home position. Reference numeral 33 denotes a sheet leading edge detection sensor which detects that the conveyed sheet has reached the stopper leading edge.

[Folding drive mechanism]
Details of the folding drive mechanism will be described with reference to FIGS.
Reference numeral 64 denotes a folding motor, and a pulley 65 is fixed on the output shaft. Reference numeral 67 denotes an idler gear pulley, which is composed of two rows of pulleys and gears on the same axis, of which one row of pulleys is wound with a timing belt 66 between the pulley 65. Reference numerals 68 and 69 denote folding gears fixed to the folding rollers 26 and 27 and engaged with each other. One end of the folding gear 68 is engaged with the gear portion of the idler gear pulley 67.

  Reference numeral 25 denotes a protruding unit. Reference numeral 25a denotes a protruding plate, which is made of a stainless material having a plate thickness of about 0.5 mm in order to move into the nip between the folding rollers 26 and 27. The protruding plate 25a is held by holders 25d and 25b, shafts 25c and 25e are fixed to the holder 25b, and a roller is rotatably attached to the outer periphery thereof. The roller is formed on the frame 8. Slide in the groove 8a. Reference numeral 73 denotes a gear having a shaft 72 on one side surface, and the gear 73 is engaged with an idler gear 75. The idler gear 75 is fixed to a shaft 76, and a folding clutch (projecting clutch) 74a made of an electromagnetic clutch is disposed on the shaft 76, and the pulley 74 on the folding clutch 74a is turned on / off by the folding clutch 74a. Controls the transmission of rotation to the shaft 76. A timing belt 70 is wound around the outer periphery of the pulley 74, and the other side of the timing belt 70 is wound around a pulley portion of an idler gear pulley 67. The gear 75 fixed to the shaft 76 meshes with the gear 73 fixed to the shaft 73a, and a flag 81 is fixed on the shaft 73a and has a notch in a part thereof. Yes. A protruding plate HP sensor 82 is disposed at a position where the notch of the flag 81 is detected, and the protruding plate 25a is disposed at a position where the protruding plate 25a is depressed most than the conveying surfaces of the guides 12 and 21.

  The rotation of the folding motor 64 is transmitted from the pulley 65 to the idler gear pulley 67 through the timing belt 66. The rotation of the idler gear pulley 67 is transmitted from the folding gear 68 to the folding gear 69, and the folding rollers 26 and 27 are driven. On the other hand, the rotation of the idler gear pulley 67 is transmitted to the pulley 74 on the folding clutch 74 a via the timing belt 70. When the folding clutch 74a is turned on / off, the rotation of the pulley 74 is transmitted to the shaft 76, the idler gear 75 rotates, and the rotation causes the gear 73 to rotate, and the shaft 72 moves circularly about the shaft 73a. The link 71 whose one end is fitted to the shaft 72 is fitted to the shaft 25c at the other end. The shaft 25c is fixed to the projecting unit 25, and further, a roller is inserted into the groove 8a of the frame 8 together with the shaft 25e. Therefore, the shaft 25c performs a linear motion along the groove 8a. By this linear movement, the protruding plate 25a provided in the protruding unit 25 can move linearly between the protruding position and the retracted position.

[Stacker ejector drive mechanism]
The drive mechanism of the stacker discharge roller 5 will be described with reference to FIG.
A shaft 5a to which the stacker discharge roller 5 is fixed is provided at the upper part of the finisher 2, and a pulley 98 is fixed to the shaft 5a. Reference numeral 95 denotes a stack discharge motor, and a pulley 96 is fixed on its output shaft.

  A timing belt 97 is wound around the pulley 96 and the pulley 98, and the rotation of the stack discharge motor 95 is transmitted from the pulley 96 to the pulley 98 via the timing belt 97, and further to the stacker discharge via the shaft 5a. The roller 5 is driven. The stack discharge motor 95 is constituted by a stepping motor, and the peripheral speed of the stacker discharge roller 5 is set faster than the peripheral speed of the discharge roller 104 of the image forming apparatus main body 1. The conveyance force of the discharge roller 104 is set higher than the conveyance force of the stacker discharge roller pair 5 and 6. Therefore, while the paper is nipped and conveyed by the discharge roller 104, if the slip occurs between the stacker discharge roller pair 5 and 6 and the discharge roller 104 is removed, the paper is conveyed by the conveyance force of the stacker discharge roller pair 5 and 6.

FIG. 11 is a block diagram related to the control of the sheet processing apparatus in the present embodiment.
Reference numeral 150 denotes a control device (hereinafter referred to as a CPU) as a control means provided in the finisher 2, and the CPU 150 serves as a core to constitute an I / O.

The following are connected to the input side of the CPU 150. An inlet sensor 83 that detects that the copy sheet discharged from the image forming apparatus main body 1 has entered the finisher 2; a sheet leading edge detection sensor 33 that detects that the sheet has arrived at a predetermined position of the finisher 2; A paper discharge sensor 29 for detecting that the paper has been discharged to the paper tray 32; a folding roller CLK sensor 216 for controlling the speed of the folding rollers 26 and 27; a roller guide HP sensor 207 for detecting the home position of the roller guide 201; Sheet positioning plate HP sensor 63 for detecting the home position of the member 23; alignment HP sensor 24e for detecting the home position of the alignment plate for aligning sheets; protrusion plate HP sensor 82 for detecting the position of the protrusion plate 25a; , 22a detects the rotational position of 22a 217; Loading limit sensor 218 for detecting tray overloading; Door switch 219 for detecting opening / closing of jamming door; Door switch 220 for detecting opening / closing of door for staple replacement processing, etc .; Staple unit needle Staple needle absence sensor 212 for detecting the presence or absence of staples; Staple HP sensor (A) 211 for detecting the stapling standby position of the staple portion; Staple needle absence sensor 215 for detecting the presence or absence of staples in the staple unit; A staple HP sensor (B) 214 for detecting a hitting standby position.
Further, on the input side of the CPU 150, there are a sheet bundle movement amount measuring means 222 for measuring the movement amount of the sheet moved from the sheet positioning member 23, and a folding operation mode selection means 223 for selecting a sheet folding operation. It is connected. The folding operation mode selection unit 223 changes the sheet folding operation mode (first folding mode, second folding mode) based on the gap information and sheet information.

  The following is connected to the output side of the CPU 150. A conveyance motor 51 for conveying a copy sheet in the finisher 2 via a driver D1; a roller guide motor 205 for moving a roller guide plate for guiding the copy sheet in the finisher 2 from a folding roller via a driver D2; A sheet positioning motor 61 for holding the copy paper in the finisher 2 at a designated position via D3; an alignment motor 24d for aligning the copy sheet in the finisher 2 via a driver D4; via a driver D5 A folding / thrusting motor 64 for folding the sheet in the finisher 2 and a folding clutch 74a for operating the ejection plate 25a via the driver D6; operating the flapper 15 for switching the transport path in the finisher 2 via the driver D7 Let Flappaso A flapper solenoid 16d that operates a flapper 16 that switches a conveyance path in the finisher 2 via a driver D8; a staple motor (A) 210 that drives a staple unit 18 for binding a bundle of sheets via a driver D9; A staple motor (B) 213 that drives the staple unit 18 for binding a bundle of sheets via the driver D10.

  Reference numeral 152 denotes a read-only memory (ROM) that stores in advance a control procedure executed by the CPU 150. A random access memory (RAM) 153 is a storage unit that stores various data such as operation data of the CPU 150 and control data received from the control device 151 (hereinafter referred to as CPU) on the image forming apparatus main body 1 side. In the present embodiment, the configuration has been described in which the CPU 150 as the control unit is provided in the finisher 2 and controls the finisher 2 as a whole. However, the CPU 150 may be provided integrally with the CPU 151 on the image forming apparatus main body 1 side. Good.

[Folding operation mode selection means]
Here, the configuration of the folding operation mode selection means in FIG. 11 will be described.
When a document is set on the document feeder 101 in FIG. 1 and the start button of the operation display device 400 is pressed, document feeding is started and a document image is read by the reading unit 102. In the reading process, image information, sheet size information, and the number of sheets can be determined from various sensors as sheet information providing means, and these data are stored in the CPU 151 on the image forming apparatus main body 1 side. It is determined whether it is fed. The basis weights of the sheets set in the respective paper feed stages 914, 915, and 925 are input in advance by the operator from the operation display device 400 as sheet information input means, and this information is stored in the CPU 151. It is. Therefore, sheet information such as the number of sheets to be fed, basis weight, size, and the like is given when the paper feed stage is determined. When a paper feed signal is output from the CPU 151, sheet feeding from the corresponding paper feed stage starts. When the sheet passes through the gap detection sensor 300 (300 ′ when provided on the finisher 2 side), the sheet gap information is added to the above-described sheet information. These data are transmitted from the CPU 151 on the image forming apparatus main body 1 side to the CPU 150 on the finisher 2 side (directly from 300 ′, the broken line portion in FIG. 11). The CPU 150 collates the received sheet information such as the number of sheets, basis weight, and the like, and each data in the sheet gap direction with the table shown in FIG. The table shown in FIG. 4 is created based on a combination of the sheet gap direction, the number of sheets, and the basis weight. As a result, the folding operation mode selection means 223 (FIG. 11) selects and determines whether the folding operation mode as the folding condition is the one-fold mode or the two-fold mode.

  Here, a table on which the folding operation mode is selected by the folding operation mode selection means will be described with reference to FIG. In the present embodiment, the sheet fold direction is based on the sheet conveying direction. That is, since the sheet is folded while being conveyed by a folding roller (sheet conveying means) as a folding means, the direction perpendicular to the sheet conveying direction is the fold direction. Therefore, the sheet gap direction information in the present embodiment is a gap direction with respect to the sheet conveyance direction.

  FIG. 4 is a diagram showing the switching criteria of the folding operation mode based on the number of sheets, the sheet basis weight, and the sheet gap direction. A line indicated by I is a reference number of folding mode switching when the sheet clearance direction is orthogonal to the sheet conveying direction, that is, when the sheet clearance direction and the crease direction are parallel, so that a crease is easily formed. On the other hand, the line indicated by J is the reference number of folding operation mode switching when the sheet clearance direction is parallel to the sheet conveyance direction, that is, when the sheet clearance direction and the crease direction are orthogonal to each other and it is difficult to crease.

For example, when the number of sheets is 8 and the sheet basis weight is 80 g / m ² (point indicated by ● in FIG. 4) and the sheet clearance direction is perpendicular to the crease direction, the switching boundary line indicated by J is The second folding mode is selected as the folding operation mode. On the other hand, even if the same sheet number is 8 and the sheet basis weight is 80 g / m ² , when the sheet clearance direction is parallel to the crease direction, the switching boundary indicated by I is selected, and the folding operation mode is The once folding mode is selected. The number of folding operations is not limited to one-fold and two-fold, and can be set to any number of times. In order to obtain a good-quality bookbinding that does not open the sheet bundle after the folding process, an appropriate number of folding operations is set, but the number of folding operations when the sheet clearance direction and the folding direction are orthogonal to each other is parallel. Is set more than the number of folding operations.

  In the present embodiment, the folding condition that is switched based on the sheet gap direction, the number of sheets, and the sheet basis weight is described as the one-fold mode and the two-fold mode. The present invention is also effective. For example, the same effect can be obtained even in a sheet processing apparatus having a folding condition for switching the folding pressure between the folding rollers 26 and 27 as folding means based on the sheet gap direction, the number of sheets, and the sheet basis weight. it can.

[Acquisition principle of sheet gap information]
Based on FIG. 1 thru | or 3, the acquisition principle of the clearance information of the sheet | seat which is the main characteristics of this invention is demonstrated. Reference numeral 300 denotes a gap direction detection device (gap detection sensor), which obtains sheet gap information by irradiating a sheet with an electromagnetic wave beam and detecting the blend direction of the fibers of the sheet using transmitted electromagnetic waves and reflected electromagnetic waves. To do.

  As the gap direction detection sensor, a sensor that detects high-frequency electromagnetic waves (terahertz waves; hereinafter simply referred to as THz waves) including frequencies in the range of 30 GHz to 30 THz is used. The sheet being conveyed is irradiated with THz waves, and at least one of a transmitted electromagnetic wave transmitted through the sheet and a reflected electromagnetic wave reflected from the sheet is detected, and the clearance direction of the sheet is detected in a non-contact manner. Since the gap (fiber arrangement) direction of the sheet gives polarization dispersion to the propagation of the THz wave, the sheet is obtained from the intensity waveform that is an output signal of at least one of the transmitted electromagnetic wave polarized as the polarized wave and the reflected electromagnetic wave. It is possible to determine the direction of the gap.

  In FIG. 2, 301 is a THz wave light source as irradiation means, 302 is a THz wave detector as detection means, 303 is a polarizer, 304 is an irradiation electromagnetic wave, and 305 is a transmission electromagnetic wave. When a high-frequency irradiation electromagnetic wave 304 having a frequency band of 30 GHz to 30 THz is irradiated from the THz wave light source 301, the irradiation electromagnetic wave 304 is polarized by the polarizer 303 and polarized to a polarization parallel to the transport direction 306. The polarized transmitted electromagnetic wave 305 passes through the sheet S being conveyed and reaches a THz wave detector disposed opposite to the THz wave light source 301, and as shown in FIG. The electromagnetic wave intensity corresponding to the gap direction is detected along.

  Since the irradiation electromagnetic wave 304 is polarized in a polarization parallel to the conveyance direction 306, the transmitted electromagnetic wave intensity becomes strong when the gap direction coincides with the conveyance direction, that is, parallel to the conveyance direction. The transmitted electromagnetic wave intensity becomes weak when orthogonal to (FIG. 3). Here, if the gap direction (sheet fiber blending direction) has an angle with respect to the conveying direction, that is, if the signal change is small, the signal of a certain area is integrated and obtained as an average value. It is possible to determine the average gap direction.

  In the present embodiment, an example is shown in which the gap detection sensor 300 is arranged on the upstream side of the image forming unit 9003 in the image forming apparatus main body 1 as shown in FIG. However, if the gap detection sensor 300 ′ is provided in the finisher 2 as shown in FIG. 5 as long as it is in the conveyance path from the sheet feeding unit 9002 to the bookbinding unit of the finisher 2, the same effect can be obtained. Needless to say. Furthermore, since the cut direction is known in the manufacturing process of the cut sheet, information on the cut direction may be written on the package at the time of product shipment. This information may be input in advance from the operation display device 400 as sheet information input means of the image forming apparatus main body 1.

[Description of operation]
Control of the sheet processing apparatus in the present embodiment will be described with reference to FIGS.
FIG. 12 shows the main routine. First, the mode information of the bookbinding mode or the stack mode is received from the image forming apparatus main body 1 to which the finisher 2 is connected. Further, it receives the length information L, the width information W, the number information N, and the number information M of sheets discharged from the image forming apparatus main body 1 and starts the operation of the finisher 2 in response to a start signal.

  Thereafter, the mode information is confirmed (S101), and if it is not the bookbinding mode, the process proceeds to the stack mode (S105). If it is in the bookbinding mode here, it is confirmed whether the length L and the width W are sizes that can be bound (S102, S103), and if the sizes are out of order, the process proceeds to the stack mode (S105). If it is determined that the sheet size is the bookbinding size, the process proceeds to S104, and a bookbinding operation mode sequence is performed.

A basic bookbinding operation mode sequence will be described with reference to FIGS.
First, if the sheet is a bookbinding size according to the size information, the process proceeds to S201, and the entrance solenoid 3d is turned on to open the path to the bookbinding mode.

  Then, the conveyance motor 51 is turned on to drive the conveyance rollers 13 and 14 and the half-moon rollers 17a and 22a so that the sheet can be conveyed (S202).

  Next, the process proceeds to S203 to control the upper and lower 15d, 16d of the switching solenoid. The forward movement of the width adjusting motor 24d is such that the distance P between the width adjusting members 24a and 24b is P = W + A (where A is a gap between the sheet size and the width adjusting member, which is usually about 10 mm). Is turned on (S204).

  Then, the width adjusting motor 24d is continuously driven until the distance P between the width adjusting members 24a and 24b becomes P = W + A (S205). When the distance P between the width adjusting members 24a and 24b becomes P = W + A, the forward rotation of the width adjusting motor 24d is turned off (S206).

  Next, the sheet positioning motor 23 turns on the forward rotation of the sheet positioning motor 61 to the position where l = L / 2 downstream from the staple point 19a of the stapler 18 (S207, S208). When the sheet positioning plate 23 reaches l = L / 2 downstream from the staple point 19a of the stapler 18 (FIG. 10), the forward rotation of the sheet positioning motor 61 is stopped (S209). At the same time, in order to move the roller guide 201 so that the sheets conveyed to the folding rollers 26 and 27 do not collide, the forward rotation of the roller guide motor 205 is turned on to a predetermined position (S210, S211). If the roller guide 201 has moved from the home position to the predetermined position, the process proceeds to S212 and the forward rotation of the roller guide motor 205 is turned off. Then, the sheet number counter CNT1 is set to 0 (S213), and the signal from the inlet sensor 83 is confirmed (S214).

  When the entrance sensor 83 is switched from ON to OFF (S215), a time for adjusting the width of the sheet is adjusted so that the sheet is aligned after t1 from the sheet size information, the time when the leading edge of the sheet hits the sheet positioning plate 23 (S216). ). The process waits for the width adjusting timer to time up (S217). If the time has increased, the process proceeds to S218 to clear the width adjusting timer.

  Thereafter, in order to move the width adjusting members 24a and 24b to a position where P = W−B (B is an amount by which the width adjusting members 24a and 24b push the sheet, usually about 2 mm), the forward rotation of the width adjusting motor 24d is performed. Is turned on (S219). Then, the forward rotation of the width adjusting motor 24d is kept ON until a position where P = W−B (S220). If the width adjusting members 24a and 24b become P = WB, the normal rotation of the width adjusting motor 24d is turned off (S221).

  Subsequently, once the width is adjusted, the reverse rotation of the width adjusting motor 24d is turned on until the width adjusting members 24a and 24b become P = W + A in order to set the waiting state for the next sheet (S222). If the width adjusting members 24a and 24b become P = W + A in S223, the reverse rotation of the width adjusting motor 24d is turned OFF (S224).

The operations of S219 to S224 are performed in a short time when the half-moon rollers 17a and 22a are not in contact with the elastic members 17d and 22d on the opposing surface. Then, the sheet number counter CNT1 is incremented by 1 (S225), and the process is repeated until the planned number N is reached (S226). If the planned number of sheets can be confirmed in S226, the conveyance motor 51 is turned off (S227), and the conveyance of the sheet is stopped.
And the operation | movement which returns the width adjusting members 24a and 24b to the position of a home position is performed.

First, reverse rotation of the width adjusting motor 24d is turned on (S228), and the width adjusting members 24a and 24b are returned to the home position (S229). If it is detected in S229 that the width adjusting members 24a and 24b have returned to the home position, the process proceeds to S230, and the reverse rotation of the width adjusting motor 24d is turned OFF.
A stapling operation (two-point binding) is performed (S231 to S236), and a plurality of sheets are made into a sheet bundle. The staple motor (A) 210 is turned on (S231) and rotated until the staple unit 18 returns to the home position (S232). When the staple HP sensor (A) 211 detects the return of the staple unit 18 to the home position, the staple motor (A) 210 is turned off (S233). Next, the staple motor (B) 213 is turned on (S234) and rotated until the staple unit 18 returns to the home position (S235). When the staple HP sensor (B) 214 detects the return of the staple unit 18 to the home position, the staple motor (B) 213 is turned OFF (S236).

  To prepare for the folding operation, the reverse rotation of the roller guide motor 205 is turned on to move the roller guide 201 to the home position (S237). The reverse rotation of the roller guide motor 205 is kept ON until the roller guide 201 returns to the home position (S238). If it is detected in S238 that the roller guide 201 has returned to the home position, the process proceeds to S239 and the reverse rotation of the roller guide motor is turned OFF (S239). Then, reverse rotation of the sheet positioning motor 61 is turned on so that the sheet positioning plate 23 becomes l = (L / 2) + C (C is the distance between the stapler position 19a and the folding position) downstream of the stapler position 19a (S240). ). Then, the reverse rotation of the sheet positioning motor 61 is kept ON until the sheet positioning plate 23 moves to a predetermined position (S241). If it is detected in S241 that the sheet positioning plate 23 has moved to a predetermined position, the process proceeds to S242, and the reverse rotation of the sheet positioning motor is turned OFF.

  The conveyance motor 51 is driven again to convey the sheet until it hits the sheet positioning plate 23 (S243). The conveyance motor 51 is continuously driven until the sheet is conveyed to a predetermined position (S244). If it is detected in S244 that the leading edge of the sheet has hit the sheet positioning plate 23, the transport motor 51 is turned off (S245), and the inlet solenoid and the switching solenoid are turned off (S246, S247).

  Next, the folding clutch 74a is turned on (S248), and the folding motor 64 is turned on (S249). By turning on the folding clutch 74 a, the protruding plate 25 starts to protrude and guides the sheet to the folding rollers 26 and 27.

  The folding clutch is kept ON until the protruding plate HP sensor 82 detects that the protruding plate 25a has reciprocated once (S250). If the protruding plate HP sensor 82 detects that the protruding plate 25a has reciprocated once in S250, the folding clutch 74a is turned off (S251).

  The folding motor 64 is turned on until the discharge sensor 29 detects the trailing end of the folded sheet bundle (S252). If the paper discharge sensor 29 detects the trailing edge of the sheet bundle in S252, the folding motor 64 is turned off (S253). Then, the copy counter CNT2 is incremented by 1 (S254). If the copy counter CNT2 has not reached the planned number of copies M in S255, the process returns to S201. If the copy counter CNT2 has reached the predetermined number of copies M, the copy counter CNT2 is cleared in S255 ′. Exit.

Next, switching solenoid control will be described with reference to FIG.
If half of the paper size L, L / 2, is larger than the length k1 (FIG. 10) from the staple point 19a to the switching flapper 15 along the guides 11 and 12, and the sum (k1 + D) of the constant D (S256). Then, the switching solenoids 15d and 16d are kept OFF, and the process ends. (Here, the constant D indicates the position of the trailing edge of the stacked sheets when the sheet positioning plate 23 is at an appropriate position.) This constant D indicates that the next sheet entering the stacked sheets is stacked. This is the amount necessary to be stacked at the top without being squeezed into the stacked sheets.
When L / 2 is larger than (k1 + D), L / 2 and (k2 + D) are further compared (S257). (K2 is the distance to the switching flapper 16 between the guides 11 and 12, similar to k1. , D is the same length as described above).
If it is determined that L / 2 is larger than (k2 + D) (S257), the upper switching solenoid 15d is turned ON (S258), and the sheet is guided by the lower switching solenoid 16d.
If it is determined that L / 2 is smaller than (k2 + D) (S257), the upper switching solenoid 15d and the lower switching solenoid 16d are turned ON (S259), and the sheets are stacked along the guide 11.

Next, details of the stack mode will be described with reference to FIG.
The sheet number counter CNT1 is set to 0 (S300). Then, the stack discharge motor 95 is turned on (S301), and the stacker discharge roller 5 is rotated.

  It is confirmed whether the stack sensor 84 is ON (S302), and if it is ON, it is further confirmed that the stack sensor 84 is OFF (S303). If the stack sensor 84 is turned off, the sheet number counter CNT1 is incremented by 1 (S304), and it is confirmed whether the sheet number counter CNT1 matches the scheduled number N (S305). The sheet number counter CNT1 is smaller than N. Return to before S302. If the sheet number counter CNT1 becomes N, the sheet trailing edge is conveyed by a predetermined amount passing through the stack sensor 84 (S307), and then the stack discharge motor 95 is turned off (S309).

A bookbinding operation mode sequence according to the embodiment of the present invention will be described with reference to FIGS.
In FIG. 17, first, if the booklet size is possible based on the size information, the process proceeds to S401, where the entrance solenoid 3d is turned on to open the path to the bookbinding mode. Then, the conveyance motor 51 is turned on to drive the conveyance rollers 13 and 14 and the half-moon rollers 17a and 22a so that the sheet can be conveyed (S402).

  Next, the process proceeds to S403 in order to control the upper and lower switching solenoids 15d and 16d. Then, the width adjusting motor 24d is rotated forward so that the distance P between the width adjusting members 24a and 24b becomes P = W + A (where A is a clearance between the sheet size and the width adjusting member, which is usually about 10 mm). Turns on (S404). Then, the width adjusting motor 24d is continuously driven until the distance P between the width adjusting members 24a and 24b becomes P = W + A (S405). When the distance P between the width adjusting members 24a and 24b becomes P = W + A, the forward rotation of the width adjusting motor 24d is turned off (S406).

  Next, forward rotation of the sheet positioning motor 61 is turned ON until the sheet positioning member 23 reaches a position where l = L / 2 downstream from the staple point 19a of the stapler 18 (S407, S408). If the sheet positioning member 23 reaches l = L / 2 downstream from the staple point 19a of the stapler 18, the forward rotation of the sheet positioning motor 61 is turned off (S409). At the same time, in order to move the roller guide 204d so that the conveyed sheet does not collide with the folding rollers 26 and 27, the forward rotation of the roller guide motor 205 is turned on to a predetermined position (S410, S411).

  If the roller guide 204d has moved from the home position to the predetermined position, the process proceeds to S412 to turn off the forward rotation of the roller guide motor 205. Then, the sheet number counter CNT1 is set to 0 (S413), and the signal of the inlet sensor 83 is confirmed (S414). When the entrance sensor 83 is turned from ON to OFF (S415), the time for the leading edge of the sheet to hit the sheet positioning member 23 and the width adjusting timer are set so that the sheets are aligned after t1 from the sheet size information (S416). The process waits for the width adjusting timer to time up (S417). If the time has increased, the process proceeds to S418 to clear the width adjusting timer.

  Thereafter, in order to move the width adjusting members 24a and 24b to a position where P = W−B (B is an amount by which the width adjusting members 24a and 24b push the sheet, usually about 2 mm), the width adjusting motor 24d is rotated forward. Turns on (S419). Then, the forward rotation of the width adjusting motor 24d is kept on until the position where P = W−B (S420). If the width adjusting members 24a and 24b become P = W−B, the forward rotation of the width adjusting motor 24d is turned off (S421).

  Subsequently, once the width is adjusted, the reverse of the width adjusting motor 24d is turned on until the position of the width adjusting members 24a and 24b becomes P = W + A in order to set the waiting state for the next sheet (S422). If the position of the width adjusting members 24a and 24b becomes P = W + A in S423, the reverse rotation of the width adjusting motor 24d is turned OFF (S424).

  The operations from S419 to S424 are performed for a short time when the meniscus rollers 17a and 22a are not in contact with the elastic members 17d and 22d on the opposite surface. Then, the sheet number counter CNT1 is incremented by 1 (S425), and the process is repeated until the planned number of sheets is reached (S426). If the planned number of sheets can be confirmed in S426, the conveyance motor 51 is turned off (S427), and the conveyance of the sheet is stopped. And the operation | movement which returns the width adjusting members 24a and 24b to the position of a home position is performed.

  In FIG. 18, the reverse rotation of the width adjusting motor 24d is turned on (S427), and the width adjusting members 24a and 24b are returned to the home position (S428). If it is detected in S428 that the width adjusting members 24a and 24b have returned to the home position, the process proceeds to S429, the reverse rotation of the width adjusting motor 24d is turned OFF, and the process proceeds to S430 to turn off the transport motor 51.

  Next, a stapling operation (two-point binding) is performed (S431 to S436), and a plurality of sheets are made into a sheet bundle. The staple motor (A) 210 is turned on (S431) and rotated until the staple unit 18 returns to the home position (S432). When the staple HP sensor (A) 211 detects the return of the staple unit 18 to the home position, the staple motor (A) 210 is turned off (S433). Next, the staple motor (B) 213 is turned on (S434) and rotated until the staple unit 18 returns to the home position (S435). When the staple HP sensor (B) 214 detects the return of the staple unit 18 to the home position, the staple motor (B) 213 is turned off (S436).

  To prepare for the folding operation, the reverse rotation of the roller guide motor 205 is turned on to move the roller guide 201 to the home position (S437). The reverse rotation of the roller guide motor 205 is kept ON until the roller guide 201 returns to the home position (S438). If it is detected in S438 that the roller guide 201 has returned to the home position, the process proceeds to S439 and the reverse rotation of the roller guide motor 205 is turned OFF (S439). Then, reverse rotation of the sheet positioning motor 61 is turned on so that the sheet positioning member 23 becomes l = (L / 2) + C (C is the distance between the stapler position 19a and the folding position) downstream of the stapler position 19a. (S440). Then, the reverse rotation of the sheet positioning motor 61 is kept ON until the sheet positioning member 23 moves to a predetermined position (S441). If it is detected in S441 that the sheet positioning member 23 has moved to a predetermined position, the process proceeds to S442, and the reverse rotation of the sheet positioning motor 61 is turned OFF.

  The conveyance motor 51 is driven again to convey the sheet bundle until it abuts against the sheet positioning member 23 (S443). The conveyance motor 51 is continuously driven until the sheet bundle is conveyed to a predetermined position (S444). If it is detected in S444 that the leading end of the sheet bundle has hit the sheet positioning member 23, the transport motor 51 is turned off (S445), and the inlet solenoid 3d and the switching solenoids 15d and 16d are turned off (S446 and S447). ).

Next, the folding clutch 74a is turned on (S448), and the folding motor 64 is turned on (S449).
By turning on the folding clutch 74a, the protruding plate 25a starts to protrude and guides the sheet bundle to the folding rollers 26 and 27. The folding clutch 74a is kept on until the protruding plate HPa 82 detects that the protruding plate 25a has reciprocated once (S450). If the protruding plate HP sensor 82 detects that the protruding plate 25a has reciprocated once in S450, the folding clutch 74a is turned off (S451).

  In step S452, the folding operation mode selection unit 223 of the CPU 150 determines whether the folding operation mode is two-fold or one-fold based on the gap information and sheet information (FIG. 11). If it is the one-fold mode, the process proceeds to S453 and proceeds to the control routine for the one-fold mode. If it is the double folding mode, the control routine for the double folding mode shown in FIG. 19 is entered.

First, the case of the once folding mode in S452 will be described.
If the folding mode is the once folding mode in S452, the folding motor 74 is turned on after the folding clutch 74a is turned off in S451 until the rear end of the folded sheet bundle is detected by the paper discharge sensor 29 (S453). Then, the copy counter CNT2 is incremented by 1 (S455), and if the copy counter CNT2 has not reached the planned number of copies M in S456, the process returns to S401. To complete S456.

Next, the case of the twice folding mode in S452 will be described.
If the double folding mode is selected in S452, the double folding counter is set in S457 in FIG. 19, and the count up is waited in S458. The double folding counter is set to 50 cp, but the distance that the sheet bundle slightly passes through the nip portion after the folding motor 64 starts operation and the sheet bundle is added to the nip portion of the folding rollers 26 and 27. It is. Therefore, the numerical value is not limited to this. In this embodiment, the movement amount of the sheet bundle is measured by pulse counting, but a timer may be used.

  If the count is up, the process proceeds to S459, the folding motor forward rotation is turned OFF, the folding motor reverse rotation is turned ON, and the double folding counter is set to 40 cp in S461. Here, although it is set to 40 cp, it represents the distance for returning in the reverse direction by the amount of conveyance of the sheet bundle by normal rotation, and does not limit the numerical value. In the present embodiment, the return movement amount of the sheet bundle is measured by pulse counting, but a timer may be used.

  The sheet bundle is returned until the count is increased again in S462, and if the count is increased, the process proceeds to S463, and the folding motor reverse rotation is turned off.

  Then, the forward rotation of the folding motor is turned on again in S464, and the process proceeds to S465 and continues to be turned on until the trailing edge of the sheet bundle is detected by the paper discharge sensor. If the trailing edge of the sheet bundle is detected in the paper discharge sensor 29 in S465, the folding motor 64 is turned off (S466). Then, 1 is added to the copy counter CNT2 (S467). If the copy counter has not reached the planned copy number M in S468, the process returns to S401. If the copy counter M has been reached, the copy counter CNT2 is cleared to 0 in S468 ′. End the operation.

  As described above, according to the table of FIG. 4, the sheet information such as the number of sheets, the basis weight, and the like, and the folding condition such as one-fold folding and two-fold folding of the sheet bundle are changed according to the sheet gap direction, so that the appearance is good. A bound sheet bundle can be completed.

CNT1 sheet number count CNT2 copy number counter 1 image forming apparatus main body 2 finisher (sheet processing apparatus)
23 Sheet positioning member (sheet storage means)
26, 27 Folding roller pair (folding means)
300 Sheet gap detection sensor (Gap direction detection device)
301 Terahertz wave generator 302 Terahertz wave detector 303 Terahertz wave polarizer

Claims (12)

An image forming unit for forming an image on a sheet;
Sheet information input means for inputting information of a sheet to be imaged;
A sheet processing apparatus for processing an image-formed sheet;
An image forming apparatus comprising:
The sheet processing apparatus includes:
Folding means for folding the sheet;
Control means for controlling the folding means;
Have
The control unit is configured to perform the folding when the sheet gap direction is orthogonal to the sheet crease direction in accordance with the gap direction information that is the blend direction of the sheet fibers of the sheet input from the sheet information input unit. An image forming apparatus characterized in that the number of folding operations by the means is controlled to be larger than the number of folding operations when the sheet score direction is parallel to the sheet score direction.   The control unit controls the number of folding operations by the folding unit based on a combination of the gap direction information, the number of sheets stored in the sheet storage unit, and a basis weight. Item 2. The image forming apparatus according to Item 1. The folding means includes a pair of forward and reverse rollers that fold and convey at least one sheet,
The control means includes a first folding mode in which a sheet is folded once through the roller pair and a second folding mode in which a sheet is folded a plurality of times through the roller pair. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is selectively switched according to sheet gap direction information. 4.   The image forming apparatus according to claim 3, wherein the control unit can perform the folding operation in the second folding mode an arbitrary number of times.   The control means selects either the first folding mode or the second folding mode based on a combination of a sheet gap direction, the number of sheets to be folded, and a basis weight. The image forming apparatus according to claim 3 or 4.   The control means changes the reference number of sheets for switching between the first folding mode and the second folding mode depending on whether the sheet gap direction is parallel to or perpendicular to the sheet folding direction. The image forming apparatus according to claim 5. An image forming unit for forming an image on a sheet;
Sheet information input means for inputting information of a sheet to be imaged;
A sheet processing apparatus having a folding means for performing a folding process on an image-formed sheet;
Control means for controlling the sheet processing apparatus;
An image forming apparatus comprising:
The control unit is configured to perform the folding when the sheet gap direction is orthogonal to the sheet crease direction in accordance with the gap direction information that is the blend direction of the sheet fibers of the sheet input from the sheet information input unit. An image forming apparatus characterized in that the number of folding operations by the means is controlled to be larger than the number of folding operations when the sheet score direction is parallel to the sheet score direction.   The control unit controls the number of folding operations by the folding unit based on a combination of the gap direction information, the number of sheets stored in the sheet storage unit, and a basis weight. Item 8. The image forming apparatus according to Item 7. The folding means includes a pair of forward and reverse rollers that fold and convey at least one sheet,
The control means includes a first folding mode in which a sheet is folded once through the roller pair and a second folding mode in which a sheet is folded a plurality of times through the roller pair. The image forming apparatus according to claim 7, wherein the image forming apparatus is selectively switched according to the gap direction information of the sheet.   The image forming apparatus according to claim 9, wherein the control unit can perform the folding operation in the second folding mode an arbitrary number of times.   The control means selects either the first folding mode or the second folding mode based on a combination of a sheet gap direction, the number of sheets to be folded, and a basis weight. The image forming apparatus according to claim 9 or 10. The control means changes the reference number of sheets for switching between the first folding mode and the second folding mode depending on whether the sheet gap direction is parallel to or perpendicular to the sheet folding direction. The image forming apparatus according to claim 11.

Images