JP2012118497A - Image forming apparatus - Google Patents

Abstract

A printing performance is ensured.
An image forming apparatus includes an image forming unit that forms an image on a recording medium, a paper discharge path that conveys a recording medium on which an image is formed by the image forming unit, and the paper discharge path. A plurality of paper discharge units 109 and 110 having rollers for changing the rotation direction to a second direction opposite to the first direction which is the paper discharge direction, and a plurality of paper discharge units; And a path changing unit 122 that selectively changes the conveyance path of the recording medium to the recording medium, and a control unit that controls the changing direction of the roller rotation direction and the path changing unit.
[Selection] Figure 2

Description

  Embodiments described herein relate generally to an image forming apparatus.

  When printing an image on both sides of a sheet of paper, there is an image forming apparatus that has two paper discharge units, one is used for reversal, and the other is dedicated for paper discharge, in order to ensure printing performance during double-sided printing. ing. However, in the case of forming an image on both sides of a plurality of sheets, there is a problem that the next sheet to be reversed needs to wait in front of the reversing path while the preceding sheet is reversed, and the printing performance is deteriorated. is there.

JP 2006-21903 A

  The problem to be solved by the present invention is to ensure printing performance.

  In order to solve the above problems, an image forming apparatus according to an embodiment of the present invention includes an image forming unit that forms an image on a recording medium, and a paper discharge path through which the recording medium on which the image is formed by the image forming unit is conveyed. A plurality of paper discharge units having rollers provided in the paper discharge path and transporting the conveyed recording medium while changing the rotation direction in a second direction opposite to the first direction as the paper discharge direction; A path changing unit that selectively changes a conveyance path of the recording medium to the plurality of paper discharge units, and a control unit that controls a rotation direction of the roller and a changing operation of the path changing unit. And

1 is a configuration diagram illustrating an image forming apparatus according to a first embodiment. 2 is an enlarged view of an internal structure of the image forming apparatus according to the first embodiment. FIG. 2 is a block diagram illustrating a control system of the image forming apparatus according to the first embodiment. FIG. FIG. 3 is an enlarged view of a paper discharge unit of the image forming apparatus according to the first embodiment. 5 is a flowchart illustrating image formation on both sides of a sheet in the first embodiment. It is a figure which shows the path | route change part which conveys the 1st paper in 1st embodiment to the 1st paper discharge part. It is a figure which shows the path | route change part which reverses the 1st paper in 1st embodiment, and conveys a 2nd paper to a 2nd paper discharge part. It is a figure which shows the path | route change part which reverses and conveys the 2nd paper in 1st embodiment. 3 is a flowchart illustrating a series of flows of the image forming apparatus according to the first embodiment. It is a figure which shows the paper conveyed to the drum in 1st embodiment. FIG. 3 is a diagram illustrating a sheet on which an image is formed in the first embodiment. FIG. 3 is a diagram illustrating a sheet conveyed to a sheet discharge unit after image formation according to the first embodiment. FIG. 4 is a diagram illustrating that a first sheet is conveyed to a first sheet discharge unit and a second sheet is conveyed to a second sheet discharge unit in the first embodiment. FIG. 6 is a diagram in which a first sheet is reversed and a second sheet is conveyed to a second sheet discharge unit in the first embodiment. FIG. 6 is a diagram in which the second sheet is reversed and the first sheet and the second sheet are conveyed to the drum again in the first embodiment. FIG. 5 is a diagram illustrating a state in which a first sheet and a second sheet after image formation on one side are waiting in the first embodiment. FIG. 10 is an enlarged view of a paper discharge unit of an image forming apparatus according to a second embodiment.

  Embodiments of an image forming apparatus will be described below with reference to the accompanying drawings.

(First embodiment)
In the first embodiment, in an image forming apparatus having two paper discharge units, the two paper discharge units have a reversing function.

  FIG. 1 is a configuration diagram illustrating the image forming apparatus according to the first embodiment, and FIG. 2 is an enlarged view of an internal structure of the image forming apparatus 100. The image forming apparatus is, for example, a multi-function peripheral (MFP), a printer, a copier, or the like.

  The image forming apparatus 100 includes a storage unit 101, an image forming unit 102, a paper discharge unit 103, a post-processing unit 104, and a stacking unit 105.

  The storage unit 101 holds a sheet as a recording medium and can be pulled out in the front direction of FIG. The image forming unit 102 forms an image on the surface of the paper by ejecting water-based ink. The image forming unit 102 includes a drum 106, an ink supply unit 107, and an inkjet head 108. The circumference of the drum 106 is long enough to attach at least two sheets of paper, and rotates in the direction of the arrow r. The drum 106 generates a negative pressure inside the drum in order to adsorb the sheet, and sucks it from a hole formed on the drum 106. As another suction method, for example, static electricity may be generated and the paper may be sucked.

  Above the drum 106, four rows of ink-jet heads 108 that eject ink onto paper according to image data are arranged. For example, an inkjet head 108Y that ejects yellow (Y) ink from the upstream, an inkjet head 108M that ejects magenta (M) ink, an inkjet head 108C that ejects cyan (C) ink, and an inkjet head that ejects black (K) ink They are arranged in the order of 108K.

  The ink supply unit 107 holds each color ink and is connected to the inkjet head 108 by a tube. In the above description, a configuration in which an image is formed with a plurality of colors of yellow, magenta, cyan, and black is shown.

The paper discharge unit 103 includes a first paper discharge unit 109 and a second paper discharge unit 110. The first paper discharge unit 109 and the second paper discharge unit 110 have a reversing function, and the first paper discharge unit 109 is located farther from the image forming unit 102 than the second paper discharge unit 110. Located in. The paper discharge unit 103 will be described later with reference to FIG.

  The post-processing unit 104 performs post-processing such as stapler, punching, center folding, and folding on the paper on which the image is formed by the image forming unit 102 and discharged from the paper discharge unit 103.

  The stacking unit 105 stacks the paper discharged from the paper discharge unit 103 and the paper that has been subjected to post-processing by the post-processing device 104 and discharged. The stacking unit 105 includes a first stacking unit 111 and a second stacking unit 112, and the discharged sheets are stacked on the first stacking unit 111 or the second stacking unit 112.

  FIG. 3 is a block diagram of the image forming apparatus 100. The image forming apparatus 100 temporarily records a central processing unit (CPU) 200 that is a control unit, a read only memory (ROM) 201 that stores various programs, and various variable data and image data. A RAM (Random Access Memory) 202, and an interface (I / F) 203 for inputting data from outside and outputting data to the outside.

  Further, the image forming apparatus 100 includes a sensor control drive circuit 204 that controls the sensors 121, 124, and 125, a drum control drive circuit 205 that controls a drum drive motor 206 connected to the drum 106, a stapler of the post-processing unit 104, A post-processing unit control drive circuit 207 for controlling a motor 208 and a solenoid 209 for driving punching, folding, folding and the like, and a solenoid 211 connected to a path changing unit 122 for selectively changing a sheet conveyance path are controlled. The path change control driving circuit 210, the conveyance roller motor control driving circuit 212 for controlling the conveyance roller motor 213 coupled to the registration roller 114 and the conveyance roller pair 115, 123, and the separation unit 116 for separating the sheet from the drum 106 are coupled. A peeling unit control drive circuit 214 for controlling the solenoid 215; A paper discharge roller motor control drive circuit 216 for controlling a paper discharge roller motor 217 connected to the paper discharge roller 118 and the second paper discharge roller 120, and the inkjet head 108Y, the inkjet head 108M, the inkjet head 108C, and the inkjet head 108K are controlled. And an inkjet head control drive circuit 218 for performing the above operation.

  The CPU 200 includes a ROM 201, a RAM 202, an I / F 203, a sensor control drive circuit 204, a drum control drive circuit 205, a post-processing unit control drive circuit 207, a path change control drive circuit 210, and a conveyance roller motor control drive circuit 212 via a bus. , A separation part control drive circuit 214, a paper discharge roller motor control drive circuit 216, and an inkjet head control drive circuit 218.

  Sensors 121, 124, and 125 detect the passage of paper. The detection result is transmitted to the CPU 200 via the sensor control drive circuit 204. The ink-jet head 108Y, the ink-jet head 108M, the ink-jet head 108C, and the ink-jet head 108K discharge ink from the nozzles onto the paper based on the signal from the ink-jet head control drive circuit 218.

  The image forming apparatus 100 according to the first embodiment forms an image on both sides of a sheet in a set of two sheets, a first sheet P1 and a second sheet P2. In the two-sheet set, a sheet on which an image is formed first is a first sheet P1, and a sheet on which an image is formed after the first sheet P1 is a second sheet P2.

  FIG. 4 is an enlarged view of the paper discharge unit 103. The paper discharge unit 103 includes a first paper discharge unit 109, a second paper discharge unit 110, conveyance roller pairs 115 and 123, and a path change unit 122. The first paper discharge unit 109 includes a first paper discharge path 117, a first paper discharge roller 118, and a sensor 124, and the second paper discharge unit 110 includes a second paper discharge path 119 and a second paper discharge path 119. Paper discharge roller 120 and sensor 125. The first paper discharge path 117 is a paper discharge path through which the paper passes, the sensor 124 detects the passage of the paper, and the first paper discharge roller 118 conveys and reversely conveys the paper. The second paper discharge path 119 is a paper discharge path through which the paper passes, the sensor 125 detects the passage of the paper P2, and the paper discharge roller 120 conveys and reversely conveys the paper. The conveyance roller pairs 115 and 123 convey and reversely convey the sheet.

  The path changing unit 122 is driven by the solenoid 211 and rotates around the axis to change the paper transport path. The path changing unit 122 has three stop positions, the first being the upper discharge position, the second being the lower discharge position, and the third being the lower reverse discharge position. The upper paper discharge position is a position where the first paper P1 after image formation is conveyed to the first paper discharge unit 109. The lower paper discharge position is a position where the second paper P2 after image formation is conveyed to the second paper discharge unit 110, and the first paper P1 is conveyed again to the image forming unit 102. The lower reverse paper discharge position is a position where the second paper P2 is conveyed to the image forming unit 102 again.

  FIG. 5 is a flowchart showing the reversal of paper accompanying double-sided printing. In 300, one side of the first paper P1 and the second paper P2 is image-formed, in 301, the path changing unit 122 is set to the upper paper discharge position, and in 302, the first paper discharge roller 118 and the conveying roller pair 115. , 123 are rotated in the forward direction. FIG. 6 shows the path changing unit 122 located at the upper paper discharge position. When the path changing unit 122 is positioned at the upper paper discharge position, the first paper P1 is transported in the arrow s direction by rotating the first paper discharge roller 118 and the transport roller pairs 115 and 123 in the forward direction.

  Thereafter, in 303 of FIG. 5, it is determined whether or not the first paper P1 is detected by the sensor 124. If the sensor 124 does not detect the first sheet P1 (No in 303), the process returns to 302, and the determination is repeated until the sensor 124 detects the first sheet P1 (Yes in 303).

  When the sensor 124 detects the first sheet P1 (Yes in 303), in 304, the rotation of the first sheet discharge roller 118 is stopped to stop the conveyance of the first sheet P1, and the path changing unit 122 is moved to the lower side. Set to the paper output position. In 305, the first paper discharge roller 118 and the transport roller pair 115 are rotated in the direction opposite to the forward direction, and the second paper discharge roller 120 and the transport roller pair 123 are rotated in the forward direction. FIG. 7 shows the path changing unit 122 located at the lower paper discharge position. The lower paper discharge position of the route changing unit 122 is a position moved in the arrow v direction from the upper paper discharge position in FIG. When the path changing unit 122 is positioned at the lower paper discharge position, the first paper P1 is conveyed in the direction of the arrow t by rotating the first paper discharge roller 118 and the conveyance roller pair 115 in the direction opposite to the normal direction. To do. Further, the second paper P2 is transported in the arrow u direction by rotating the second paper discharge roller 120 and the transport roller pair 123 in the forward direction.

  Thereafter, in 306 of FIG. 5, it is determined whether or not the sensor 125 detects the second sheet P2. If the sensor 125 does not detect the second sheet P2 (No in 306), the process returns to 305, and the determination is repeated until the sensor 125 detects the second sheet P2 (Yes in 306).

  When the sensor 125 detects the second paper P2 (Yes in 306), in 307, the rotation of the second paper discharge roller 119 is stopped to stop the conveyance of the second paper P2, and the path changing unit 122 is moved to the lower side. Set to the reverse delivery position. In 308, the second paper discharge roller 120 and the transport roller pair 115, 123 are rotated in the direction opposite to the forward direction. FIG. 8 shows the path changing unit 122 located at the lower reverse discharge position. The lower reverse paper discharge position of the path changing unit 122 is a position further moved in the arrow v direction from the lower paper discharge position in FIG. When the path changing unit 122 is positioned at the lower reverse paper discharge position, the second paper reverse roller 120 and the conveying roller pair 115 and 123 are rotated in the direction opposite to the normal direction, whereby the second paper P2 is moved to the arrow direction. Transport in the w direction.

  After that, in 309 in FIG. 5, an image is formed on the unprinted surfaces of the first paper P1 and the second paper P2, and in 310, the first paper P1 and the second paper P2 that have been printed on both sides are changed to the second paper P2. Paper is discharged to the stacking unit 105 via the paper discharge unit 110.

  Hereinafter, a series of flows of the image forming apparatus at the time of duplex printing will be described with reference to the flowchart of FIG. When a print instruction is given from the CPU 200 as the control unit, the first sheet P1 is fed from the storage unit 101 in 400. In 401, the leading end position of the fed first sheet P <b> 1 is determined by the registration roller 114. When the first sheet P1 reaches the registration roller 114 and a predetermined time elapses, the first sheet P1 is sent out by the registration roller 114. In 402, the first sheet P1 is held by the drum 106 and conveyed together with the drum 106 rotating in the direction of the arrow r. The sheet is held on the drum 106 by electrostatic adsorption or negative pressure adsorption.

  In step 403, printing is performed on the first sheet P1 held on the drum 106. When the sensor 121 detects the passage of the first sheet, a detection signal is transmitted to the CPU 200. When a predetermined time elapses from the detection signal, it is determined that the first sheet P1 has reached a predetermined position, and the inkjet head 108 is driven by the control signal. The driven inkjet head 108 ejects ink and forms a first image on the first paper P1. After the first image is formed, the inkjet head 108 moves in a direction orthogonal to the transport direction of the first paper P1 by a predetermined distance.

  The first paper P1 paper on which the first image is formed rotates together with the drum 106 and reaches the detection position of the sensor 121 again. Thereafter, when a predetermined time has elapsed from the detection signal, the inkjet head 108 is driven by the control signal. The driven inkjet head 108 ejects ink and forms a second image. Thereafter, the inkjet head 108 is moved and printed a required number of times n times, and the first to nth images are superimposed on one side of the paper to form an image.

  In 404, it is determined whether or not the n-th printing is finished. If the n-th printing is not completed (No in 404), the printing is repeated in 403. When the n-th printing is completed (Yes in 404), the solenoid 215 of the peeling unit 116 operates in 405 to perform peeling. The peeling claw in contact with the drum 106 peels off the leading edge of the first paper P1 and peels off the first paper P1 from the drum 106.

  For the first sheet P1 peeled off from the drum 106, in 406, it is determined whether or not image formation on the final surface has been completed. If image formation on the final surface has been completed (Yes in 406), the paper is discharged onto the stacking unit 105 via the paper discharge unit 103 in 409, and the process ends.

  If the image formation on the final surface has not been completed (No in 406), the first sheet P1 is conveyed to the first paper discharge path 117 in 407, reversed in 408, and returns to 401. After the reversal, the process returns to 401 to perform image formation on the surface where no image is formed.

  In 400, the second sheet P2 is fed from the storage unit 101 in 411 after a certain period of time 410 has elapsed since the first sheet P1 was fed from the storage unit 101. In 412, the leading end position of the fed second sheet P <b> 2 is determined by the registration roller 114. When the second sheet P2 reaches the registration roller 114 and a predetermined time elapses, the second sheet P2 is sent out by the registration roller 114. In 413, the second paper P2 is held by the drum 106 and conveyed together with the drum 106 rotating in the direction of the arrow r. As shown in FIG. 10, the second sheet P2 is conveyed together with the first sheet P1. The sheet is held on the drum 106 by electrostatic adsorption or negative pressure adsorption.

  In 414 of FIG. 9, image formation is performed on the second paper P2 held on the drum 106 by the same method as the first paper P1. As shown in FIG. 11, the first sheet P1 and the second sheet P2 are held by the drum 106 to form an image.

  In 415 of FIG. 9, it is determined whether or not the n-th printing is finished. If the n-th printing is not completed (No in 415), the printing is repeated in 414. If the n-th printing is completed (Yes in 415), the solenoid 215 of the peeling unit 116 operates in 416 to perform peeling. Following the peeling of the first paper P1, the peeling claw in contact with the drum 106 peels off the tip of the second paper P2, and peels the second paper P2 from the drum 106. FIG. 12 shows a state where the first paper P1 is peeled off from the drum 106 by the peeling portion 116.

  For the second paper P2 peeled off from the drum 106, it is determined at 417 in FIG. 9 whether or not the image formation on the final surface has been completed. If the image formation on the final surface has been completed (Yes in 417), the paper is discharged onto the stacking unit 105 via the paper discharge unit 103 in 420, and is completed.

  If image formation on the final surface has not been completed (No in 417), the second paper P2 is conveyed to the second paper discharge path 119 in 418, reversed in 419, and returned to 412. After the reversal, the process returns to 412 to perform image formation on the surface where no image is formed.

  The flow of the first paper P1 and the second paper P2 after peeling will be described with reference to FIG. 13, FIG. 14, FIG. 15, and FIG. FIG. 13 is a diagram in which the first sheet P1 is conveyed to the first sheet discharge unit 109 and the second sheet P2 is conveyed to the second sheet discharge unit 110. The first sheet P1 is conveyed in the direction of arrow s, and the second sheet P2 is conveyed in the direction of arrow u.

  FIG. 14 is a diagram in which the first paper P 1 is reversed and the second paper P 2 is conveyed to the second paper discharge unit 110. The first paper P1 conveyed to the first paper discharge unit 109 and detected by the sensor 124 is conveyed in the direction of arrow t, which is the direction opposite to the direction of arrow s. The second paper P2 is conveyed to the second paper discharge unit 110.

  FIG. 15 is a diagram in which the second sheet P2 is reversed and the first sheet P1 and the second sheet P2 are conveyed again to the image forming unit 102. The first sheet P1 that has been transported in the reverse direction is transported in the direction of arrow w. The second paper P2 conveyed to the second paper discharge unit 110 and detected by the sensor 125 is conveyed in the arrow x direction, which is the opposite direction to the arrow u direction.

  FIG. 16 is a diagram illustrating a state in which the first sheet P1 and the second sheet P2 after image formation on one side are waiting. The second sheet P2 conveyed in the reverse direction is conveyed in the arrow w direction following the first sheet P1. After the reversal of the first paper P1 at 408 and after the reversal of the second paper P2 at 419, the first paper P1 is in front of the registration roller 114, and the second paper P2 is a predetermined paper from the first paper P. Wait at a distance. Thereafter, a printing operation is started at a predetermined timing, image formation on the second side is performed, and paper is discharged.

  When three or more images are to be formed, during the reversal operation, the third and subsequent sheets, for example, the third sheet P3 and the fourth sheet P4 are the first sheet P1 and the second sheet P2. The image is formed on the drum 106 in the same procedure. At this time, when the third paper P3 is peeled off, the first paper P1 is waiting after the registration position, and the second paper P2 is waiting after the first paper P1. Thereafter, while the third paper P3 and the fourth paper P4 are performing the reversing operation, the first paper P1 and the second paper P2 are subjected to image formation on the second side and discharged. Thereafter, the same procedure is repeated when images are formed on the fifth paper P5 and the sixth paper P6. Even if there are three or more sheets, image formation is repeated in the same procedure. In addition, when forming an image on only one side without forming an image on both sides of the sheet, the sheet is discharged from the second discharge unit 110 without performing the reversing operation in the discharge unit 103.

  With the image forming apparatus as described above, the second sheet P2 can be reversed without waiting for the first sheet P1 to be reversed, and the space between the first sheet P1 and the second sheet P2 can be reduced. Therefore, printing performance can be ensured even when an image is formed with a set of two sheets.

  In the above-described embodiment, the image forming apparatus that forms an image by holding a sheet on a drum and ejecting ink from an inkjet head by multipass has been described. However, the present invention is not limited thereto, and a plurality of paper discharge units are reversed. Any image forming apparatus that has a function and forms and conveys a plurality of sheets of paper as a set may be used. For example, the paper may be held on a belt instead of a drum, or an image may be formed by a single pass. Further, an image may be formed by using toner or a developer containing toner without discharging ink from the inkjet head.

(Second embodiment)
The second embodiment has three paper discharge units, and in an image forming apparatus that forms an image with a set of three sheets, the three paper discharge units have a reversing function. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals.

  FIG. 17 is an enlarged view of the paper discharge unit 103. The paper discharge unit 103 includes a first paper discharge unit 109, a second paper discharge unit 110, a third paper discharge unit 400, conveyance roller pairs 115 and 123, and path changing units 122 and 404. The first paper discharge unit 109 includes a first paper discharge path 117, a first paper discharge roller 118, and a sensor 124. The second paper discharge unit 110 includes a second paper discharge path 119, a second paper discharge roller 120, and a sensor 125. The third paper discharge unit 400 includes a third paper discharge path 401, a third paper discharge roller 402, and a sensor 403.

  The first paper discharge path 117 is a paper discharge path through which the paper passes. The sensor 124 detects the passage of the paper, and the paper discharge roller 118 conveys and reversely conveys the paper. The second paper discharge path 119 is a paper discharge path through which the paper passes. The sensor 125 detects the passage of the paper, and the paper discharge roller 120 conveys and reversely conveys the paper. The third transport path 401 is a paper discharge path through which the paper passes. The sensor 403 detects the passage of the paper, and the paper discharge roller 402 transports and reversely transports the paper. The conveyance roller pairs 115 and 123 convey and reversely convey the sheet. The path changing units 122 and 404 are driven by a solenoid 211 and rotate around an axis to change a paper transport path.

  The path changing units 122 and 404 have three stop positions, the first being the upper discharge position, the second being the lower discharge position, and the third being the lower reverse discharge position. The upper paper discharge position of the path changing unit 122 is a position for conveying the first paper P1 after image formation to the first paper discharge unit 109, and the lower paper discharge position is the second paper after image formation. This is a position where P2 is transported to the second paper discharge unit 110 and the first paper P1 is transported again to the image forming unit 102. The lower reverse paper discharge position is the position where the second paper P2 is transported again. It is a position to convey to.

  The upper paper discharge position of the path changing unit 404 is a position for conveying the first paper P1 after image formation to the first paper discharge unit 109 and the second paper P2 to the second paper discharge unit 110. The lower paper discharge position is a position where the third paper P3 after image formation is conveyed to the third conveyance unit 400, and the lower reverse paper discharge position is the third paper P3 again to the image forming unit 102. This is the transport position.

  When forming an image on only one side without forming an image on both sides of the sheet, the sheet is discharged from the third discharge unit 400 without performing the reversing operation in the discharge unit 103.

  The image forming apparatus as described above can reverse the first paper P1 and the third paper P3 without waiting for the second paper P2, so that the first paper P1, the second paper P2, and the third paper P3 can be reversed. The space between the sheets P3 can be reduced. Therefore, even when an image is formed with a set of three sheets, printing performance can be ensured.

  In the above-described embodiment, the image forming apparatus that forms an image by holding a sheet on a drum and ejecting ink from an inkjet head by multipass has been described. However, the present invention is not limited thereto, and a plurality of paper discharge units are reversed. Any image forming apparatus that has a function and forms and conveys a plurality of sheets of paper as a set may be used. For example, the paper may be held on a belt instead of a drum, or an image may be formed by a single pass. Further, an image may be formed by using toner or a developer containing toner without discharging ink from the inkjet head. Further, the image forming apparatus is not limited to having three paper discharge units, and may have three or more paper discharge units. At this time, if there are N paper discharge units, an image is formed with a set of N sheets (N ≧ 3).

  Although several embodiments have been described, these embodiments have been 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 spirit of the invention. These embodiments and modifications thereof are included in the gist of the invention, and in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Storage part 102 Image forming part 103 Paper discharge part 104 Post-processing part 105 Stacking part 106 Drum 107 Ink supply part 108 Inkjet head 109 First paper discharge part 110 Second paper discharge part 114 Registration roller 115, 123 Conveying roller pair 117 First paper discharge path 118 First paper discharge roller 119 Second paper discharge path 120 Second paper discharge rollers 121, 124, 125, 403 Sensor 122, 404 Path changing unit 200 CPU (control Part)
204 sensor control drive circuit 205 drum control drive circuit 206 post-processing unit control drive circuit 210 path change control drive circuit 212 transport roller motor control drive circuit 214 peeling unit control drive circuit 216 discharge roller motor control drive circuit 218 inkjet head control drive circuit 400 Third paper discharge unit 401 Third paper discharge path 402 Third paper discharge roller

Claims (7)

An image forming unit for forming an image on a recording medium;
A paper discharge path through which the recording medium on which the image is formed by the image forming unit is conveyed, and a second direction which is provided in the paper discharge path and which is opposite to the first direction which is the paper discharge direction. A plurality of paper discharge units having rollers for changing the rotation direction to the direction of
A path changing unit that selectively changes a conveyance path of the recording medium to the plurality of paper discharge units;
A control unit for controlling the rotation direction of the roller and the changing operation of the path changing unit;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the plurality of paper discharge units include a first paper discharge unit and a second paper discharge unit.   The first paper discharge unit has a first sensor for detecting passage of a recording medium, and the second paper discharge unit has a second sensor for detecting passage of a recording medium. Item 3. The image forming apparatus according to Item 2.   When the first sensor detects the recording medium, the rotation of the roller is stopped to stop the conveyance of the recording medium, and the conveyance path is changed by the path changing unit so that the recording medium is conveyed to the image forming unit. The image forming apparatus according to claim 3, further comprising changing the rotation of the roller in the second direction.   When the second sensor detects the recording medium, the rotation of the roller is stopped to stop the conveyance of the recording medium, and the conveyance path is changed by the path changing unit so that the recording medium is conveyed to the image forming unit. The image forming apparatus according to claim 3, further comprising changing the rotation of the roller in the second direction. Forming an image on a recording medium,
A paper discharge path through which an image-formed recording medium is transported, and a rotation direction of the transported recording medium provided in the paper discharge path in a second direction that is opposite to the first direction, which is the paper discharge direction. Having a plurality of paper discharge units having rollers for conveying
An image forming apparatus that selectively changes a conveyance path of a recording medium to the plurality of paper discharge units.   The image forming apparatus according to claim 6, wherein the plurality of paper discharge units include a first paper discharge unit and a second paper discharge unit.

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