Folding device

Abstract

To provide a folding device capable of allowing a user not to perform a paper jam removal operation by preventing a height of a folded bundle from exceeding an allowable upper limit, and discharging paper sheets without causing a paper jam at a discharge port, a folding roller pair or the like.SOLUTION: A folding device escapes a subsequent recording medium from a folded bundle by displacing a folding position and forms the spread-like folded bundle by alternately forming a folding width in designated length and a folding width shorter than the designated length from a folding operation after a predetermined number of sheets, when it is determined that the folding bundle exceeds a predetermined height capable of passing through a discharge port or a folding roller pair by continuing folding processing with a constant folding width, based on the total length of the recording medium and the folding width.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a folding device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, folding devices have been disclosed that are configured to fold paper into an accordion shape, align the folding positions neatly, and store the folded bundle in a predetermined size. Summary of the Invention [Problem to be solved by the invention]

[0003] In conventional folding devices, the general goal is to accurately align the fold position without misalignment. This results in thicker paper around the fold position due to bulging, and if this thickening occurs vertically, the sides of the folded stack tend to be higher. This can cause the sides of the folded stack to get caught in the exit port when ejecting from the folding device, or the folded stack's thickness exceeds the limit of the passable width between the rolls, resulting in a paper jam. To prevent this, a certain limit must be set for the number of folds, and when the limit is detected during the folding process, the folding operation must be stopped and the paper must be manually trimmed before ejecting. Thus, conventional folding devices have the problem of requiring additional work for the user.

[0004] To provide an apparatus for preventing a folded bundle from exceeding an upper limit of allowance in advance, and for discharging paper without causing paper jams at the discharge port or folding roller pair, thereby eliminating the need for a user to remove paper jams. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems and achieve the object, the present invention provides a folding device having a pair of folding rollers that folds a recording medium multiple times, a pair of conveying rollers that convey the recording medium to the pair of folding rollers, a guide section that switches the folding direction of the recording medium by the pair of folding rollers and folds the recording medium, an outlet that discharges a folded bundle that has been folded multiple times by the pair of folding rollers, and a detection section that can measure the fold width, wherein, based on the total length and fold width of the recording medium, it is determined that continuing the folding process at a constant fold width will cause the folded bundle to exceed a predetermined height that allows it to pass through the outlet or the pair of folding rollers, and from the folding operation onwards, from a predetermined number of sheets onwards, a fold width of a specified length and a fold width shorter than the specified length are alternately formed, thereby shifting the folding position and allowing the subsequent recording medium to escape from the folded bundle, and forming the folded bundle in a spread shape. [Effects of the Invention]

[0006] According to the present invention, it is possible to prevent the height of the folded bundle from exceeding the upper limit of the allowance, discharge the paper without causing a paper jam at the discharge outlet or the folding roller pair, etc., and thereby to provide the effect of eliminating the need for the user to remove the paper jam. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a folding device according to an embodiment, illustrating the time when a recording medium that has been transported into the folding device by the downward rotation of a pair of transport rollers from an image forming device (not shown) or the like enters the pair of folding rollers under the guidance of a folding knife. [Figure 2] FIG. 2 is a diagram showing the folding device of the embodiment, illustrating the time when the folded bundle approaches the discharge outlet or the upper limit that can pass through the pair of folding rollers and the folding position is about to be shifted. [Figure 3]FIG. 3 is a diagram showing the folding device of the embodiment, illustrating the point in time when the next folding position of the recording medium is nipped by the pair of folding rollers due to the downward conveying rotation of the pair of conveying rollers, the rightward conveying rotation of the pair of folding rollers, and the guidance of the folding knife. [Figure 4] FIG. 4 is a cross-sectional view of the folded bundle in the embodiment, showing the folded bundle when the folding operation starts from the point when the folded bundle approaches a height that allows it to pass through the discharge outlet and starts to form a spread-shaped folded bundle. [Figure 5] FIG. 5 is a diagram showing an example of a folding method different from that shown in FIG. 4 in shifting the folding position for escape according to the embodiment. [Figure 6] FIG. 6 is a diagram showing a folding method for reducing the length of the spread-shaped portion after release in the embodiment. [Figure 7] FIG. 7 is a flowchart of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, a folding device according to an embodiment will be described with reference to the accompanying drawings.

[0009] In the folding device of the embodiment, the folding process, which normally involves folding at a fixed fold width, takes into account the thickness and type of recording medium, the number of remaining folds, and the remaining length. If it determines that continuing the folding process at a fixed fold width would result in the folded bundle exceeding the height required to pass through the exit or the pair of folding rollers, resulting in a paper jam, the folding device then shifts the fold position by, for example, slightly shortening or lengthening the fold width of the even-numbered folds, creating a slope on the side of the folded bundle and dispersing the thickness at the fold position (hence the shape, resembling a deck of cards laid out in a horizontal row, henceforth referred to as a "spread shape" for convenience), thereby reducing the final height of the folded bundle. This prevents the folded bundle from exceeding the allowable height limit and allows the paper to be discharged without jamming at the exit or the pair of folding rollers, thereby eliminating the need for the user to remove the jam. The folding device is also referred to as a bellows folding device, and the discharge outlet is also referred to as a paper output port.

[0010] These will be explained below using diagrams.

[0011] 1 is a diagram showing a folding device 11 according to an embodiment, illustrating the time when a recording medium 7, which has been conveyed into the folding device 11 from an image forming device (not shown) or the like by the downward conveyance rotation of a conveying roller pair 10, enters the folding roller pair 1 under the guidance of a folding knife 8. The recording medium 7 is paper.

[0012] The pair of folding rollers 1 rotates to the right. At this time, the first fold width 7a of the recording medium 7 is determined by the measurement of the latter of the fold width detection sensors 6 and 5, both of which are provided on the conveying guide plate 3. The pair of conveying rollers 10 then rotates upward and the pair of folding rollers 1 rotates leftward, temporarily pulling the recording medium 7 back. The folding knife 8 then retracts, and the pair of conveying rollers 10 rotates downward and the pair of folding rollers 1 and 2 rotate leftward, conveying the recording medium 7 toward the pair of folding rollers 2. The folding knife 9 then guides the recording medium 7, nipping it between the pair of folding rollers 2 at the fold width 7a, forming a fold. This operation is repeated, and the fold width 7a is accumulated in a bellows-like shape. The folded bundle being discharged after folding may be higher than the outlet 4, resulting in a paper jam. This is a problem that this embodiment aims to solve.

[0013] FIG. 2 is a diagram showing the folding device 11 of the embodiment, illustrating the time when the folded bundle approaches the upper limit of the length that it can pass through the discharge outlet 4 and the folding roller pair 1 and the folding roller pair 2, and is about to shift the folding position.

[0014] Based on the overall length and folding width 7a of the recording medium 7, the system determines whether the folded bundle will exceed the predetermined height required to pass through the discharge outlet 4 or the pair of folding rollers 2 if folding continues at a constant folding width. Specifically, when folding the recording medium 7 to a certain width, the height of each folded bundle in the stacking direction is defined as h1, and the number of folded sheets to be formed in the folding job input by the user is defined as M. The system determines whether the value of h1 x M exceeds the predetermined height 7'. The predetermined height 7' is the lower of the upper limit of the height at which the folded bundle can be conveyed by the pair of folding rollers 1 and 2 in the folding device 11 and the upper limit of the height at which the folded bundle can pass through the discharge outlet 4. If the system determines that the predetermined height 7' will be exceeded, the folding width detection sensor 6 measures the folded width 7b (thick line) shorter than the original fold width 7a from the folding operation onwards for the specified number of sheets. This difference in length represents the deviation in the folding position required to form a spread. In this example, we will assume that it is shortened by 10 mm, but it is possible to automatically or manually set the length of the fold width 7b (= how much the folding position is shifted) appropriately taking into account the type and thickness of the recording medium 7, the number of folds, etc.

[0015] FIG. 3 is a diagram showing the folding device 11 of the embodiment, and like FIG. 1, shows the point in time when the next folding position of the recording medium 7 is nipped by the folding roller pair 1 due to the downward conveying rotation of the conveying roller pair 10, the rightward conveying rotation of the folding roller pair 1, and the guidance of the folding knife 8.

[0016] In this example, fold width 7b is 10 mm shorter than fold width 7a, resulting in a misaligned fold and a spread, as shown in the figure. At this point, fold width detection sensor 5 measures the next fold width 7c, but its length is the same as the original (i.e., the same length as fold width 7a). Detection begins at the end of fold width 7a. By subtracting the cumulative difference in length between fold width 7a and fold width 7b—10 mm in this example—the result can be considered a measurement from the end of fold width 7b. From there, fold width 7c (i.e., fold width 7a) and fold width 7b are alternately formed until the end. This repeats a long fold width, a short fold width, a long fold width, and so on. The fold position shifts (toward the left in this example), resulting in a spread-like shape on the side of the folded stack. The spread-like shape reduces the height of the folded stack, preventing it from getting caught and jamming as it passes through exit 4 or folding roller pair 1 and folding roller pair 2.

[0017] FIG. 4 is a cross-sectional view of a folded bundle in an embodiment, showing the folded bundle when the folding operation starts and the spread-shaped folded bundle begins to be formed from the point when the folded bundle approaches a height that allows it to pass through the discharge outlet 4.

[0018] While the recording medium 7 is being folded in the conventional accordion-like manner at its original folding width 7a, if it is determined that the folded bundle will reach the upper limit height 7' that it can be conveyed through the folding device 11 if the folding width continues as is, from that point on, the folding position is shifted to the left by pinching a folding width 7b (thick line) shorter than the original folding width 7a every other time, thereby allowing the folded bundle to escape and form a spread-shaped folded bundle. Here, in this embodiment, the act of shifting the folding position to allow the subsequent recording medium 7 to land sideways from the top of the folded bundle is called escape.

[0019] This prevents the height of the folded bundle from exceeding 7' as shown in the figure, and the folded bundle can be discharged from the discharge outlet 4 without causing a paper jam, eliminating the need for the user to remove the jammed paper.

[0020] At this time, it is possible to set how many of the remaining sheets are to have their folding positions shifted for escape, relative to the maximum height 7' that can be conveyed within the folding device 11. Here, the above "number of sheets" refers to the number of overlapping recording media 7 in the accordion-folded folded bundle. For example, the number of sheets in a accordion-folded bundle that is folded once on each side (forming a "Z" when viewed from the side) is three.

[0021] When the maximum number of folded sheets is set to X, which corresponds to the maximum height of 7' that can be conveyed, the following occurs: Deviation A = Original fold width 7a / (X / 2+1) This becomes:

[0022] The folding width in the forward direction 12 is set to a folding width 7b shorter than the original folding width 7a, and the folding width in the backward direction 13 is maintained at the original folding width 7a, thereby forming the deviation amount A.

[0023] FIG. 5 is a diagram showing an example of a folding method different from that shown in FIG. 4 in shifting the folding position for escape according to the embodiment.

[0024] Unlike in FIG. 4, the folding width in the forward direction 12 is set to a folding width 7d that is shorter than the original folding width 7a, and the folding width in the backward direction 13 is also set to a folding width 7d that is shorter than the original folding width 7a, and the folding width may be gradually shortened to allow the sheet to escape.

[0025] However, when the previous embodiments are used, the spread-like portion after escaping will continue to grow horizontally, which may cause problems with the horizontal length of the recording medium 7 when it is transported through the folding device 11. For this reason, to make the best use of this embodiment, it is important to find a way to reduce the length of the spread-like portion. A solution to this problem will be explained with reference to FIG. 6.

[0026] FIG. 6 is a diagram showing a folding method for reducing the length of the spread-shaped portion after release in the embodiment.

[0027] If the maximum number of folded sheets corresponding to the maximum height of 7' that can be conveyed is Y, then Deviation B = Original fold width 7a / (Y / 2+1) This becomes:

[0028] The folding width in the forward direction 12 is set to 7e, which is shorter than the original folding width 7a, and the folding width in the backward direction 13 is maintained at the original folding width 7a, thereby forming the deviation amount B. This deviation amount B is the optimum deviation amount for suppressing the length of the spread-like portion.

[0029] FIG. 7 is a flowchart of an embodiment. More specifically, FIG. 7 is a flowchart based on the folding method of FIG. 6. The following process is executed by a control device. The control device is, for example, a computer. Here, if the accordion paper discharge outlet 4 is on the right side, folding in the outgoing direction 12 is the outgoing path, and folding in the returning direction 13 is the returning path.

[0030] In S1, the control device sets the remaining number of sheets X and the folding width 7a based on user input via the operation panel of the folding device 11 or a PC connected to the folding device 11. In Figures 5 and 6, the remaining number of sheets X is the number of sheets to be folded over the folding width 7a while gradually reducing the paper width included within the folding width 7a after a predetermined number of sheets have been folded at the original folding width 7a. In Figure 6, two sheets with a width of 3 x A, two sheets with a width of 2 x A, and two sheets with a width of A are stacked in the area above the folding width 7a, so the value of X is six, which is the total. The folding width 7a is also called a uniform width.

[0031] In S2, the paper is conveyed so that the leading edge of the recording medium 7 is at the leading edge of the stack of papers that are piled up at the folding width 7a. At this point, the current number of sheets m, "1", is set in the counter.

[0032] In steps S3 and S4, the folding operation is repeated with a folding width of 7a.

[0033] In S5, the folding operation determines whether the maximum number of folds minus the current number of folds m is equal to or less than the remaining number of sheets set in S1 (6 in the example of Figure 6). If the answer is "Yes," the process proceeds to S6. The maximum number of folds is the maximum number of folds Y, which corresponds to the maximum height 7' that can be conveyed. The value of Y is stored in advance in the device's memory for each thickness and type of recording medium 7 to be folded.

[0034] In S6 and S7, the folding operation is performed with a fold width of (fold width 7a - offset amount A) if the direction is toward the discharge outlet 4, and with a fold width of 7a if the direction is away from the discharge outlet 4. In Figure 6, two sheets with a 3 x A width, two sheets with a 2 x A width, and two sheets with an A width are stacked in the area above fold width 7a. When these six sheets are stacked, the sheets are folded so that the amount that they protrude from the 7-width stack of paper on the left side in Figure 6 gradually increases.

[0035] In S8, when the current number of folds m reaches the maximum number of folds Y, the flow proceeds to S9, which is the maximum number of folds Y, which is 13 in the example of FIG.

[0036] In S9, folding is performed in an area to the left of the paper stack having a folding width 7a in FIG.

[0037] In S10, if the rear end of the recording medium 7 is detected by the sensor 21, the process proceeds to S11. Here, the sensor 21 is installed a predetermined distance to the left of the area where the recording medium 7 is being folded (upstream in the conveyance direction of the recording medium 7), as shown in FIG.

[0038] In S11, the folding operation is completed, and the entire folded recording medium 7 is discharged from the discharge opening 4 (FIG. 2). Note that if the overall length (the overall length in the left-right direction in FIG. 6) of the recording medium 7 that is folded while being shifted by the shift amount B is long, the already folded portion of the recording medium 7 may be partially discharged from the discharge opening 4 while the folding operation in S9 is being performed, and the entire recording medium 7, including the rear end, may be discharged in S11.

[0039] In the case of the folding configuration in Figure 5, when the specified folding width - offset amount A is used, the folding position on the return path remains the same, and when the specified folding width - offset amount B is used, the folding width is changed only on the outgoing path. In the case of the folding configuration in Figure 6, when the specified folding width - offset amount A is used and when the specified folding width - offset amount B is used, the folding width is changed only on the outgoing path. When the maximum number of sheets in the roll width is reached with X sheets remaining, Deviation A = Original fold width 7a / (X / 2+1) Furthermore, if the maximum number of folded sheets is Y, then Deviation B = Original fold width 7a / (Y / 2+1) is.

[0040] As described above, in this embodiment, the folding device 11 has the folding roller pair 1, the conveying roller pair 10, the folding knives 8 and 9 (guiding units), the discharge outlet 4, and the width detection sensors 5 and 6 (detecting units). The folding roller pair 1 folds the recording medium 7 multiple times. The conveying roller pair 10 causes the folding roller pair 1 to convey the recording medium 7. The folding knives 8 and 9 cause the folding roller pair 1 to switch the folding direction of the recording medium 7 and fold the recording medium 7. The discharge outlet 4 discharges the folded bundle that has been folded multiple times by the folding roller pair 1. The width detection sensors 5 and 6 can measure the fold width. If the folding device 11 determines, based on the overall length and folding width of the recording medium 7, that continuing the folding process at a constant folding width will cause the folded bundle to exceed the predetermined height required to pass through the discharge outlet 4 or the pair of folding rollers 1, it shifts the folding position by alternately folding the specified length and folding the width shorter than the specified length from the predetermined number of sheets onwards, thereby allowing the subsequent recording media to escape from the folded bundle and forming a spread-shaped folded bundle. The folding operation after the predetermined number of sheets is, for example, the operation of performing folding operations such as S6 and S9 after the number of sheets for which S5 in FIG. 7 is answered Yes.

[0041] With this configuration, if it is determined that the height of the folded bundle has reached the limit for passing through the discharge outlet 4, the above process can be performed urgently to avoid a paper jam. Although a folded bundle different from the user's intention may be discharged, the folded bundle can be completely discharged without causing a paper jam in the folding device 11, eliminating the need for the user to remove the paper jam. In addition, the height of the folded bundle can be dispersed before it exceeds the upper limit of the allowable height, allowing the paper to be discharged without causing a paper jam at the discharge outlet 4, the folding roller pair 1, etc.

[0042] Even if the above process is applied to avoid paper jams in the height of the conveyance path in the folding device 11, there is a possibility that paper jams may occur in the horizontal length of the conveyance path. Therefore, the folding device 11 of this embodiment can set the value of the remaining number of sheets X to any value. This makes it possible to shorten the length of the spread-shaped folded bundle after it has escaped, thereby avoiding paper jams in the horizontal length as well.

[0043] According to this configuration, by arbitrarily setting the value of the remaining number of sheets X, the user can arbitrarily select to increase the number of sheets to be folded at equal widths (by decreasing X), or to output most of the entire recording medium 7 in spread form (by increasing X), according to his or her intention.

[0044] In addition, in the folding device 11, the number of remaining sheets is defined as X, and the maximum number of sheets that can be folded when the folded bundle is tall enough to pass through the discharge outlet 4 or the pair of folding rollers 1 is defined as Y. The first shift amount is defined as (specified folding width) / (X / 2+1), and the second shift amount is defined as (specified folding width) / (Y / 2+1). The operation of moving the recording medium 7 in the forward direction 12 (first direction) toward the discharge outlet 4 and folding the recording medium is defined as the first-direction folding operation, and the operation of moving the recording medium 7 in the return direction 13 (second direction) opposite to the forward direction 12 and folding the recording medium is defined as the second-direction folding operation. In the above case, the folding device 11 performs the first operation when the remaining number of sheets is less than the value obtained by subtracting the current number of sheets to be folded from the maximum number of sheets to be folded, performs the second operation when the remaining number of sheets is equal to or greater than the value obtained by subtracting the current number of sheets to be folded from the maximum number of sheets to be folded, and performs the third operation when the current number of sheets to be folded is equal to or greater than the maximum number of sheets to be folded. The first operation involves folding the sheet with a specified folding width in both the first-direction folding operation and the second-direction folding operation. The second operation involves setting the folding width in the first-direction folding operation to a value obtained by subtracting the first offset amount from the specified folding width, and setting the folding width to the specified folding width in the second-direction folding operation. The third operation involves setting the folding width in the first-direction folding operation to a value obtained by subtracting the second offset amount from the specified folding width, and setting the folding width to the specified folding width in the second-direction folding operation. Note that the maximum number of folds may also be the maximum number of folds.

[0045] According to this configuration, the recording medium 7 can be folded while keeping the overall width (left-right direction in FIG. 6) of the recording medium 7, including the spread shape, compact.

[0046] Finally, the above-described embodiment is presented as an example and is not intended to limit the scope of the present invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, the embodiment and modifications thereof are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0047] 1 Pair of folding rollers 4 Outlet 5,6 Width detection sensor (detection part) 7 Recording media 8,9 Folding knife (guiding part) 10 conveying roller pair 11 Folding device [Prior art documents] [Patent documents]

[0048] [Patent Document 1] Special Publication No. 07-039312 [Patent Document 2] Special Publication No. 2002-519216 [Patent Document 3] Japanese Patent Application Publication No. 08-151168 [Patent Document 4] Japanese Patent Application Publication No. 05-238635

Claims

1. a pair of folding rollers that fold the recording medium multiple times; a pair of conveying rollers that convey the recording medium to the pair of folding rollers; a guide unit that switches the direction in which the folding roller pair folds the recording medium and folds the recording medium; a discharge port for discharging the folded bundle that has been folded multiple times by the pair of folding rollers; A detection unit that can measure the folding width, In a folding device having A folding device characterized in that, when it is determined based on the overall length and folding width of the recording medium that continuing the folding process at a constant folding width will cause the folded bundle to exceed a predetermined height that will allow it to pass through the discharge outlet or the pair of folding rollers, from the folding operation of a predetermined number of sheets onwards, the folding device alternately forms folding widths of a specified length and folding widths shorter than the specified length, thereby shifting the folding position to allow subsequent recording media to escape from the folded bundle and forming the folded bundle in a spread shape.

2. The folding device according to claim 1, A folding device characterized in that the number of remaining sheets can be set to any value.

3. The folding device according to claim 2, The remaining number is X, The maximum number of folded sheets when the folded bundle has a height that allows it to pass through the discharge outlet or the pair of folding rollers is defined as Y, The first shift amount is (the specified folding width) / (X / 2+1), The second shift amount is (the specified folding width) / (Y / 2+1), an operation of moving the recording medium in a first direction toward the discharge port and folding the recording medium is defined as a first direction folding operation; When an operation of moving the recording medium in a second direction opposite to the first direction and folding the recording medium is defined as a second direction folding operation, When the remaining number of sheets is less than a value obtained by subtracting the current number of folded sheets from the maximum number of folded sheets, a first operation is performed; when the remaining number of sheets is equal to or greater than a value obtained by subtracting the current number of folded sheets from the maximum number of folded sheets, a second operation is performed; and when the current number of folded sheets is equal to or greater than the maximum number of folded sheets, a third operation is performed; The first operation includes performing a folding operation with the specified folding width in both the first direction folding operation and the second direction folding operation, In the second operation, in the first direction folding operation, the folding width is set to a value obtained by subtracting the first shift amount from a specified folding width, and in the second direction folding operation, the folding width is set to the specified folding width; the third operation, in the first direction folding operation, sets the folding width to a value obtained by subtracting the second shift amount from a specified folding width, and in the second direction folding operation, sets the folding width to the specified folding width.

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