Cutting device, sheet-fed processing system, and control method for rotary cutter

Abstract

To stably cut a single-fed sheet in a direction intersecting the transport direction. [Solution] The cutting device cuts the sheets of paper S transported by the transport unit 60. The cutting device 1 includes a rotary cutter 10 that cuts the sheets of paper S in a direction intersecting the transport direction A, a paper detection sensor 20 positioned upstream of the rotary cutter 10 in the transport path of the sheets of paper S and detecting the edge of the sheets of paper S, and a cutter control device 30 that controls the rotary cutter 10. After the paper detection sensor 20 detects the edge of the sheets of paper S, the cutter control device 30 controls the speed of the rotary cutter 10 based on the transport speed of the transport unit 60, the position of the cutting blade 12 provided on the rotary cutter 10, and the cutting position on the sheets of paper S.

Description

[Technical Field]

[0001] The present disclosure relates to a cutting device, a sheet processing system for cut sheets, and a control method for a rotary cutter. [Background Art]

[0002] Conventionally, as a cutting device for cutting a conveyed sheet (for example, a cut sheet), the sheet cutting device disclosed in Patent Document 1, for example, is known. Patent Document 1 discloses a first cutting section that cuts a sheet supplied from a paper feed section along the sheet conveyance direction into a plurality of strip-shaped sheets; a first direction changing section disposed downstream of the first cutting section that feeds the strip-shaped sheets in a second direction perpendicular to the first conveyance direction; and a second cutting section disposed downstream of the first direction changing section that cuts the strip-shaped sheets along the conveyance direction (the second direction).

[0003] The second cutting section includes a plurality of rotating shafts extending in a direction perpendicular to the conveyance direction of the strip-shaped sheets, and a plurality of circular blades (round cutters) attached to each rotating shaft so as to be movable in the axial direction of the shaft. During cutting, each circular blade is set at a predetermined position based on initial information such as the size of the sheet and sub-sheet received from a printing device that is a pre-processing machine, and the strip-shaped sheet is cut into a plurality of sub-sheets by the rotating blades while passing through the second cutting section. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2014-201439 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] In the sheet cutting device disclosed in Patent Document 1 mentioned above, both the first and second cutting sections perform cutting in a direction along the conveying direction. Therefore, in order to cut the sheet along both the longitudinal and width directions, a device is required between the first and second cutting sections to rotate the sheet's direction by 90 degrees. For this reason, miniaturization of the device has been difficult.

[0006] Rotary cutters are sometimes used to cut roll paper. Because roll paper is a continuous sheet, the paper is fed to the rotary cutter in a stable manner. In contrast, sheet-fed paper is supplied to the rotary cutter intermittently, making it susceptible to warping, friction, and static electricity, and making it difficult to adjust the cutting timing. For this reason, the control methods for roll paper cannot be directly applied to cutting sheet-fed paper.

[0007] This disclosure has been made in view of these circumstances and aims to provide a cutting device, a sheet processing system, and a rotary cutter control method that can stably cut a sheet in a direction intersecting the transport direction. [Means for solving the problem]

[0008] One aspect of the present disclosure is a cutting device for cutting a sheet of paper transported by a transport means, comprising: a rotary cutter for cutting the sheet of paper in a direction intersecting the transport direction; a paper detection means positioned upstream of the rotary cutter in the transport path of the sheet of paper for detecting the edge of the sheet of paper; and a control means for controlling the rotary cutter, wherein the control means controls the speed of the rotary cutter based on the transport speed of the transport means, the position of the cutting blade provided on the rotary cutter, and the cutting position on the sheet of paper after the paper detection means has detected the edge of the sheet of paper.

[0009] One aspect of this disclosure is a sheet-fed processing system equipped with the above-mentioned cutting device.

[0010] One aspect of the present disclosure is a control method for a rotary cutter that cuts a sheet of paper transported by a transport means in a direction intersecting the transport direction, wherein, after it is detected that the sheet of paper has passed a reference position virtually set upstream of the rotary cutter in the transport path of the sheet of paper, the control method for the rotary cutter controls the speed of the rotary cutter based on the transport speed of the transport means, the position of the cutting blade provided on the rotary cutter, and the cutting position on the sheet of paper.

[0011] One aspect of this disclosure is a program for causing a computer to execute the control method for the rotary cutter described above. [Effects of the Invention]

[0012] The sheet can be cut continuously in a direction intersecting the sheet's transport direction. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows a schematic configuration of a cutting device according to the first embodiment of this disclosure. [Figure 2] This figure schematically shows cutting by a cutting device according to the first embodiment of this disclosure. [Figure 3] This figure illustrates the rotational position control of a rotary cutter according to the first embodiment of the present disclosure. [Figure 4] This figure shows an example of the hardware configuration of a cutter control device according to the first embodiment of this disclosure. [Figure 5] This flowchart shows an example of the processing procedure for the control method of a rotary cutter according to the first embodiment of this disclosure. [Figure 6] This flowchart shows an example of the processing procedure for the synchronization process according to the first embodiment of this disclosure. [Figure 7] This is a flowchart showing an example of the processing procedure for continuous cutting according to the first embodiment of this disclosure. [Figure 8]It is a diagram for explaining the first threshold, the second threshold, and the stop threshold according to the first embodiment of the present disclosure. [Figure 9] It is a diagram showing an example of a pulse table according to the first embodiment of the present disclosure. [Figure 10] It is a diagram for explaining speed control of the rotary cutter according to the first embodiment of the present disclosure. [Figure 11] It is a diagram showing an example of a system configuration diagram of a bookbinding system according to an embodiment of the present disclosure. Mode for Carrying Out the Invention

[0014] [First Embodiment] Hereinafter, a cutting device and a control method for a rotary cutter according to the first embodiment of the present disclosure will be described with reference to the drawings. Hereinafter, a sheet of paper will be exemplified as a sheet to be described, but the present disclosure is not limited thereto. For example, the sheet may be made of a material other than paper such as film or plastic. FIG. 1 shows a schematic configuration of a cutting device 1 according to the first embodiment of the present disclosure. FIG. 2 is a diagram schematically illustrating cutting by the cutting device 1 according to the present embodiment.

[0015] The cutting device 1 includes a rotary cutter 10, a paper detection sensor (paper detection means) 20 that detects a sheet of paper (sheet) S, and a cutter control device (controller: control means) 30.

[0016] The sheet S is conveyed to the cutting device 1 by, for example, a conveyance unit (conveyance means) 60. The conveyance unit 60 includes, for example, a suction-type belt conveyor 61 and a conveyance roller pair 62. The conveyance roller pair 62 includes an upper roller 62a and a lower roller 62b.

[0017] The belt conveyor 61 is driven, for example, by a transport drive unit 63. The transport roller pair 62 is driven, for example, by a transport drive unit 64. The transport drive units 63 and 64 are equipped, for example, with servo motors. The transport drive units 63 and 64 are controlled by a transport control device 65. The transport control device 65 synchronously controls the belt conveyor 61 and the transport roller pair 62, so that the sheets of paper S are transported stably at the same speed.

[0018] The transport roller pair 62 is equipped with a speed detection sensor for detecting the transport speed. For example, the speed detection sensor outputs a pulse corresponding to the transport speed. An example of a speed detection sensor is a rotary encoder (not shown). The output signal of the rotary encoder is transmitted to the cutter control device 30, which will be described later.

[0019] The rotary cutter 10 cuts the sheets of paper S, which have been transported by the transport unit 60, in a direction intersecting the transport direction A. Specifically, the cutting device 1 cuts the sheets of paper S in a direction perpendicular to the transport direction A. Figure 2 shows an example in which the sheets of paper S are cut at two locations, cutting lines (cutting positions) LN1 and LN2.

[0020] The rotary cutter 10 comprises a rotatably supported cylindrical base 11 and a cutting blade 12 positioned on the outer circumferential surface of the base 11. As shown in Figure 2, the cutting blade 12 is provided to extend in the direction of the rotation axis of the base 11. In other words, the cutting blade 12 is provided to extend from one end of the base 11 to the other end. The cutting blade 12 may be provided at an angle to the rotation axis of the base 11, as shown in Figure 2, or it may be provided parallel to the rotation axis.

[0021] By positioning the cutting blade 12 at an angle (diagonally) to the rotation axis of the base 11, the sheets of paper S can be gradually cut as if with scissors. In this case, in order to cut the sheets of paper S in a direction perpendicular to the transport direction A, the rotary cutter 10 is installed at an angle to the direction perpendicular to the transport direction A.

[0022] A fixed blade 13 is positioned opposite the rotary cutter 10 across the transport path. The cutting blade 12 on the rotary cutter 10 and the fixed blade 13 engage to cut the transported sheet of paper S.

[0023] The paper detection sensor 20 is installed upstream of the rotary cutter 10 in the transport direction A of the sheet paper S. When the paper detection sensor 20 detects the leading edge of the sheet paper S in the transport direction A, for example, it outputs a sensor detection signal to the cutter control device 30.

[0024] The rotary cutter 10 is driven by a cutter drive unit 15. The cutter drive unit 15 includes, for example, a servo motor. The cutter control device 30 controls the rotational speed of the rotary cutter 10. The cutter control device 30 controls the speed of the rotary cutter 10 based, for example, on the transport speed of the transport unit 60, the position (rotational position θ) of the cutting blade 12 provided on the rotary cutter 10, and the cutting lines on the sheet paper S (for example, LN1 and LN2 in Figure 3). Specifically, the cutter control device 30 controls the rotational speed of the rotary cutter 10 by providing a speed control command (command pulse) to the cutter drive unit 15.

[0025] The cutter control device 30 acquires information regarding the transport speed of the transport unit 60, for example. For example, the cutter control device 30 is configured to receive pulse signals from rotary encoders (hereinafter referred to as "transport encoders") provided on the transport roller pair 62 of the transport unit 60.

[0026] Furthermore, the rotary cutter 10 is equipped with a rotation position detection unit (not shown) to detect the rotation position θ of the cutting blade 12 with respect to a virtually set reference position P0 on the base 11, as shown in Figure 3, for example. An example of a rotation position detection unit is a rotary encoder. The cutter control device 30 calculates the rotational position (0° to 360°) of the cutting blade 12 relative to the reference position P0 based on the output pulse from the rotational position detection unit. Figure 3 shows an example where the uppermost point is set as the reference position P0 (0°), but the reference position P0 can be set arbitrarily. In the following description, the position where the cutting blade 12 engages with the fixed blade 13 to cut the sheet of paper S is called the cut position Pc. Furthermore, as shown in Figure 2, when the cutting blade 12 is positioned diagonally with respect to the rotation axis of the base 11, the reference position of the rotation of the cutting blade 12 can be set arbitrarily. In this embodiment, as shown in Figure 3, the position of the leading cutting blade 12 in the rotation direction is set as the reference position.

[0027] The cutting lines LN1 and LN2 (see Figure 2) on the sheet-fed paper S can be obtained from job data supplied by a higher-level system that manages each device in the bookbinding system, or by a pre-processing device (e.g., a printing device) that performs pre-processing (e.g., printing) on ​​the sheet-fed paper S, for example, when the cutting device 1 is applied to a bookbinding system. The job data includes information such as the size of the sheet-fed paper S, the layout on the sheet-fed paper S, and the margins. The cutter control device 30 identifies cutting lines LN1 and LN2 on the sheet paper S from the job data. The cutter control device 30 then controls the rotation speed of the rotary cutter 10 based on the transport speed of the transport unit 60, the rotation position θ of the cutting blade 12 in the rotary cutter 10, and the cutting lines LN1 and LN2 in the sheet of paper S, so that the cutting blade 12 reaches the cutting position Pc at the same time that the cutting lines LN1 and LN2 reach the cutting position Pc.

[0028] Figure 4 shows an example of the hardware configuration of the cutter control device 30. The cutter control device (Controller) 30 is a computer and includes, for example, a CPU (Central Processing Unit: processor) 31, main memory 32, secondary storage (memory) 33, etc.

[0029] Furthermore, the cutter control device 30 may also include a communication interface 34 for sending and receiving information with other devices, an external interface 35 for connecting external devices, an input device 36 for the user to perform input operations, a display 37 for displaying data, and the like.

[0030] The CPU 31 may consist of one or more units that cooperate with each other to perform processing.

[0031] The main memory 32 is composed of writable memory such as RAM (Random Access Memory), and is used as a work area for reading the CPU 31's executable program and writing processing data by the executable program. Multiple main memory 32s may be provided.

[0032] The secondary storage device 33 is a non-transitory computer-readable storage medium. The secondary storage device 33 is, for example, a semiconductor memory, such as a flash memory or an SSD (Solid State Drive). Other examples of secondary storage devices 33 include magnetic disks, magneto-optical disks, CD-ROMs, and DVD-ROMs. Multiple secondary storage devices 33 may be provided, and programs and data for implementing the processing (functions) described later may be divided and stored in each secondary storage device 33.

[0033] A series of processes for realizing various functions are stored in the secondary storage device 33 in the form of a program, for example. The CPU 31 reads this program into the main memory device 32 and performs information processing and calculations to realize the various functions. The program may be pre-installed in the secondary storage device 33, provided stored on a computer-readable storage medium, or distributed via wired or wireless communication. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memory, etc.

[0034] Examples of cutter control devices 30 include microcontrollers (MCUs), PLCs (Programmable Logic Controllers), and FPGAs (Field Programmable Gate Arrays).

[0035] Next, the control method for the rotary cutter 10, which is performed by the cutter control device 30, will be described with reference to Figure 5. Figure 5 is a flowchart showing an example of the processing procedure for the control method of the rotary cutter 10 according to this embodiment.

[0036] First, when the cutter control device 30 detects a sheet of paper S (hereinafter referred to as "target paper") using the paper detection sensor 20, and receives a paper detection signal from the paper detection sensor 20 (SA1:YES), it performs a synchronization process to synchronize the speed of the rotary cutter 10 with the speed of the transport unit 60 (SA2). Hereinafter, the speed of the rotary cutter 10 synchronized with the transport speed will be referred to as the synchronized speed.

[0037] Figure 6 is a flowchart showing an example of the processing procedure for the synchronization process performed in step SA2. As shown in Figure 6, first the cutter control device 30 acquires the rotational position θ of the cutting blade 12 (SB1).

[0038] Next, the cutter control device 30 sets the start position (SB2). Specifically, the cutter control device 30 sets the start position on the transport path by using the current values ​​of a predetermined calculation formula, which has the cutting line on the target paper (distance from the leading edge of the paper) and the rotation position θ of the cutting blade 12 as parameters. This calculation formula also includes the acceleration applied to the rotary cutter 10 after the start of operation. As a result, at the synchronization completion point described later, it becomes possible to rotate the rotation position θ of the cutting blade 12 to a desirable position relative to the cutting line.

[0039] Next, it is determined whether the cutting line for the target paper has reached the start position on the transport path (SB3). If the cutting line for the target paper has not reached the start position, the system waits until it does (SB3:NO). The arrival position of the target paper is calculated based on the elapsed time since detection by the paper detection sensor 20 and the transport speed. Then, when the cutting line of the target paper reaches the start position (SB3:YES), the cutter control device 30 starts operating the rotary cutter 10 and performs acceleration control (SB4). Details of the acceleration control will be described later. Next, the cutter control device 30 determines whether the rotational speed of the rotary cutter 10 is synchronized with the transport speed (SB5). If they are not synchronized, in other words, if the rotational speed of the rotary cutter 10 does not match the transport speed (SB5: NO), acceleration control is performed until they match. Then, when the rotational speed of the rotary cutter 10 is synchronized with the transport speed (SB5: YES), this synchronization process is terminated. This leads to the cutting edge position adjustment process shown in Figure 5 (SA3).

[0040] In the blade position adjustment process (SA3 in Figure 5), it is determined whether the rotation angle of the cutting blade 12 and the cutting line of the target paper are synchronized. Specifically, the cutter control device 30 determines whether the time when the cutting line of the target paper reaches the cut position Pc coincides with the time when the cutting blade 12 reaches the cut position Pc. If there is a discrepancy between the two, the rotation speed of the rotary cutter 10 is increased or decreased to adjust the timing so that the two coincide. This ensures that the rotation angle of the cutting blade 12 is properly adjusted, and the target paper is cut along the cutting line (SA4).

[0041] Next, the cutter control device 30 determines whether the cut in step SA4 is the final cut on the target paper (SA5). If it is determined that it is not the final cut (SA5: NO), the process proceeds to step SA8. On the other hand, in the case of the final cut (SA5:YES), it is determined whether or not the next paper detection signal has been received (SA6). In other words, it is determined whether or not a new sheet of paper S has been detected by the paper detection sensor. If the result is that the next paper detection signal has not been received (SA6:NO), the process proceeds to step SA7, the cutting blade 12 is stopped at the standby position (=reference position P0), and the process returns to step SA1, where the system remains in standby mode until the next paper detection signal is received.

[0042] On the other hand, in step SA6, if the next paper detection signal is received (SA6:YES), the cutter control device 30 calculates the distance X to the next cutting position (cutting line) (SA8). Subsequently, it is determined whether the distance X is greater than a preset stop threshold Cs (SA9).

[0043] Here, the stop threshold Cs is set to a value greater than the circumference C of the rotary cutter 10, as shown in Figure 8. Specifically, the stop threshold Cs is set to a value that corresponds to the transport distance of the sheet of paper S corresponding to the period of one rotation of the rotary cutter 10 at the minimum speed (lower limit speed), or a value that is a predetermined value smaller than said transport distance. Here, the minimum speed is a speed slower than the synchronous speed.

[0044] As shown in Figures 2 and 8, when the cutting blade 12 is positioned diagonally with respect to the rotation axis of the base 11, for example, the stop threshold Cs is set to the transport distance of the sheet S corresponding to the period during which the rotary cutter 10 is rotated at the minimum speed (lower limit speed) for a distance obtained by subtracting the circumferential distance Cd from one end to the other of the cutting blade 12 from the circumference C of the rotary cutter 10 (= C - Cd). In other words, the stop threshold Cs is set to a value that is a predetermined value smaller than the transport distance, with a predetermined margin.

[0045] If the distance X exceeds the stop threshold Cs (SA9: YES), even if the rotary cutter 10 is rotated at the minimum speed, the cutting line will not reach the cutting position Pc before the cutting blade 12 reaches the cutting position Pc. Therefore, in this case, the process proceeds to step SA10, stopping the cutting blade 12 at the standby position (= reference position P0), and then proceeding to step SB3 in Figure 6. This results in a standby state until the next cutting line reaches the operation start position (SB3 in Figure 6).

[0046] On the other hand, if the distance X is less than or equal to the stop threshold Cs (SA9:NO), proceed to step SA11, perform continuous cutting, and return to step SA3.

[0047] Next, the continuous cutting process will be explained with reference to Figure 7. Figure 7 is a flowchart showing an example of the processing procedure for continuous cutting. First, the cutter control device 30 determines whether the distance X is less than or equal to a preset first threshold C1 (SC1). Here, the first threshold C1 is set to a value that is a predetermined distance shorter than the circumference C of the rotary cutter 10, as shown in Figure 8.

[0048] If the distance X is less than or equal to the first threshold C1 (SC1: YES), the cutter control device 30 synchronizes the rotation speed of the rotary cutter 10 with the transport speed by first rotating the rotary cutter 10 at a speed faster than the transport speed of the sheet paper S, and then decelerating it. Specifically, first, the cutter control device 30 accelerates the rotational speed of the rotary cutter 10, performing high-speed operation at a speed faster than the conveying speed of the sheet paper S (SC2).

[0049] Next, the cutter control device 30 calculates the distance Xc from the current rotational position θ of the cutting blade 12 to the cutting position Pc and the distance X to the cutting line (distance from the cutting position Pc to the cutting line), and calculates the difference ΔX (=X-Xc). Then, it determines whether the difference ΔX is less than or equal to a predetermined value X1 (SC3). If the difference ΔX is not less than or equal to the predetermined value X1 (SC3:NO), high-speed operation continues. If the difference ΔX is less than or equal to a predetermined position (SC3:YES), deceleration control is performed to slow down the rotary cutter 10 (SC4) and synchronize it with the transport speed. Then, when the rotation speed of the rotary cutter 10 and the transport speed are synchronized (SC5:YES), the continuous cutting process is terminated.

[0050] Next, in step SC1, if the distance X is not less than or equal to the first threshold C1 (SC1:NO), it is determined whether the distance X is greater than the first threshold C1 and less than the second threshold C2 (SC6). Here, the second threshold C2 is set to a value that is a predetermined distance longer than the circumference C of the rotary cutter 10, as shown in Figure 8. Also, the second threshold C2 is set to a value that is smaller than the stop threshold Cs.

[0051] The cutter control device 30 terminates this process if the distance X is greater than the first threshold C1 and less than the second threshold C2 (SC6: YES). More specifically, the case where the distance X is greater than the first threshold C1 and less than the second threshold C2 means that the distance X is approximately the same length as the circumference C of the rotary cutter 10. In this case, there is no need to perform the high-speed operation (SC3) described above or the low-speed operation (SC7) described later. Therefore, this process is terminated while maintaining synchronous control that follows the transport speed. In this case, the position adjustment of the cutting blade 12 is performed in the blade tip position adjustment process in step SA3 of Figure 5 described above.

[0052] On the other hand, in step SC6, if the distance X is greater than the first threshold C1 and not less than the second threshold C2 (SC6:NO), in other words, if the distance X is greater than or equal to the second threshold C2 and less than or equal to the stopping threshold Cs, the rotation speed of the rotary cutter 10 is synchronized with the transport speed by rotating it at a speed slower than the transport speed of the sheet paper and then accelerating it.

[0053] Specifically, the cutter control device 30 performs low-speed operation to reduce the rotational speed of the rotary cutter 10 (SC7). Next, the cutter control device 30 calculates the distance Xc from the current rotational position θ of the cutting blade 12 to the cutting position Pc and the distance X to the cutting line (distance from the cutting position Pc to the cutting line), and calculates the difference ΔX (=X-Xc). Then, it determines whether the difference ΔX is less than or equal to a predetermined value X1 (SC8). If the difference ΔX is not less than or equal to the predetermined value X1 (SC8:NO), the low-speed control is continued. If the difference ΔX is less than or equal to a predetermined position (SC8:YES), acceleration control is performed to accelerate the rotary cutter 10 (SC9) and synchronize it with the transport speed. Then, when the rotation speed of the rotary cutter 10 and the transport speed are synchronized (SC10:YES), the continuous cutting process is terminated.

[0054] In this way, once the continuous cutting process is completed, the process returns to step SA3 in Figure 5, the blade position adjustment process is performed, cutting is performed on the next cutting line (SA4), and the subsequent processes are repeated.

[0055] Next, an example of control of the cutter drive unit 15 by the cutter control device 30 described above will be explained. The cutter control device 30 controls the rotational speed of the rotary cutter 10 by outputting command pulses to the cutter drive unit 15.

[0056] For example, the cutter control device 30 has information relating the number of input pulses and the number of command pulses of the transport encoder in synchronous control, and uses this information to control the speed of the rotary cutter 10. When operating at high speed, the cutter control device 30 increases the ratio of the number of command pulses to the number of input pulses of the transport encoder compared to when operating at synchronous control, and when operating at low speed, it decreases the ratio of the number of command pulses to the number of input pulses of the transport encoder compared to when operating at synchronous control.

[0057] Furthermore, in the cutting edge position adjustment process (SA3 in Figure 5), the speed of the rotary cutter 10 is increased or decreased by gradually changing the ratio of the number of command pulses to the number of input pulses of the transport encoder.

[0058] More specifically, the cutter control device 30 has a pulse table that associates the number of transport pulses corresponding to the sheet transport speed, in other words, the number of pulses from the transport encoder, with the timing for outputting command pulses related to the rotational speed of the rotary cutter 10, in other words, command pulses related to the rotational speed of the rotary cutter. The cutter control device 30 then uses the pulse table and the number of transport pulses input from the transport unit 60 to control the speed of the rotary cutter 10. In the pulse table, the output timing of the command pulse is set separately for each of the multiple speed levels.

[0059] Figure 9 shows an example of a pulse table. As shown in Figure 9, the output timing of the command pulse is indicated for each command pulse speed level, corresponding to the number of pulses from the carrier encoder. For example, the timings marked with a circle (〇) are the timings at which the command pulse is output. For example, for speed level "5", it indicates that the command pulse is output when the number of pulses from the carrier encoder is 0, 4, 8, 12, and 16. In this way, the pulse table sets the timings at which the command pulse is output at equal intervals for each speed level.

[0060] For both high-speed operation (SC2 in Figure 7) and low-speed operation (SC7 in Figure 7), the applicable speed levels are pre-registered. In both high-speed and low-speed operation, the cutter control device 30 refers to the pulse table corresponding to the speed level and outputs a command pulse with the number of transport encoder pulses specified in that pulse table.

[0061] Furthermore, in the blade position adjustment process (SA3 in Figure 5), the speed of the rotary cutter 10 is increased or decreased by gradually changing the speed level used. More specifically, the error in the positional relationship between the rotational position of the cutting blade and the cutting line is converted into the number of command pulses, and the number of command pulses is increased or decreased to cancel out the converted number of command pulses. For example, if the rotational position of the cutting blade 12 is lagging behind the cutting line, additional command pulses are output at the currently used speed level to advance the rotational position of the cutting blade 12. Conversely, if the rotational position of the cutting blade 12 is ahead of the cutting line, the output of some command pulses is canceled at the currently used speed level to delay the rotational position of the cutting blade 12. Thus, in the cutting edge position adjustment process, the command pulse can be adjusted in single-pulse units, enabling more precise control compared to the high-speed and low-speed operations described above. Furthermore, by keeping the speed difference from the synchronous speed to a maximum of ±25%, high responsiveness can be achieved.

[0062] Furthermore, in the case of acceleration control (SB4 in Figure 6, SC9 in Figure 7), the speed level is continuously switched to gradually increase each time the input pulse of the carrier encoder reaches N, at a predetermined speed change period. Similarly, in the case of deceleration control (SC4 in Figure 7), the speed level is continuously switched to gradually decrease each time the input pulse of the transport encoder reaches N, in other words, at a predetermined speed change cycle.

[0063] Next, the operation of the cutting device 1 according to this embodiment will be briefly described with reference to Figures 5 to 7 and Figure 10. First, at time T1 in Figure 10, the paper detection sensor 20 detects a sheet of paper S (target paper), and when the paper detection signal is input to the cutter control device 30 (SA2 in Figure 5), the cutter control device 30 calculates and sets the start position of operation (SB2 in Figure 6). Then, at time T2 in Figure 10, when the target paper reaches the start position, the cutter control device 30 starts acceleration control to accelerate the speed of the rotary cutter 10 (SB4). As a result, a command pulse is output to the cutter drive unit 15 based on, for example, the acceleration control pulse table (see Figure 9), and the rotational speed of the rotary cutter 10 gradually accelerates (times T2-T3 in Figure 10). Then, at time T3, once the synchronization between the rotational speed of the rotary cutter 10 and the transport speed is complete, the blade tip position adjustment process is performed as needed (SA3 in Figure 5). Specifically, the cutter control device 30 determines whether the rotation angle of the cutting blade 12 and the cutting line of the target paper are synchronized, and if there is an error, it increases or decreases the rotational speed of the rotary cutter 10 to adjust so that the timing of both matches. Next, the target paper is cut from time T4 (cut-in) to time T5 (cut-out) in Figure 10. During the cutting of the target paper, for example, synchronous control is performed to synchronize the transport speed and the speed of the rotary cutter 10.

[0064] Next, after cutting at time T5, it is determined whether this is the last cut on the target paper (SA5 in Figure 5), whether the next paper detection signal has been received (SA6), and whether the distance X exceeds the stop threshold (SA9). Based on these determinations, it is decided whether to stop operation or continue cutting. If operation is stopped, the rotation speed is gradually reduced (times T5-T6 in Figure 10), and at time T6, the rotary cutter 10 stops. At this time, the cutting blade 12 is adjusted to the standby position (=P0). On the other hand, if continuous cutting is performed, the speed of the rotary cutter 10 is controlled according to the distance X (see mainly Figure 7).

[0065] As described above, according to this embodiment, the cutting device 1 includes a rotary cutter 10 that cuts the sheet paper S in a direction intersecting the transport direction A, a paper detection sensor 20 positioned upstream of the rotary cutter 10 in the transport path of the sheet paper S and detecting the edge of the sheet paper S, and a cutter control device 30 that controls the rotary cutter 10. The cutter control device 30 controls the speed of the rotary cutter 10 based on the transport speed of the transport unit 60, the position θ of the cutting blade 12 provided on the rotary cutter 10, and the cutting line on the sheet paper S, after the paper detection sensor 20 has detected the edge of the sheet paper S.

[0066] This makes it possible to stably cut the sheet paper S in a direction intersecting the transport direction A using the rotary cutter 10. As a result, when it is necessary to cut the sheet paper S in both the longitudinal and width directions, as in the conventional method, it is no longer necessary to rotate the sheet paper 90 degrees when performing the subsequent cutting process. This makes it possible to miniaturize the device.

[0067] In this embodiment, when the paper detection sensor 20 detects the edge of the sheet of paper S, the cutter control device 30 performs a synchronization process to match the rotation speed of the rotary cutter 10 to the transport speed of the sheet of paper S. Once the synchronization process is complete, it performs a blade tip position adjustment process to increase or decrease the rotation speed of the rotary cutter 10 so that the position of the cutting blade 12 coincides with the cutting line on the sheet of paper S.

[0068] In this way, by performing a blade tip position adjustment process after the synchronization process, the position of the cutting blade 12 and the cutting line can be made to almost coincide, thereby reducing cutting errors.

[0069] In this embodiment, after cutting a sheet of paper S, if the cutting is not the last cutting of that sheet of paper (target paper), or if the next sheet of paper has been detected by the paper detection sensor 20, the cutter control device 30 performs a continuous cutting process by controlling the speed of the rotary cutter 10 based on the distance X to the next cutting position.

[0070] This makes it possible to perform continuous cutting without stopping the transport of the sheets of paper S, even when multiple cutting lines are set on the sheet. Furthermore, by controlling the speed according to the distance X, stable continuous cutting becomes possible.

[0071] In this embodiment, during continuous cutting, the cutter control device 30 synchronizes the rotation speed of the rotary cutter 10 with the transport speed by rotating the rotary cutter 10 at a speed faster than the transport speed (synchronous speed) of the sheet paper S and then decelerating it when the distance X to the next cutting position is less than or equal to a predetermined first threshold C1 set to a value smaller than the circumference C of the rotary cutter 10.

[0072] Thus, when the distance X is less than or equal to the first threshold C1, the rotary cutter is rotated at a speed faster than the synchronous speed, and then decelerated to match the synchronous speed. This makes it possible to achieve stable cutting even when the distance to the next cutting position is relatively short.

[0073] In this embodiment, the cutter control device 30 synchronizes the rotation speed of the rotary cutter 10 with the transport speed by rotating the rotary cutter 10 at a speed slower than the transport speed of the sheet of paper S, and then accelerating it, when the distance X to the next cutting position is greater than a predetermined second threshold C2, which is set to be greater than the circumference C of the rotary cutter 10, and less than or equal to a stop threshold Cs. Here, the stop threshold Cs is set to be greater than the second threshold and less than or equal to the transport distance corresponding to the period it takes to rotate the rotary cutter 10 once at the lowest speed.

[0074] Thus, when the distance X is greater than or equal to the second threshold C2 and less than or equal to the stop threshold Cs, the rotary cutter 10 is rotated at a speed slower than the synchronous speed, and then accelerated to match the synchronous speed. This makes it possible to achieve stable cutting even when the distance to the next cutting position is relatively far.

[0075] In this embodiment, the cutter control device 30 maintains synchronized control with the transport speed when the distance X to the next cutting position is greater than a predetermined first threshold C1 set to a value smaller than the circumference C of the rotary cutter 10, and less than a predetermined second threshold C2 set to a value larger than the circumference C of the rotary cutter 10.

[0076] This makes it possible to rotate the rotary cutter 10 at a stable speed.

[0077] In this embodiment, the cutter control device 30 stops the rotary cutter 10 at a predetermined rotation angle after cutting a sheet of paper S, if the cutting is the last cutting on the sheet of paper (target paper), and the paper detection sensor 20 has not detected the next sheet of paper S.

[0078] This suppresses unnecessary rotation of the rotary cutter 10.

[0079] In this embodiment, after cutting a sheet of paper S, the cutter control device 30 stops the rotary cutter 10 at a predetermined rotation angle if the distance X to the next cutting position is greater than the stop threshold Cs.

[0080] This suppresses unnecessary rotation of the rotary cutter 10.

[0081] In this embodiment, the cutter control device 30 has a pulse table that associates the number of transport pulses corresponding to the transport speed of the sheet paper S with the timing of outputting command pulses related to the rotation speed of the rotary cutter 10. The cutter control device 30 then uses the pulse table and the number of transport pulses input from the transport unit 60 to control the speed of the rotary cutter 10.

[0082] This simplifies the control of the rotary cutter 10, making it possible to easily achieve speed control.

[0083] In this embodiment, a pulse table is provided for each speed level of the rotary cutter 10, and the cutter control device 30 changes the speed of the rotary cutter by switching the pulse table to be used.

[0084] This allows the speed of the rotary cutter 10 to be easily changed. Furthermore, since control is defined for each speed level, stable speed control can be achieved.

[0085] [Second Embodiment] Next, a control method for a cutting apparatus and a rotary cutter according to a second embodiment of this disclosure will be described with reference to the drawings.

[0086] In the first embodiment described above, during the synchronization process in step SA2 of Figure 5, control is performed to match the rotational speed of the rotary cutter 10 with the transport speed. After synchronization is completed, the synchronized state is maintained by outputting a command pulse corresponding to the number of pulses detected by the transport encoder from the cutter control device 30 to the cutter drive unit 15.

[0087] For example, as shown in Figure 10 at times T3 to T5, the transport speed is usually constant, and the rotational speed of the rotary cutter 10, which is controlled to follow this speed, will also match the transport speed. However, the resistance generated when the cutting blade 12 contacts the sheet of paper S may cause the sheet of paper S to be slightly pushed back, resulting in a slight decrease in the transport speed. In this case, the reduction in transport speed is detected by the transport encoder, and the cutter control device 30 performs synchronous control based on the reduced transport speed. That is, control is performed to decelerate the rotary cutter 10 to follow the reduced transport speed. This can lead to a vicious cycle where the resistance to the sheet of paper S becomes even stronger during cutting (see times T4-T5 in Figure 10), further reducing the rotation speed of the rotary cutter 10. Because this speed change occurs in a very short time, the cutter drive unit (servo motor) 15 may not be able to keep up. As a result of this phenomenon, even if the change in the transport speed of the sheet of paper S is within the allowable range of the specifications, the actual cutting accuracy may deteriorate more than expected.

[0088] To solve these problems, the cutting device and rotary cutter control method according to this embodiment controls the rotary cutter 10 to maintain the speed at which the synchronization process was completed, without performing follow-up control to make it follow the transport speed of the sheet paper S during cutting (for example, at times T4 to T5 in Figure 10).

[0089] Specifically, after performing the synchronization process according to the first embodiment described above and synchronizing the rotational speed of the rotary cutter 10 with the transport speed, the synchronized speed is maintained. More specifically, until the cutting is completed, in other words, during the period from cut-in (time T4) to cut-out (time T5) in Figure 10, a constant command pulse is output to the cutter drive unit 15 regardless of the number of input pulses from the transport encoder, thereby rotating the rotary cutter 10 at a constant speed.

[0090] Thus, according to this embodiment, the rotary cutter 10 is rotated at the synchronous speed before cutting, regardless of the transport speed, for at least the period from the start of cutting (for example, time T4 in Figure 10) to the end of cutting (for example, time T5 in Figure 10) at the cutting position of the sheet paper S. This makes it possible to avoid a decrease in cutting accuracy caused by a slight decrease in the transport speed of the paper sheet S due to the resistance generated when the cutting blade 12 comes into contact with the paper sheet S.

[0091] [Examples of application] Next, an example of a sheet-fed processing system to which the control method of the cutting device 1 and rotary cutter 10 according to the first or second embodiment described above is applied will be explained. Figure 11 is a diagram showing an example of a system configuration diagram of a bookbinding system 80 according to one embodiment of the present disclosure. As shown in Figure 11, the bookbinding system 80 mainly comprises a paper feeder 81, a first cutting device 82, a second cutting device 83, a stacking device 84, a bookbinding device 85, and a three-sided cutting device 86.

[0092] The paper feeder 81 feeds the sheets of paper S one sheet at a time. The first cutting device 82 cuts the sheets of paper S in a direction perpendicular to the transport direction. The cutting device 1 according to the first or second embodiment described above can be used as the first cutting device 82. The second cutting device 83 cuts the paper cut by the first cutting device 82 in a direction along the transport direction. As the cutting means of the second cutting device 83, for example, a slitter (round cutter) as disclosed in Patent Document 1 can be used.

[0093] The paper cut by the second cutting device 83 is accumulated in the stacking device 84. In this stacking device 84, the cut paper is stacked to form a book block. Next, the bookbinding device 85 wraps the book block with a cover and binds it. The three-sided trimming device 86 finishes trimming the top, bottom, and fore-edge. This completes the production of the final product, the book.

[0094] The bookbinding system 80 described above is just one example of the control method for the cutting device 1 and rotary cutter 10 according to this disclosure, and is not limited to this example. In other words, the control method for the cutting device 1 and rotary cutter 10 according to this disclosure can be broadly applied to sheet processing systems that have a process of cutting individual sheets (sheets cut to a predetermined size) in a direction intersecting the transport direction, rather than using roll paper.

[0095] Although the present disclosure has been described above using embodiments, the technical scope of this disclosure is not limited to the scope described in the embodiments above. Various modifications or improvements can be made to the embodiments without departing from the gist of the disclosure, and such modified or improved forms are also included in the technical scope of this disclosure. Furthermore, the embodiments above may be combined as appropriate. Furthermore, the processing procedure described in the above embodiment is merely an example, and unnecessary steps may be deleted, new steps added, or the processing order rearranged, without departing from the spirit of this disclosure. [Explanation of Symbols]

[0096] 1: Cutting device 10: Rotary cutter 11: Base 12: Cutting blade 13: Fixed blade 15: Cutter drive unit 20: Paper detection sensor (paper detection means) 30: Cutter control device (control means) 31: CPU 32: Main memory 33:Secondary storage device 34: Communication Interface 35: External Interface 36: Input Devices 37: Display 60: Conveying unit (conveying means) 61: Belt conveyor 62: Conveyor roller pair 62a: Upper roller 62b: Lower roller 63: Conveyor drive unit 64: Conveyor drive unit 65: Conveyor control device 80: Bookbinding System 81: Paper feeder 82: First cutting device 83: Second cutting device 84: Integration device 85: Bookbinding machine 86: Three-sided trimming device A: Conveying direction C: Circumference C1: First threshold C2: Second threshold Cs: Stop threshold LN1: Cutting line LN2: Cutting line P0: Reference position PC: Cutting position S: Sheet paper

Claims

1. A cutting device for cutting a sheet of material that has been transported by a transport means, A rotary cutter that cuts the aforementioned sheet in a direction intersecting the conveying direction, A paper detection means is positioned upstream of the rotary cutter in the transport path for the sheet of paper, and detects the edge of the sheet of paper. Control means for controlling the rotary cutter and Equipped with, The control means is A cutting device that, after the paper detection means detects the edge of the sheet, controls the speed of the rotary cutter based on the transport speed of the transport means, the position of the cutting blade provided on the rotary cutter, and the cutting position on the sheet.

2. The control means is When the paper detection means detects the edge of the sheet, it performs a synchronization process to match the rotation speed of the rotary cutter to the transport speed of the sheet. The cutting device according to claim 1, wherein, upon completion of the synchronization process, a cutting edge position adjustment process is performed to increase or decrease the rotational speed of the rotary cutter so that the position of the cutting blade coincides with the cutting position on the sheet.

3. The cutting apparatus according to claim 2, wherein the control means performs a continuous cutting process that controls the speed of the rotary cutter based on the distance to the next cutting position if, after cutting the sheet, the cutting is not the last cutting of the sheet, or if the next sheet has been detected by the paper detection means.

4. The cutting apparatus according to claim 3, wherein the control means synchronizes the rotation speed of the rotary cutter with the transport speed by, in the continuous cutting process, rotating the rotary cutter at a speed faster than the transport speed of the sheet and then decelerating it when the distance to the next cutting position is less than or equal to a predetermined first threshold set to a value smaller than the circumference of the rotary cutter.

5. The control means synchronizes the rotation speed of the rotary cutter with the transport speed by rotating the rotary cutter at a speed slower than the transport speed of the sheet, and then accelerating it, when the distance to the next cutting position is greater than a predetermined second threshold value set to be greater than the circumference of the rotary cutter, and less than or equal to a stop threshold value. The cutting device according to claim 3, wherein the stop threshold is greater than the second threshold and is set to be less than or equal to the transport distance corresponding to the period of one rotation of the rotary cutter at the lowest speed.

6. The cutting apparatus according to claim 3, wherein the control means maintains synchronized control with the transport speed when the distance to the next cutting position is greater than a predetermined first threshold set to a value smaller than the circumference of the rotary cutter, and less than a predetermined second threshold set to a value larger than the circumference of the rotary cutter.

7. The cutting apparatus according to claim 1, wherein the control means stops the rotary cutter at a predetermined rotation angle after cutting the sheet, if the cutting is the last cutting to the sheet and the next sheet has not been detected by the paper detection means.

8. The control means, after cutting the sheet, stops the rotary cutter at a predetermined rotation angle if the distance to the next cutting position is greater than a stop threshold. The cutting device according to claim 1, wherein the stop threshold is set to a transport distance equivalent to the period of time it takes to rotate the rotary cutter once at the lowest speed, or to a predetermined value smaller than the transport distance.

9. The cutting apparatus according to claim 2, wherein the control means rotates the rotary cutter at the synchronous speed before cutting, regardless of the conveying speed of the sheet, during the period from the start to the end of cutting the sheet.

10. The cutting apparatus according to claim 1, wherein the control means has a pulse table associated with the number of transport pulses corresponding to the transport speed of the sheet and the timing for outputting a command pulse relating to the rotation speed of the rotary cutter, and the speed of the rotary cutter is controlled using the pulse table and the number of transport pulses input from the transport means.

11. The pulse tables are provided for each speed level of the rotary cutter, The cutting apparatus according to claim 10, wherein the control means changes the speed of the rotary cutter by switching the pulse table being used.

12. A sheet-fed processing system comprising a cutting device according to any one of claims 1 to 11.

13. A control method for a rotary cutter that cuts a sheet of material conveyed by a conveying means in a direction intersecting the conveying direction, A rotary cutter control method that, after detecting that the sheet has passed a virtually set reference position upstream of the rotary cutter in the sheet transport path, controls the speed of the rotary cutter based on the transport speed of the transport means, the position of the cutting blade provided on the rotary cutter, and the cutting position on the sheet.

14. A program for causing a computer to execute the control method of a rotary cutter described in claim 13.

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