Image forming apparatus

Abstract

To provide an image forming apparatus capable of smoothly removing a residual sheet from the inside of the apparatus by preventing a moving blade from stopping on the way.SOLUTION: The CPU101 executes a change process of changing a duty ratio of a pulse-width-modulated drive current supplied to the cutter motor 106 based on an output from the encoder 113, and an abnormality process of stopping the movement of the movable blade 15 and returning the movable blade 15 to a movement start position when the duty ratio becomes equal to or greater than a predetermined value in moving the movable blade 15 in the sheet widthwise direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present application relates to an image forming apparatus equipped with a cutter unit that cuts a sheet. [Background technology]

[0002] Patent Document 1 describes a sheet cutting device that can detect signs of the moving blade running over the fixed blade, which can occur when a load is applied to the moving blade, and can cut more reliably. More specifically, when this sheet cutting device detects signs of running over the fixed blade, it changes the cutting control so that the cutting force is stronger. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-5969 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if the sheet cutting device described in Patent Document 1 is designed to cut with a stronger force, there is a risk that it will not be able to cut if the sheet is thicker than expected or if multiple sheets are being fed at once.

[0005] Furthermore, if a sheet remains at the cutting position due to a jam or transport error when the moving blade is returned to the standby position after cutting is complete, the load on the moving blade may increase, causing the moving blade to stop. In this case, the user must move the stopped moving blade and remove the remaining sheet. Depending on the location of the sheet cutting device, this may require removing a cover, which may take time to restore operation.

[0006] An object of the present application is to provide an image forming apparatus that can smoothly remove residual sheets from within the apparatus by preventing the moving blade from stopping midway. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the image forming apparatus described in the embodiment comprises a conveying section that conveys a sheet in a conveying direction, an image forming section that forms an image on the sheet, a cutter unit that is arranged downstream of the image forming section in the sheet conveying path and cuts the image-formed sheet conveyed by the conveying section, and a control section, wherein the cutter unit has a fixed blade that extends in the sheet width direction perpendicular to the sheet conveying direction, a movable blade that cuts the image-formed sheet by moving in the sheet width direction while in sliding contact with the fixed blade, a drive motor that imparts a driving force to the movable blade to move the movable blade, and an encoder that outputs rotation information of the drive motor, and the control section performs a change process that changes the duty ratio of the pulse-width modulated drive current supplied to the drive motor based on the output from the encoder, and an abnormality process that stops the movement of the movable blade and returns the movable blade to its starting position when the duty ratio becomes equal to or greater than a predetermined value when the movable blade is moved in the sheet width direction. [Effects of the Invention]

[0008] According to the image forming device described in the embodiment, when the movable blade is moved in the sheet width direction, if the duty ratio becomes equal to or greater than a predetermined value, the movement of the movable blade is stopped and the movable blade is returned to the starting position of the movement, thereby preventing the movable blade from stopping midway, and thereby enabling the remaining sheet to be smoothly removed from the device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a multifunction peripheral according to an embodiment. [Figure 2] FIG. 10 is a perspective view showing a state in which the cutter unit is attached by being sandwiched between the cutter attachment frame. [Figure 3] 10A and 10B are diagrams showing the carriage moving from a standby position ((a)) to a return position ((b)). [Figure 4]FIG. 2 is a block diagram showing the electrical configuration of the multifunction peripheral shown in FIG. [Figure 5] 4 is a flowchart showing the procedure of a cut and print process executed by the multifunction peripheral of FIG. 1, particularly by a CPU. [Figure 6] 6 is a flowchart showing the detailed procedure of the sheet printing and transporting process in FIG. 5. [Figure 7] 6 is a flowchart showing the detailed procedure of the sheet discharge process in FIG. 5. [Figure 8] 6 is a flowchart showing detailed procedures for the first cutter error process ((a)) and the second cutter error process ((b)) in FIG. 5. [Figure 9] 6 is a flowchart showing detailed steps of a third cutter error process in FIG. 5. [Figure 10] 8 is a flowchart showing the detailed procedure of the discharge error process in FIG. 7. [Figure 11] 4 is a flowchart showing the procedure of a cutter motor control process executed by the multifunction peripheral of FIG. 1, particularly by a CPU. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present application will be described in detail with reference to the drawings.

[0011] FIG. 1 is a cross-sectional view showing a schematic configuration of a multifunction peripheral 1 according to one embodiment. The multifunction peripheral 1 is an example of an image forming device and has functions such as printing, copying, and scanning. The multifunction peripheral 1 may also have a fax function in addition to these functions. The multifunction peripheral 1 does not necessarily have to have the copying and scanning functions. For ease of explanation, the up-down direction and the front-rear direction of the multifunction peripheral 1 are defined as shown by the arrows in FIG. 1. The left-right direction is defined as the direction from the front of the multifunction peripheral 1 facing the left-hand side of the user, and the right-hand side is defined as the direction from the front of the multifunction peripheral 1 facing the left-hand side. Note that when arrows indicating directions are shown in places other than FIG. 1, the directions should follow the arrows.

[0012] The multifunction device 1 includes a housing 20, a conveying unit 3, a process unit 4, a fixing unit 6, a scanner unit 9, and a cutter unit 10. The housing 20 is the exterior of the multifunction device 1. The scanner unit 9 is used to read documents in the copy function and the scanner function. The housing 20 is formed in a substantially rectangular parallelepiped shape. The multifunction device 1 can form a monochrome image on a sheet S by an electrophotographic method using the process unit 4. The multifunction device 1 may also be able to form a full-color image on a sheet S by the process unit 4.

[0013] The multifunction peripheral 1 further has a front cover 21, a rear cover 23, a supply tray 31, a discharge tray 22, a conveying path 201, and a re-conveying path 202. The front cover 21 is attached to the front of the housing 20 in an openable and closable manner. The rear cover 23 is made up of a first rear cover 23A and a second rear cover 23B, and is attached to the rear of the housing 20 in an openable and closable manner. The supply tray 31 is detachably attached to the bottom of the housing 20. Sheets S are placed on the supply tray 31. The sheets S are standard-sized sheets such as A4 size. The sheets S are paper media such as plain paper or cardboard, but are not limited to these, and may also be transparencies. The discharge tray 22 is provided at the top of the housing 20, and sheets S on which images have been formed are placed on the discharge tray 22.

[0014] The transport path 201 is a path for transporting the sheet S placed on the supply tray 31 in a transport direction toward the discharge tray 22 via the process unit 4. The transport path 201 branches into a first discharge path 201A and a second discharge path 201B at a branch position D1. Therefore, the sheet S transported via the process unit 4 may be discharged to the discharge tray 22 via the first discharge path 201A or via the second discharge path 201B.

[0015] The re-conveying path 202 is a path for conveying the sheet S, on one side of which an image has been formed, in the direction opposite to the conveying direction, again toward the process unit 4. The re-conveying path 202 is a path that starts from a switchback position D2 on the first discharge path 201A, which is downstream in the conveying direction from the branching position D1, and ends at a junction position J on the conveying path 201.

[0016] The conveying section 3 has a pickup roller 33, a separation roller 34, a registration roller 35, a conveying roller 36, an upstream cut roller 85, a downstream cut roller 86, a discharge roller 87, a flapper 88, re-conveying rollers 38, 39, a main motor 108 (see Figure 4), and a discharge motor 109 (see Figure 4).

[0017] The pickup roller 33 picks up the sheets S in the supply tray 31 that have been pushed upward by the sheet pressure plate 32, and transports them toward the transport path 201. The separation roller 34 separates the sheets S picked up by the pickup roller 33 one by one.

[0018] The registration rollers 35 are disposed upstream of the process unit 4 on the conveying path 201. The registration rollers 35 align the direction of the leading edge of the sheet S, and then convey the sheet S toward the process unit 4. The conveying rollers 36 convey the sheet S after it has passed through the fixing unit 6 toward the cut upstream rollers 85 or the discharge rollers 87.

[0019] The upstream cutting roller 85 and the downstream cutting roller 86 are disposed on the second discharge path 201B. The upstream cutting roller 85 is disposed at a position upstream of the cutter position SP where the cutter unit 10 is disposed, and the downstream cutting roller 86 is disposed at a position downstream of the cutter position SP.

[0020] The upstream cutting roller 85 is rotated by the driving force from the discharge motor 109 (see FIG. 4). A first driven roller 85' is arranged at a position facing the upstream cutting roller 85 across the second discharge path 201B. The first driven roller 85' is rotated in accordance with the rotation of the upstream cutting roller 85. The downstream cutting roller 86 is also rotated by the driving force from the discharge motor 109. A second driven roller 86' is arranged at a position facing the downstream cutting roller 86 across the second discharge path 201B. The second driven roller 86' is rotated in accordance with the rotation of the downstream cutting roller 86.

[0021] The cutting upstream roller 85 and the cutting downstream roller 86 rotate to transport the sheet S in the transport direction, thereby discharging the sheet S onto the discharge tray 22. The rotation to transport the sheet S in the transport direction corresponds to a counterclockwise rotation around the left-right direction of the housing 20 as an axis.

[0022] On the other hand, the discharge roller 87 is disposed on the first discharge path 201A. The discharge roller 87 is rotated by a driving force from a discharge motor 109 (see FIG. 4). A third driven roller 87' is disposed at a position facing the discharge roller 87 across the first discharge path 201A. The third driven roller 87' is rotated in accordance with the rotation of the discharge roller 87. The discharge roller 87 rotates to transport the sheet S in the transport direction, thereby discharging the sheet S onto the discharge tray 22. The discharge roller 87 also rotates in a direction opposite to the rotation that transports the sheet S in the transport direction, thereby transporting the sheet S to the re-conveyance path 202. The rotation in the direction opposite to the rotation that transports the sheet S in the transport direction corresponds to a clockwise rotation around an axis that is the left-right direction of the housing 20.

[0023] Re-conveying rollers 38 and 39 are arranged on the re-conveying path 202. The re-conveying rollers 38 and 39 convey the sheet S conveyed to the re-conveying path 202 toward the process unit 4. The re-conveying rollers 38 and 39 re-convey the sheet S, on one side of which an image has been formed, toward the process unit 4 via the re-conveying path 202, thereby making it possible to form images on both sides of the sheet S.

[0024] The flapper 88 is a component that switches between guiding the sheet S to the first discharge path 201A and guiding the sheet S to the second discharge path 201B. The ASIC 105 (see FIG. 4) switches the position of the flapper 88 between a first position (position 88A indicated by a two-dot chain line in FIG. 1) and a second position (position 88B indicated by a solid line in FIG. 1) by switching a flapper solenoid (not shown) ON and OFF. The flapper 88 is in the first position when the flapper solenoid is ON (default state), and in the second position when the flapper solenoid is OFF. Depending on the type of solenoid, the first position and the second position can be switched by changing the direction of current. The first position 88A is a position where the sheet S conveyed by the conveyance roller 36 is guided to the first discharge path 201A. The first position 88A is also a position where the sheet S on the first discharge path 201A is guided to the re-conveyance path 202. The second position 88B is a position where the sheet S conveyed by the conveying roller 36 is guided to the second discharge path 201B.

[0025] The process unit 4 forms an image on the sheet S and is housed in the housing 20. The process unit 4 has a drum cartridge 5 and a laser unit 7. The drum cartridge 5 has a photosensitive drum 51, a toner storage unit 57, a supply roller 56, a developing roller 55, a charger 52, a transfer roller 53, and a pinch roller 54. The drum cartridge 5 can be removed from the housing 20 by opening the front cover 21. The pinch roller 54 of the drum cartridge 5 faces the registration roller 35. The pinch roller 54 rotates following the rotation of the registration roller 35 and transports the sheet S together with the registration roller 35.

[0026] The photosensitive drum 51 is rotated by a driving force from a main motor 108 (see FIG. 4) to transport the sheet S in the transport direction, thereby transporting the sheet S in the transport direction. The photosensitive drum 51 rotates clockwise around an axis that extends in the left-right direction of the housing 20. Toner is stored in the toner storage section 57. The supply roller 56 supplies the toner in the toner storage section 57 to the developing roller 55. The charger 52 is a scorotron charger that uniformly charges the surface of the photosensitive drum 51. The charger 52 may be a charging roller.

[0027] A transfer roller 53 is disposed at a position facing the photosensitive drum 51. The transfer roller 53 forms a transfer nip TN between itself and the photosensitive drum 51 on the transport path 201. Note that a transfer belt may be used instead of the transfer roller 53.

[0028] The housing 20 has a laser unit 7 at its upper part. The laser unit 7 has a polygon mirror, a laser emitting unit, a polygon motor, a lens, a reflecting mirror, etc. (not shown). The laser unit 7 exposes the surface of the photosensitive drum 51 by scanning the surface of the photosensitive drum 51 at high speed with laser light (see the two-dot chain line in FIG. 1) based on image data emitted from the laser emitting unit.

[0029] An electrostatic latent image based on image data is formed on the surface of the photosensitive drum 51 by exposing it to light with the laser unit 7. The developing roller 55 supplies toner to the electrostatic latent image formed on the surface of the photosensitive drum 51, thereby forming a toner image on the surface of the photosensitive drum 51.

[0030] A transfer voltage is applied to the transfer roller 53 by a high-voltage power supply board (not shown). The transfer roller 53 transports the sheet S between itself and the photosensitive drum 51, thereby transferring the toner image formed on the surface of the photosensitive drum 51 onto the sheet S passing through the transfer nip TN. In this way, an image is formed on the sheet S.

[0031] The fixing unit 6 is disposed downstream of the process unit 4 on the conveying path 201. The fixing unit 6 has a heating roller 61, a pressure roller 62, and a heater 63. The heating roller 61 heats the sheet S. The pressure roller 62 forms a nip N between itself and the heating roller 61 and applies pressure to the sheet S. The pressure roller 62 rotates by the driving force of the main motor 108 to convey the sheet S in the conveying direction. The pressure roller 62 rotates counterclockwise around an axis that corresponds to the left-right direction of the housing 20 to convey the sheet S in the conveying direction. The heater 63 is, for example, a halogen heater, and heats the heating roller 61.

[0032] The fixing device 6 heats the sheet S with the heating roller 61 and rotates the pressure roller 62, thereby conveying the sheet S while applying pressure with the heating roller 61 and the pressure roller 62, thereby fixing the image formed on the sheet S by the process unit 4 to the sheet S.

[0033] A cutter unit 10 is disposed between the upstream cutting roller 85 and the downstream cutting roller 86 in the second discharge path 201B. The cutter unit 10 is disposed downstream of the fixing unit 6 in the conveyance direction of the sheet S. When the position on the sheet S to be cut reaches the cutter position SP, the multifunction device 1 stops the rotation of the upstream cutting roller 85 and the downstream cutting roller 86. With the rotation of the upstream cutting roller 85 and the downstream cutting roller 86 stopped, the multifunction device 1 cuts the sheet S using the cutter unit 10.

[0034] 2 shows the cutter unit 10 mounted between cutter mounting frames 40A and 40B. The cutter mounting frames 40A and 40B to which the cutter unit 10 is mounted are suspended from left and right main body frames (neither of which is shown) that are erected inside the housing 20.

[0035] Fig. 3 is a front view of the cutter unit 10 alone, seen from the direction opposite to the conveying direction (discharge direction) of the sheet S in Fig. 2. Fig. 3(a) shows a state in which the carriage 16 is at a standby position P1, and Fig. 3(b) shows a state in which the carriage 16 is at a return position P2.

[0036] As shown in FIG. 3, the cutter unit 10 includes a cutter frame 11, a slide rail 12, a fixed blade 13, a sheet passage 14, a movable blade 15, a carriage 16, an HP sensor 17, a belt 18, a pair of pulleys 19A and 19B, a cutter motor 106, and an encoder 113 (see FIG. 2). The cutter motor 106 is an example of a drive motor. The cutter frame 11 extends in the sheet width direction (left-right direction). The slide rail 12 is a rail formed on the cutter frame 11 and extends in the sheet width direction. The fixed blade 13 is a flat blade fixed to the cutter frame 11 and extends in the sheet width direction. The sheet passage 14 is a space formed in the cutter frame 11 through which the sheet S passes. The sheet width direction is the direction perpendicular to the conveying direction of the sheet S, that is, in Figure 2, the direction in which the sheet S passes through the sheet passing section 14 and is conveyed from the rear side (upstream side) of the cutter unit 10 to the front side (downstream side).

[0037] The carriage 16 is composed of a moving blade holder 16A and a slider 16B. The moving blade holder 16A rotatably holds the moving blade 15, which is a disc-shaped blade. The slider 16B engages with the slide rail 12 and is attached to the cutter frame 11 so as to be slidable along the slide rail 12. The slider 16B holds the moving blade holder 16A in a replaceable manner.

[0038] The slider 16B is fixed to the belt 18. The pair of pulleys 19A, 19B are disposed separated from each other in the left-right direction. The pulley 19A is a drive pulley that is driven to rotate by the cutter motor 106. The belt 18 is an endless circular belt that is stretched over the pair of pulleys 19A, 19B. The pulley 19B is a driven pulley that is rotated by the belt 18 that runs as a result of the rotation of the pulley 19A. Hereinafter, the pulley 19A will be referred to as the drive pulley 19A, and the pulley 19B will be referred to as the driven pulley 19B. Note that the driven pulley 19B in the drawings is not a pulley itself but is drawn as a pulley unit that also functions as a tensioner, but may be a pulley alone.

[0039] The HP sensor 17 is configured, for example, by a microswitch having an actuator 17A. The HP sensor 17 is positioned so that when the carriage 16 is at the standby position P1, the bottom of the carriage 16 presses the actuator 17A of the HP sensor 17, turning it on. In other words, the HP sensor 17 functions as a sensor that detects whether or not the carriage 16 is at the standby position P1. The HP sensor 17 is an example of a moving blade detection sensor.

[0040] When the cutter motor 106 is driven to rotate forward, the drive pulley 19A rotates counterclockwise in FIG. 3, and the belt 18 rotates left. This causes the carriage 16 to move from the standby position P1 toward the return position P2. Conversely, when the cutter motor 106 is driven to rotate in the reverse direction, the drive pulley 19A rotates clockwise in FIG. 3, and the belt 18 rotates right. This causes the carriage 16 to move from the return position P2 toward the standby position P1.

[0041] Next, the electrical configuration and drive configuration of the multifunction device 1 will be described with reference to Fig. 4. As shown in Fig. 4, the multifunction device 1 further includes an ASIC 105, a ROM 102, a RAM 103, an NVRAM 104, a discharge front sensor SE1, a cut discharge sensor SE2, and a communication interface (I / F) 130.

[0042] ASIC 105 is equipped with CPU 101. CPU 101 is an example of a control unit and performs overall control of each unit of multifunction device 1. ASIC 105 is electrically connected to ROM 102, RAM 103, NVRAM 104, cutter motor 106, encoder 113, HP sensor 17, electromagnetic clutch 107, main motor 108, discharge motor 109, discharge front sensor SE1, cut discharge sensor SE2, operation panel PA, communication I / F 130, drum cartridge 5, fuser 6, and laser unit 7 (not shown in FIG. 4). Operation panel PA is an example of a display unit.

[0043] The ROM 102 stores various control programs and various settings for controlling the multifunction peripheral 1. Some or all of these various control programs and various settings may be stored in the NVRAM 104.

[0044] The RAM 103 is used as a working area from which various control programs are read, and as a storage area for temporarily storing image data included in a print job. The CPU 101 controls each part of the multifunction peripheral 1 in accordance with the control programs read from the ROM 102 and signals output from various sensors, while storing the processing results in the RAM 103. The cut printing process (see FIG. 5) and cutter motor control process (see FIG. 11), which will be described later, are included in the control programs.

[0045] The CPU 101 drives the cutter motor 106 to move the carriage 16, thereby moving the movable blade 15 in the width direction of the sheet S while sliding against the fixed blade 13, thereby cutting the sheet S. An encoder 113 is attached to the rotation shaft of the cutter motor 106, and the encoder 113 outputs a signal corresponding to the rotation of the cutter motor 106. The CPU 101 receives the signal output from the encoder 113 and acquires the rotation direction, rotation position, and rotation speed of the cutter motor 106 based on the received signal. This allows the CPU 101 to know where the carriage 16 is located on the slide rail 12 and how fast it is moving, i.e., where the movable blade 15 is located in the sheet width direction and how fast it is moving. The rotation direction can be determined from the direction of the current supplied to the cutter motor 106, but if the encoder 113 supports two-phase output, it can also be determined from the phase difference.

[0046] The main motor 108 transmits driving force to the pickup roller 33, the registration roller 35, the conveying roller 36, the re-conveying rollers 38 and 39, the pressure roller 62, and the drum cartridge 5. When the CPU 101 drives the main motor 108 to rotate in the forward direction, the driving force is transmitted to the conveying roller 36, the pressure roller 62, the photosensitive drum 51, the developing roller 55, the pickup roller 33, and the registration roller 35. Then, the conveying roller 36, the pressure roller 62, the photosensitive drum 51, the developing roller 55, the pickup roller 33, and the registration roller 35 rotate in a direction to convey the sheet S in the conveyance direction.

[0047] Specifically, the conveying roller 36 and the pressure roller 62 rotate counterclockwise. The photosensitive drum 51 rotates clockwise. The developing roller 55 rotates counterclockwise. The pickup roller 33 rotates counterclockwise. The registration roller 35 rotates counterclockwise.

[0048] On the other hand, even if the CPU 101 drives the main motor 108 in the reverse direction, the driving force is not transmitted to the conveying roller 36, the pressure roller 62, the drum cartridge 5, the pickup roller 33, and the registration roller 35.

[0049] The discharge motor 109 is, for example, a stepping motor, and transmits driving force to the upstream cutting rollers 85 and the downstream cutting rollers 86. When the CPU 101 drives the discharge motor 109 in the forward direction, the upstream cutting rollers 85 and the downstream cutting rollers 86 rotate counterclockwise. As a result, the sheet S is discharged onto the discharge tray 22. On the other hand, when the CPU 101 drives the discharge motor 109 in the reverse direction, the upstream cutting rollers 85 and the downstream cutting rollers 86 rotate clockwise. As a result, the sheet S is transported in the direction opposite to the transport direction.

[0050] Furthermore, the CPU 101 drives the main motor 108 in the forward direction, causing the re-conveying rollers 38 and 39 to rotate clockwise. On the other hand, the CPU 101 drives the main motor 108 in the reverse direction, causing the re-conveying rollers 38 and 39 to rotate clockwise. As a result, the sheet S transported in the direction opposite to the transport direction is transported toward the image forming unit 4 via a re-conveying path 202.

[0051] CPU 101 controls electromagnetic clutch 107. By turning on electromagnetic clutch 107, CPU 101 brings about a state in which the driving force of main motor 108 is transmitted to pickup roller 33, and by turning off electromagnetic clutch 107, CPU 101 brings about a state in which the driving force of main motor 108 is not transmitted to pickup roller 33.

[0052] The discharge front sensor SE1 is disposed between the fixing unit 6 and the conveying rollers 36 on the conveying path 201, and detects the passage of the sheet S. The discharge front sensor SE1 may be a sensor having an actuator that swings when the sheet S comes into contact with it, or an optical sensor. The discharge front sensor SE1 outputs an ON signal when the sheet S is passing, and outputs an OFF signal when the sheet S is not passing. The detection signal from the discharge front sensor SE1 is output to the CPU 101.

[0053] The cut discharge sensor SE2 is disposed between the cutter position SP and the downstream cutter roller 86, and detects the passage of the sheet S. The cut discharge sensor SE2 has the same configuration as the discharge front sensor SE1. A detection signal by the cut discharge sensor SE2 is output to the CPU 101.

[0054] As shown in FIG. 1, the operation panel PA is disposed on the upper surface of the front side of the device body 2. Since a user operates the operation panel PA from a position in front of the multifunction device 1, the operation panel PA is disposed in a position that allows easy operation by the user from the front of the multifunction device 1. The operation panel PA has, for example, a touch panel in which a touchpad and a display are integrally formed, and a key button section. The operation panel PA receives user operations and outputs the received information to the CPU 101. For example, the user can set whether or not to cut the sheet S by operating the operation panel PA. The operation panel PA may be disposed near the scanner unit 9.

[0055] The communication I / F 130 is connected to a network such as a LAN, and enables connection to an external device such as a PC incorporating a driver for the multifunction device 1. The CPU 101 can receive a print job via the communication I / F 130. The print job includes various information required to form an image on the sheet S, such as image data for image formation, the size and type of the sheet S to be used for image formation, and information on whether or not to cut the sheet S.

[0056] The cut and print process in which the multifunction peripheral 1 configured as above, particularly the CPU 101, cuts and prints the sheet S based on a print job instructed to perform cut and print will be described with reference to FIGS.

[0057] FIG. 5 shows the steps of the cut printing process executed by CPU 101. The cut printing process in FIG. 5 is initiated when CPU 101 acquires a print job instructed to perform cut printing. As described above, the print job may be acquired by receiving a print job output by an external device via communication I / F 130, or by reading a print job already stored in RAM 103 or NVRAM 104. Alternatively, the print job may be acquired by generating a print job for printing image data obtained by scanning an original with scanner unit 9 in response to an instruction to execute copying. The cut printing instruction may be set in the print job, or may be issued based on an operation received from the user via operation panel PA. Hereinafter, in the explanation of each process, steps will be abbreviated as "S."

[0058] 5, when the cut printing process is started, CPU 101 initializes TIMER to "0" (S10). TIMER may be configured as a software timer that functions as a timer by having CPU 101 count up a predetermined area (not shown) on RAM 103 at predetermined intervals. This is not a limitation, and TIMER may also be configured as a hardware timer. It is assumed that TIMER is constantly timing at least while the cut printing process is being executed.

[0059] Next, the CPU 101 determines whether the HP sensor 17 is on (S11). This determination determines whether the carriage 16 is at standby position P1. When the cut printing process starts, the carriage 16 is usually at standby position P1, so the determination in S11 determines whether the carriage 16 has moved from standby position P1 toward return position P2 for some reason, or whether the carriage 16 is in an unusual state where it has not yet fully returned from the return position P2 to standby position P1.

[0060] If it is determined in S11 that the HP sensor 17 is on (S11: YES), that is, if the carriage 16 is at the standby position P1, the CPU 101 executes the sheet printing and transport process. FIG. 6 shows the detailed procedure of the sheet printing and transport process. In FIG. 6, the CPU 101 starts driving the main motor 108 (S60), and then picks up one sheet S from the supply tray 31 and supplies it to the transport path 201 (S61). At this time, the CPU 101 turns on the electromagnetic clutch 107 to transmit the driving force of the main motor 108 to the pickup roller 33, and pushes the sheet pressure plate 32 upward to push the sheet S in the supply tray 31 upward so that the pickup roller 33 can pick up the sheet S. Then, the CPU 101 prints on the sheet S being transported along the transport path 201, that is, forms an image (S62). Furthermore, if cut printing is instructed, the sheet S on which the image is formed is discharged to the discharge tray 22 via the second discharge path 201B, and therefore the flapper 88 is switched to the second position 88B.

[0061] Next, the CPU 101 waits until the discharge front sensor SE1 outputs an ON signal (S63: NO). Then, when the discharge front sensor SE1 outputs an ON signal (S63: YES), the CPU 101 starts driving the discharge motor 109 (S64). As a result, the conveyance of the sheet S is switched from conveyance by the main motor 108 to conveyance by the discharge motor 109. The point at which the discharge front sensor SE1 outputs an ON signal is the point at which the discharge front sensor SE1 detects the leading edge of the sheet S in the conveyance direction (hereinafter abbreviated as "the leading edge of the sheet S"). Therefore, when the discharge front sensor SE1 detects the leading edge of the sheet S, the discharge motor 109 starts driving the cut upstream rollers 85, the cut downstream rollers 86, and the discharge rollers 87.

[0062] Next, CPU 101 waits until sheet S reaches the position where it should be cut (S65: NO). When sheet S reaches the position where it should be cut (S65: YES), CPU 101 stops driving discharge motor 109 (S66) and then ends the sheet print transport process. The position where sheet S should be cut is, for example, the halfway position in the transport direction of sheet S. In this case, when sheet S reaches the position where it should be cut, it means that the halfway position in the transport direction of sheet S reaches cutter position SP (see FIG. 1). Whether the halfway position in the transport direction of sheet S has reached cutter position SP can be determined, for example, by determining whether a predetermined time has elapsed since cut discharge sensor SE2 detected the leading edge of sheet S. Here, the predetermined time is the time assumed by the developer of multifunction peripheral 1 that the halfway position in the transport direction of sheet S will reach cutter position SP after the predetermined time has elapsed since cut discharge sensor SE2 detected the leading edge of sheet S, if transport unit 3 is transporting sheet S normally without jamming. The predetermined time is determined by dividing the transport distance required for the half position of the sheet S in the transport direction to reach the cutter position SP (see Figure 1) after the cut and discharge sensor SE2 detects the leading edge of the sheet S by the transport speed, for example.

[0063] 5, the CPU 101 sets the constant PWMF1 to 70% and the constant PWMF2 to 60% (S13). In this embodiment, the cutter motor 106 is configured by, for example, a DC motor, and the number of rotations and rotation speed of the cutter motor 106 are controlled using, for example, PWM control. The constants PWMF1 and PWMF2 indicate constant values ​​of the duty ratio in PWM control.

[0064] Next, the CPU 101 starts driving the cutter motor 106 in the forward direction (S14). FIG. 11 shows the procedure of the cutter motor control process executed by the CPU 101 to control the cutter motor 106. The cutter motor control process starts when an instruction to start driving the cutter motor 106 in the forward direction or an instruction to start driving the cutter motor in the reverse direction is given. In FIG. 11, the CPU 101 determines whether or not an instruction to start driving the forward direction has been given (S120). If an instruction to start driving the forward direction has been given (S120: YES), the CPU 101 executes the processes of S121 to S127. If an instruction to start driving the forward direction has not been given (S120: NO), that is, if an instruction to start driving the reverse direction has been given, the CPU 101 executes the processes of S131 to S137.

[0065] In S121, the CPU 101 sets the PWM value to an initial value for forward rotation, for example, 60%. The PWM value is the duty ratio in PWM control, but it is not a constant value but a variable value. Next, the CPU 101 PWM-controls the maximum current Imax supplied to the cutter motor 106 in accordance with the duty ratio indicated by the PWM value (S122). Specifically, if one cycle is 10 μs and the duty ratio indicated by the PWM value is 60%, the CPU 101 supplies the cutter motor 106 with the current Imax for 6 μs of one cycle and with a current of 0 for 4 μs. This control is equivalent to supplying the cutter motor 106 with the current Imax×PWM value obtained by multiplying the current Imax by the PWM value, and therefore S122 in FIG. 11 is written as "supplying Imax×PWM value to the cutter motor." The same applies to S133, which will be described later.

[0066] Next, the CPU 101 acquires the rotation speed of the cutter motor 106 (S123). As described above, the rotation speed of the cutter motor 106 is acquired based on the output from the encoder 113. The CPU 101 then compares the acquired rotation speed with the target forward rotation speed. If the acquired rotation speed is less than the target forward rotation speed (S124: YES), the CPU 101 increases the PWM value by a predetermined increment (e.g., 5%) (S125) and then determines whether or not a command to stop forward rotation drive has been issued (S126). If the command to stop forward rotation drive has not been issued (S126: NO), the CPU 101 returns the process to S122 and PWM-controls the maximum value Imax of the current supplied to the cutter motor 106 in accordance with the duty ratio indicated by the PWM value increased by the predetermined increment. Now, since the PWM value has been increased from 60% to 65%, in S122, the CPU 101 supplies Imax×0.65 to the cutter motor 106. On the other hand, if it is determined in S124 that the acquired rotation speed is equal to or greater than the target forward rotation speed (S124: NO), the CPU 101 decreases the PWM value by a predetermined amount (for example, 5%) (S127), and then proceeds to the process of S126.

[0067] In this way, the CPU 101 repeatedly executes the processes of S122 to S125 and S127 until an instruction to stop the forward rotation drive is received (S126: YES).

[0068] Meanwhile, in S131, the CPU 101 sets the PWM value to an initial reverse value, for example, 50%. The reason why the initial reverse value of the PWM value is set smaller than the initial forward value is because the sheet S is cut when the cutter motor 106 is driven in the forward direction, but the sheet S is not cut when the cutter motor 106 is driven in the reverse direction. In other words, when cutting the sheet S, it is necessary to increase the rotation speed of the cutter motor 106 to counter the load when cutting the sheet S. Next, the CPU 101 PWM-controls the maximum value (maximum absolute value) -Imax of the negative side of the current supplied to the cutter motor 106 in accordance with the duty ratio indicated by the PWM value (S132). Since the PWM value is now set to 50%, which is the initial reverse value, in S132, the CPU 101 supplies -Imax × 0.5 to the cutter motor 106.

[0069] Next, the CPU 101 acquires the rotation speed of the cutter motor 106 in the same manner as in S123 (S133). Then, the CPU 101 compares the acquired rotation speed with the target reverse rotation speed using their absolute values. If the acquired rotation speed (absolute value) is less than the target reverse rotation speed (absolute value) (S134: YES), the CPU 101 increases the PWM value by a predetermined increment (e.g., 5%) (S135) and then determines whether or not a command to stop reverse driving has been issued (S136). If the CPU 101 determines that a command to stop reverse driving has not been issued (S136: NO), the CPU 101 returns the process to S132 and PWM-controls the maximum value (maximum absolute value) -Imax of the negative side of the current supplied to the cutter motor 106 in accordance with the duty ratio indicated by the PWM value increased by the predetermined increment. Now, since the PWM value has been increased from 50% to 55%, in S132, the CPU 101 supplies -Imax × 0.55 to the cutter motor 106. On the other hand, if the determination in S134 is that the obtained rotation speed is equal to or greater than the target reverse rotation speed (S134: NO), the CPU 101 decreases the PWM value by a predetermined amount (for example, 5%) (S137), and then proceeds to the process of S136.

[0070] In this way, the CPU 101 repeatedly executes the processes of S132 to S135 and S137 until an instruction to stop the reverse driving is received (S136: YES).

[0071] Returning to FIG. 5, next, the CPU 101 determines whether the current PWM value is equal to or greater than the constant PWMF1 (=70%) (S15). This determination is made to determine whether an excessive load is being applied to the moving blade 15 via the cutter motor 106. In other words, the duty ratio indicated by the constant PWMF1 is the lower limit value for determining whether an excessive load is being applied to the moving blade 15.

[0072] If the determination in S15 is that the current PWM value is smaller than the constant PWMF1 (S15: NO), that is, if it is determined that no excessive load is being applied to the moving blade 15, the CPU 101 determines whether the moving blade 15 has reached the return position P2 (see FIG. 3B) (S16). This determination may be made based on the output from the encoder 113. This determination determines whether the moving blade 15 has reached the return position P2, not whether the carriage 16 has reached the return position P2. However, the positions of the moving blade 15 and the carriage 16 are substantially the same. Even if they are not the same, the position of the carriage 16 can be easily converted from the position of the moving blade 15, and conversely, the position of the carriage 16 can be easily converted from the position of the moving blade 15. Therefore, the determination of whether the moving blade 15 has reached the return position P2 and the determination of whether the carriage 16 has reached the return position P2 can be considered to be the same determination.

[0073] If it is determined in S16 that the moving blade 15 has not reached the return position P2 (S16: NO), the CPU 101 returns the process to S15. That is, based on the determinations in S15 and S16, it is determined whether the moving blade 15 has reached the return position P2 under the condition that the current PWM value is smaller than the constant PWMF1. If the moving blade 15 has reached the return position P2 under the condition that the current PWM value is smaller than the constant PWMF1 (S16: YES), the CPU 101 stops the forward rotation of the cutter motor 106 (S17). As a result, the moving blade 15 moves from the standby position P1 to the return position P2 under the condition that the load on the moving blade 15 is not greater than the expected load, and the sheet S is cut at the position where it should be cut. Strictly speaking, in S17, the CPU 101 executes a process to instruct the cutter motor 106 to stop the forward rotation. As a result, the CPU 101 determines "YES" in S126 of the cutter motor control process and ends the cutter motor control process, thereby stopping the forward rotation of the cutter motor 106. The circumstances regarding S17 are the same as those for S14 above and S19, S24, S64, S66, S70, S75, S80, S90, S91, S93, S100, S101, S103, and S110 described below.

[0074] Next, the CPU 101 executes the sheet discharge process (S18). Fig. 7 shows the detailed procedure of the sheet discharge process. In Fig. 7, the CPU 101 resumes driving the discharge motor 109 (S70), and then initializes the TIMER to "0" (S71) in the same manner as in S10 (see Fig. 5) above.

[0075] Next, the CPU 101 determines whether the cut discharge sensor SE2 turns off while the timing time of the TIMER does not exceed the time TJAM, based on the determination of S72 and the determination of S77. Here, the time TJAM is the time assumed by the developer of the multifunction device 1 as the time elapsed from when the sheet S is cut until both the downstream and upstream pieces of the cut sheet S are discharged to the discharge tray 22 and the carriage 16 returns from the return position P2 to the standby position P1, provided that the conveyance unit 3 normally conveys the sheet S without jam occurrence. A time obtained by adding a predetermined margin time to this time may be used as the time TJAM. Note that the time TJAM is an example of the first time.

[0076] In the determination of S72 and the determination of S77, when the cut discharge sensor SE2 turns off (S72: YES) while the timing time of the TIMER does not exceed the time TJAM (S77: NO), the CPU 101 determines whether TSRT ≤ TIMER < TOVER based on the determination of S73 and the determination of S74. Here, the time TSRT is the time assumed by the developer of the multifunction device 1 as the time obtained by adding the time when the downstream piece of the cut sheet S is discharged to the discharge tray 22 to the time until the cut discharge sensor SE2 turns off, i.e., until the rear end of the downstream piece is detected, when the conveyance unit 3 conveys only the downstream piece of the two cut pieces of the sheet S after cutting. A time obtained by adding a predetermined margin time to this time may be used as the time TSRT. Also, the time TOVER is the time assumed by the developer of the multifunction device 1 as the time obtained by adding the time when the upstream piece of the cut sheet S is discharged to the discharge tray 22 to the time until the cut discharge sensor SE2 turns off, i.e., until the rear end of the upstream piece is detected, when the conveyance unit 3 conveys both the downstream and upstream pieces of the two cut pieces of the sheet S after cutting. A time obtained by adding a predetermined margin time to this time may be used as the time TOVER. The time TSRT is an example of the third time, and the time TOVER is an example of the fourth time.

[0077] In the determination of S73 and the determination of S74, when TSRT ≦ TIMER < TOVER (S73: NO and S74: NO), after the CPU 101 stops driving the discharge motor 109 (S75), it ends the sheet discharge process.

[0078] On the other hand, in the determination of S72 and the determination of S77, when the cut discharge sensor SE2 is in the on state (S72: NO) and the elapsed time of TIMER becomes equal to or more than the time TJAM (S77: YES), after the CPU 101 executes the discharge error process (S76), it ends the cut printing process. FIG. 10(a) shows the detailed procedure of the discharge error process. In FIG. 10(a), the CPU 101 stops driving the discharge motor 109 (S110), displays "sheet remaining error" on the operation panel PA (S104), and then ends the discharge error process. In the determination of S77, when it is determined as "YES", if the conveyance unit 3 is normally conveying the sheet S without jamming, both the downstream piece and the upstream piece of the two cut pieces of the sheet S should be discharged to the discharge tray 22, and furthermore, the time until the carriage 16 returns from the return position P2 to the standby position P1 should have elapsed. Nevertheless, the cut discharge sensor SE2 is still detecting the cut sheet S. That is, since the cut sheet S remains in the second discharge path 201B, the CPU 101 is configured to execute the discharge error process.

[0079] On the one hand, in the determination of S73, when TIMER < TSRT (S73: YES), or in the determination of S74, when TOVER ≤ TIMER (S74: YES), after the CPU 101 executes the discharge error processing (S76), it ends the cut printing processing. Since the details of the discharge error processing have been described above, they will not be repeatedly explained here. In the determination of S73, when it is determined as "YES", it is presumed that one of the two cut pieces of the sheet S on the upstream side is not conveyed and remains in the second discharge path 201B. Therefore, the CPU 101 is configured to execute the discharge error processing. On the other hand, in the determination of S74, when it is determined as "YES", although the cut discharge sensor SE2 detects the trailing edge of one of the two cut pieces of the sheet S on the upstream side, it is presumed that one of the pieces remains in the second discharge path 201B without being discharged to the discharge tray 22. Therefore, the CPU 101 is configured to execute the discharge error processing.

[0080] When the sheet discharge process ends with a return, the CPU 101 proceeds to S19 in FIG. 5 and starts reverse driving of the cutter motor 106. Then, the CPU 101 determines whether the current PWM value is equal to or greater than the constant PWMF2 (=60%) (S20). If the current PWM value is less than the constant PWMF2 (S20: NO), the CPU 101 determines whether the moving blade 15 has reached the standby position P1 (see FIG. 3A) (S21). If the moving blade 15 has not reached the standby position P1 (S21: NO), the CPU 101 returns the process to S20. That is, based on the determinations in S20 and S21, it is determined whether the moving blade 15 has reached the standby position P1 in a state where the current PWM value is less than the constant PWMF2. Then, when the current PWM value is smaller than the constant PWMF1 (S20: NO) and the moving blade 15 reaches the standby position P1 (S21: YES), the CPU 101 initializes the TIMER to "0" (S22), as in S10 above. The CPU 101 makes the determination in S21 based on the signal output from the encoder 113. For this reason, for example, the CPU 101 may determine "YES" in S21 even when the carriage 16 has not actually reached the standby position P1 because the belt 18 is slipping on the drive pulley 19A or the driven pulley 19B. Therefore, the CPU 101 determines in S23 whether the HP sensor 17 is on.

[0081] If the determination in S23 is that the HP sensor 17 is on (S23: YES), the CPU 101 stops the reverse driving of the cutter motor 106 (S24), and then determines whether or not there is a next page in the print job acquired when starting the cut printing process (S25). If the determination is that there is a next page (S25: YES), the CPU 101 returns the process to S12 and repeats the processes from S12 onwards. On the other hand, if there is no next page (S25: NO), the CPU 101 ends the cut printing process.

[0082] On the other hand, if the determination in S23 is that the HP sensor 17 is off (S23: NO), the CPU 101 determines whether TIMER is greater than the predetermined time WAIT2 (S50), and if TIMER is equal to or less than the predetermined time WAIT2 (S50: NO), the CPU 101 returns the process to S23. Here, the predetermined time WAIT2 is the time assumed by the developer of the multifunction peripheral 1 as the time that elapses from when an instruction to start reverse driving of the cutter motor 106 is issued with the carriage 16 at the return position P2 until the carriage 16 returns to the standby position P1, provided that the cutter unit 10 is in a normal state. The predetermined time WAIT2 may be calculated by adding a predetermined margin to this time.

[0083] On the other hand, if the headphone sensor 17 is off (S23: NO) and TIMER is greater than the predetermined time WAIT2 (S50: YES), the CPU 101 executes the first cutter error process (S51) and then terminates the cut printing process. FIG. 8A shows the detailed procedure for the first cutter error process. In FIG. 8A, the CPU 101 stops the reverse rotation of the cutter motor 106 (S80), displays "Cutter Error" on the operation panel PA (S81), and then terminates the first cutter error process. If the determination in S50 is "YES," the CPU 101 starts the reverse rotation of the cutter motor 106 in S19. Even if the determination in S21 is that the output from the encoder 113 indicates that the moving blade 15 has reached the standby position P1 (S21: YES), the CPU 101 executes the first cutter error process because the headphone sensor 17 has been off for longer than the predetermined time WAIT2 (S50: YES).

[0084] On the other hand, in the determination of S15 above, if the current PWM value is equal to or greater than the constant PWMF1 (S15: YES), the CPU 101 executes a second cutter error process (S40) and then ends the cut printing process. If the determination of S15 is "YES," this is because an excessive load is being applied to the moving blade 15 while the moving blade 15 is cutting the sheet S (S16: NO), and if further cutting of the sheet S is attempted, the moving blade 15 may stop before completing cutting of the sheet S.

[0085] FIG. 8B shows a detailed procedure for the second cutter error processing. The second cutter error processing is an example of the first abnormality processing. In FIG. 8B, the CPU 101 stops the forward rotation of the cutter motor 106 (S90) and then starts the reverse rotation of the cutter motor 106 (S91). The CPU 101 then waits until the moving blade 15 reaches the standby position P1 (S92: NO). When the moving blade 15 reaches the standby position P1 (S92: YES), the CPU 101 stops the reverse rotation of the cutter motor 106 (S93). The CPU 101 then displays "Sheet Remaining Error" on the operation panel PA (S94) and then ends the second cutter error processing. In this way, the second cutter error processing not only stops the forward rotation of the cutter motor 106 (S90), but also starts the reverse rotation of the cutter motor 106 (S91) and returns the moving blade 15 to the original standby position P1 (S92: YES). This prevents the moving blade 15 from getting in the way when removing the sheet S remaining near the cutter unit 10.

[0086] On the other hand, if the determination in S20 above is that the current PWM value is equal to or greater than the constant PWMF2 (S20: YES), the CPU 101 executes a third cutter error process (S40) and then ends the cut and print process. If the determination in S20 is "YES," an excessive load is applied to the moving blade 15 while the moving blade 15 is returning from the return position P2 to the standby position P1 (S21: NO), and if the moving blade 15 is returned any further toward the standby position P1, it is assumed that the moving blade 15 may stop before reaching the standby position P1.

[0087] FIG. 9 shows a detailed procedure for the third cutter error processing. The third cutter error processing is an example of the second abnormality processing. In FIG. 9, the CPU 101 stops the reverse rotation of the cutter motor 106 (S100), and then starts the forward rotation of the cutter motor 106 (S101). The CPU 101 then waits until the moving blade 15 reaches the return position P2 (S102: NO). When the moving blade 15 reaches the return position P2 (S102: YES), the CPU 101 stops the forward rotation of the cutter motor 106 (S103). The CPU 101 then displays "Sheet Remaining Error" on the operation panel PA (S104), and then ends the third cutter error processing. In this way, in the third cutter error processing, not only is reverse driving of the cutter motor 106 stopped (S100), but forward driving of the cutter motor 106 is started (S101), and the moving blade 15 is returned to the original return position P2 (S102: YES). This is convenient for the user because it is not necessary to return the moving blade 15 to the return position P2 again.

[0088] On the other hand, if the headphone sensor 17 is off in the determination in S11 (S11: NO), the CPU 101 starts reverse driving of the cutter motor 106. If the headphone sensor 17 is off, the carriage 16 is not at the standby position P1, so the CPU 101 starts reverse driving of the cutter motor 106 to return the carriage 16 to the standby position P1. The CPU 101 then determines whether TIMER is greater than the predetermined time WAIT1 (S31). If TIMER is less than or equal to the predetermined time WAIT1 (S31: NO), the CPU 101 returns the process to S11. Here, the predetermined time WAIT1 is the time assumed by the developer of the multifunction peripheral 1 as the time that elapses from when the cutter unit 10 is in a normal state and the carriage 16 is at the return position P2, when a command to start reverse driving of the cutter motor 106 is issued, until the carriage 16 returns to the standby position P1. The predetermined time WAIT1 may be calculated by adding a predetermined margin to this time. The definition of this predetermined time WAIT1 is the same as the definition of the predetermined time WAIT2 described above. However, the predetermined time WAIT2 may be shorter than the predetermined time WAIT1. The reason why this is acceptable is that the predetermined time WAIT2 is determined after it is determined based on the output from the encoder 113 that the moving blade 15 has returned from the return position P2 to the standby position P1 (S21: YES), and then it is determined whether the time during which the HP sensor 17 is off exceeds the predetermined time WAIT2 (S50).

[0089] On the other hand, if the HP sensor 17 remains off for a predetermined time WAIT2 even after the cutter motor 106 has started to be driven in the reverse direction (S32: YES), the CPU 101 executes the first cutter error process (S32) in the same manner as in S51 above, and then ends the cut and print process. The details of the first cutter error process have been described above, so they will not be repeated here.

[0090] As described above, the multifunction peripheral 1 of this embodiment includes the conveying section 3 that conveys the sheet S in the conveying direction, the process section 4 that forms an image on the sheet S, the cutter unit 10 that is arranged downstream of the process section 4 in the conveying path 201 of the sheet S and that cuts the sheet S on which the image has been formed and that has been conveyed by the conveying section 3, and the CPU 101. The cutter unit 10 includes a fixed blade 13 that extends in the sheet width direction perpendicular to the conveying direction of the sheet S, a movable blade 15 that cuts the sheet S on which the image has been formed by moving in the sheet width direction while making sliding contact with the fixed blade 13, a cutter motor 106 that imparts a driving force to the movable blade 15 to move the movable blade 15, and an encoder 113 that outputs rotation information of the cutter motor 106. The CPU 101 is characterized by executing a change process to change the PWM value of the pulse-width modulated drive current supplied to the cutter motor 106 based on the output from the encoder 113 (S125, S135), and an abnormality process to stop the movement of the movable blade 15 (S90, S100) and return the movable blade 15 to the movement start position (S91, S101) if the PWM value becomes equal to or greater than the constants PWMF1, PWMF2 when moving the movable blade 15 in the sheet width direction (S15: YES or S20: YES).

[0091] In this way, in the multifunction device 1 of this embodiment, when the moving blade 15 is moved in the sheet width direction, if the PWM value becomes equal to or greater than the constants PWMF1 and PWMF2, the movement of the moving blade 15 is stopped and the moving blade 15 is returned to the starting position of the movement. This prevents the moving blade 15 from stopping midway, thereby enabling the remaining sheets S to be smoothly removed from within the device 1.

[0092] Furthermore, the multifunction device 1 further includes an operation panel PA, and when the CPU 101 executes an abnormality process, it executes an error display process (S94, S104) for displaying an error display on the operation panel PA in a display mode based on the direction in which the moving blade 15 is returned and the PWM value, thereby enabling the user to know the cause of the error.

[0093] The CPU 101 also moves the movable blade 15 between the standby position P1 and the return position P2, and the abnormality processing includes a cutter second error processing in which, if the PWM value becomes equal to or greater than a constant PWMF1 when moving the movable blade 15 from the standby position P1 to the return position P2, the movement of the movable blade 15 is stopped (S90) and the movable blade 15 is returned to the standby position P1, which is the movement start position (S91), and a cutter third error processing in which, if the PWM value becomes equal to or greater than a constant PWMF2 when moving the movable blade 15 from the return position P2 to the standby position P1, the movement of the movable blade 15 is stopped (S100) and the movable blade 15 is returned to the return position P2, which is the movement start position (S101).The error display processing is characterized in that, if the CPU 101 executes the cutter second error processing, the CPU 101 displays an error display in a first display mode on the operation panel PA (S94), and if the CPU 101 executes the cutter third error processing, the CPU 101 displays an error display in a second display mode on the operation panel PA (S104). This allows the user to know whether the second cutter error processing or the third cutter error processing has been executed simply by looking at the display format of the error display displayed on the operation panel PA.

[0094] Furthermore, the constant PWMF2 is smaller than the constant PWMF1. When the moving blade 15 moves from the return position P2 to the standby position P1, there is no need to cut the sheet S, so if the target speed is the same, the PWM value should be lower than when moving from the standby position P1 to the return position P2. Therefore, by making the constant PWMF2 smaller than the constant PWMF1, it is possible to detect an abnormal state such as a remaining sheet S.

[0095] The multifunction device 1 further includes a cut / discharge sensor SE2 that is disposed on the second discharge path 201B for discharging the sheet S conveyed via the cutter unit 10 out of the multifunction device 1 and detects the presence or absence of the sheet S, and an operation panel PA, and when the time during which the cut / discharge sensor SE2 detects the presence of the sheet S exceeds the time TJAM, the CPU 101 causes the conveying unit 3 to stop conveying the sheet S (S110) and displays an error message in the third display mode on the operation panel PA (S104). This makes it possible to display an error message on the operation panel PA indicating that the sheet S remains without being discharged from the second discharge path 201B.

[0096] Furthermore, the CPU 101 moves the movable blade 15 between the standby position P1 and the return position P2, and when the cut and discharge sensor SE2 detects the presence of the sheet S (S72: NO) and then detects the absence of the sheet S (S72: NO), it determines whether to move the movable blade 15 from the return position P2 to the standby position P1 depending on the length of time the cut and discharge sensor SE2 detects the presence of the sheet S (S73, S74) (return from S75, end the cut printing process from S76). As a result, if a cut sheet S remains near the movable blade 15 without being discharged, the movable blade 15 is not moved from the return position P2 to the standby position P1, thereby preventing the cut remaining sheet S from being cut again. On the other hand, if no cut sheet S remains near the movable blade 15, the movable blade 15 is moved from the return position P2 to the standby position P1, and conveyance of the next sheet on which an image is to be formed can be started with the movable blade 15 at the standby position P1.

[0097] Furthermore, when the cut and discharge sensor SE2 detects the presence of a sheet S (S72: NO) and then detects the absence of a sheet S (S72: YES), and when the TIMER during which the cut and discharge sensor SE2 detects the presence of a sheet S is shorter than the time TSRT (S73: YES) or longer than the time TOVER (S74: YES), the CPU 101 does not move the movable blade 15 from the return position P2 to the standby position P1 and displays an error message in the fourth display mode on the operation panel PA (S104). At this time, since the cut sheet S may remain near the movable blade 15 without being discharged, by not moving the movable blade 15 from the return position P2 to the standby position P1, it is possible to prevent the cut remaining sheet S from being cut again.

[0098] Furthermore, the CPU 101 moves the movable blade 15 between the standby position P1 and the return position P2, and if there is a sheet on which an image is to be formed next (S25: YES), moves the movable blade 15 from the standby position P1 to the return position P2 (S14 to S17), and then, after the movement from the return position P2 to the standby position P1 is completed (S19 to S24), causes the conveying unit 3 to start conveying the sheet on which an image is to be formed next (S12). This allows the conveying of the sheet on which an image is to be formed next to start while the movable blade 15 is in the standby position P1.

[0099] The cutter unit 10 further includes an HP sensor 17 that detects whether the moving blade 15 is at the standby position P1, and the CPU 101 determines whether the movement of the moving blade 15 from the return position P2 to the standby position P1 is complete based on the output from the HP sensor 17 and the output from the encoder 113. This makes it possible to reliably determine whether the movement of the moving blade 15 from the return position P2 to the standby position P1 is complete.

[0100] Furthermore, when moving movable blade 15 between standby position P1 and return position P2 and cutting sheet S with cutter unit 10, CPU 101 controls conveyance unit 3 to convey sheet S to the cutting position and stops it (S65, S66), moves movable blade 15 from standby position P1 to return position P2 to cut sheet S (S14-S16), and then, with movable blade 15 at return position P2 (S17), controls conveyance unit 3 to resume conveyance of sheet S (S70), and after the trailing edge of the sheet remaining upstream of fixed blade 13 in the conveying direction of sheet S passes fixed blade 13 (S72: YES), controls cutter motor 106 to move movable blade 15 from return position P2 to standby position P1 (S19). This prevents the cut sheet S from being cut again.

[0101] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0102] (1) In the above embodiments, the multifunction peripheral 1 is given as an example of a printing device, but the printing device is not limited to the multifunction peripheral 1 and may be a standalone printer or copier. In each of the above embodiments, the multifunction peripheral 1 that prints on the sheet S by an electrophotographic method is given, but the printing device may be a printing device that prints on the sheet S by an inkjet method.

[0103] (2) In the above embodiment, an example was described in which the processes shown in Figures 7 to 12, 24, and 26 are executed by CPU 101. However, these processes may be executed not only by CPU 101 but also by ASIC 105 or other logic integrated circuits, or these processes may be executed by cooperation between CPU 101, ASIC 105, and other logic integrated circuits.

[0104] (3) In the above embodiment, the drive control and stop control of the main motor 108 and the discharge motor 109 are performed based on time. However, this is not limited to this. Depending on the type of motor used, the control may be performed based on factors other than time, specifically, the number of steps input to the stepping motor or the signal output from the encoder, such as a step signal.

[0105] (4) In the above embodiment, the sheet S is cut by the moving blade 15 when the carriage 16 is moved from the initial position FP to the completion position KP, that is, when it is moved in one direction. However, this is not limiting, and the sheet S may also be cut when it is returned from the completion position KP to the initial position FP. In this case, the sheet S may be cut on both the forward and backward paths.

[0106] (5) In the above embodiment, the conveyance of the sheet S is performed by switching from the main motor 108 to the discharge motor 109, but this is not limited to this. The conveyance of the sheet S from the time the sheet S is picked up from the supply tray 31 to the time the sheet S is discharged to the discharge tray 22 may be performed by a single main motor 108.

[0107] (6) In the above embodiment, in the cutter motor control process, the rotation speed of the cutter motor 106 is varied by PWM controlling the current value supplied to the cutter motor 106 while varying the duty ratio. However, the target of PWM control may be a voltage value instead of a current value, and the rotation speed of the cutter motor 106 may be varied by PWM controlling the voltage value supplied to the cutter motor 106 while varying the duty ratio. [Explanation of symbols]

[0108] 1...multifunction device, 3...conveyor section, 4...process section, 10...cutter unit, 12...slide rail, 13...fixed blade, 14...sheet passing section, 15...moving blade, 16...carriage, 16A...moving blade holder, 16B...slider, 17...HP sensor, 18...belt, 19A...driving pulley, 19B...driven pulley, 20...casing, 40A, 40B...cutter mounting frame, 85...upstream cutter roller, 85'...first driven roller, 86...downstream cutter roller, 86'...second driven roller moving roller, 87...discharge roller, 87'...third driven roller, 101...CPU, 102...ROM, 103...RAM, 104...NVRAM, 105...ASIC, 106...cutter motor, 109...discharge motor, 113...encoder, 201...conveying path, 201A...first discharge path, 201B...second discharge path, D1...branching position, P1...standby position, P2...return position, PA...operation panel, S...sheet, SE1...discharge front sensor, SE2...cut discharge sensor.

Claims

1. a conveying unit that conveys the sheet in a conveying direction; an image forming unit that forms an image on the sheet; a cutter unit disposed downstream of the image forming unit in a conveyance path of the sheet, the cutter unit cutting the sheet on which an image has been formed and which has been conveyed by the conveyance unit; A control unit; Equipped with The cutter unit is a fixed blade extending in a sheet width direction perpendicular to a sheet conveyance direction; a movable blade that cuts the sheet on which the image has been formed by moving in the sheet width direction while being in sliding contact with the fixed blade; a drive motor that applies a drive force to the moving blade to move the moving blade; an encoder that outputs rotation information of the drive motor; and The control unit a change process for changing the duty ratio of a pulse-width modulated drive current supplied to the drive motor based on an output from the encoder; an abnormality process in which, when the duty ratio becomes equal to or greater than a predetermined value while the movable blade is being moved in the sheet width direction, the movement of the movable blade is stopped and the movable blade is returned to a movement start position; To execute An image forming apparatus characterized by:

2. The image forming apparatus further comprises: display section, Equipped with The control unit further includes: an error display process for displaying an error message on the display unit in a display mode based on the return direction of the movable blade and the duty ratio when the abnormality process is executed; To execute 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The control unit moves the movable blade between a standby position and a return position, The abnormality processing is a first abnormality process for stopping the movement of the movable blade and returning the movable blade to the standby position, which is the movement start position, when the duty ratio becomes equal to or greater than a first predetermined value when the movable blade is moved from the standby position to the return position; a second abnormality process for stopping the movement of the movable blade and returning the movable blade to the return position, which is the movement start position, when the duty ratio becomes equal to or greater than a second predetermined value when the movable blade is moved from the return position to the standby position; Including, In the error display process, the control unit: When the first abnormality process is executed, an error display in a first display mode is displayed on the display unit, When the second abnormality process is executed, an error display in a second display mode is displayed on the display unit.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

4. The second predetermined value is smaller than the first predetermined value.

4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

5. The image forming apparatus further comprises: a detection sensor that is disposed on a discharge path for discharging the sheet conveyed via the cutter unit to the outside of the image forming apparatus, and that detects the presence or absence of the sheet; A display unit; Equipped with The control unit When the time during which the detection sensor detects the presence of the sheet exceeds a first time, the conveyance unit is caused to stop conveying the sheet, and an error message in a third display mode is displayed on the display unit.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. The control unit The movable blade is moved between a standby position and a return position, When the detection sensor detects the presence of the sheet and then the absence of the sheet, it is determined whether or not to move the moving blade from the return position to the standby position depending on the length of time during which the detection sensor detects the presence of the sheet.

6. The image forming apparatus according to claim 5,

7. The control unit When the detection sensor detects the presence of the sheet and then detects the absence of the sheet, if the time during which the detection sensor detects the presence of the sheet is shorter than a third time or longer than a fourth time, the moving blade is not moved from the return position to the standby position, and an error message in a fourth display mode is displayed on the display unit.

7. The image forming apparatus according to claim 6, wherein the image forming apparatus is a recording medium.

8. The control unit The movable blade is moved between a standby position and a return position, Next, if there is a sheet on which an image is to be formed, After the moving blade is moved from the standby position to the return position, the conveying unit is caused to start conveying the sheet on which an image is next formed after the moving blade has completed moving from the return position to the standby position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. The cutter unit further comprises: a moving blade detection sensor that detects when the moving blade is at the standby position; and The control unit determining whether or not the movement of the movable blade from the return position to the standby position has been completed based on the output from the movable blade detection sensor and the output from the encoder; 9. The image forming apparatus according to claim 8,

10. The control unit The movable blade is moved between a standby position and a return position, When the sheet is cut by the cutter unit, the conveying unit conveys the sheet to a position where it is to be cut and stops the sheet, the movable blade is moved from the standby position to the return position to cut the sheet, and then, with the movable blade in the return position, the conveying unit resumes conveying the sheet, and the drive motor is controlled so that, after the rear end of the sheet remaining upstream of the fixed blade in the sheet conveying direction passes the fixed blade, the movable blade is moved from the return position to the standby position.

10. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images