JP7805564B2 - Paper cutting device - Google Patents

Description

The present invention relates to a paper cutting device that cuts paper while transporting it.

Patent document 1 discloses a cutter device equipped with a clamping means that, when cutting a recording material, raises the recording material near the upstream side of the cutter blade from a conveying position when not cutting and presses it against the underside of a shearing plate, thereby clamping and holding the recording material between the shearing plate and the recording material across the width.

Patent No. 3879819

In the above-mentioned cutter device, the cutter blade is not configured to be able to move in any direction other than the width direction of the recording material, so if the recording material is tilted relative to the conveying direction, there is a risk that the recording material will not be cut accurately.

The applicant has therefore proposed in Japanese Patent Application No. 2020-142470 a paper cutting device equipped with a processing unit having a novel configuration, as shown in Figures 3 and 4 of the present application, as an invention that solves various problems in the prior art.

With this paper cutting device, the processing unit has an angle adjustment unit that can adjust the angle of inclination of the cutting unit and holding unit relative to the paper transport direction. This configuration makes it possible to realize a paper cutting device that can accurately cut even paper that is tilted relative to the transport direction.

However, adjusting the tilt angle of the processing unit and holding unit relative to the paper transport direction does not pose any accuracy issues up to the first cut position, which is a relatively short distance, after detecting the tilt detection mark 101 or the leading edge of the paper P. However, if the paper P is skewed when transporting from the first cut position to the second cut position, which is a predetermined distance or more away, the desired product will not be obtained when cutting at the second cut position at the same tilt angle as the first cut position. Possible causes of skew during paper transport include the type of paper and environmental factors.

The present invention aims to provide a paper cutting device that can cut accurately even if the cutting position is a predetermined distance or more from the skew detection mark 101 or the leading edge of the paper P, and the paper P is skewed during paper transport.

The invention of claim 1 provides a paper cutting device comprising a transport section that transports paper along a transport path, a processing section that processes paper transported by the transport section, and a control section that controls the transport section and the processing section. The processing section has a cutting section that cuts the paper in a direction perpendicular to the paper transport direction using a pair of cutting blades that are arranged opposite each other across a paper transport surface, and an angle adjustment section that can adjust the inclination angle of the cutting section with respect to the paper transport direction. The angle adjustment section has a plurality of sensors that are arranged side by side in a direction perpendicular to the paper transport direction as a correction means for the inclination angle of the cutting section, and adjusts the angle of the paper transport direction. The device is equipped with a skew detection unit as a first skew angle correction means that detects the skew angle relative to the direction, a memory unit that stores pre-measured skew characteristics specific to the paper cutting device, and a skew correction amount calculation unit as a second skew angle correction means that calculates the skew correction amount of the cutting unit based on the skew characteristics specific to the paper cutting device stored in the memory unit, and is characterized in that the angle adjustment unit uses the first skew angle correction means and the second skew angle correction means appropriately to adjust the skew angle of the cutting unit based on whether the cut position is a predetermined distance or more away from the skew detection mark or the leading edge position of the paper.

The invention described in claim 2 is characterized in that, in the paper cutting device described in claim 1 , the skew detection unit detects the skew angle of the paper relative to the paper transport direction from the difference in timing at which the multiple sensors detect skew detection marks provided downstream of the paper.

The invention described in claim 3 is characterized in that, in the paper cutting device described in claim 1 or 2 , the skew characteristics unique to the paper cutting device are information that includes at least the amount of skew and the skew direction when the paper is transported a predetermined distance.

According to the invention described in claim 1 , by providing and using a first tilt angle correction means and a second tilt angle correction means, cutting can be performed with even greater precision even if the cutting position is a predetermined distance or more from the tilt detection mark or the leading edge position of the paper and the paper is skewed during paper transport.

According to the invention described in claim 2 , the skew detection unit in the second inclination angle correction means detects the inclination angle of the paper relative to the paper transport direction from the difference in timing when multiple sensors detect inclination detection marks provided downstream of the paper, thereby enabling cutting to be done reliably and accurately.

According to the invention described in claim 3 , the skew characteristics specific to the paper cutting device are information that includes at least the amount and direction of skew when the paper is transported a predetermined distance, so that the skew state of the paper can be reliably identified with little information.

1 is a plan view showing the overall configuration of a paper processing system according to an embodiment of the present invention. 2 is a schematic overall configuration diagram of a paper feeder and a first paper cutting device in the paper processing system of FIG. 1; FIG. FIG. 2 is a perspective view showing a processing unit in the first paper cutting device. FIG. 2 is a perspective view showing a processing unit in the first paper cutting device. FIG. 2 is a perspective view showing a state in which a holding portion of the first paper cutting device is in a holding position. FIG. 10 is a perspective view showing a state in which a holding portion of the first paper cutting device is in a release position. 2 is a block diagram of a paper feeder and a first paper cutting device in the paper processing system of FIG. 1; FIG. FIG. 4 is a schematic plan view showing a skew angle detection unit of the first sheet cutting device. 10A and 10B are diagrams showing how paper is processed in a processing section of the first paper cutting device; 10A and 10B are diagrams showing how paper is processed in a processing section of the first paper cutting device; 10A and 10B are diagrams showing how paper is processed in a processing section of the first paper cutting device; 10A and 10B are diagrams illustrating skew correction by a second tilt angle correction unit.

[Overall configuration of paper processing system 100]
1 is a plan view showing the overall configuration of a paper processing system 100 according to one embodiment of the present invention. The paper processing system 100 of this embodiment is mainly composed of, from the upstream side in the conveying direction, a paper feeder 10, a first paper cutter 20, a cross conveyor 30, an insertion unit 40, a second paper cutter 50, and a conveyor stacker 60.

In recent years, there has been a trend toward larger maximum paper sizes that can be printed on general-purpose printers, and it is becoming increasingly common for printers to be able to print sizes larger than B3 size.
This paper processing system 100 accepts printed paper (P) that is larger than a certain size, cuts out a predetermined portion of the printed paper (paper after cutting: P1), and performs a processing process that leaves only the printed portion (paper after processing: P2).

The second paper cutting device 50 is a general-purpose paper cutting device that has been commonly used on the market for some time, and the maximum paper size that can be processed is, for example, B3 size. The first paper cutting device 20 can also process sizes larger than B3 size, for example. This paper processing system 100 is configured so that the first paper cutting device 20 pre-cuts and processes paper to a paper size that can be accepted by the second paper cutting device 50, and then passes the processed paper to the second paper cutting device 50.

[Paper feeding device 10]
1 and 2, the paper feeder 10 includes an air feed unit 11 using an air suction belt, an elevator-type paper feed tray 12 that rises and falls depending on the amount of paper loaded, and a pair of transport rollers 13 that transport the paper fed by the air feed unit further downstream in the transport direction. In this embodiment, the device is configured to feed paper up to a maximum size B2. When a paper sheet P is transported by the pair of transport rollers 13 and its leading edge reaches a leading edge detection sensor 21 of the first paper cutter 20 described below, the pressure between the pair of transport rollers 13 in the paper feeder is released, and the paper is transported solely by the three pairs of transport rollers 23 in the first paper cutter 20 described below.

[First sheet cutting device 20]
1 and 2, the first sheet cutting device 20 is installed to perform pre-cutting (primary processing) of sheets to a size acceptable to the general-purpose second sheet cutting device 50. It has leading edge detection sensors 21 (21a, 21b) that detect when the leading edge of the sheet P conveyed from the sheet feeder 10 reaches the sheet P, and laser sensors 27 (27a, 27b) that detect the positions of the leading edge of the sheet P and a registration mark (in this embodiment, a line 101 for detecting skew) previously applied to the sheet P, and detect the angle of inclination of the printed image relative to the sheet conveyance direction. The leading edge detection sensors 21 and the laser sensors 27 are each located at two positions in the width direction, perpendicular to the sheet conveyance direction. The first sheet cutting device 20 also has an angle adjustment unit 33 that can adjust the angle of the cross-cut cutting unit 22 so that it is perpendicular to the conveyance direction of the printed image, based on the inclination angle of the printed image detected by the laser sensor 27.

The first paper cutting device 20 includes a cutting unit 22 that cuts paper in a direction perpendicular to the paper transport direction using a pair of cutting blades (in this embodiment, a pair of upper and lower rotary blades 221a, 221b) arranged opposite each other across the paper transport surface, a pair of transport rollers 25 as a transport unit that transports paper and is arranged upstream of the cutting unit 22 in the paper transport direction, and a pair of transport rollers 26 arranged downstream of the cutting unit 22 in the paper transport direction. Furthermore, it includes a movable guide 70 that is arranged between the cutting unit 22 and the pair of transport rollers 26 and supports the transported paper so that it can be raised and lowered.

The cutting unit 22 stops the paper P at a preset cutting position, and then cuts the paper P by moving a pair of cutting blades (a pair of upper and lower rotary blades 221a, 221b) in the width direction perpendicular to the direction in which the paper P is transported. After cutting, the paper P1 is discharged onto the cross conveyor device 30 by three transport rollers (26, 24, 24). The discharge of the paper P1 is detected by a discharge sensor 29.

[Cross conveyor device 30]
The cross conveyor device 30 receives the paper P1 that has been cut and processed by the first paper cutting device 20 and transported in a first direction, transports it in a second direction intersecting the first direction, and sends it to the second paper cutting device processing device 50.
The cross conveyor device 30 is disposed downstream of the first paper cutting device 20, and is provided with an inclined conveying means for receiving the paper P1 discharged from the first paper cutting device 20 onto an endless belt 31 (a single belt having a predetermined width), and conveying the paper P1 diagonally toward the guide wall 32 so that the edge of the received paper P1 is aligned with the guide wall 32, while conveying the paper P1 downstream in the conveying direction.

[Insertion unit 40]
An insertion unit 40 is arranged downstream of the cross conveyor device 30 to deliver the paper P<b>1 discharged from the cross conveyor device 30 to the paper feed opening of the second paper cutting device 50 .
The insertion unit 40 is equipped with a skew conveying means that conveys the received paper P1 diagonally toward the guide wall 41 using air suction, while conveying the paper P1 downstream in the conveying direction, so that the edge of the paper P1 is aligned with the guide wall 41.

[Second paper cutting device 50]
The second sheet cutting device 50 is a sheet cutting device that has conventionally been widely used on the market, and the sheets P1 that have been pre-cut (primary processing) by the first sheet cutting device 20 to a sheet size that can be accepted by the second sheet cutting device 50 are delivered from the insertion unit 40 to the sheet feed opening of the second sheet cutting device 50. The sheets P1 are then fed out one by one in the sheet transport direction, and the fed sheets P1 are cut while being transported in the device main body based on the preset job content, and the cut sheets P2 are discharged from the device main body.

[Conveyor stacker device 60]
A conveyor stacker 60 may be connected to the discharge side of the second sheet cutting device 50. The conveyor stacker 60 is a device that slowly transports cut sheets P2 discharged from the second sheet cutting device 50 on a belt conveyor and stacks the sheets at an angle on a stacker 61 provided at the end of the belt conveyor.

[Embodiment of processed portion 2]
As shown in FIG. 3, the processing unit 2 has a cutting unit 22, a holding unit 325, and an angle adjustment unit 33, and performs processing including cutting on the paper P conveyed by the paper feed unit 10.
In this embodiment, the processing unit 2 has a support frame 34 that supports the cutting unit 22 and the holding unit 325 and is connected to the angle adjustment unit 33. The support frame 34 has a pair of support wall portions 341 that are spaced apart in a second direction (e.g., the Y direction) that intersects the first direction X, and a pair of rail members 342 that extend in the second direction Y and have both ends connected to the pair of support wall portions 341. The rail members 342 are spaced apart in a third direction (e.g., the Z direction) that intersects the first direction X and the second direction Y.

The cutting unit 22 is disposed, for example, near the holding unit 325 and downstream in the transport direction of the paper P (the direction of arrow A in FIG. 1), and is configured to be able to cut the paper P along a cutting line L2 (see FIG. 5) extending in the second direction Y. Specifically, as shown in FIG. 3, the cutting unit 22 has a pair of rotary blades 221 (221a, 221b) that are movable in the second direction Y, and a pair of moving devices 312 that move each cutting blade 221 in the second direction Y. Each cutting blade 221 can be configured, for example, with a circular blade, a fixed blade, and a movable blade. The pair of cutting blades 221 may be a combination of circular blades, a combination of a circular blade and a fixed blade, or a combination of a fixed blade and a movable blade. The movable blade may also be of a guillotine type. In this case, a moving device that moves the cutting blade in the second direction Y is not required.

In this embodiment, each moving device 312 is arranged at a distance from one another in the third direction Z and is composed of a pair of pulleys 313, a belt member 314 wound around the pair of pulleys 313, and a first motor 525 (see Figure 7) that rotates one of the pair of pulleys 313. Each pulley 313 is approximately cylindrical and rotatably attached to the respective support wall portion 341. A pulley (not shown) is attached to the drive shaft of the first motor 525. A belt member (not shown) is wound around one of the pulleys 313 in the upper moving device 312, one of the pulleys 313 in the lower moving device 312, and a pulley attached to the drive shaft of the first motor 525. By driving the first motor 525, one of the pulleys 313 in each moving device 312 rotates via the belt member, and the belt member 314 rotates around the pair of pulleys 313. Each rotary blade 221 has a generally cylindrical shape and is arranged between a pair of moving devices 312 with a slight offset from each other in the first direction X. Each rotary blade 221 is supported by a rail member 342 of the support frame 34 so as to be movable in the second direction Y, and is connected to a belt member 314 of the moving device 312. In other words, each cutting blade 221 is configured to move in the second direction Y between the pair of support wall portions 341 as the belt member 314 rotates.

The holding unit 325, which serves as a paper transport unit, transports paper P and is configured to be movable between a holding position h1 (see FIG. 5) where it clamps and holds paper P in its thickness direction (in other words, the third direction Z), and a release position h2 (see FIG. 6) where it releases the hold on paper P. Specifically, as shown in FIG. 3, the holding unit 325 has a pair of rollers 25a, 25b extending in the second direction Y, and a second motor 526 (see FIG. 7), an example of a drive device that rotates one or both of the pair of rollers 25a, 25b. Each roller 25a, 25b is arranged side by side in the third direction Z and is supported by a pair of support walls 341 so as to be rotatable forward and backward around a central axis CL1 (see FIG. 4) extending in the second direction Y.

As shown in FIG. 5, the rollers 25 a and 25 b are provided on shaft members 326 and 327 constituting the central axis CL 1 except for both ends in the second direction Y, and rotate together with the shaft members 326 and 327 .
Each roller 25a, 25b is positioned so that a holding line L1 formed on the paper P when the paper P is held is approximately parallel to the cutting line L2. The holding line L1 forms the boundary between each roller 25a, 25b and the paper P when the paper P is nipped and held by the pair of rollers 25a, 25b.

In this embodiment, of the pair of rollers 25a, 25b, the upper roller 25a in the third direction Z is configured to be movable in the third direction Z. Specifically, as shown in Figures 5 and 6, bearing members 323, 324 are provided at both ends of each shaft member 326, 327 in the second direction Y. The bearing member 323 of the upper shaft member 326 has a generally circular disk shape, and the bearing member 324 of the lower shaft member 327 has a generally elliptical shape. The outer peripheries of the bearing members 323, 324 abut against each other, and when the bearing member 324 is rotated, the upper roller 25a moves between the holding position h1 and the release position h2 via the bearing member 323. This allows the distance in the third direction Z between the pair of rollers 25a, 25b to be adjusted. In other words, the upper roller 221 is an example of a movable holding member configured to move in the thickness direction of the paper P to adjust the distance between the pair of rollers 25a, 25b. The lower roller 25b and the lower bearing member 324 may be configured to rotate together, or they may be configured to rotate individually and independently. If the lower roller 25b and the lower bearing member 324 are configured to rotate together, for example, the bearing member 324 can be rotated by configuring the lower roller 25b to be rotatable by a second motor 526. If the lower roller 25b and the lower bearing member 324 are configured to rotate individually and independently, for example, the bearing member 324 can be rotated by providing a motor (not shown) that rotates only the lower bearing member 324.

The angle adjustment unit 33 is configured to adjust the angle of the cutting unit 22 and the holding unit 325 relative to the first direction X. When adjusting the angle of the cutting unit 22 and the holding unit 325 relative to the paper P at the cutting position during paper cutting, the holding unit 325 is moved to the release position h2, which releases the holding of the paper P, and then the angle is adjusted to prevent wrinkles from forming on the paper P. If the angle adjustment is within a fine range due to the design, the cutting unit 22 alone may be rotated, without rotating the holding unit 325.

Specifically, as shown in FIG. 4, the angle adjustment unit 33 has a drive mechanism that can rotate the cutting unit 22 and the holding unit 325 together around a rotation axis CL2 that extends in the thickness direction of the paper P (i.e., the third direction Z). The drive mechanism has a rotation shaft portion 331 that is provided approximately in the center of the support frame 34 in the second direction Y and forms the rotation axis CL2, and a drive unit 332 connected to one of the pair of support wall portions 341.

The drive unit 332 is composed of multiple pulleys 333, a belt member 334 wound around the multiple pulleys 333, and a third motor 527 (see Figure 7) that rotates one of the multiple pulleys 333. By driving the third motor 527 to rotate one of the pulleys 333, the belt member 334 rotates around the multiple pulleys 333, moving the support wall portion 341, to which the drive unit 332 is connected, in the first direction X. This causes the support frame 34 to rotate around the rotation axis CL2, adjusting the angle of the cutting unit 22 and holding portion 325 relative to the first direction X.

The control unit 530 includes, for example, a CPU for performing calculations, and ROM, RAM, and non-volatile memory (EEPROM) for storing programs and data necessary for the operation of the first paper cutting device 20. In this embodiment, as shown in FIG. 7, the control unit 530 controls the paper feed unit 10 and the first motor 525, second motor 526, and third motor 527 of the processing unit 2 based on information input by the user via the operation unit 532 and information detected by the skew angle detection unit 531.

[Skew angle correction]
The processing unit 2 can adjust (correct) the angle of the cutting unit 22 during paper cutting so that it is perpendicular to the conveyance direction of the print image using the angle adjustment unit 33. The angle adjustment unit 33 includes a skew angle detection unit 531 as a first skew angle correction means, a memory unit that stores skew characteristics specific to the paper cutting device that have been measured in advance, and a skew correction amount calculation unit (control unit 530) as a second skew angle correction means that calculates a skew correction amount for the cutting unit based on the skew characteristics specific to the paper cutting device stored in the memory unit, and the angle adjustment unit 33 adjusts (corrects) the skew angle of the cutting unit 22 based on the skew angle detected by the first skew angle correction means and/or the skew correction amount calculated by the second skew angle correction means.

[First tilt angle correction means]
First, the first tilt angle correction unit will be described. The skew angle detection unit 531 in the first tilt angle correction unit detects the angle θ of the paper P with respect to the first direction X. Specifically, as shown in FIG. 8 , the skew angle detection unit 531 has multiple sensors 27 (e.g., 27a, 27b) arranged side by side in the second direction Y. Each sensor 27 detects a skew detection line 101 (registration mark) provided downstream in the transport direction of the paper P or the leading edge of the paper P. The skew angle detection unit 531 detects the angle θ of the paper P with respect to the first direction X from the difference in timing at which each sensor 27 detects the skew detection line 101 or the leading edge of the paper P. The angle adjustment unit 33 adjusts (corrects) the tilt angle of the cutting unit 22 based on the skew angle θ detected by the skew angle detection unit 531 in the first tilt angle correction unit. The skew detection line 101 is, for example, arranged parallel to one side of an image having a rectangular outline, and is printed together with the image on the paper P. This allows the paper P to be cut accurately at a cutting position set in accordance with the image, not only when the paper P itself is skewed with respect to the first direction X, but also when the paper P itself is not skewed with respect to the first direction X but the image printed on the paper P is skewed.

As a result of the above, the angle of inclination of the paper relative to the paper transport direction is detected from the difference in timing of detecting the inclination detection marks, allowing for reliable and accurate cutting.

[Second tilt angle correction means]
Next, the second tilt angle correction means will be described. The second tilt angle correction means includes a memory unit (a non-volatile memory EEPROM in the control unit 530) that stores previously measured skew characteristics specific to the paper cutting device, and a skew correction amount calculation unit (a CPU in the control unit 530) that calculates a skew correction amount for the cutting unit based on the skew characteristics specific to the paper cutting device stored in the memory unit. The angle adjustment unit 33 adjusts (corrects) the tilt angle of the cutting unit 22 based on the skew correction amount calculated by the second tilt angle correction means.

The skew characteristics specific to the paper cutting device are information that includes at least the amount and direction of skew when the paper P is transported a specified distance. Therefore, the skew state of the paper can be reliably identified with minimal information.

Furthermore, the skew characteristics specific to the paper cutting device are measured in advance before the paper cutting device 20 is shipped and stored in the memory unit, or are measured in advance by an operator in the market before using the paper cutting device and stored in the memory unit. Therefore, cutting can be performed with high precision in accordance with the skew characteristics specific to the paper cutting device.

The control unit 530 can switch between a normal processing mode, in which processing is performed on the transported paper P, and a test mode, in which testing is performed through reference paper. In test mode, the skew characteristics specific to the paper cutting device are measured when the reference paper is transported, and stored in the memory unit. Therefore, the measurement of the skew characteristics specific to the paper cutting device and the storage (storage) of the measurement data are clear and easy to understand.

Adjusting the tilt angle of the processing unit 2 and holding unit 325 relative to the paper transport direction does not pose any accuracy issues up to the first cut position (corresponding to cutting line L2 in Figure 8), which is a relatively short distance after detecting the tilt detection mark 101 or the leading edge of the paper P. However, if the paper P is skewed when transporting the paper to the second cut position, which is a predetermined distance or more away from the first cut position, the desired product will not be obtained when cutting at the second cut position at the same tilt angle as the first cut position. Possible causes of skew during paper transport include the type of paper and environmental factors.

Next, specific skew correction using the second tilt angle correction means will be explained using Figures 9 to 12.

In Figures 9 to 11, (a) shows the cutting position of the first cut 91, (b) shows the cutting position of the second cut 92, and (c) shows the finished product 95 after the first cut 91 and the second cut 92 have been completed; the front end cut groove 93 and the rear end cut groove 94 are discarded.

9 shows a schematic diagram of a case where there is no skew during conveyance from the first cut 91 to the second cut 92. The dashed dotted line in the cutting unit 22 indicates the path through which the pair of rotary blades 221 pass.
In Fig. 9(a), angle adjustment (correction) is performed by the first tilt angle correction means at the time of the first cut 91. Next, because there is no skew during transport from the first cut 91 to the second cut 92, in Fig. 9(b), at the time of the second cut 92, the cutting section 22 remains at the same tilt angle as at the first cut 91 position (no skew correction), and there is no problem with the product 95. In other words, even if the paper P itself is tilted with respect to the transport direction in Fig. 9(c), the paper P can be accurately cut at the second cut 92 position, which is the cutting position set in accordance with the tilt of the paper.

Figure 10 schematically shows a case where there is skew during transport from the first cut 91 to the second cut 92. In Figure 10(a), angle adjustment (correction) is performed by the first tilt angle correction means during the first cut 91. Next, because there is skew during transport from the first cut 91 to the second cut 92 in Figure 10(b), if the cutting section 22 remains at the same tilt angle as the position of the first cut 91 during the second cut 92, as shown in Figure 10(c), the second cut 92 position will not be properly cut in accordance with the skew of the paper.

Figure 11 schematically shows a case where there is skew during transport from the first cut 91 to the second cut 92. In Figure 11(a), angle adjustment (correction) is performed by the first tilt angle correction means during the first cut 91. Next, because there is skew during transport from the first cut 91 to the second cut 92, angle adjustment (correction) is performed by the second tilt angle correction means described below in Figure 11(b). As a result, as shown in Figure 11(c), the paper P can be cut accurately at the second cut 92 position, which is the cutting position set to match the skew of the paper.

Figure 12 shows a specific example of angle adjustment (correction) by the second tilt angle correction means at the second cut 92 position.

12A, first, the skew characteristics specific to the paper cutting device are measured in advance before shipping the paper cutting device 20. Specifically, in a test mode for passing a single piece of reference paper as a test, the skew characteristics specific to the paper cutting device are measured while the reference paper is being transported, and the results are stored in the memory unit. Note that it is advisable to use the paper to be actually processed as the reference paper.
The skew characteristics specific to the paper cutting device are information that includes at least the amount and direction of skew when the paper P is transported a specified distance, and the skew characteristics show a certain tendency (habit) and reproducibility for each machine.

12(a) shows the state after a sheet of paper P to be actually processed is passed through the first paper cutting device 20 as a reference paper in test mode and actually cut at two locations, the first cut 91 and the second cut 92. By measuring the lengths X1 and X2 of both ends of the paper P from the first cut 91 to the second cut 92 with a caliper or the like after processing, the skew characteristics (skew amount, skew direction) specific to the paper cutting device can be derived. That is, as shown in FIG. 12(b),
(1) If x1=x2, it is determined that there is no skew when the paper is transported from the first cut 91 to the second cut 92.
(2) If x1<x2, then X2-X1 is the amount of skew, and the skew direction is determined to be rightward with respect to the conveying direction.
(3) If x1>x2, X1-X2 is the amount of skew. The skew direction is determined to be leftward inclined relative to the conveying direction.

More specifically, based on the above procedure, if the skew amount is measured in advance in test mode as 0.1 mm (right slant) when the paper transport distance from the first cut 91 to the second cut 92 is 100 mm, the measurement data is stored in the memory unit (non-volatile memory EEPROM in the control unit 530). Then, during normal processing (normal processing mode), the skew correction amount calculation unit (CPU in the control unit 530) calls up the measurement data (skew characteristics specific to the paper cutting device) stored in the memory unit and calculates the skew correction amount for the cutting unit 22 at the second cut 92 position. For example, if the second cut 92 to be cut this time is 300 mm from the first cut 91, the correction amount (skew amount) is estimated to be 0.3 mm by multiplying the skew amount of 0.1 mm when the paper transport distance is 100 mm by three using a magnification ratio, and this is applied (corrected) as the skew amount. The angle adjustment unit 33 then adjusts (corrects) the inclination angle of the cutting unit 22 based on the amount of skew correction calculated by the second inclination angle correction means.

As described above, even if the cutting position is a predetermined distance or more from the skew detection mark or the leading edge of the paper and the paper is skewed during paper transport, accurate cutting is possible. Furthermore, by providing and using a first skew angle correction means and a second skew angle correction means, cutting can be performed with even greater accuracy. While the position of the first cut 91 in the above-described embodiment was subjected to angle adjustment (correction) by the first skew angle correction means, the position of the first cut 91 may also be configured to perform skew correction by applying the second skew angle correction means. Furthermore, while the above-described embodiment describes cutting at two locations, the first cut 91 and the second cut 92, the second skew angle correction means can also be applied to the third cut and beyond.

The angle adjustment unit 33 is not limited to the above embodiment, and any configuration that allows adjustment of the angle θ of the cutting unit 22 and the holding unit 325 relative to the first direction X can be adopted. For example, the rotation shaft unit 331 does not have to be located approximately in the center of the support frame 34 in the second direction Y, but may be located at one end of the support frame 34 in the second direction Y.

It is clear that the present invention is not limited to this embodiment, and that within the scope of the technical concept of the present invention, this embodiment can be modified as appropriate in ways other than those suggested in this embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to this embodiment, and can be any number, position, shape, etc. that is suitable for implementing the present invention.

A conveying direction P paper 2 processing unit 20 first paper cutting device 22 cutting unit 25 pair of rollers 33 angle adjustment unit 91 first cutting unit 92 second cutting unit 93 front end cut groove 94 rear end cut groove 95 product 101 line for detecting tilt 221 pair of rotary blades 312 pair of moving devices 313 pair of pulleys 314 belt member 325 holding unit 341 pair of support wall units 342 pair of rail members 323 bearing member 324 bearing member 326 shaft member 327 shaft member

Claims (3)

A paper cutting device including a conveying unit that conveys paper along a conveying path, a processing unit that processes the paper conveyed by the conveying unit, and a control unit that controls the conveying unit and the processing unit,
The processing unit has a cutting unit that cuts the paper in a direction perpendicular to the paper transport direction using a pair of cutting blades that are arranged opposite to each other across a paper transport surface, and an angle adjustment unit that can adjust the inclination angle of the cutting unit with respect to the paper transport direction,
The angle adjusting unit serves as a means for correcting the inclination angle of the cutting unit.
a skew detection unit serving as a first skew angle correction unit having a plurality of sensors arranged in a direction perpendicular to the paper transport direction, and detecting a skew angle of the paper relative to the paper transport direction;
a storage unit that stores skew characteristics specific to the paper cutting device that have been measured in advance, and a skew correction amount calculation unit that serves as a second inclination angle correction means that calculates a skew correction amount for the cutting unit based on the skew characteristics specific to the paper cutting device that have been stored in the storage unit,
A paper cutting device characterized in that the angle adjustment unit uses a first inclination angle correction means and a second inclination angle correction means to adjust the inclination angle of the cutting unit based on whether the cutting position is a predetermined distance or more from a mark for detecting inclination or the leading edge of the paper. The paper cutting device according to claim 1, wherein the skew detection unit detects the skew angle of the paper relative to the paper transport direction from the difference in timing at which the plurality of sensors detect skew detection marks provided downstream of the paper. 3. The paper cutting device according to claim 1 , wherein the skew characteristics specific to the paper cutting device are information including at least the amount and direction of skew when the paper is transported a predetermined distance.