Image forming apparatus

Abstract

To reduce noise generated when a sheet is conveyed in an image formation device comprising a gate mechanism.SOLUTION: An image formation device has a conveyance path and a gate. The conveyance path branches off into a plurality of paths, and a sheet is conveyed in a conveyance direction. The gate is provided at the position where the conveyance path branches off into the plurality of paths to change a path where the sheet is conveyed. The image formation device rotates the gate to a direction where a contact of the gate which faces a top surface of the sheet being conveyed and is located where a rear end of the sheet contacts the gate for the first time and the top surface of the sheet being conveyed face each other.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] Embodiments of the present invention relate to an image forming apparatus.

Background Art

[0002] In an image forming apparatus, the conveyance path of a sheet is switched between single-sided printing and double-sided printing, and a gate is used to switch the path of the conveyance path. A solenoid is used as the drive source of the gate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in the conveyance of a sheet in an image forming apparatus, a gate mechanism has been adopted to reverse the front and back of the sheet, and the rear end of the conveyed sheet may contact the gate and make a sound. The problem to be solved by the present invention is to reduce the sound generated during the conveyance of a sheet in an image forming apparatus provided with a gate mechanism.

Means for Solving the Problems

[0005] To solve the above problems, the image forming apparatus of the present embodiment includes a conveyance path, a gate, The control unit, and has. The conveyance path branches into a plurality of paths, and the sheet is conveyed along the conveyance direction. The gate is provided at a position where the conveyance path branches into a plurality of paths, and switches the path along which the sheet is conveyed. The image forming apparatus rotates the gate in a direction in which the contact point of the gate, which faces the surface of the conveyed sheet and is located at the position where the rear end of the sheet first contacts the gate, faces the surface of the conveyed sheet. The control unit controls the gate to rotate in a direction in which the contact point of the gate, which faces the surface of the conveyed sheet and is located at the position where the trailing edge of the sheet first contacts the gate, and the surface of the conveyed sheet face each other, and controls the gate to rotate in the facing direction before the trailing edge of the sheet reaches the contact point.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

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Figure 10

Embodiments for Carrying Out the Invention

[0007] Hereinafter, embodiments will be described with reference to the drawings.

[0008] FIG. 1 is a diagram showing the schematic configuration of the multifunction device 1. The image forming apparatus according to the present embodiment is the multifunction device 1. The multifunction device 1 prints an image on a sheet-like medium such as paper. The multifunction device 1 shown in FIG. 1 includes a conveyance unit 2, a control panel 3, a scanner 4, a printer 5, a paper feeding unit 6, a paper discharging unit 7, a gate mechanism 8, and an inversion unit 9. The multifunction device 1 includes a conveyance path 21 for the sheet with the paper feeding unit 6 on the upstream side and the paper discharging unit 7 on the downstream side in the sheet conveyance direction.

[0009] FIG. 2 is a block diagram showing an example of the hardware configuration of the multifunction machine 1. As shown in FIG. 2, the multifunction machine 1 further includes a storage unit 11 and a control unit 12. The control unit 12 controls the conveyance unit 2, the control panel 3, the scanner 4, the printer 5, the paper feeding unit 6, the paper discharging unit 7, the gate mechanism 8, the reversing unit 9, and the storage unit 11.

[0010] The conveyance unit 2 conveys the sheet taken out from the paper feeding unit 6 to the printer 5 along the conveyance path 21. After printing an image on the sheet by the printer 5, the conveyance unit 2 conveys the sheet to the paper discharging unit 7. The conveyance unit 2 includes a plurality of conveyance rollers at various positions in the conveyance path 21 as conveyance means for conveying the sheet.

[0011] The control panel 3 includes a plurality of buttons for receiving user operations. The control panel 3 outputs a signal corresponding to the operation performed by the user to the control unit 12 of the multifunction machine 1. Note that the control panel 3 is configured as a touch panel integrated with the display 31. The display 31 displays information regarding the multifunction machine 1. The display 31 is an image display device such as a liquid crystal display or an organic EL (Electro Luminescence) display.

[0012] The scanner 4 reads the image to be read and stores it as image information. The scanner 4 includes, for example, an ADF (Auto Document Feeder) or a DSDF (Dual Scan Document Feeder). The stored image information may be transmitted to other information processing devices via a network. The recorded image information may be printed as an image on a sheet by the printer 5.

[0013] The printer 5 forms a toner image on a sheet based on the image information transmitted from an external device such as the scanner 4 or a PC (Personal Computer).

[0014] The multi-function machine 1 includes a resist roller 52 and a fixing roller 51. The resist roller 52 is provided upstream of the printer 5 in the sheet conveyance direction. The fixing roller 51 is provided downstream of the printer 5 in the sheet conveyance direction. The resist roller 52 temporarily stops the conveyance of the sheet and conveys the sheet to the printer 5 at an arbitrary timing by the control unit 12. The fixing roller 51 fixes the toner image formed on the sheet by the printer 5 by heat and pressure. The fixing roller 51 conveys the sheet to the paper discharge unit.

[0015] The paper feed unit 6 accommodates, for example, the sheets on which images are printed. The paper feed unit 6 includes a plurality of paper feed cassettes 61 and a manual feed tray 62. Note that the sheets on which images are printed may be the sheets accommodated in the paper feed cassette 61 or the sheets manually inserted into the manual feed tray 62. The sheets are conveyed along the conveyance path 21 from the paper feed cassette 61 or the manual feed tray 62, pass through the printer 5, and are conveyed to the paper discharge unit 7.

[0016] With reference to FIGS. 3 to 7, the paper discharge unit 7 and the reversing unit 9 will be described. FIG. 3 is a perspective view showing a gate. FIG. 4 is a view showing a state where the path to the reversing unit 9 in the conveyance path 21 is closed. That is, FIG. 4 shows a state where the sheet is not conveyed to the reversing unit 9. FIG. 5 is a view showing a state where the path to the reversing unit 9 in the conveyance path 21 is open. That is, FIG. 5 shows a state where the sheet is conveyed to the reversing unit 9. FIG. 6 is a first view showing the conveyance of the sheet in the conveyance path 21. FIG. 6 is a view showing a state where the path to the first paper discharge port 72 is further opened compared to FIG. 4. FIG. 7 is a second view showing the conveyance of the sheet in the conveyance path 21. A and B indicated by the arc arrows in FIG. 4 indicate the directions (A direction, B direction) in which the gate 81 rotates. The dashed arrow C shown in FIG. 4 and the dashed arrows D and E shown in FIG. 5 indicate the sheet conveyance direction. The position of the gate 81 where the path to the first paper discharge port 72 is open as shown in FIG. 4 is set as the initial position. When the gate 81 is in the initial position, the sheet conveyed from the printer 5 is guided to the paper discharge unit 7. The gate 81 in the initial position is rotatable in the A direction or the B direction.

[0017] The sheet discharging unit 7 discharges the conveyed sheet onto the sheet discharge tray 73. The sheet discharging unit 7 is provided with an entry sensor 71.

[0018] The entry sensor 71 detects that the sheet has been conveyed to the sheet discharging unit 7. The entry sensor 71 is arranged upstream of the gate 81 in the sheet conveyance direction. The entry sensor 71 is, for example, a solenoid type sensor. Note that the type of the sensor is not limited as long as the entry sensor 71 can detect that the sheet has been conveyed to the sheet discharging unit 7.

[0019] The gate mechanism 8 defines which of the plurality of branched conveyance paths 21 the sheet is to be conveyed to. The gate mechanism 8 includes a gate 81 and a motor 82. In a state where there is no step between the gate 81 in the posture of guiding the sheet to the first discharge port 72 of the sheet discharging unit 7 and the conveyance path 21, or in a state where the gate 81 in the said posture bulges more than the conveyance path 21, the point where the gate 81 in the said posture and the rear end of the sheet conveyed to the discharge port 72 first come into contact is defined as the first contact point. That is, the first contact point is the point where the gate 81 and the rear end of the sheet conveyed to the discharge port 72 first come into contact in a state where the rear end of the sheet does not strike the gate 81 in the said posture. The first contact point may change for each conveyed sheet.

[0020] Also, when the gate 81 in the posture of guiding the sheet to the first discharge port 72 of the sheet discharging unit 7 is recessed more than the conveyance path 21 and a step is generated, the point where the rear end of the sheet conveyed to the discharge port 72 first comes into contact with the gate 81 in the said posture is downstream of the first contact point in the sheet conveyance direction. In this case, the rear end of the sheet conveyed to the discharge port 72 does not come into contact with the first contact point.

[0021] As shown in FIG. 3, the gate 81 is a member having a plurality of protrusions extending in a direction intersecting an axis extending in the width direction of the sheet being conveyed. The gate 81 is driven by a motor 82. The gate 81 rotates about the axis by the operation of the motor 82. The gate 81 guides the sheet conveyed from the printer 5 by the conveying unit 2 to the first paper discharge port 72 of the paper discharge unit 7 or the reversing unit 9. The gate 81 is driven by a motor 82. The gate 81 is provided at the branch point between the paper discharge unit 7 and the reversing unit 9 in the conveyance path 21. The switching of the conveyance path of the sheet in the conveyance path 21 is based on the relative rotation amount from the initial position of the gate 81 to the position where the gate 81 has rotated. The rotation amount is the amount of movement when the gate 81 rotates from one position to another position.

[0022] The motor 82 drives the gate 81. The motor 82 is a stepping motor that rotates by a predetermined rotation amount every time it receives a pulse signal. The predetermined rotation amount is based on the number of steps of the stepping motor. For example, in the case of a stepping motor with 36 steps, 1 step is 10 degrees. Therefore, the stepping motor rotates by a rotation amount of 10 degrees every time it receives a pulse signal once. The rotation speed of the motor 82 is controlled by the speed at which it receives the pulse signal. The motor 82 can rotate forward and backward. For example, when the motor 82 rotates forward, the gate 81 rotates in the B direction, and when the motor 82 rotates backward, the gate 81 rotates in the A direction. The rotation amount of the gate 81 is based on the rotation amount of the motor 82. The rotation speed at which the gate 81 rotates is based on the rotation speed of the motor 82. The motor 82 is controlled by the control unit 12.

[0023] The reversing unit 9 reverses the sheet when printing on both sides of the sheet. The reversing unit 9 has a reversing sensor 91 and a reversing roller 92. The reversing unit 9 is an Automatic Duplexing Unit (ADU).

[0024] The inversion sensor 91 detects that the sheet has been conveyed to the inversion section 9. The inversion sensor 91 is arranged downstream of the gate 81 in the sheet conveyance direction. The inversion sensor 91 is, for example, a solenoid-type sensor. Note that the type of the sensor is not limited as long as the inversion sensor 91 can detect that the sheet has been conveyed to the inversion section 9.

[0025] The inversion roller 92 conveys the sheet in the inversion section 9. The inversion roller 92 can rotate forward and backward. The rotation direction of the inversion roller 92 is controlled by the control unit 12.

[0026] When the sheet is conveyed to the first paper discharge port 72, the gate 81 does not need to open to the maximum angle in the movable range in the A direction, and any angle is acceptable as long as the sheet is conveyed to the first paper discharge port 72. When the sheet is conveyed to the inversion section 9, the gate 81 does not need to open to the maximum angle in the movable range in the B direction, and any angle is acceptable as long as the sheet is conveyed to the inversion section 9.

[0027] The operation of the gate mechanism 8 will be described by taking the flow of the sheet in image printing as an example. For example, when printing an image on one side of the sheet, the sheet fed from the sheet feeding section 6 is printed with an image by the printer 5. The sheet that has passed through the printer 5 is guided to the gate 81 and conveyed in the direction of the dashed arrow C shown in FIG. 4, that is, to the first paper discharge port 72. The sheet is discharged from the first paper discharge port 72 and stacked on the paper discharge tray 73.

[0028] For example, when printing images on both sides of a sheet, the sheet fed from the paper feeding unit 6 has an image printed on one side by the printer 5. The sheet that has passed through the printer 5 is guided to the gate 81 driven in the B direction and conveyed in the direction of the dashed arrow D shown in FIG. 5, that is, to the second paper discharge port 93. At this time, depending on the size of the sheet, the leading edge of the sheet may be discharged from the second paper discharge port 93, but the trailing edge of the sheet is not discharged. When the sheet passes through the inversion sensor 91, the motor 82 is driven to return the gate 81 to its initial position, and the inversion roller 92 rotates in the reverse direction to convey the sheet in the direction of the dashed arrow E. The sheet that has been switched back is conveyed to the registration roller 52. The sheet conveyed by the registration roller 52 has an image printed on the other side by the printer 5. The sheet that has passed through the printer 5 is guided to the gate 81 and conveyed in the direction of the dashed arrow C shown in FIG. 4, that is, to the first paper discharge port 72. The sheet is discharged from the first paper discharge port 72 and stacked on the paper discharge tray 73.

[0029] The storage unit 11 is, for example, an HDD (Hard Disc Drive) or an SSD (Solid State Drive). The storage unit 11 acquires, for example, image data obtained or generated by each component of the multifunction device 1. The storage unit 11 stores information about the sheet and information about the gate. The sheet information includes information about the type of sheet and information about the processing surface of the sheet. The information about the type of sheet is, for example, plain paper or thick paper. The information about the processing surface of the sheet is information about whether to print on one side of the sheet or on both sides of the sheet. The gate information includes information about the rotation direction of the gate 81 and information about the amount of rotation of the gate 81. The gate information is stored in association with the sheet information. The information about the amount of rotation of the gate 81 may be stored, for example, as the number of pulse signals given to the motor 82. The information about the rotation direction of the gate 81 may be stored, for example, as + (plus) or - (minus).

[0030] FIG. 8 is a table showing an example of sheet information and control information of motor 82. The types of sheets shown in FIG. 8 are such that sheet SB is thicker and has a stronger restoring force than sheet SA. The type of sheet is defined by the settings of control panel 3 and paper feed cassette 61. In the present embodiment, sheet SA is plain paper and sheet SB is thick paper. The processing surface shown in FIG. 8 is the surface on which processing is performed on the sheet. The processing is, for example, printing an image on the sheet. One side is one surface of the sheet. Both sides include one surface and the other surface of the sheet. In the rotation direction of FIG. 8, when gate 81 rotates in the A direction, it is indicated by -(minus), and when gate 81 rotates in the B direction, it is indicated by +(plus). In the amount of rotation of FIG. 8, 0 indicates the amount of rotation of gate 81. 0 means, for example, not giving a pulse signal to the motor. 1 indicates the amount of rotation of gate 81, and the amount of rotation is larger than 0. 1 is, for example, the amount of rotation of gate 81 when a pulse signal is given to motor 82 once. 2 indicates the amount of rotation of gate 81, and the amount of rotation is larger than 1. 2 is, for example, the amount of rotation of gate 81 when a pulse signal is given to motor 82 twice. 3 indicates the amount of rotation of gate 81, and the amount of rotation is larger than 2. 3 is, for example, the amount of rotation of gate 81 when a pulse signal is given to motor 82 three times. When the amount of rotation is 0, since gate 81 does not rotate, the rotation direction is not described. The number of pulse signals given to motor 82 can be appropriately changed depending on the number of steps of motor 82 and the like. The first to fifth operations will be described later.

[0031] Control unit 12 includes a processor composed of a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) and a memory. The memory is, for example, a semiconductor memory, and has a ROM (Read Only Memory) that stores various control programs and a RAM (Random Access Memory) that provides a temporary working area for the processor. Control unit 12 controls each part of multifunction machine 1 based on various programs and the like stored in the ROM.

[0032] The control unit 12 controls the motor 82 according to the type of the conveyed sheet, and by rotating the gate 81, the position of the gate 81 can be changed to a position suitable for each type of sheet.

[0033] For example, the gate 81 shown in FIG. 4 shows the state when conveying the sheet SA. The gate 81 shown in FIG. 6 shows the state when conveying the sheet SB with a stronger restoring force than the sheet SA. The gate 81 shown in FIG. 6 is rotated more greatly in the A direction than the gate shown in FIG. 4. FIGS. 6 and 7 show the sheet SB.

[0034] When conveying a sheet with a strong restoring force such as the sheet SB, it is desirable to control the motor 82 to rotate the gate 81 in the A direction. As shown in FIG. 6, the sheet SB is conveyed while curving along the inclination of the conveyance path, but since the angle of the gate 81 is widely opened in the A direction compared to FIG. 4, the load on the sheet and the gate 81 etc. is reduced. By controlling the position of the gate 81 according to the type of sheet, the load on the conveyed sheet and the multifunction machine 1 is reduced.

[0035] By rotating the gate 81 in the direction (B direction) in which the surface of the sheet conveyed toward the paper discharge port 72 faces the first contact point, the sound generated by the rear end of the sheet contacting the gate 81 as if hitting it can be reduced. By rotating the gate 81 in the B direction so that the surface and the rear end of the sheet conveyed toward the paper discharge port 72 continuously contact the first contact point of the gate 81, the sound generated by the rear end of the sheet contacting the gate 81 as if hitting it can be further reduced. As shown in FIG. 7, by rotating the gate 81 in the B direction before the rear end of the sheet SB reaches the first contact point of the gate 81, the sound generated by the contact between the rear end of the sheet SB and the gate 81 due to the restoring force of the curved sheet SB is reduced.

[0036] The first operation to the fifth operation shown in FIG. 8 will be described.

[0037] The first operation and the second operation show the operation of the gate 81 when the sheet is conveyed to the reversing unit 9 during double-sided printing. In the first operation, the gate 81 is rotated in the B direction to connect the path to the reversing unit 9. In the second operation, the gate 81 is rotated in the A direction to close the path to the reversing unit 9. The second operation returns the position of the gate 81 rotated by the first operation to the initial position. In the case of single-sided printing, the first operation and the second operation are not processed.

[0038] The third operation and the fourth operation show the operation of the gate 81 when the sheet is conveyed to the first paper discharge port 72. In the third operation, the operation of the gate 81 is controlled so that the position of the gate 81 becomes a position suitable for the sheet to be conveyed. The third operation controls the amount of rotation of the gate 81 according to the type of the sheet. For example, the position of the gate 81 suitable for conveying the sheet SA with a weaker restoring force than the sheet SB is the initial position. Therefore, as the third operation when conveying the sheet SA, the gate 81 is not rotated. For example, the position of the gate 81 suitable for conveying the sheet SB with a stronger restoring force than the sheet SA is a position where the gate 81 is moderately opened in the A direction to the extent that the sheet is conveyed to the first paper discharge port 72. Therefore, as the third operation when conveying the sheet SB, the gate 81 is rotated in the A direction so that the amount of rotation becomes 1.

[0039] The fourth operation controls the operation of the gate 81 so that the first contact point of the gate 81 continuously contacts the surface of the sheet being conveyed and the rear end of the sheet. The fourth operation controls the amount of rotation of the gate 81 according to the type of the sheet. For example, in order for the first contact point of the gate 81 to continuously contact the surface of the sheet SA being conveyed and the rear end of the sheet, the gate 81 is rotated in the B direction so that the amount of rotation becomes 1. For example, in order for the first contact point of the gate 81 to continuously contact the surface of the sheet SB being conveyed and the rear end of the sheet, the gate 81 is rotated in the B direction so that the amount of rotation becomes 2.

[0040] The fifth operation shows the operation of gate 81 when the rear end of the sheet passes through the first contact of gate 81. The fifth operation returns the position of gate 81 rotated by the third and fourth operations to the initial position. For example, when the rear end of sheet SA passes through the first contact of gate 81, gate 81 is rotated in the A direction so that the rotation amount becomes 1. For example, when the rear end of sheet SB passes through the first contact of gate 81, gate 81 is rotated in the A direction so that the rotation amount becomes 1.

[0041] FIG. 9 is a flowchart diagram showing an example of the operation of the multifunction machine 1 when discharging a sheet. Referring to FIGS. 8 and 9, an example of the operation when the multifunction machine 1 prints an image on a sheet will be described. The multifunction machine 1 receives a print job (FIG. 9, ACT1). The print job includes information on the type of the sheet to be conveyed and information on the processing surface of the sheet as sheet information. The control unit 12 reads out the gate information from the storage unit 11 based on the sheet information of the print job. When receiving the print job, the sheet is fed from the paper feed unit 6, and a toner image is formed on the sheet by the printer 5. Thereafter, the sheet passes through the fixing unit 51 from the printer 5 and is conveyed toward the paper discharge unit 7.

[0042] The control unit 12 determines whether to print on one side or both sides of the sheet based on the print job (FIG. 9, ACT2). When printing on both sides (FIG. 9, ACT2, YES), when the entry sensor 71 detects the sheet conveyed to the paper discharge unit 7 (FIG. 9, ACT3), the control unit 12 controls the motor 82 to rotate the gate 81 in the B direction (FIG. 9, ACT4). That is, it is controlled so that the conveyed sheet is guided to the reversing unit 9. For example, when printing on both sides of sheet SB in this embodiment, a pulse signal is transmitted three times to the motor 82 so that the gate 81 rotates in the B direction (the first operation in FIG. 8).

[0043] When the sheet is conveyed to the inversion unit 9 and the inversion sensor 91 detects the sheet, the control unit 12 controls the motor 82 to rotate the gate 81 in the A direction so that the position of the gate 81 becomes the initial position (Fig. 9, ACT5). For example, when double-sided printing the sheet SB in this embodiment, a pulse signal is transmitted to the motor 82 three times so that the gate 81 rotates in the A direction (Fig. 8, the second operation). When the position of the gate 81 becomes the initial position, the control unit 12 rotates the inversion roller 92 in the reverse direction and conveys the sheet in the direction of the dashed arrow E shown in Fig. 5. The sheet is conveyed to the registration roller 52 located upstream of the fixing roller 51 in the conveyance direction. The front and back of the sheet that has passed through the inversion unit 9 are reversed compared to when the sheet is fed from the sheet feeding unit 6. Also, the position of the gate 81 when the sheet is switched back only needs to be a position where the sheet does not flow back in the direction of the entry sensor 71 and a position where the sheet can be conveyed in the direction of the dashed arrow E.

[0044] In this embodiment, as shown in Fig. 8, in the case of single-sided printing, the first operation and the second operation are not performed.

[0045] When printing on both sides (Fig. 9, ACT2, YES) and the entry sensor 71 detects the sheet for the second time (Fig. 9, ACT6), or when printing on one side (Fig. 9, ACT2, NO) and the entry sensor 71 detects the sheet for the first time (Fig. 9, ACT6), the control unit 12 controls the motor 82 to rotate the gate 81 in the B direction (Fig. 9, ACT7). For example, when double-sided printing the sheet SB in this embodiment, a pulse signal is transmitted to the motor 82 once so that the gate 81 rotates in the A direction (Fig. 8, the third operation). In ACT7, the amount of rotation for rotating the gate 81 is based on the type of the sheet to be conveyed. By setting the position of the gate 81 to a position suitable for the type of the sheet, the load on the sheet and the multifunction machine 1 can be reduced. Note that depending on the type of the sheet, the position of the gate 81 may remain unchanged at the initial position. For example, when printing the sheet SA in this embodiment, since no pulse signal is transmitted, the gate 81 does not rotate (Fig. 8, the third operation).

[0046] The control unit 12 controls the motor 82 to rotate the gate 81 in the B direction (Fig. 9, ACT8) so that the surface of the sheet being conveyed and the rear end of the sheet continuously contact the first contact point of the gate 81. For example, when double-sided printing the sheet SB in this embodiment, a pulse signal is transmitted to the motor 82 twice so that the gate 81 is driven in the B direction (Fig. 8, the fourth operation). By rotating the gate 81 in the B direction so that the surface of the sheet and the rear end of the sheet continuously contact the first contact point of the gate 81, the sound generated by the rear end of the sheet hitting the gate 81 due to the restoring force of the curved sheet is reduced.

[0047] When the sheet is discharged from the first paper discharge port 72, the control unit 12 controls the motor 82 to rotate the gate 81 in the A direction (Fig. 9, ACT9) so that the position of the gate 81 becomes the initial position. For example, when double-sided printing the sheet SB in this embodiment, a pulse signal is transmitted to the motor 82 once so that the gate 81 rotates in the A direction (Fig. 8, the fifth operation).

[0048] If there is no image to be printed subsequently (Fig. 9, ACT10, YES), the control is terminated. If there is an image to be printed subsequently (Fig. 9, ACT10, NO), the control unit 12 controls the multifunction machine 1 to print the image based on the print job.

[0049] In this embodiment, the control unit 12 controls the operations of ACT4 and ACT7 based on the timing when the entry sensor 71 detects the sheet, but it may also be controlled based on the timing when the resist roller 52 is activated.

[0050] Fig. 10 is a diagram showing a modified example of the gate 81 of this embodiment. A case where the axis for rotating the gate 81 is located upstream in the sheet discharge direction from the tip of the gate 81 will be described. The gate 81 shown in Fig. 10 is driven by the motor 82 and rotates in the directions of the arc arrows A and B.

[0051] In a modified example, the gate 81 has a second contact point. In a state where there is no step between the gate 81 in a posture that guides the sheet to the first discharge port 72 of the discharge unit 7 and the conveyance path 21, or in a state where the gate 81 in the posture bulges more than the conveyance path 21, a point located at a position where the gate 81 in the posture and the rear end of the sheet conveyed to the discharge port 72 come into contact last is defined as the second contact point. The second contact point may change for each conveyed sheet.

[0052] In a modified example, by rotating the gate 81 in a direction (B direction) in which the surface of the sheet conveyed toward the discharge port 72 and the second contact point are separated from each other, the sound generated when the rear end of the sheet contacts and hits the conveyance path 21 can be reduced. By rotating the gate 81 in the B direction so that the rear end of the sheet conveyed toward the discharge port 72 does not contact the second contact point of the gate 81, the sound generated when the rear end of the sheet contacts and hits the conveyance path 21 can be further reduced.

[0053] In the present embodiment, the motor 82 is used as the drive source of the gate 81, but for example, a mechanism that rotates the gate 81 to a predetermined position using a plurality of solenoids may also be used.

[0054] In the present embodiment, the multifunction device 1 has been described as an example, but it may be an image erasing machine that erases an image formed using a developer that can be erased by heat. In that case, the information on the processing surface of the sheet is information on whether to erase one side of the sheet or both sides of the sheet.

[0055] In the present embodiment, the multifunction device 1 has been described as an example, but it may be a printing machine that does not have functions such as a FAX, a scanner, and a finisher.

[0056] Although embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0057] 1 ··· Multifunction device 11 ··· Storage unit 12 ··· Control unit 2 ··· Conveyor unit 21 ··· Conveyor path 5 ··· Printer 52 ··· Registration roller 6 ··· Paper feeding unit 7 ··· Paper discharging unit 71 ··· Entry sensor 81 ··· Gate 82 ··· Motor 9 ··· Inverting unit

Claims

1. A conveyance path that branches into a plurality of paths and conveys a sheet along the conveyance direction, A gate provided at a position where the conveyance path branches into the plurality of paths and switches the path along which the sheet is conveyed, A contact point of the gate that faces the surface of the conveyed sheet and is located at a position where the rear end of the sheet first contacts the gate, and the surface of the conveyed sheet, and a control unit that controls the gate to rotate in a direction in which the gate faces the surface of the conveyed sheet, The control unit controls the gate to rotate in the facing direction before the rear end of the sheet reaches the contact point. An image forming apparatus.

2. A first position that is a position of the gate where the contact point and the surface of the conveyed sheet do not contact, and a second position that is a position of the gate where the contact point, the surface and the rear end of the conveyed sheet are in continuous contact, The gate is controlled by the control unit so that the first position and the second position are switched before the rear end of the sheet reaches the contact point. The image forming apparatus according to claim 1.

3. The control unit that controls the gate at a timing when the conveyed sheet passes through the gate, The image forming apparatus according to claim 1 or claim 2.

4. An entry sensor provided upstream of the gate in the conveyance direction of the sheet and detecting that the sheet has been conveyed, The control unit executes the control based on the detection result of the entry sensor. The image forming apparatus according to any one of claims 1 to 3.

5. A registration roller provided upstream of the gate in the conveyance direction of the sheet and arbitrarily conveying the sheet by the control unit, The control unit executes the control based on the timing of driving the registration roller. The image forming apparatus according to any one of claims 1 to 3.

Images