JP6217229B2 - Sheet processing apparatus, image forming system, and sheet bundle additional folding method - Google Patents

Description

  The present invention relates to a sheet processing apparatus, an image forming system, and a sheet bundle additional folding method, and in particular, a sheet-like recording medium such as paper, recording paper, transfer paper (hereinafter simply referred to as “sheet” in the present specification). The present invention relates to a sheet processing apparatus including a folding processing unit that folds the sheet processing apparatus, an image forming system including the sheet processing apparatus, and a sheet bundle additional folding method executed by the sheet processing apparatus.

  2. Description of the Related Art Conventionally, in a post-processing apparatus used in combination with an image forming apparatus such as a copying machine, a sheet is formed by a pair of folding rollers that are bound in the center of a sheet and installed in parallel with the sheet folding direction for one or a plurality of sheets Some bookbinding saddle-stitched booklets by folding the center of the bundle. Furthermore, in order to reinforce the fold of the saddle stitch booklet, a technique of additionally folding by a roller moving along the back of the booklet is already known.

  For example, a paper folding apparatus described in Japanese Patent Application Laid-Open No. 2010-018440 (Patent Document 1) is known as a technique for increasing the folding. The sheet folding device includes a middle folding unit that folds the central portion of the sheet bundle to form a fold, and a folding roller that reciprocates along the direction of the fold while sandwiching and pressing the fold to reinforce the fold of the sheet bundle. And a control unit for setting the number of reciprocating movements of the folding roller in accordance with the thickness of the sheet included in the sheet bundle. With this configuration, even when the paper type or the booklet creation conditions in the booklet creation mode are changed, an appropriate number of foldings can be set without complicated operations to form a good crease. I can do it.

  Specifically, in order to give a sufficient additional folding effect to booklets with different sheet number conditions, one additional folding is performed for a booklet with a small number of sheets, and two or more times for a booklet with a large number of sheets. It is intended to be added. It is also possible to cope with such a method that the number of times of folding is changed in accordance with the number of sheets, instead of changing the paper type or booklet creation conditions.

  However, if the number of times of folding (the same as that in the later-described embodiment) is set as in the former case, the processing time increases for a sheet bundle (booklet) having a large number of sheets, resulting in a decrease in production efficiency. It will be. Further, when the additional folding pressure is adjusted in accordance with the number of sheets as in the latter case, the mechanism becomes complicated.

  Therefore, the problem to be solved by the present invention is that a simple configuration is sufficient without reducing productivity even for sheet bundles having different sheet bundle conditions when the back of a saddle-stitched sheet bundle is added and folded. It is to be able to obtain an additional folding effect.

In order to solve the above-described problem, according to one aspect of the present invention , a folding unit that folds a sheet bundle and a fold portion of the sheet bundle that is folded by the folding unit are pressed in the thickness direction of the sheet bundle and further folded. In a sheet processing apparatus comprising: a pressing unit; and a moving unit that reciprocates the pressing unit in the width direction of the sheet bundle. A decompression unit that reduces the pressure applied by the pressing unit according to the position of the pressing unit. The pressing means includes a first pressurizing unit that pressurizes with an elastic force in an additional folding direction, and a second pressurizing unit that pressurizes with an elastic force in a direction opposite to the additional folding direction. To do .

According to one aspect of the present invention, when a saddle-stitched sheet bundle is folded back and folded, a sufficient increase in folding effect can be achieved with a simple configuration without reducing productivity even for sheet bundles having different sheet bundle conditions. Can be obtained. Note that problems, configurations, and effects other than those described above will be clarified in the following description of embodiments.

1 is a diagram illustrating a system configuration of an image forming system including an image forming apparatus and a plurality of sheet processing apparatuses according to an embodiment of the present invention. FIG. 9 is an operation explanatory diagram of the saddle stitch bookbinding apparatus showing a state when the sheet bundle is carried into a half-fold conveyance path. FIG. 10 is an operation explanatory diagram of the saddle stitch bookbinding apparatus showing a state at the time of saddle stitching of a sheet bundle. FIG. 10 is an operation explanatory diagram of the saddle stitch bookbinding apparatus illustrating a state when the movement to the center folding position of the sheet bundle is completed. FIG. 10 is an operation explanatory diagram of the saddle stitching bookbinding apparatus showing a state at the time of executing the folding process of the sheet bundle. FIG. 10 is an operation explanatory diagram of the saddle stitching apparatus showing a state at the time of paper discharge after the end of folding of a sheet bundle. It is a principal part front view which shows an additional folding roller unit and a folding roller pair. It is the principal part side view which looked at FIG. 7 from the left side. It is a figure which shows the detail of a guide member. It is a principal part enlarged view of FIG. 9 which shows a state when the path | route switching nail | claw is not switched. It is a principal part enlarged view of FIG. 9 which shows the state by which the 1st path | route switching nail | claw was switched. It is operation | movement explanatory drawing which shows the initial state of an additional folding operation | movement. It is operation | movement explanatory drawing which shows the state at the time of the forward movement start of an additional folding roller unit. FIG. 12 is an operation explanatory diagram illustrating a state when the third folding path is reached near the center of the sheet bundle of the additional folding roller unit. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit pushes the 1st path | route switching nail | claw and enters into a 2nd guidance path | route. FIG. 10 is an operation explanatory diagram illustrating a state when the additional folding roller unit moves in the end direction while pressing the sheet bundle. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to the final position of an outward movement along the 2nd guidance path | route. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit starts a backward movement from the last position of a forward movement. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit starts a backward movement, and has reached the 6th guidance path | route. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit reaches the 6th guidance path | route and transfers to a press state from a press release state. It is operation | movement explanatory drawing which shows a state when it will be in a perfect press state, if an additional folding roller unit enters the 6th guidance 5th guidance path | route. It is operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to a 5th guide path | route as it is, and returned to the initial position. It is operation | movement explanatory drawing which shows the operation | movement at the time of the additional folding of the additional folding roller unit which concerns on this embodiment which provided the pressure reduction spring in addition to the pressurization spring. FIG. 6 is a characteristic diagram illustrating a relationship between the number of sheets and a load during additional folding. It is a figure which shows the structure of the pressure reduction spring provided with the adjustment mechanism. It is a block diagram which shows the control structure of an image forming system.

  The present invention is characterized in that there is provided a pressure reducing means for applying pressure in a direction that cancels out the additional folding pressure. The decompression means optimizes the pressure by suppressing the pressure of the additional folding by the pressurizing means when the booklet having a small number of sheets is further folded, and the decompression means does not act when the booklet having a large number of sheets is additionally folded. Thus, the sheet was further folded by the pressure applied by the pressurizing means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a system configuration of an image forming system SY including an image forming apparatus and a plurality of sheet processing apparatuses in the present embodiment. In the present embodiment, the first and second sheet post-processing apparatuses 1 and 2 are connected in this order at the subsequent stage of the image forming apparatus PR. In the present exemplary embodiment, the sheet processing apparatus is disposed at the subsequent stage of the image forming apparatus PR, and thus is referred to as a sheet post-processing apparatus.

  The first sheet post-processing apparatus 1 is a sheet post-processing apparatus having a sheet bundle creating function for receiving sheets one by one from the image forming apparatus PR, sequentially aligning and aligning them, and creating a sheet bundle in a stack unit. The first sheet post-processing apparatus 1 discharges the sheet bundle from the sheet bundle discharge roller 10 to the second sheet post-processing apparatus 2 at the subsequent stage. The second sheet post-processing apparatus 2 is a saddle stitch bookbinding apparatus that receives a conveyed sheet bundle and performs saddle stitching and folding (in this specification, the second sheet post-processing apparatus is also referred to as a saddle stitch bookbinding apparatus). Called).

  The saddle stitch binding apparatus 2 discharges the booklet (sheet bundle) as it is, or further discharges it to a sheet post-processing apparatus (not shown) in the subsequent stage. The image forming apparatus PR forms a visible image on a sheet-like recording medium based on input image data or image data of a read image. For example, a copier, a printer, a facsimile machine, or a digital multifunction machine having at least two of these functions corresponds to this. The image forming apparatus PR is a known system such as an electrophotographic system or a droplet ejection system, and any image forming system may be used.

  In the figure, the saddle stitch bookbinding apparatus 2 includes an entrance conveyance path 241, a sheet through conveyance path 242, and a center folding conveyance path 243. An inlet roller 201 is provided at the most upstream portion in the sheet conveyance direction of the inlet conveyance path 241, and the aligned sheet bundle is carried into the apparatus from the sheet bundle discharge roller 10 of the first sheet post-processing apparatus 1. . In the following description, the upstream side in the sheet conveyance direction is simply referred to as the upstream side, and the downstream side in the sheet conveyance direction is simply referred to as the downstream side.

  A branching claw 202 is provided on the downstream side of the inlet roller 201 in the inlet conveyance path 241. The branching claw 202 is installed in the horizontal direction in the figure, and branches the sheet bundle conveyance direction to the sheet-through conveyance path 242 or the half-fold conveyance path 243. The sheet through conveying path 242 is a conveying path that extends horizontally from the inlet conveying path 241 and guides the sheet bundle to a processing apparatus or a sheet discharge tray (not shown) in the subsequent stage. The sheet bundle is discharged to the subsequent stage by the upper discharge roller 203. The The middle folding conveyance path 243 extends vertically downward from the branch claw 202 and is a conveyance path for performing saddle stitching and middle folding processing on the sheet bundle.

  The middle folding conveyance path 243 includes a bundle conveyance guide plate upper 207 that guides the sheet bundle at the upper part of the folding plate 215 for folding in, and a lower bundle conveyance guide plate 208 that guides the sheet bundle at the lower part of the folding plate 215. I have. The bundle conveying guide plate 207 is provided with an upper bundle conveying roller 205, a rear end tapping claw 221, and a lower bundle conveying roller 206 from the top. The rear end tapping claw 221 is erected on a rear end tapping claw driving belt 222 driven by a drive motor (not shown). The rear end tapping claw 221 strikes (presses) the rear end of the sheet bundle toward the movable fence described later by the reciprocating rotation of the drive belt 222, and performs the sheet bundle alignment operation. Further, when the sheet bundle is carried in and when the sheet bundle is raised for the middle folding, the sheet bundle is retracted from the middle folding conveyance path 243 on the bundle conveyance guide plate 207 (a broken line position in FIG. 1).

  Reference numeral 294 denotes a rear end tapping claw HP sensor for detecting the home position of the rear end tapping claw 221, and detects the position of the broken line in FIG. 1 (solid line position in FIG. 2) retracted from the intermediate folding conveyance path 243 as the home position. The rear end tapping claw 221 is controlled based on this home position.

  A saddle stitching stapler S1, a saddle stitching jogger fence 225, and a movable fence 210 are provided on the lower bundle conveyance guide plate 208 from above. The lower bundle conveyance guide plate 208 is a guide plate that receives the sheet bundle conveyed through the upper bundle conveyance guide plate 207. A pair of saddle stitch jogger fences 225 is installed in the width direction, and the front end of the sheet bundle abuts (supports) below, and the movable fence 210 is provided to be movable up and down.

  The saddle stitching stapler S1 is a stapler that binds the central portion of the sheet bundle. The movable fence 210 moves up and down while supporting the leading end of the sheet bundle, and the center position of the sheet bundle is positioned at a position facing the saddle stitching stapler S1, and stapling, that is, saddle stitching is performed at that position. . The movable fence 210 is supported by the movable fence drive mechanism 210a and is movable from the position of the movable fence HP sensor 292 in the upper part of the drawing to the lowest position. The movable range of the movable fence 210 with which the front end of the sheet bundle abuts ensures a stroke that can be processed from the maximum size that can be processed by the saddle stitch binding apparatus 2 to the minimum size. For example, a rack and pinion mechanism is used as the movable fence drive mechanism 210a.

  A folding plate 215, a pair of folding rollers 230, an additional folding roller unit 260, and a lower paper discharge roller 231 are provided between the upper and lower bundle conveying guide plates 207, that is, substantially at the center of the intermediate folding conveying path 243. Yes. In the additional folding roller unit 260, additional folding rollers are arranged up and down across a paper discharge conveyance path between the pair of folding rollers 230 and the lower paper discharge roller 231. The folding plate 215 can reciprocate in the horizontal direction shown in the drawing, and the nip of the pair of folding rollers 230 is positioned in the operation direction when performing the folding operation, and the paper discharge conveyance path 244 is installed on the extension. . The lower paper discharge roller 231 is provided on the most downstream side of the paper discharge conveyance path 244 and discharges the sheet bundle that has been folded to the subsequent stage.

  A sheet bundle detection sensor 291 is provided on the lower end side of the upper bundle conveyance guide plate 207 and detects the leading edge of the sheet bundle that is carried into the middle folding conveyance path 243 and passes the middle folding position. In addition, a fold portion passage sensor 293 is provided in the paper discharge conveyance path 244, and detects the leading end of the folded sheet bundle and recognizes the passage of the sheet bundle.

  In general, in the saddle stitch bookbinding apparatus 2 configured as shown in FIG. 1, the saddle stitching and folding operation is performed as shown in the operation explanatory diagrams of FIGS. That is, when the saddle stitching middle fold is selected from the operation panel (not shown) of the image forming apparatus PR, the sheet bundle SB for which the saddle stitching middle fold is selected is conveyed by the bifurcating operation of the branching claw 202 in the counterclockwise direction. Guided to the path 243 side. The branching claw 202 is driven by a solenoid. A motor drive may be used instead of the solenoid.

  The sheet bundle SB carried into the middle folding conveyance path 243 is conveyed downward along the middle folding conveyance path 243 by the entrance roller 201 and the bundle conveyance roller upper 205. Then, after the passage is confirmed by the sheet bundle detection sensor 291, the sheet bundle SB is conveyed to a position where the leading end of the sheet bundle SB hits the movable fence 210 by the lower bundle conveyance roller 206 as shown in FIG. 2. At that time, the movable fence 210 stands by at different stop positions according to the sheet size information from the image forming apparatus PR, here, the size information in the conveying direction of each sheet bundle SB. At this time, in FIG. 2, the lower bundle conveying roller 206 holds the sheet bundle SB in the nip, and the rear end tapping claw 221 is waiting at the home position.

  In this state, as shown in FIG. 3, the nipping pressure of the lower bundle conveying roller 206 is released (in the direction of arrow a), and the front end of the sheet bundle comes into contact with the movable fence 210 and the rear end becomes free. Then, the trailing edge tapping claw 221 is driven, and the trailing edge of the sheet bundle SB is hit to perform final alignment in the conveying direction (direction of arrow c).

  Next, the alignment operation in the width direction (direction orthogonal to the sheet conveyance direction) is performed by the saddle stitching jogger fence 225, and the alignment operation in the conveyance direction is performed by the movable fence 210 and the trailing edge hitting claw 221. Thereby, the alignment operation in the width direction and the conveyance direction of the sheet bundle SB is completed. At this time, the pushing amount of the trailing edge hitting claw 221 and the saddle stitching jogger fence 225 is changed to an optimum value and matched based on the sheet size information, the sheet bundle number information, and the sheet bundle thickness information.

  In addition, if the bundle is thick, the space in the transport path is reduced, and there are many cases where alignment cannot be performed by a single alignment operation. Therefore, in such a case, the number of matching is increased. Thereby, a better alignment state can be realized. Furthermore, since the time for sequentially stacking sheets on the upstream side increases as the number of sheets increases, the time until the next sheet bundle SB is received becomes longer. As a result, even if the number of times of matching is increased, there is no time loss as a system, so that a good matching state can be realized efficiently. Therefore, it is possible to control the number of matchings according to the upstream processing time.

  The standby position of the movable fence 210 is normally set to a position where the saddle stitching position of the sheet bundle SB faces the binding position of the saddle stitching stapler S1. This is because if the alignment is performed at this position, the movable fence 210 can be bound as it is at the stacked position without being moved to the saddle stitching position of the sheet bundle SB. Therefore, at this standby position, the stitcher of the saddle stitching stapler S1 is driven in the center of the sheet bundle SB in the direction of arrow b, the binding process is performed with the clincher, and the sheet bundle SB is saddle stitched.

  The movable fence 210 is positioned by pulse control from the movable fence HP sensor 292, and the rear end tapping claw 221 is positioned by pulse control from the rear end tapping claw HP sensor 294. Positioning control of the movable fence 210 and the trailing edge tapping claw 221 is executed by the CPU 2b of the control circuit 2a of the saddle stitch bookbinding apparatus 2.

  The sheet bundle SB that has been saddle-stitched in the state of FIG. 3 is in a state of being saddle-stitched (sheet bundle SB) as the movable fence 210 is moved upward in a state where the pressure of the lower bundle conveying roller 206 is released as shown in FIG. Is moved to a position facing the folding plate 215. This position is also controlled based on the detection position of the movable fence HP sensor 292.

  When the sheet bundle SB reaches the position shown in FIG. 4, the folding plate 215 moves in the nip direction of the pair of folding rollers 230 as shown in FIG. 5, and the sheet bundle SB near the staple needle where the sheet bundle SB is bound is moved. It abuts from a substantially right angle direction and extrudes to the nip side. The sheet bundle SB is pushed by the folding plate 215, guided to the nip of the folding roller pair 230, and pushed into the nip of the folding roller pair 230 that has been rotated in advance. The pair of folding rollers 230 pressurizes and conveys the sheet bundle SB pushed into the nip. By this pressurizing and conveying operation, folding is performed at the center of the sheet bundle SB to form a simple bound sheet bundle SB. FIG. 5 shows a state where the tip of the fold portion SB1 of the sheet bundle SB is sandwiched and pressed by the nip of the pair of folding rollers 230.

  In FIG. 5, the sheet bundle SB whose center is folded in half is conveyed by the pair of folding rollers 230 as a sheet bundle SB as shown in FIG. 6, and is further sandwiched by the lower paper discharge roller 231 and discharged to the subsequent stage. . At this time, when the rear end of the sheet bundle SB is detected by the fold portion passage sensor 293, the folding plate 215 and the movable fence 210 are returned to the home position, and the lower bundle conveying roller 206 is returned to the pressurized state. Prepare for carrying in SB. If the next job has the same number and the same number of sheets, the movable fence 210 may move to the position shown in FIG. 2 again and wait. These controls are also executed by the CPU 2b of the control circuit 2a.

  FIG. 7 is a main part front view showing the additional folding roller unit and the pair of folding rollers, and FIG. 8 is a main part side view of FIG. 7 viewed from the left side. The additional folding roller unit 260 is installed in a paper discharge conveyance path 244 between the pair of folding rollers 230 and the lower paper discharge roller 231, and includes a unit moving mechanism 263, a guide member 264, and a pressing mechanism 265. The unit moving mechanism 263 reciprocates the additional folding unit 260 along the guide member 264 in the illustrated depth direction (direction perpendicular to the sheet conveying direction) by a driving source and a driving mechanism (not shown). The pressing mechanism 265 is a mechanism that applies pressure from above and below to press the sheet bundle SB, and includes an additional folding roller / upper unit 261 and an additional folding roller / lower unit 262.

  The additional folding roller / upper unit 261 is supported to be movable in the vertical direction by the support member 265b with respect to the unit moving mechanism 263, and the additional folding roller / lower unit 262 cannot be moved to the lower end of the support member 265b of the pressing mechanism 265. It is attached. The upper additional folding roller 261a of the additional folding roller / upper unit 261 can be pressed against the lower additional folding roller 262a, and presses the sheet bundle SB between the nips thereof. The pressing force is applied by a pressurizing spring 265c as a first pressurizing unit that pressurizes the additional folding roller / upper unit 261 with an elastic force. Then, in the pressurized state, the sheet bundle SB moves in the width direction (direction of arrow D1 in FIG. 8) as will be described later, and additional folding is performed on the fold portion SB1.

FIG. 9 is a diagram showing details of the guide member 264. The guide member 264 includes a guide path 270 that guides the additional folding roller unit 260 in the width direction of the sheet bundle SB.
1) A first guide path 271 that guides the pressing mechanism 265 in a released state during forward movement
2) Second guide path 272 for guiding the pressing mechanism 265 in a pressed state during forward movement
3) A third guide path 273 that switches the pressing hand 265 from the pressing release state to the pressing state during the forward movement.
4) A fourth guide path 274 for guiding the pressing mechanism 265 in the pressed release state during the backward movement.
5) A fifth guide path 275 for guiding the pressing mechanism 265 in a pressed state during the backward movement.
6) A sixth guide path 276 that switches the pressing mechanism 265 from the pressed release state to the pressed state during the backward movement.
These six routes are set.

  10 and 11 are enlarged views showing the main part of FIG. As shown in FIGS. 10 and 11, the first route switching claw is provided at the intersection of the third guide route 273 and the second guide route 272 and at the intersection of the sixth guide route 276 and the fifth guide route 275, respectively. 277 and a second path switching claw 278 are installed. As shown in FIG. 11, the first route switching claw 277 can be switched from the third guide route 273 to the second guide route 272, and the second route switching claw 278 can be switched from the sixth guide route 276 to the fifth guide. Switching to the path 275 is possible. However, in the former, switching from the second guide route 272 to the third guide route 273 is impossible, and in the latter, switching from the fifth guide route 275 to the sixth guide route 276 is impossible. That is, it is configured not to be switched in the reverse direction. In addition, the arrow in FIG. 11 has shown the movement locus | trajectory of the guide pin 265a.

  The reason why the pressing mechanism 265 moves along the guide path 270 is that the guide pin 265a of the pressing mechanism 265 is movably fitted in the guide path 270 in a loose fit state. That is, the guide path 270 functions as a cam groove and functions as a cam follower that changes its position while the guide pin 265a moves along the cam groove.

  12 to 22 are operation explanatory views of the additional folding operation by the additional folding roller unit in this embodiment.

  FIG. 12 shows a state in which the sheet bundle SB folded by the folding roller 230 is conveyed to a preset additional folding position and stopped, and the additional folding roller unit 260 is in the standby position. This state is the initial position of the additional folding operation.

  From the initial position (FIG. 12), the additional folding roller unit 260 starts to move in the right direction (arrow D2 direction) (FIG. 13). At that time, the pressing mechanism 265 in the additional folding roller unit 260 moves along the guide path 270 of the guide member 264 by the action of the guide pin 265a. Immediately after the operation is started, the vehicle moves along the first guide route 271. At that time, the pair of additional folding rollers 261a and 262a is in a pressed release state. Here, the pressed release state is a state where the additional folding rollers 261a, 262a and the sheet bundle SB are in contact with each other but almost no pressure is applied, or the additional folding rollers 261a, 262a are separated from the sheet bundle SB. Represents.

  When the third guide path 273 is reached in the vicinity of the center of the sheet bundle SB (FIG. 14), the pressing mechanism 265 starts to descend along the third guide path 273 and pushes the first path switching claw 277 to the second position. 2 enters the guide route 272 (FIG. 15). At this time, the pressing mechanism 265 is in a state of pressing the additional folding roller / upper unit 261, and the additional folding roller / upper unit 261 is in contact with the sheet bundle SB and is in a pressing state.

  The additional folding roller unit 260 further moves in the direction of the arrow D2 while being pressed (FIG. 16). At that time, since the second path switching claw 278 cannot move in the reverse direction, the second path switching claw 278 moves along the second guide path 272 without being guided by the sixth guide path 276, and exits the sheet bundle SB. It is located at the final position of the forward movement (FIG. 17). When moved so far, the guide pin 265a of the pressing mechanism 265 moves from the second guide path 272 to the upper fourth guide path 274. As a result, the restriction of the position of the guide pin 265a by the upper surface of the second guide path 272 is released, so that the upper folding roller 261a is separated from the lower folding roller 262a and is in a pressed release state.

  Next, the additional folding roller unit 260 starts moving backward by the unit moving mechanism 263 (FIG. 18). In the backward movement, the pressing mechanism 265 moves along the fourth guide path 274 in the left direction (arrow D3 direction) in the figure. When the pressing mechanism 265 reaches the sixth guide path 276 by this movement (FIG. 19), the guide pin 265a is pressed downward along the shape of the sixth guide path 276, and the pressing mechanism 265 is released from the pressed release state. Transition to the pressed state (FIG. 20).

  Then, when entering the fifth guide path 275, it is in a completely pressed state, and the fifth guide path 275 is moved in the direction of the arrow D3 as it is (FIG. 21), and the sheet bundle SB is exited (FIG. 22).

  In this way, the additional folding roller unit 260 is reciprocated to perform additional folding on the sheet bundle SB. At that time, additional folding from the central portion of the sheet bundle SB to one side is started, and the sheet bundle SB passes through one end portion SB2. Thereafter, the sheet is passed over the additionally folded sheet bundle SB, and the folding from the center part of the sheet bundle to the other side is started, and the additional folding is performed by the operation of exiting the other end part SB2.

  When operated in this way, the additional folding roller pair 261a, 262a comes into contact with the end portion SB2 of the sheet bundle SB from the outside of the sheet bundle SB when the folding start is started or when one side is pulled out and then returned to the other. Neither is it pressurized. In other words, when the end portion SB2 of the sheet bundle SB is passed from the outside of the end portion, the additional folding roller unit 260 is in a pressed release state. Therefore, damage to the end portion SB2 of the sheet bundle SB does not occur. Further, since the sheet SB is further folded from the vicinity of the center of the sheet bundle SB to the end SB, the distance traveled by contacting the sheet bundle SB at the time of additional folding is shortened, and wrinkles that cause wrinkles and the like are not easily accumulated. Therefore, when the fold portion (back) SB1 of the sheet bundle SB is further folded, the end portion SB2 of the sheet bundle SB is not damaged, and the crease portion SB1 and the wrinkles and wrinkles in the vicinity due to the accumulation of the crease are generated. Can also be suppressed.

In order to prevent the additional folding roller pair 261a, 262a from riding on the end SB2 from the outside of the end SB2 of the sheet bundle SB, the following is performed. That is, assuming that the distance that the additional folding roller unit 260 moves on the sheet bundle when the pressure is released during the forward movement is La, and the distance that the sheet bundle is moved while the pressure is released when the backward movement is Lb, the sheet bundle is Lb. The relationship between the length L in the width direction and the distances La and Lb is as follows:
L> La + Lb
It is essential (FIGS. 12 to 14 and FIGS. 17 to 19).

  Further, it is desirable that the distances La and Lb are set to be substantially the same, and pressing is started in the vicinity of the central portion in the width direction of the sheet bundle SB (FIGS. 16 and 20).

  In the additional folding roller unit 260 in this embodiment, an additional folding roller / lower unit 262 is prepared, and additional folding is performed by the additional folding roller pair 261a and 262a. On the other hand, the additional folding roller / lower unit 262 is deleted, and the additional folding roller / upper unit 261 and a receiving member (not shown) having an abutment surface facing the additional folding roller / upper unit 261 are provided and pressed between them. May be.

  Further, the additional folding roller unit 260 in the present embodiment is configured such that the additional folding roller / upper unit 261 is movable up and down, and the additional folding roller / lower unit 262 is configured not to move in the vertical direction. In contrast, the additional folding roller / lower unit 262 can also be configured to be movable in the vertical direction. With this configuration, the upper and lower rollers 261a and 262a move toward and away symmetrically with respect to the additional folding position, so that the additional folding position is constant regardless of the thickness of the sheet bundle SB and further suppresses damage such as scratches. be able to.

  FIG. 23 is an operation explanatory view showing an operation at the time of additional folding of the additional folding roller unit 260 according to this embodiment in which a pressure reducing spring 251 is provided in addition to the pressure spring 265c. (A) is a diagram showing a standby state, (b) is a diagram showing an operation during an additional folding operation by the pressure spring 265c, and (c) is an additional folding by the pressure spring 265c and the decompression spring 251. It is a figure which shows the operation | movement at the time of operation | movement. The pressure reducing spring 251 is a second pressing means having a function of reducing the pressure applied by the pressure spring 265c, and is constituted by a leaf spring. One end of the leaf spring is fixed to a part of the additional folding roller / lower unit 262, for example, the upper surface. The leaf spring shape of the pressure reducing spring 251 is a U-shape when viewed from the side, and the other end is a free end 251a.

  The standby state in FIG. 23A corresponds to the states in FIGS. In this case, the free end 251 a of the pressure reducing spring 251 does not touch the additional folding roller / upper unit 261. FIG. 23B shows a state where the sheet bundle SB having a large number of sheets is additionally folded. The pressure reducing spring 251 does not touch the additional folding roller / upper unit 261 in this case as well. FIG. 23C shows a state where the sheet bundle SB with a small number of sheets is additionally folded. The pressure-reducing spring 251 hits the roller shaft 261a1 of the additional folding roller / upper unit 261 and is elastically deformed, and applies a load upward (presses the roller shaft 261a1). Thus, only when the number of sheets of the sheet bundle SB is small, the pressure reducing spring 251 increases and abuts against the folding roller / upper unit 261 and pressurizes upward, in other words, acts to reduce the pressure applied by the pressure spring 265c. . The relationship between the number of sheets at this time and the load at the time of additional folding is as shown in the characteristic diagram of FIG.

  In this embodiment, the pressure spring 265c that presses the additional folding roller / upper unit 261 is a compression spring, so that the additional folding load changes in a linear proportional state with respect to the number of sheet bundles SB or the thickness of the sheet bundle SB. To do. When the number of sheets is small, there is a concern about damage to the folds or damage to the staples unless the pressure of the additional folding roller / upper unit 261 is reduced. In order to cope with this, it is preferable that the pressure is weak when the number of sheets is small, and the pressure is large when the number is large. In order to configure the pressure spring 265c in such a pressure relationship, it is necessary to extremely increase the spring constant.

  However, if the spring constant is increased, it is likely to be affected by an error, so that the configuration of the pressure spring 265c becomes unreasonable. On the other hand, as shown in FIG. 23, the pressure reducing spring 251 is installed and the additional folding load is adjusted as shown in the graph, so that the additional folding can be performed with an appropriate pressing force according to the number of sheets. In FIG. 24, the portion indicated by a straight line including the dotted line portion is the additional folding characteristic of only the pressure spring 265c, and the solid line having a broken line portion bent halfway from the straight portion is the pressure spring 265c and the pressure reducing spring 251. This is an additional folding characteristic.

  In the pressure roller unit 260 shown in FIG. 23, the position where the pressure-reducing spring 251 is in contact with the roller shaft 261a1 of the additional folding roller / upper unit 261 is constant. On the other hand, when the adjustment mechanism 250 is provided as shown in FIG. 25 and the vertical position of the pressure reducing spring 251 can be adjusted, the position of contact with the roller shaft 261a1 can be changed. As a result, the relationship between the number of sheets in the sheet bundle SB and the additional folding load can be changed. FIG. 25 is a diagram showing a configuration of a pressure reducing spring provided with an adjusting mechanism.

  In FIG. 25, the adjustment mechanism 250 basically includes, for example, a drive motor 252, a speed reduction mechanism 253, a screw member 254, and a connection member 255. The drive motor 252 is integrally attached to the additional folding roller / lower unit 262 via a support member 256. The speed reduction mechanism 253 decelerates the rotation of the motor shaft of the drive motor 252 and transmits it to the screw member 254. The connecting member 255 is joined integrally with the pressure reducing spring 251, and the screw portion of the screw member 254 is inserted into the female screw portion of the connecting member 255. Accordingly, when the screw member 254 rotates, the connecting member 255 is raised and lowered according to the rotation direction, and the pressure reducing spring 251 is raised and lowered integrally therewith.

  For example, this adjustment is automatically performed according to one or more conditions of sheet number information, paper thickness information, and paper type information. In addition, the adjustment amount can be changed from the operation panel PRc (see FIG. 26) so that the user can make adjustments.

  FIG. 26 is a block diagram showing a control configuration of the image forming system SY in the present embodiment.

  In FIG. 26, the image forming apparatus PR, the first sheet post-processing apparatus 1, and the saddle stitch bookbinding apparatus 2 are each a control circuit equipped with a microcomputer having CPU_PRb, 1b, 2b, RAM, ROM, I / O interface, and the like. PRa, 1a, 2a are provided. The CPU 1b of the first sheet post-processing apparatus 1 receives signals from the CPU_PRb of the image forming apparatus PR, each switch of the operation panel PRc, and each sheet detection sensor (not shown) via the communication interface 1c. Similarly, a signal from the CPU 1b of the first sheet post-processing apparatus or a signal from the image forming apparatus PR is input to the CPU 2b of the saddle stitch bookbinding apparatus 2 via the communication interface 2c.

  The CPU 2b of the saddle stitch bookbinding apparatus 2 executes preset control based on a signal input from the image forming apparatus PR side. Furthermore, the CPU 2b drives and controls the solenoid and the motor via the driver and the motor driver. The control is defined by the program code while the CPU 2b reads a program code stored in a ROM (not shown) or a hard disk HD and expands it in a RAM (not shown) and uses the RAM as a work area and a data buffer. It is executed based on the program.

  The additional folding operation and the control of the drive motor 256 are executed based on the program. In the saddle stitch binding apparatus 2, the position of the pressure reducing spring 251 is automatically set to an optimum load based on one or more pieces of information such as sheet number information, paper thickness information, and paper type information transmitted from the image forming apparatus PR. Move to position. For the movement position, for example, in the characteristics shown in FIG. 24, an appropriate additional folding load may be set according to the number of sheets in the sheet bundle SB. Therefore, the characteristics shown in FIG. 24 are stored in the ROM of the half-fold bookbinding apparatus 2 as a table, and the optimum load is set by referring to the folding load increased from the number of sheets transmitted from the image forming apparatus PR side, for example. can do.

  When this load adjustment is performed according to the user's intention, when the adjustment amount is input or selected from the operation panel PRc of the image forming apparatus PR, the information is transmitted to the CPU 2b of the half-fold bookbinding apparatus 2. Unlike the case where it is automatically performed, the CPU 2b sets an additional folding load corresponding to the input adjustment amount, and moves the pressure reducing spring 251 to the height. As a result, additional folding can be performed with an additional folding load according to the user's intention.

  Furthermore, in the present embodiment, the adjustment mechanism 250 is mounted on the additional folding roller / lower unit 262 of the additional folding roller unit 260 that moves in the sheet width direction. It is also possible to adjust according to the positional relationship. For example, by pressing slightly at the peripheral portion of the staple and by pressing strongly at the other portions, a good fold can be obtained while avoiding sheet bundle damage that may occur as a result of sandwiching the staple.

  According to this embodiment, there are the following effects.

(1) A pressing mechanism 265 that presses the folding plate 215 and the folding roller pair 230 (folding unit) for folding the sheet bundle SB and the fold portion SB1 of the folded sheet bundle SB in the thickness direction of the sheet bundle SB and further folds the sheet bundle SB. In the saddle stitch bookbinding apparatus 2 (sheet processing apparatus) provided with (pressing means) and a unit moving mechanism 263 (moving means) for reciprocating the pressing mechanism 265 in the width direction of the sheet bundle SB, the pressing mechanism 265 adds Since the pressure reducing spring 251 (pressure reducing means) for reducing the pressure according to the position of the upper side additional folding roller 261a (pressing means) of the pressing mechanism 265 is provided, the pressure according to the position of the upper side additional folding roller 261a without reducing the productivity. Can be folded with an appropriate load.

  The position of the upper side additional folding roller 261a is a position for pressing the sheet bundle PB to be pressed, and changes according to the thickness of the sheet bundle SB to be pressed. Therefore, the pressure is reduced according to the change in thickness (for example, it is large when the thickness is small and small when the thickness is thick). Thereby, it is possible to perform additional folding with an appropriate load by the pressure of the pressurizing spring 265a decompressed by the decompression spring 251. In this way, in order to apply a pressure suitable for the thickness of the sheet bundle to be additionally folded, the number of additional folding operations is only one regardless of the thickness or the number of sheet bundles, and the productivity is not affected. be able to.

(2) The pressing mechanism 265 (pressing means) includes a pressure spring 265c (first pressing means) that pressurizes in the additional folding direction, and a pressure reducing spring 251 (second pressing force) that presses in the direction opposite to the additional folding direction. The sheet bundle SB is thicker than a preset thickness, and is pressed by the pressure spring 265c (first pressurizing means), and the sheet bundle SB is equal to or less than the preset thickness. In addition, since the pressure reducing spring 251 (second pressing means) pressurizes and depressurizes in the opposite direction under the pressure applied by the pressure spring 265c, the productivity is lowered even for sheet bundles having different number conditions. In addition, a sufficient additional folding effect can be obtained with a simple configuration.

(3) The pressure reduction is performed by the roller shaft 261a1 (pressing means) of the upper side additional roller 261a of the pressing mechanism 265 hitting the pressure reducing spring 251 (second pressure means), and the pressure reducing spring 251 is elastically deformed. Therefore, the additional folding load can be reduced with a simple configuration.

(4) Since the roller shaft 261a1 (pressing means) of the upper folding roller 261a of the pressing mechanism 265 is provided with the adjusting mechanism 250 (adjusting means) for adjusting the position where the roller shaft 261a1 abuts against the pressure reducing spring 251 (second pressing means). The pressure applied by the pressure spring 265c can be adjusted by changing the abutting position. As a result, additional folding can be performed with a pressure suitable for the sheet bundle conditions, and the folding quality of the sheet bundle SB can be improved.

(5) Since the adjustment mechanism 250 (adjustment means) performs the adjustment based on at least one of the information on the number of sheets conveyed, the paper thickness information, and the paper type information, it is suitable for the sheet bundle condition. It is possible to automatically adjust the pressure, and the folding quality of the sheet bundle SB can be improved.

(6) Since the adjustment mechanism 250 (adjustment means) performs the adjustment according to an instruction from an operation panel PRc (operation means) that can be operated by the user, it is possible to adjust the pressure according to the user's intention. The folding quality of the sheet bundle SB can be improved.

(7) The pressure reducing spring 251 (second pressing means) is installed in a movable pressing mechanism 265 (pressing means) and reciprocates in the width direction of the sheet bundle SB. The pressure reducing action can be performed while moving to.

(8) Since the adjusting mechanism 250 (adjusting means) adjusts the position where the pressing mechanism 265 (pressing means) and the sheet bundle SB collide with each other in the width direction, the pressure is applied only at a specific location such as a staple position. Can be adjusted so as to weaken the sheet bundle, and the folding quality of the sheet bundle SB can be improved.

(9) According to the image forming system SY provided with the saddle stitch bookbinding apparatus 2 (sheet processing apparatus) and the image forming apparatus PR described in (1) to (8), it is described in (1) to (8). An image forming system having an effect can be obtained.

(10) A pressing mechanism 265 that presses the folding plate 215 and the folding roller pair 230 (folding unit) for folding the sheet bundle SB and the fold portion SB1 of the folded sheet bundle SB in the thickness direction of the sheet bundle SB and further folds. (Pressing means) and unit folding mechanism 263 (moving means) for reciprocating the pressing mechanism 265 in the width direction of the sheet bundle SB, the additional folding of the sheet bundle SB in the saddle stitch binding apparatus 2 (sheet processing apparatus) In the method, since the pressure applied by the pressing mechanism 265 is reduced and increased according to the position of the upper folding roller 261a (pressing means) of the pressing mechanism 265, the thickness of the sheet bundle SB that is pressed without reducing productivity. Depending on the thickness, additional folding can be performed with an appropriate load.

  In the description of the effects in the above-described embodiment, the constituent elements in the claims are indicated in parentheses for each part of the present embodiment, or a reference numeral is attached, and the correspondence between the two is clarified.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, and all the technical matters included in the technical idea described in the claims are all included. The subject of the present invention. The above embodiment shows a preferable example, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification, These are included in the technical scope described in the appended claims.

2 Saddle stitch binding device (sheet processing device)
215 Folding plate 230 Folding roller pair (folding means)
250 Adjustment mechanism (adjustment means)
251 Pressure reducing spring (pressure reducing means, second pressure applying means)
261a Upper side additional folding roller 261a1 Roller shaft (pressing means)
263 Unit moving mechanism (moving means)
265 Pressing mechanism (pressing means)
265c Pressure spring (first pressure means)
PR Image forming device PRc Operation panel (operation means)
SB sheet bundle SB1 crease SY image forming system

JP 2010-018440 A

Claims (10)

Folding means for folding the sheet bundle, pressing means for pressing the fold portion of the sheet bundle folded by the folding means in the thickness direction of the sheet bundle, and further folding, and the pressing means in the width direction of the sheet bundle A sheet processing apparatus comprising: a moving means for reciprocally moving;
A pressure reducing means for reducing the pressure applied by the pressing means according to the position of the pressing means ;
The pressing means is
First pressurizing means for pressurizing with an elastic force in the additional folding direction;
A second pressurizing unit that pressurizes with an elastic force in a direction opposite to the additional folding direction;
Sheet processing apparatus, which comprises a. The sheet processing apparatus according to claim 1,
The decompression unit, when the following thickness before Symbol sheet bundle is set in advance, said first pressurized second pressurizing means under a pressurized state by the pressure means is reduced in pressure pressurized to the opposite direction A sheet processing apparatus. The sheet processing apparatus according to claim 2,
The sheet processing apparatus according to claim 1, wherein the pressure reduction is performed by the pressing unit striking the second pressing unit and the second pressing unit elastically deforming. The sheet processing apparatus according to claim 3,
A sheet processing apparatus, comprising: an adjusting unit that adjusts a position at which the pressing unit abuts against the second pressing unit. The sheet processing apparatus according to claim 4, wherein
The sheet processing apparatus, wherein the adjustment unit performs the adjustment based on at least one condition of information on the number of sheets conveyed, paper thickness information, and paper type information. The sheet processing apparatus according to claim 4, wherein
The sheet processing apparatus, wherein the adjustment unit performs the adjustment according to an instruction from an operation unit operable by a user. The sheet processing apparatus according to any one of claims 4 to 6,
The sheet processing apparatus, wherein the second pressurizing unit is installed in the movable pressing unit and reciprocates in the width direction of the sheet bundle. The sheet processing apparatus according to claim 7, wherein
The sheet processing apparatus, wherein the adjusting unit adjusts the abutting position according to a relative position in the width direction of the pressing unit and the sheet bundle.   An image forming system comprising the sheet processing apparatus according to claim 1. Folding means for folding the sheet bundle, pressing means for pressing the fold portion of the sheet bundle folded by the folding means in the thickness direction of the sheet bundle, and further folding, and the pressing means in the width direction of the sheet bundle A sheet bundle refolding method in a sheet processing apparatus comprising:
The pressing means is
First pressurizing means for pressurizing with an elastic force in the additional folding direction;
A second pressurizing unit that pressurizes with an elastic force in a direction opposite to the additional folding direction;
Including
Additionally folding method of the sheet bundle, characterized by folding under reduced pressure by the second pressure means in accordance with pressure applied by said first pressurizing means to the position of the pressing means.