JP4484768B2 - Paper folding apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an improvement in a sheet folding device used as a post-processing device or the like for an image forming apparatus main body.

Arbitrary paper as one of the post-processing devices that receive image formation by the image forming apparatus main body such as copying machines, printers, facsimile machines, ink jet printers, printing apparatuses, etc. There is known a paper folding device that bends at the position of.
There are two folding roller pairs that fold the paper and a conveying roller pair that feeds the paper to any one of the folding roller pairs, and further deflecting means for switching which folding roller the paper is folded (folding direction). Japanese Patent Application Laid-Open No. 2004-67266 discloses an apparatus that can alternately fold and continuously fold a plurality of lines. Japanese Patent Laid-Open No. 11-349218 discloses a paper folding method aimed at eliminating variations in the folding width of each surface when a plurality of sheets of paper are diffracted in the same apparatus.
That is, Japanese Patent Application Laid-Open No. 2004-67266 discloses an apparatus that performs an operation of bending a sheet in a zigzag shape. In this apparatus, a leading end portion of the supplied sheet is configured as, for example, a second folding roller pair. (The fold knife as the deflecting means guides the leading edge of the paper at this time), and then guides the paper part that becomes the first fold of the zigzag fold with the folding knife. Then, the first fold roller pair is sandwiched between the upper roller and the lower roller, and the portion that becomes the next fold of the zigzag fold is then guided with a fold knife to form the second fold roller pair with the upper roller. Repeat the action of holding between the lower rollers. In this conventional example, the deflecting means moves to the vicinity of each of the two folding roller pairs, but does not directly contact the folding roller pair and the paper. For this reason, the sheet is bent in an arc shape from the position where the middle part of the sheet is pushed and stopped, and the pair of folding rollers comes into contact with the sheet, and is sandwiched in the nip portion of the pair of folding rollers, and the sheet is folded. The sheet is bent in an arc shape, and when the pair of folding rollers abuts against the sheet, the force with which the sheet comes into contact with the folding roller is only a restoring force due to the rigidity of the sheet (a force to return from the bent state to the flat state). Therefore, when the paper comes into contact with the bending and folding roller pair, the conveying force of the folding roller varies depending on the rigidity of the paper, that is, the thickness of the paper (usually thicker paper has higher rigidity).
Next, in Japanese Patent Laid-Open No. 11-349218, as means for preventing the folding position of a sheet from varying, first and second folding width detection sensors disposed outside the opposing first and second folding roller pairs. Detects the leading edge of the sheet or the folded edge of the sheet, and determines the length L1 from the leading edge of the sheet to the folded edge of the first sheet as the length L2 from the second folded edge to the third folded edge, A method is provided in which the length L3 from the end to the fourth folding end is controlled to be longer than the length Ln.
In the case of this conventional method, the sheet is fed from a pair of conveying rollers that feeds the sheet to the pair of folding rollers, the leading end of the sheet is sandwiched and conveyed by the first pair of folding rollers, and is conveyed by the first folding width detection sensor. Is detected, measurement for controlling the folding length is started.
JP 2004-67266 A JP-A-11-349218

However, when a sheet with a curled tip is inserted into the sheet folding device, an unnecessary slack is formed on the sheet until the sheet is fed from the pair of conveying rollers and the leading end of the sheet is inserted into the pair of folding rollers. The first folding width detection sensor detects the leading edge of the sheet and starts length measurement, and the first and second folding roller pairs are reversed while the sheet is continuously fed by the conveying roller pair. Even if it is attempted to form the first bent portion by holding the middle of the paper into the second folding roller pair, there is a high possibility that an unintended portion of the paper will be held in the folding roller pair due to this unnecessary slack. . That is, the length L1 from the front end of the paper to the first folding end varies depending on the state of the front end of the paper.
The present invention has been made in view of such a problem, and is a sheet folding apparatus in which variation in the length L1 from the leading end of the sheet to the first folding end is reduced even when a sheet having a curled tip is used. And an image forming apparatus.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a sheet between the first and second folding roller pairs arranged at a predetermined interval and the first and second folding roller pairs. A pair of conveying rollers to be fed, a sheet leading end detection sensor which is disposed in the vicinity of the pair of conveying rollers and detects that the leading end of the sheet enters between the first and second folding roller pairs, and the first and second The first and second folding width detection sensors that are arranged outside the nip portions of the pair of folding rollers and detect the paper ends, respectively, and operate to guide the paper ends to the nip portion of one of the folding roller pairs. Two deflecting means and control means for controlling them, and the first and second folding roller pairs and the respective deflecting means cooperate to switch the folding direction alternately and continuously. A paper folding device capable of diffracting multiple times, The control means guides the leading edge of the sheet fed from the pair of conveying rollers using the deflecting means to the nip portion of the first or second folding roller pair and feeds it to the outside, and then feeds the conveyance The control means performs a plurality of folding of the paper by sequentially repeating stop, reverse rotation, and normal rotation of the first and second folding roller pairs while continuing to feed the paper by the roller pair. One of the deflecting means is fed out toward one folding roller pair so that the leading edge of the sheet is inserted into the one folding roller pair, and then the other deflecting means is operated so that the middle portion of the sheet is moved to the other folding roller. In the step of forming the first bent portion by holding it in a pair, the timing of starting the feeding of the other deflection means for determining the length from the front end of the paper to the first bent portion End detection sensor is characterized in that measured from the time of detecting the leading edge of the sheet.
According to a second aspect of the present invention, there is provided an image forming apparatus comprising the main body of the image forming apparatus and the paper folding apparatus according to the first aspect.

  The present invention is arranged in the vicinity of two first and second folding roller pairs for folding a sheet, a conveying roller pair for feeding a sheet to the first or second folding roller pair, and the conveying roller. A sheet leading edge detection sensor that detects that the sheet leading edge enters the two pairs of folding rollers, and first and second sheets that are disposed outside the nip portions of the first and second folding roller pairs and detect the sheet edges. Deflection means for switching the direction in which the sheet is folded by the second folding width detection sensor and the first or second folding roller, the deflection means being directed toward the nip portion of the folding roller pair on the sheet folding side A paper folding apparatus capable of alternately folding the paper by alternately switching the direction in which the paper is folded, wherein the leading edge of the paper fed from the pair of transport rollers is First After feeding to the outside of the first and second folding roller pairs by the folding roller pair, the first and second folding roller pairs are stopped while the sheet feeding by the transport roller pair is continued, and then reversely rotated. Further, in the step of feeding the deflecting means to the second pair of folding rollers and adding the middle of the paper to the second pair of folding rollers to form the first folding portion, the first folding of the paper from the leading edge of the paper is performed. Since the timing of starting the pushing of the deflecting means for determining the length of the first folding surface up to the bent portion is measured from the time when the paper leading edge detection sensor detects the leading edge of the paper, It is difficult to be affected by the slack generated in the portion (intermediate portion), the variation in the length of the first surface of the bellows fold is reduced, and the folding can be accurately performed at the target position.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is a schematic cross-sectional view showing a configuration example of an image forming apparatus in which a paper folding apparatus of the present invention is mounted on a copying apparatus main body (image forming apparatus main body), and FIGS. FIGS. 6 and 6 are drive configuration diagrams of the sheet folding device, FIGS. 7 and 8 are perspective views showing the configuration of the deflecting means, FIG. 9 is a block diagram of the sheet folding device, and FIGS. 10 and 11 are flowcharts of this embodiment. FIG. 12 is an enlarged view when the sheet of the present embodiment enters the folding roller, and FIGS. 13 and 14 are views when the rear end of the sheet is on the left side and the right side after the final folding, and when the sheet is discharged. It is explanatory drawing which shows the operation | movement which has contact | abutted the deflection | deviation means to the paper upper surface.
First, the overall configuration (image forming apparatus) of the folding apparatus and copying apparatus main body (image forming apparatus main body) of the present invention will be described with reference to FIG. Reference numeral 200 is a copying apparatus main body, 1 is connected to a side surface of the copying apparatus main body 200 provided with a paper discharge port, and is subjected to end-face folding, bellows-like folding, etc., on an image-formed paper P received from the copying apparatus main body 200. Is a sheet folding device for applying The sheet folding device 1 includes a connecting portion 6 connected to the apparatus main body 200, an end surface folding portion 2 that folds the end surface of the front end of the paper received from the connecting portion 6, and a sheet whose end surface is folded by the end surface folding portion 2 in the transport direction. A sheet folding section 3 that folds along a bellows shape, and a tray 13 that discharges and stacks sheets folded in a bellows shape at the sheet folding section 3.

An image reading device 205 (reading optical system 205a, automatic document feeder 205b) is disposed at the upper part of the copying machine main body 200, and an image forming unit 206 and a manual feed tray 208 are sequentially provided at the lower part thereof. Has been placed. When the paper set on the manual paper feed tray 208 is fed toward the reading unit, the paper is temporarily stopped by the registration roller 207 and supplied to the image forming unit 206 at a timing. In the image forming unit 206, a latent image corresponding to the image data is formed on the photoconductor 206a, the latent image is developed with toner from the developing device 206b, and the toner is transferred onto a sheet by the transfer device 206c. It is fixed by. The recorded paper on which the toner is fixed by the fixing device 210 is discharged to the paper folding device 1 by the recorded paper discharge roller 211 when the paper is folded. When the sheet is not folded, the sheet is discharged into the main body by the upper discharge roller 209 by a switching claw (not shown).
Next, when folding the paper, the paper is sent from the recorded paper discharge roller 211 to the connecting portion 6 to the paper folding device 1 and further sent to the inside by the entrance conveyance roller pair 7. When folding the end face of the sheet, the end face of the end of the sheet is folded by the end face folding unit 2. After the end surface of the sheet is folded by the end surface folding unit 2, the sheet is folded into a bellows shape a required number of times in the transport direction by the sheet folding unit 3, and the sheet that has completed the bellows folding is stacked on the tray 13.

Next, the configuration of the first embodiment of the paper folding device that folds the paper in a bellows shape in the conveyance direction will be described. FIGS. 2 to 5 show a state in which the main part of the sheet folding unit 3 in FIG. 1 is enlarged and its operation.
First, the leading edge detection sensor 15 for detecting the leading edge of the sheet P conveyed in FIG. 2 is disposed at the entrance of the sheet folding unit 3, the conveyance roller pair 14 is disposed downstream thereof, and the nip portion of the conveyance roller pair 14. It is configured such that the paper enters the paper. On both the left and right sides of the downstream side of the conveying roller pair 14, left and right folding roller pairs (second folding roller pairs) 11 (11a, 11b) that convey while changing the conveying direction to a direction orthogonal to the paper conveying direction, 12 (first folding roller pair) (12a, 12b) are arranged, and the folding roller pairs 11, 12 rotate in a normal direction, stop, reverse, and fold the paper in a bellows shape. A folding width left detection sensor 16 and a folding width right detection sensor 17 are arranged on the outside of each folding roller pair 11 and 12 to detect the leading edge of the sheet and the folding edge of the folded sheet. Further, a lower guide plate 18 is disposed between the pair of folding rollers 11 and 12, and the folded edge of the folded paper is guided to the pair of folding rollers 11 and 12, respectively. The left side of the folding roller pair 11 is the direction in which the folded paper is discharged.
The folding roller pair 12 is a first folding roller pair, and the folding roller pair 11 is a second folding roller pair (discharge-side folding roller pair).
On both the left and right sides of the conveying roller pair 14, deflecting means 20 and 21 that selectively switch the conveying direction of the leading edge of the sheet to the folding roller pair 11 or 12 are arranged to be movable up and down. The deflection means 20 is a deflection means on the second folding roller pair 12 side, and the deflection means 21 is a deflection means on the first folding roller pair 11 side.
When the deflecting means 20 and 21 are moved up and down, respectively, a substantially arcuate shape or an arcuate shape is brought into contact with the lower folding rollers 12b and 11b (near the nip portions of the folding roller pairs 12 and 11) at the respective leading ends. It is driven by drive gears 22 and 23 that operate along the movement trajectory and mesh with gear portions 20b 'and 21b' formed along the outer peripheral surfaces of the deflecting means 20 and 21, respectively. The leading edge of the sheet conveyed downward by the conveying roller pair 14 is guided to the vicinity of the folding roller pairs 12 and 11 by the operation of the deflecting means 20 and 21 and enters the nip of each folding roller pair 12 and 11. At this time, depending on which of the deflecting means 20 and 21 is operated, it is selected which of the folding roller pairs 12 and 11 the paper leading edge enters. In the following description, the deflecting means 20 for guiding the right folding roller pair 12 will be described as the right deflecting means, and the deflecting means 21 for guiding the left folding roller pair 11 as the left deflecting means. The deflecting means 20 and 21 guide one surface of the sheet to the nip of the pair of folding rollers 12 and 11 when the sheet is folded. At this time, the rollers 20a and 21a formed at the tips of the deflecting means 20 and 21 come into contact with the lower folding rollers 12b and 11b, respectively.

Next, a specific configuration example of the deflection unit will be described with reference to FIGS. The changing means shown here is the left deflection means 21, but the right deflection means 20 has the same configuration as the left deflection means 21 except that it has a bilaterally symmetric shape. The left deflection means 21 has a substantially rectangular frame shape with a rectangular space inside, and is provided with side plates 21b on both sides in the longitudinal direction. Each side plate 21b is formed with a gear portion 21b ′ that meshes with the gear 23. ing. The lower end portions of both side plates 21b are connected by a guide plate 21d that guides the leading edge of the sheet, and the upper end portions of both side plates 21b are connected by a stay 21e. The stay 21e has a light shielding plate 21c that shields the deflection means home position sensor (hereinafter referred to as the deflection means HP sensor) 25 shown in FIG. 2 and the like (the right deflection means 20 includes the deflection HP sensor 24 and the light shielding plate 20c). Provided). The deflecting means HP sensors 24 and 25 are arranged outside the movement trajectories of the deflecting means 20 and 21, and the light shielding plates 20 c and 21 c are arranged at positions where the home positions can be detected by the sensors 24 and 25. .
A roller 21a having a length equal to or greater than the maximum sheet width is rotatably supported at the lower ends (tips) of the side plates 21b. The rollers 21a are not only supported at both ends by the side plates, but are also guided by a guide plate 21d. The outer peripheral surface is supported by a tip portion (tip edge) 21g. In this example, the tip 21g of the guide plate 21d supports the entire width of the roller 21a, but may be partially supported. The tip 21g of the guide plate may be made to have low friction resistance by being coated with Teflon (registered trademark), but the guide plate 21d itself may be made of a resin material having a low friction coefficient. The roller 21a may be a pipe material.
Further, a plurality of rollers 21f are arranged on the outer surface of the both side plates 21b. As shown in FIG. 8, each roller 21f is provided in the rail groove 60a of the arc-shaped groove grooves 60a and 60b provided on the inner surface of the rail member 60 disposed on both outer sides of the deflecting means 21 and 20, respectively. The deflection means 21 is configured to move up and down along an arcuate trajectory and to come into contact with the lower folding roller 11b at the tip thereof by being fitted and rolled. Similarly, a roller 20f (not shown) provided on the other deflecting means 20 is fitted into the rail groove 60b and guided up and down, and comes into contact with the lower folding roller 12b at its tip. As a result, the deflecting means 21 and 20 can move up and down individually while drawing a circular locus. The rollers 21f and 20f roll in the rail grooves 60a and 60b, the gear portions 21b 'and 20b' of the deflecting means 21 and 20 are engaged with the drive gears 23 and 22, and the rollers 21f and 20f are rail rails 60a and 60b. By rolling inward, the deflecting means 21 and 20 rotate while drawing an arc trajectory so as to contact and separate from the lower folding rollers 11b and 12b, respectively.

Next, the configuration of the drive mechanism of the sheet folding device of this embodiment will be described with reference to the schematic diagrams shown in FIGS. 6 (a), 6 (b), and 6 (c).
FIG. 6A is a diagram schematically illustrating the driving-side rollers of the conveying roller pair 14 in relation to the driving source. The conveying roller pair 14 includes a pulley 50 and a driving belt 51 connected to the shaft end portions thereof. Rotational force from the transport motor 52 is transmitted via and is driven in the transport direction (arrow direction). Further, a tip detection sensor 15 is disposed at the center in the longitudinal direction of the transport roller pair 14.
Next, FIG. 6B is an explanatory diagram of the drive mechanism of the deflecting means. The drive of the deflecting means 20 and 21 is bilaterally symmetrical and has the same drive configuration. Only will be described. First, drive gears 23 are connected to gear portions 21b ′ provided on the side plates 21b located at both ends of the left deflection means 21, respectively. The drive gears 23 at both ends are fixed on the same drive shaft 54, and the left deflection means 21 moves up and down along an arcuate locus by the amount that the drive gear 23 is rotationally driven by the drive shaft 54. become. A drive pulley 42a is coupled to the drive shaft 54 via a torque limiter 42b, the drive pulley 42a and the drive pulley 40 are coupled and driven by the drive belt 41, and the drive pulley 55 on the same shaft 39 as the drive pulley 40 is coupled to the drive belt. 37 is connected to the deflection means left motor 36 through 37. Accordingly, when the deflection means left motor 36 rotates in the arrow direction, the left deflection means 21 moves in the arrow direction. At that time, when a load equal to or greater than the rotational load torque (allowable torque) of the torque limiter 42b is applied to the left deflection means 21, the slipping is generated while generating torque between the torque limiter 42b and the drive pulley 42a. Further, a light shielding plate 21c is provided at a suitable end portion of the left deflection unit 21, and the deflection unit left HP sensor 25 is shielded from light at a position where the left deflection unit 21 is waiting to be lifted, thereby detecting a standby position. The right deflection means 20 has the same configuration, and FIG. 6B shows the rotation direction when the right deflection means 20 descends.

Next, the drive mechanism of the folding roller pairs 11 and 12 will be described with reference to FIG. The driving pulley 35 is connected to the end of the driving side upper folding roller 11a, and the shaft center of the driving pulley 33b is connected and fixed to the end of the driving side upper folding roller 12a. The driving pulley 35 and the driving pulley 33b are connected to each other. They are connected by a drive belt 34. Further, the drive pulley 33 a coaxially integrated with the drive pulley 33 b is connected to the drive pulley 57 a via the drive belt 31, and the drive pulley 57 b integrated with the drive pulley 57 a is folded via the drive belt 56. It is connected to the output shaft of the motor 30. Therefore, when the folding motor 30 rotates in the direction of the arrow in the drawing, the upper folding rollers 11a and 12a on the driving side rotate in the direction of the arrow in synchronization. Further, a driving belt (not shown) connects the driving-side upper folding roller 11a and the driven-side lower folding roller 11b, and the driving-side upper-folding roller 12a and the driven-side lower folding roller 12b, respectively. When the roller 30 is rotated, the rollers constituting the folding roller pair 11 and 12 are configured to rotate in the conveyance direction in synchronization with each other. Further, a folding width right detection sensor (first folding width sensor) 17 and a folding width left detection sensor (second folding width sensor) 16 are arranged outside the center part in the longitudinal direction of the pair of folding rollers 11 and 12, respectively. Yes.
Each drive mechanism described above is driven by controlling each motor by the paper folding controller (control means) 100 shown in FIG. Further, by the operation from the operation unit 201 of the image forming apparatus main body 200, the main body control board 202 receives input signals such as the folding type (folding mode) and size, and the information is sent to the paper folding controller 100, and each sensor information is received. Based on this, each motor is controlled to perform a sheet folding operation.

The sheet folding apparatus having the above configuration has the following characteristic configuration. Here, a case will be described in which the signal related to the paper folding type is a paper folding type signal that causes the leading end of the paper to enter the folding roller pair (first paper folding roller pair) 12 whose first paper transport direction is the right side.
In other words, the sheet folding device 1 of the present invention includes two pairs of folding rollers 11 and 12 (second and first folding roller pairs) and a pair of folding rollers that are arranged close to each other at a predetermined interval in the left-right direction. 11 and 12, a pair of conveying rollers 14 that feed the paper P from above, and a front end of the paper that is disposed near the conveying roller pair 14 enters the first folding roller 12 or the second folding roller 11. A sheet leading edge detection sensor 15 to detect, a first folding width sensor 17 that is disposed outside the nip portion of the first and second folding roller pairs 12 and 11 and detects the sheet edge, respectively, and a second folding width detection. The sensor 16 has two deflecting means 20 and 21 that operate to guide the leading edge of the sheet to the nip portion of one of the pair of folding rollers 12 and 11, respectively, and a control means 100 that controls these deflecting means. Means 20 and 21 fold the paper Has a mechanism for pushing out the sheet toward the nip portion of the pair of folding rollers, and the folding direction is alternately changed by the cooperation of the first and second folding roller pairs 12 and 11 and the deflecting means 20 and 21. It is possible to diffract multiple times continuously by switching to. Further, in the sheet folding apparatus 1 of the present invention, the control unit 100 uses the deflection units 20 and 21 to change the leading edge of the sheet fed from the conveying roller pair 12 and 11 to the first or second folding roller pair. After feeding to the nip portion and feeding it to the outside, the first and second folding roller pairs 12 and 11 are repeatedly stopped, reversely rotated, and forwardly rotated in order while the sheet feeding by the conveying roller pair 14 is continued. Execute multiple folds of paper. Further, the control means 100 feeds the leading end of the sheet into the first folding roller pair 12 by feeding out one deflection means 20 toward the first folding roller pair 12, and then the other deflection means 21 is moved. The length of the first folding surface from the leading edge of the paper to the first folding portion of the paper in the step of making the first folding portion by operating and inserting the middle of the paper into the second folding roller pair 11 The timing of starting the feeding of the other deflecting means 21 for determining the leading edge is measured from the time when the leading edge detection sensor 15 detects the leading edge of the sheet.
Because of such a configuration, even when a paper sheet with a curled tip is used, variation in the length L1 from the paper tip to the first folding end can be reduced.
When the front end of the paper is first entered into the second paper folding roller pair 11 on the left side, the operation of each part is reversed to the left and right.

Next, a series of sheet folding operations by the sheet folding apparatus of the present invention will be described based on the configuration explanatory diagrams of FIGS. 1 to 9 and the flowcharts of FIGS. Here, the case where the leading edge of the sheet is caused to enter the pair of folding rollers 12 whose first sheet conveying direction is the right side will be described.
First, when a paper folding presence signal is input by the operation of the main body operation unit 201 in FIG. 9, the signal is sent to the paper folding controller 100 via the main body control board 202. In that case, on the sheet folding apparatus 1 side, the flowchart of FIG. 10 starts, the transport motor 52 shown in FIGS. 6A and 9 is turned on, and the transport roller pair 14 starts to rotate in the direction of the arrow in FIG. (S0). Next, the sheet is fed from the apparatus main body 200 toward the sheet folding apparatus 1 and enters the sheet folding unit 3, the leading edge of the sheet passes through the leading edge detection sensor 15, and the ON signal of the leading edge detection sensor 15 is changed to the sheet folding controller 100. Is input, the paper folding controller 100 starts measuring the time Tx until the driving of the left deflection means 21 is started in order to form the first fold (S1). Next, based on a signal indicating the sheet folding type input from the main body operation unit 201, it is determined whether or not the sheet folding type (mode) is such that the leading end of the sheet enters the right folding roller pair 12 in the first sheet conveyance (see FIG. S2). Here, a case will be described in which the signal regarding the sheet folding type is the sheet folding type that enters the right folding roller pair 12 in the first sheet conveyance.

Next, the folding motor 30 shown in FIG. 6C and FIG. 9 is turned on and rotates in the direction of the arrow (here, normal rotation) (S3). Next, the deflection means right motor 43 shown in FIG. 6B and FIG. 9 is turned on, and the right deflection means 20 starts moving from the solid line position in FIG. 2 toward the broken line position (the rotation direction at this time is normal). (S4). At this time, the deflection means right HP sensor 24 is turned off (S5), and after the drive time T1 seconds required for the right deflection means 20 to reach the broken line position from the solid line position in FIG. 2, the deflection means right motor 43 is turned off (S6). ). At this time, as shown in FIG. 2, the roller 20a at the tip of the right deflection means 20 and the lower folding roller 12b are not in contact with each other, and the right deflection means 20 is stopped with a slight gap between them. In this state, as shown in FIG. 2, the leading edge of the paper P enters the nip portion of the right folding roller pair 12, and the folding width right detection sensor 17 located outside is turned on (S7). Thereafter, in order to return the right deflection means 20 to the standby position, the deflection means right motor 43 is turned on in the reverse direction (S8), the deflection means right HP sensor 24 is turned on (S9), and the deflection means right motor 43 is turned off ( S9), the right deflection means 20 returns to the standby state at the solid line position in FIG.
Next, after the leading edge of the sheet enters the nip portion of the right folding roller pair 12, it is determined whether or not there is a next folding operation (left folding) (S11). explain. T4 seconds after the folding width right detection sensor 17 is turned on, the folding motor 30 is turned off (S12), and this time the left deflection means 21 is operated to guide the inside of the sheet to the nip portion of the left folding roller pair 11. Therefore, the deflection means left motor 36 in FIG. 6B is turned on. The timing when the deflection means left motor 36 is turned on and the left deflection means 21 is started is when the leading edge of the sheet turns on the leading edge detection sensor 15. This is done after Tx, which starts counting from the beginning. When the deflection means left motor 36 is turned on, the left deflection means 21 in FIG. 3 starts to move in the direction of the arrow (the rotation direction at this time is assumed to be normal rotation) (S13). At this time, since the left deflection means 21 leaves the home position, the deflection means left HP sensor 25 is turned OFF (S14).

  Simultaneously with the operation of the left deflection means 21, the folding motor 30 is turned on in the reverse direction T3 seconds after the tip detection sensor 15 is turned on as shown in FIG. 3 (S15). For this reason, the sheet starts to be returned to the left by the reverse rotation of the folding roller pair 12. At this time, since the moving speed of the left deflecting means 21 is set to be faster than the slacking speed of the paper, the slack of the paper disappears as shown by the broken line in FIG. 21a contacts. After this time, the moving speed of the left deflecting means 21 cannot move beyond the slacking speed of the sheet, so that a load is applied to the torque limiter 42b in FIG. 6B, and the torque between the torque limiter 42b and the drive pulley 42a is applied. Begin to slip while generating. Accordingly, the roller 21a at the front end of the left deflection unit 21 applies tension to the paper by the amount of the idling torque of the torque limiter 42b, and the paper moves while keeping the tensioned state, and the front end of the left deflection unit 21 as shown in FIG. The roller 21a brings the paper into contact with the left lower folding roller 11b. Further, as shown in FIG. 12, since the pressure F corresponding to the idling torque of the torque limiter 42b is applied to the leading roller 21a and the downward folding roller 11b, the paper P further forms a slack as shown by a one-dot chain line to form a loop. Then, the top of the loop is inserted into the nip portion of the left folding roller pair 11 that rotates in the direction of the arrow as shown in FIG. 12 and conveyed to the outside of the nip portion, and the paper is folded to the left. The sheet continues to be fed to the left, and is turned on when the leading end of the folded sheet reaches the folding width left sensor 16 (S16). Thereafter, in order to return the left deflection means 21 to the standby position, the deflection means left motor 36 is stopped (S17), further turned on in the reverse direction (S18), the deflection means left HP sensor 25 is turned on (S9), and the deflection means The left motor 43 is turned off (S20), and the right deflection means 21 returns to the standby state at the solid line position in FIG. 2, thereby completing the first folding and forming the first surface of the bellows folding.

Differences in the paper folding operation depending on the presence or absence of curling at the leading edge of the paper will be described with reference to FIGS. 15A and 15B and FIGS. 16A and 16B. FIGS. 15A and 15B show the case where the leading edge of the sheet is caught in the right folding roller pair 12 with no curl at the leading edge of the sheet and no slack. FIGS. 16A and 16B show the leading edge of the sheet. A case is shown in which the slack is caused by curling and is held by the pair of right folding rollers 12. In the description here, the case where the paper folding type signal is the paper folding type to be inserted into the folding roller pair 12 whose first paper transport direction is the right side will be described.
First, in FIG. 15A, the leading edge of the sheet P passes through the leading edge detection sensor 15 and is fed by the conveying roller 14 and is held by the pair of right folding rollers 12, and the left deflection means 21 is moved to the sheet P after a time Tx. When the movement starts toward an appropriate position (midway) of the surface, the end of the paper (midway portion) is nipped by the left folding roller pair 11 and the first surface of the bellows fold is folded at a desired length.
On the other hand, FIG. 16A is a diagram showing a state in which a slack is formed on the paper P due to circumstances such as a case where there is a deformation such as a curl at the leading edge of the paper, but is similar to the case of FIG. After the leading edge of the sheet passes the leading edge detection sensor 15, the movement of the left deflection means 21 is started after time Tx. At this time, in either case of FIG. 15A or FIG. 16A, the movement of the left deflection means 21 is started after a certain time of time Tx has elapsed since the leading edge of the paper P has passed the leading edge detection sensor 15. Therefore, the length from the leading edge detection sensor 15 to the leading edge of the paper P is constant during the elapse of time Tx.
On the other hand, when the timing of starting the movement of the left deflection means 21 is measured (timed) from when the leading edge of the paper P passes through the folding width right sensor 17, there is no slack in the paper P in FIG. Although the timing is almost the same as that measured from the time when the leading edge of the sheet passes through the leading edge detection sensor 15, if the slack has occurred in the middle of the sheet P as shown in FIG. The length of the paper P that is sent between the two will differ by the amount of Tgosa. That is, in the case of FIG. 16A, the time for the leading edge of the sheet to reach the folding width right sensor 17 is delayed due to the presence of slack, and the above error occurs.
That is, after this, the right folding roller pair 12 and the left folding roller pair 11 are reversely rotated, and the length from the leading edge of the paper P to the position where the leading edge of the left deflection means 21 is in the middle of the paper P is shown in FIG. ) When the case where there is no slack in the middle of the paper P and the case where there is slack in the middle of the paper P in FIG. 16B, Tz and Tz ′ are obtained, respectively, and a difference corresponding to Tgosa occurs. .
From the above, as a method of measuring the timing of starting the movement of the left deflection means 21, if the timing is started from the time when the leading edge of the paper P passes the leading edge detection sensor 15, the leading edge of the paper is curled, etc. Even when sagging occurs in the middle of the paper, the length of the fed paper is always substantially constant, and therefore the variation in the folding length of the first surface of the bellows fold is small.
In particular, the present invention is an effective method when roll paper is used in a copier connected upstream with respect to the paper inserted into the paper folding machine.

Next, for reference, a series of operations until the entire sheet is folded and discharged will be described. In the determination of whether or not there is a next fold in S11 of the flowchart of FIG. 10, if there is no fold, the paper discharge direction is on the left folding roller pair 11 side, so the paper is discharged after switching back once. When the trailing edge of the sheet passes through the leading edge detection sensor 15 with the right folding roller pair 12 carrying the sheet, the folding motor 30 is turned off (S22), and the folding motor 30 is reversed (S23). Is conveyed toward the left folding roller pair 11 and enters the discharge operation flow C.
In the determination of whether or not the first sheet conveyance in S2 is the type of paper folding to be inserted into the right folding roller 12, if it is the type of paper folding to be inserted into the left folding roller pair 11, it is inserted into the right folding roller 12. The same movement from S24 to S42 is performed depending on the difference between the case and the left and right. However, since it is determined whether or not there is a next fold in S32, if there is no fold, the paper discharge direction is on the opposite side to the left fold roller, so there is no need to switch back once before discharging, so the discharging operation is performed as it is. Enter flow C.
Here, it is determined whether or not there is repeated folding (S21, S42). When the first folding is on the left side and there is repeated folding, the flow enters the right repeated folding flow B and there is no repeated folding. Does not need to be discharged after being switched back once, and therefore enters the discharge operation flow C as it is.
Also, when the first fold is on the right side and there are repeated folds, the flow enters the repetitive fold flow A on the left side, and if there are no repeated folds, it is necessary to switch back once before discharging, so the right fold roller When the trailing edge of the sheet passes through the leading edge detection sensor 15 and is turned OFF while the pair 12 is transporting the sheet, the folding motor 30 stops OFF (S43), this time the folding motor 30 is reversed (S44), and the trailing edge of the sheet is folded to the left. The sheet is conveyed toward the roller pair 11 and enters the discharge operation flow C.
Note that S24 to S42 when the first paper transport is a left folding roller pair corresponds to S3 to S21 where the first paper transport is a right folding roller pair.

Next, the case of repeated folding flows A and B will be described. First, in the left-folding flow A, the timing for reversing the folding motor 30 in S48 is substantially the same as the first-folding flow S12 to S21. In the case of repeated folding, T6 seconds after the folding width right detection sensor 17 is turned on. It is reversed. Similarly, in the right-folding flow B, when the folding motor 30 in S58 is rotated in the forward direction substantially the same as the first-folding flows S33 to S42, and when the folding motor 30 rotates forward repeatedly, the folding width right detection sensor 16 is turned on and T6 seconds later. It is reversed. Note that S49 to S53 of the flow A show the operation for returning the left deflection means 21 to HP, and S59 to S63 of the flow B show the operation for returning the right deflection means 20 to HP. Yes.
After that, if there are further folds, flow A and B are repeated, and if the final fold is on the right side, the paper discharge direction is on the opposite side of the left fold roller, so it will be discharged after switching back once. When the trailing edge of the sheet passes through the leading edge detection sensor 15 and is turned OFF while the pair of right folding rollers 12 conveys the sheet, the folding motor 30 is turned off (S65), and the folding motor 30 is reversed (S66). Is conveyed toward the left folding roller pair 11 and enters the discharge operation flow C. If the final fold is on the left side, the discharge operation flow C is entered as it is.
Finally, in the discharge operation flow C, the trailing edge of the sheet passes the folding width left detection sensor 16 and the folding width left detection sensor 16 is turned OFF (S67), and then the folding motor 30 is stopped (S68) and the conveyance motor 52 is stopped. (S69) The discharge is completed.

As described above, when the paper sheet is repeatedly folded so that the right folding and the left folding are sequentially performed, the paper is folded in a zigzag manner and is nipped and conveyed by the pair of folding rollers 11 and 12. In such a sheet bundle state, the sheet forms a loop and enters the nip of the pair of folding rollers 11 and 12 as shown in FIGS. . When the sheet is repeatedly folded, the sheet bundle expands depending on the degree of the fold of the folded sheet, and the thickness of the sheet bundle is T in FIG. When the sheet bundle enters the nip portion of the left folding roller pair 11, the leading roller 21a of the deflecting means 21 applies a pressure F corresponding to the idling torque of the torque limiter 42b as shown in FIG. Since the sheet bundle is brought into contact with 11b, the thickness of the sheet bundle becomes a thickness T 'that is close to the thickness obtained by stacking the thicknesses of the sheets themselves by crushing the bulge of the bundle. From this state, the paper P enters a nip portion of the pair of left folding rollers 11 that forms a loop as indicated by a one-dot chain line and rotates in the direction of the arrow, is gripped, and the paper is folded to the left.
In this embodiment, as shown in FIG. 1, the paper repeatedly folded in a bellows shape is stacked on the tray 13 by the discharge roller 19, but the paper folded in a bellows shape is further folded into a cross shape and folded vertically and horizontally into a certain size. The same applies to the case of using the folder, and the present embodiment can also be used for the folder cross-folding mechanism.
The present invention can be applied not only to an electrophotographic image forming apparatus main body such as a copying machine, a printer, and a facsimile machine, but also to other image forming apparatus main bodies such as an ink jet printer and a printing machine.

1 is a schematic cross-sectional view showing an example of the configuration of an image forming apparatus in which a paper folding device of the present invention is mounted on a copying apparatus main body. Explanatory drawing which shows operation | movement of a paper folding apparatus. Explanatory drawing which shows operation | movement of a paper folding apparatus. Explanatory drawing which shows operation | movement of a paper folding apparatus. Explanatory drawing which shows operation | movement of a paper folding apparatus. The drive block diagram of a paper folding apparatus. The perspective view which shows the structure of a deflection | deviation means. The principal part perspective view which shows the structure of a deflection | deviation means. The block diagram of the control system of a paper folding apparatus. The figure which shows the flowchart of this embodiment. The figure which shows the flowchart of this embodiment. The enlarged view when the paper of this embodiment approachs a folding roller. Explanatory drawing which shows the operation | movement which has contact | abutted the deflection | deviation means to the paper upper surface at the time of discharge | emission when the last fold is the right side. Explanatory drawing which shows the operation | movement which has contact | abutted the deflection | deviation means to the paper upper surface at the time of discharge | emission when the last fold is the left side. The figure which shows the difference in the paper folding operation | movement by the presence or absence of the curl of a paper front end. The figure which shows the difference in the paper folding operation | movement by the presence or absence of the curl of a paper front end.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper folding device, 2 End surface folding part, 3 Paper folding part, 11, 12 Folding roller pair, 14 Conveying roller pair, 15 Tip detection sensor, 16 Folding width left detection sensor, 17 Folding width right detection sensor, 20, 21 Deflection Means, 20a, 21a Roller, 24, 25 Deflection means HP sensor, 30 Folding motor, 36, 43 Deflection means motor, 52 Conveyance motor, 100 Paper folding controller, 200 Copier main body, 201 Operation unit, 202 Main body control board

Claims (2)

A pair of first and second folding rollers arranged at a predetermined interval, a pair of conveying rollers for feeding paper between the first and second folding roller pairs, and in the vicinity of the pair of conveying rollers A sheet leading end detection sensor that detects that the sheet leading end enters between the first and second folding roller pairs, and a sheet disposed outside each nip portion of the first and second folding roller pairs. First and second folding width detection sensors for detecting the end, two deflecting units each operating to guide the sheet end to the nip portion of one of the pair of folding rollers, and a control unit for controlling them, A sheet folding apparatus capable of continuously diffracting a plurality of times by alternately switching the folding direction by the cooperation of the first and second folding roller pairs and the deflecting units,
The control means guides the leading edge of the sheet fed from the pair of conveying rollers using the deflecting means to the nip portion of the first or second folding roller pair and feeds it to the outside thereof, and then the conveying In carrying out multiple folds of paper by sequentially repeating stop, reverse rotation and forward rotation of the first and second folding roller pairs while continuing to feed the paper by the roller pair,
The control means feeds one of the deflecting means toward one folding roller pair so that the leading edge of the sheet is inserted into the one folding roller pair, and then operates the other deflecting means so that a middle portion of the sheet. In the process of forming the first bent portion by inserting the second bent roller pair into the other folding roller pair, the timing of starting the feeding of the other deflecting means for determining the length from the front end of the sheet to the first bent portion A sheet folding device, wherein the sheet leading edge detection sensor detects the leading edge of the sheet. An image forming apparatus comprising: an image forming apparatus main body; and the sheet folding device according to claim 1.

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