Sheet post-processor and image forming system

Abstract

To provide a sheet post-processor capable of cooling a heat-generating member around a processing tray without spoiling the alignment of sheets on the processing tray.SOLUTION: A sheet post-processor comprises a processing tray 15, a first sheet transport unit, a staple unit 112, a first discharge tray, a cooling fan 17 and a post-processing control unit. The staple unit 112 performs post-processing on sheets stacked on the processing tray 15. The cooling fan 17 blows air such that an air stream passes over the processing tray 15. The post-processing control unit stops the cooling fan 17 from rotating during a sheet-drawing operation to draw a sheet fed by the first sheet transport unit onto the processing tray 15.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a sheet post-processing device that performs post-processing on a sheet after an image has been formed on it by an image forming apparatus, and an image forming system that includes the sheet post-processing device. [Background technology]

[0002] Sheet post-processing devices are known that perform post-processing such as stapling (binding) and folding on sheets after an image has been formed by an image forming device such as a copier or printer. Such sheet post-processing devices are provided with motors and circuit boards for driving and controlling mechanisms related to the post-processing, and may also be provided with cooling fans for cooling these components.

[0003] For example, the conventional paper post-processing device disclosed in Patent Document 1 has a cooling fan disposed on the rear side of the staple unit. The cooling fan is disposed so as to create an airflow in the paper width direction, which is perpendicular to the paper transport direction. This allows sufficient airflow to reach the circuit boards and other components disposed on the rear side of the paper post-processing device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-240779 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional technology had a problem in that when the cooling fan was started to operate at the start of image formation, the airflow from the cooling fan hit the recording sheets stacked on the stapling table for stapling, which caused the upper sheets of the stack to float up due to the airflow, which raised concerns about the deterioration of the integrity of the recording sheets.

[0006] The present invention has been made in consideration of the above points, and aims to provide a sheet post-processing device and image forming system that can cool heat-generating components around the processing tray without compromising the alignment of sheets on the processing tray. [Means for solving the problem]

[0007] In order to solve the above problems, the sheet post-processing device of the present invention comprises a processing tray, a conveying unit, a post-processing unit, a discharge tray, a cooling fan, and a control unit. The processing tray is configured to hold sheets to be post-processed. The conveying unit conveys the sheets to the processing tray. The post-processing unit applies the post-processing to the sheets stacked on the processing tray. The discharge tray is disposed downstream of the processing tray in the sheet conveying direction, and discharges the sheets. The cooling fan blows air so that air flows over the processing tray. The control unit controls the operation of the conveying unit, the post-processing unit, and the cooling fan. The control unit stops the rotation of the cooling fan during a sheet drawing operation that draws the sheets transported by the conveying unit onto the processing tray. [Effects of the Invention]

[0008] According to the configuration of the present invention, when sheets are drawn onto the processing tray, no airflow from the cooling fan is generated on the processing tray. In other words, it is possible to prevent the sheets from floating up or shifting position when stacked on the processing tray, and the sheets can be stacked neatly on the processing tray. This makes it possible to cool the heat-generating components around the processing tray without impairing the alignment of the sheets on the processing tray. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view of an image forming system according to an embodiment of the present invention; [Figure 2] 2 is a schematic cross-sectional front view of the sheet post-processing device of FIG. 1. [Figure 3]3 is a block diagram showing a schematic configuration of the sheet post-processing device of FIG. 2. FIG. [Figure 4] 3 is a partial cross-sectional front view showing the periphery of a first sheet discharge portion of the sheet post-processing device of FIG. 2. FIG. [Figure 5] FIG. 5 is a perspective view showing the periphery of the processing tray in FIG. 4. [Figure 6] 6 is a perspective view showing the periphery of the processing tray in FIG. 5, showing a state in which the staple unit has been moved to a first post-processing position. FIG. [Figure 7] 3 is a flowchart showing post-processing of sheets in the sheet post-processing device of FIG. 2; DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the following.

[0011] 1 is a front view of an image forming system 301 according to an embodiment. As shown in FIG. 1, the image forming system 301 includes an image forming apparatus 201 and a sheet post-processing device 1.

[0012] The image forming apparatus 201 is, for example, a monochrome multifunction device that has an electrophotographic printing mechanism and is equipped with functions such as printing, scanning (image reading), facsimile transmission, etc. The image forming apparatus 201 may be, for example, a copying machine, a printer, or a color machine.

[0013] The image forming apparatus 201 includes an image forming unit, a transfer unit, and a fixing unit (none of which are shown). The image forming unit supplies toner to an electrostatic latent image of an original image formed on the surface of a photosensitive drum by laser light, developing it to form a toner image of the original image. The transfer unit transfers the toner image formed on the surface of the photosensitive drum to a sheet. The fixing unit heats and presses the sheet onto which the toner image has been transferred, fixing the toner image to the sheet. In this way, the image forming apparatus 201 forms (prints) an image on the sheet. Then, the image forming apparatus 201 transports the sheet after the image formation to the sheet post-processing device 1.

[0014] The sheet post-processing device 1 is detachably connected to the side of the image forming apparatus 201. The sheet post-processing device 1 can be connected to devices such as copiers and printers in addition to multifunction peripherals. The sheet post-processing device 1 performs predetermined post-processing on sheets after an image has been formed (printed) in the image forming apparatus 201, and discharges the sheets to a first discharge tray (discharge tray) 33, a second discharge tray 53, or a third discharge tray 73, which will be described later.

[0015] Fig. 2 is a schematic cross-sectional front view of the sheet post-processing device 1 of Fig. 1. Fig. 3 is a block diagram showing a schematic configuration of the sheet post-processing device 1 of Fig. 2. As shown in Figs. 2 and 3, the sheet post-processing device 1 includes a sheet loading section 2, a first sheet discharge section 3, a first sheet conveying section 4, a second sheet discharge section 5, a second sheet conveying section 6, a third sheet discharge section 7, a third sheet conveying section 8, a post-processing section 11, and a post-processing control section (control section) 12.

[0016] The sheet carrying-in section 2 has a sheet carrying-in opening 2e. The sheet carrying-in opening 2e is provided on the side of the sheet post-processing device 1 facing the image forming device 201, and opens. A sheet conveyed from the image forming device 201 toward the sheet post-processing device 1 is carried into the inside of the sheet post-processing device 1 through the sheet carrying-in opening 2e and the sheet carrying-in section 2.

[0017] The sheet carrying-in section 2 extends substantially horizontally from the sheet carrying-in opening 2e to a sheet folding section 113 (described later) in a direction away from the image forming apparatus 201 (to the left in FIG. 2). The sheet carrying-in section 2 has a first branching section 2a and a second branching section 2b arranged in this order from the upstream side (the sheet carrying-in opening 2e side) in the sheet conveying direction.

[0018] The first branching section 2a switches the sheet transport direction of a sheet transported downstream from the sheet entrance 2e side between a direction to guide the sheet to the first sheet discharge section 3 and the second sheet discharge section 5, and a direction to guide the sheet to the third sheet discharge section 7. The second branching section 2b switches the sheet transport direction of a sheet transported downstream from the sheet entrance 2e side between a direction to guide the sheet to the first sheet discharge section 3 and a direction to guide the sheet to the second sheet discharge section 5.

[0019] The first sheet discharge section 3 is provided on a side surface 1a of the sheet post-processing device 1 opposite to the side surface facing the image forming device 201. The first sheet discharge section 3 has a first discharge opening 31, a first discharge roller pair 32, and a first discharge tray 33.

[0020] The first discharge outlet 31 is located at the downstream end in the sheet conveying direction of the first sheet conveying section 4. The first discharge roller pair 32 is disposed at the first discharge outlet 31. The first discharge tray 33 is located downstream in the sheet conveying direction of the first discharge outlet 31. The sheet that has been conveyed through the first sheet conveying section 4 and reached the first discharge outlet 31 is discharged by the first discharge roller pair 32 through the first discharge outlet 31 onto the first discharge tray 33.

[0021] The first sheet conveying section 4 continues from the downstream end of the sheet carrying-in section 2 in the sheet conveying direction and extends substantially horizontally to the first sheet discharging section 3 in a direction away from the image forming apparatus 201 (to the left in FIG. 2).

[0022] The second sheet discharge section 5 is provided on the side surface 1a of the sheet post-processing device 1, above the first sheet discharge section 3. The second sheet discharge section 5 has a second discharge opening 51, a second discharge roller pair 52, and a second discharge tray 53.

[0023] The second discharge outlet 51 is located at the downstream end of the second sheet transport section 6 in the sheet transport direction. The second discharge roller pair 52 is disposed at the second discharge outlet 51. The second discharge tray 53 is located downstream of the second discharge outlet 51 in the sheet transport direction. The sheet that has been transported through the second sheet transport section 6 and reached the second discharge outlet 51 is discharged by the second discharge roller pair 52 through the second discharge outlet 51 onto the second discharge tray 53.

[0024] The second sheet conveying section 6 branches off from the second branching section 2b located downstream in the sheet conveying direction of the sheet loading section 2, and extends horizontally and upwardly in a direction away from the image forming device 201 (to the left in Figure 2) to the second sheet discharge section 5.

[0025] The third sheet discharge section 7 is provided on the side surface 1a of the sheet post-processing device 1, below the first sheet discharge section 3. In other words, the third sheet discharge section 7 is disposed near the bottom of the sheet post-processing device 1. The third sheet discharge section 7 has a third discharge opening 71, a third discharge roller pair 72, and a third discharge tray 73.

[0026] The third discharge outlet 71 is located at the downstream end in the sheet conveying direction of the third sheet conveying section 8. The third discharge roller pair 72 is disposed at the third discharge outlet 71. The third discharge tray 73 is located downstream in the sheet conveying direction of the third discharge outlet 71. The sheet that has been conveyed through the third sheet conveying section 8 and reached the third discharge outlet 71 is discharged by the third discharge roller pair 72 through the third discharge outlet 71 onto the third discharge tray 73.

[0027] The third sheet conveying section 8 branches off from the first branching section 2a located downstream of the sheet carrying-in section 2 in the sheet conveying direction, and extends downward to the third sheet discharging section .

[0028] The post-processing unit 11 performs predetermined post-processing on the sheets on which images have been formed by the image forming device 201 and which have been transported into the sheet post-processing unit 1. The post-processing unit 11 includes a punching unit 111, a stapling unit 112, a sheet folding unit 113, and a binding unit 114.

[0029] The punching unit 111 is disposed immediately downstream of the sheet entrance 2e of the sheet carrying-in unit 2. The punching unit 111 performs a punching process on the sheet being transported on the sheet carrying-in unit 2, and can form punch holes.

[0030] The stapler unit 112 is disposed below the first sheet conveying unit 4 and in the vicinity of the first sheet discharging unit 3. The stapler unit 112 can staple (bind) a sheet bundle formed by stacking a plurality of sheets, and bind the sheet bundle.

[0031] The sheet folding unit 113 is disposed downstream of the punching unit 111 and upstream of the stapling unit 112 in the sheet conveying direction of the sheet carrying-in unit 2. The sheet folding unit 113 can perform a folding process on a single sheet to form a crease.

[0032] The binding section 114 is disposed downstream in the sheet conveying direction of the third sheet conveying section 8, near the third sheet discharge section 7. The binding section 114 can form a booklet by performing center folding and saddle stitching on a sheet bundle formed by stacking a plurality of sheets, in which the sheets are folded and bound at approximately the center in the sheet conveying direction.

[0033] The post-processing control unit 12 includes a CPU, an image processing unit, a memory unit, and other electronic circuits and electronic components (none of which are shown). The post-processing control unit 12 is communicably connected to the image formation control unit (not shown) of the image forming apparatus 201. The post-processing control unit 12 receives commands from the image formation control unit and, using the CPU, controls the operation of each component provided in the sheet post-processing device 1 based on control programs and data stored in the memory unit to perform processing related to the functions of the sheet post-processing device 1. The sheet loading unit 2, the first sheet discharge unit 3, the first sheet conveying unit 4, the second sheet discharge unit 5, the second sheet conveying unit 6, the third sheet discharge unit 7, the third sheet conveying unit 8, and the post-processing unit 11 each receive commands individually from the post-processing control unit 12 and perform post-processing on sheets in cooperation with each other. The function of the post-processing control unit 12 may be provided by the image formation control unit of the image forming apparatus 201.

[0034] Next, the configuration around the first sheet discharge section 3 will be described in detail with reference to Figs. 4, 5, and 6. Fig. 4 is a partial cross-sectional front view showing the periphery of the first sheet discharge section 3 of the sheet post-processing device 1 of Fig. 2. Fig. 5 is a perspective view showing the periphery of the processing tray 15 of Fig. 4. Fig. 6 is a perspective view showing the periphery of the processing tray 15 of Fig. 5, illustrating a state in which the staple section 112 has been moved to the first post-processing position. Figs. 5 and 6 show the configuration around the processing tray 15 as seen from the rear side of the sheet post-processing device 1 and from the side 1a of the sheet post-processing device 1.

[0035] With respect to the sheet conveying direction Dc shown in Fig. 4, the right side (image forming apparatus side) of the left side in Fig. 4 is the "upstream side" of the sheet conveying direction Dc, and the left side (first sheet discharge section 3 side) of the right side in Fig. 4 is the "downstream side" of the sheet conveying direction Dc. Also, the "sheet width direction" orthogonal to the sheet conveying direction Dc is the direction perpendicular to the paper surface of Fig. 4.

[0036] As shown in FIG. 4, the sheet post-processing device 1 includes a first sheet conveying section (conveying section) 4, a feed roller pair 4r, a processing tray 15, a first discharge outlet 31, a first discharge roller pair 32, a first discharge tray (discharge tray) 33, a pair of cursors 16, a staple section (post-processing section) 112, and a cooling fan 17.

[0037] A feed roller pair 4r is disposed in the first sheet conveying section 4. The feed roller pair 4r is rotated by a driving force applied from a motor (not shown). The feed roller pair 4r conveys the sheet that has passed through the sheet carrying-in section 2 and reached the second branch section 2b toward the downstream side in the sheet conveying direction Dc on the first sheet conveying section 4, i.e., toward the first sheet discharge section 3 and the processing tray 15. The operation of the first sheet conveying section 4 is controlled by the post-processing control section 12.

[0038] The processing tray 15 is disposed below the downstream portion of the first sheet transport section 4 in the sheet transport direction Dc. Specifically, the processing tray 15 is located downstream of the feed roller pair 4r disposed downstream of the first sheet transport section 4 and immediately below the upstream portion of the first discharge roller pair 32 in the sheet transport direction Dc. A sheet placement surface 15a of the processing tray 15 has an inclination that rises toward the downstream side in the sheet transport direction Dc. Sheets Sh transported through the first sheet transport section 4 are stacked on the processing tray 15, and predetermined post-processing is performed on the sheets Sh.

[0039] The first discharge outlet 31 is disposed at the downstream end of the first sheet conveying section 4 and downstream of the processing tray 15 in the sheet conveying direction Dc. A first discharge roller pair 32 is disposed at the first discharge outlet 31. The sheet Sh for which the predetermined post-processing has been completed in the processing tray 15 and the sheet that has passed over the processing tray 15 without being subjected to post-processing in the processing tray 15 are discharged through the first discharge outlet 31 toward the first discharge tray 33.

[0040] The first discharge roller pair 32 is disposed at the first discharge opening 31. The first discharge roller pair 32 discharges the sheet Sh on the processing tray 15 in the sheet conveyance direction Dc, and further discharges the sheet Sh from the first discharge opening 31 to the first discharge tray 33. A rotation axis of the first discharge roller pair 32 extends along the sheet width direction. The first discharge roller pair 32 includes a pair of a lower discharge roller 32a and an upper discharge roller 32b.

[0041] The lower discharge roller 32a and the upper discharge roller 32b are connected to a discharge drive unit 32D (see FIG. 3) and rotate independently of each other. The lower discharge roller 32a and the upper discharge roller 32b can rotate forward to discharge the sheet Sh toward the first discharge tray 33, and can rotate backward to pull the sheet Sh toward the processing tray 15. The lower discharge roller 32a and the upper discharge roller 32b have their peripheral surfaces in contact with each other to form a nip portion 32N, and convey the sheet Sh held in the nip portion 32N.

[0042] The sheet Sh discharged from the first discharge outlet 31 by the forward rotation of the first discharge roller pair 32 is stacked on the first discharge tray 33. Furthermore, when the first discharge roller pair 32 is rotated in the reverse direction while the sheet Sh is held at the nip portion 32N of the first discharge roller pair 32 and the upstream end of the sheet Sh in the sheet conveying direction Dc has passed through the nip portion 4N of the feed roller pair 4r, the sheet Sh is conveyed to the processing tray 15. That is, when conveying the sheet Sh to the processing tray 15, the post-processing control unit 12 performs a sheet drawing operation to switch back the sheet Sh and draw it onto the processing tray 15 after the downstream end of the sheet Sh in the sheet conveying direction Dc has passed the first discharge outlet 31. In FIGS. 4, 5, and 6, an arrow Dp is drawn indicating the drawing direction of the sheet Sh onto the processing tray 15.

[0043] The first discharge tray 33 is disposed downstream and below the first discharge outlet 31 in the sheet conveying direction Dc. The first discharge tray 33 is disposed outside the side surface 1a of the sheet post-processing device 1, facing the side surface 1a. The sheet stacking surface 33a of the first discharge tray 33 has a slope that rises toward the downstream side in the sheet conveying direction Dc. The upstream end of the first discharge tray 33 in the sheet conveying direction Dc is located below the first discharge outlet 31. The first discharge tray 33 is loaded with sheets Sh discharged from the first discharge outlet 31 by the first discharge roller pair 32.

[0044] The pair of cursors 16 are arranged on the sheet placement surface 15a of the processing tray 15. Each of the pair of cursors 16 is arranged on one end side and the other end side of the center of the first sheet conveying unit 4 in the sheet width direction, and faces each other in the sheet width direction. The pair of cursors 16 are connected to a cursor driving unit 16D (see FIG. 3) including a motor and the like, and are given a driving force, so that the pair of cursors 16 move back and forth so as to approach and move away from each other in the sheet width direction. The pair of cursors 16 come into contact with the side edges of the sheets Sh stacked on the processing tray 15, on one end side and the other end side in the sheet width direction. The operation of the pair of cursors 16 is controlled by the post-processing control unit 12.

[0045] The staple unit 112 is disposed upstream of the processing tray 15 in the sheet conveying direction Dc. The sheet post-processing device 1 can use the staple unit 112 to staple (bind) a sheet bundle formed by stacking a plurality of sheets Sh on the processing tray 15, thereby binding the sheet bundle.

[0046] The stapler 112 is mounted on a stapler moving mechanism 112D (see FIG. 3) including a motor and the like, and is given a driving force for moving the stapler 112 itself, causing it to reciprocate between one end and the other end in the sheet width direction. That is, the sheet post-processing device 1 can staple the sheet stack at multiple binding positions in the sheet width direction, and bind the sheet stack.

[0047] Fig. 5 illustrates a state in which the stapler unit 112 is disposed at a first post-processing position Ps1, which is a corner of the sheet stack at one end side in the sheet width direction (the front side of the sheet post-processing device 1), by the stapler unit moving mechanism 112D. Fig. 6 illustrates a state in which the stapler unit 112 is disposed at a second post-processing position Ps2, which is a corner of the sheet stack at the other end side in the sheet width direction (the rear side of the sheet post-processing device 1), by the stapler unit moving mechanism 112D. In addition, the stapler unit moving mechanism 112D can also move the stapler unit 112 to the center in the sheet width direction, etc.

[0048] The cooling fan 17 is disposed behind the processing tray 15 and above the sheet placement surface 15a of the processing tray 15. The cooling fan 17 blows air toward the processing tray 15, which is located in front of the cooling fan 17, as well as toward heat-generating components such as a motor and a circuit board (none of which are shown). In other words, the cooling fan 17 blows air so that the air flows over the processing tray 15. This makes it possible to cool the sheets loaded on the processing tray 15, the motor, the circuit board, etc. In FIGS. 5 and 6, an arrow Df is drawn indicating the direction of air blown by the cooling fan 17.

[0049] The cooling fan 17 starts rotating when the sheet post-processing device 1 is powered on, and basically rotates constantly while the sheet post-processing device 1 is in operation, cooling the periphery of the processing tray 15. The post-processing control unit 12 stops the rotation of the cooling fan 17 while a sheet pulling operation is being performed to pull the sheets conveyed by the first sheet conveying unit 4 onto the processing tray 15. For example, when stapling is performed on a sheet stack on the processing tray 15, the post-processing control unit 12 stops the rotation of the cooling fan 17 while a sheet pulling operation is being performed on the sheets onto the processing tray 15.

[0050] According to the above configuration, when sheets are drawn onto the processing tray 15, no airflow is generated on the processing tray 15 by the cooling fan 17. In other words, it is possible to prevent the sheets from floating up or shifting position when stacking the sheets on the processing tray 15, and the sheets can be stacked neatly on the processing tray 15. In addition, the cooling fan 17 can cool the periphery of the processing tray 15 at times other than when the sheet drawing operation into the processing tray 15 is being performed. This makes it possible to cool the heat-generating components around the processing tray 15 without impairing the alignment of the sheets on the processing tray 15.

[0051] On the other hand, when the post-processing control unit 12 discharges the sheet to the first discharge tray 33 without performing the sheet pulling operation into the processing tray 15, the post-processing control unit 12 continues to rotate the cooling fan 17. In other words, when the post-processing control unit 12 passes the sheet transported by the first sheet transport unit 4 over the processing tray 15 without transporting the sheet to the processing tray 15 and discharges the sheet to the first discharge tray 33, the post-processing control unit 12 continues to rotate the cooling fan 17.

[0052] According to the above configuration, the cooling fan 17 can cool the periphery of the processing tray 15 at any time other than when the sheet is being drawn into the processing tray 15. This makes it possible to improve the effectiveness of cooling the heat-generating members around the processing tray 15 without impairing the alignment of the sheets on the processing tray 15.

[0053] Furthermore, with regard to the movement of the staple unit 112, the staple unit moving mechanism 112D moves the staple unit 112 to a post-processing position (second post-processing position Ps2) between the processing tray 15 and the cooling fan 17. When the staple unit 112 is disposed at the second post-processing position Ps2, the airflow generated by the cooling fan 17 reaches heat-generating components such as the motor and the circuit board, but is blocked by the staple unit 112 and does not reach the processing tray 15.

[0054] Then, when the post-processing control unit 12 moves the staple unit 112 to the second post-processing position Ps2 by the staple unit moving mechanism 112D before executing the sheet drawing operation into the processing tray 15, it continues to rotate the cooling fan 17. According to this configuration, even when the sheets are drawn onto the processing tray 15, the airflow by the cooling fan 17 is blocked by the staple unit 112 and is not generated above the processing tray 15. This makes it possible to improve the effect of cooling the heat-generating members around the processing tray 15 without impairing the alignment of the sheets on the processing tray 15.

[0055] The staple unit 112 is a post-processing unit that moves in the sheet width direction according to the binding position, and can be moved to a post-processing position (second post-processing position Ps2) between the processing tray 15 and the cooling fan 17. That is, by installing the staple unit 112, it is possible to create a state in which an air flow caused by the cooling fan 17 is not generated above the processing tray 15 even when the sheet is pulled onto the processing tray 15.

[0056] Next, there will be described a flow of post-processing of sheets in the sheet post-processing device 1. Fig. 7 is a flowchart showing post-processing of sheets in the sheet post-processing device 1 of Fig. 2.

[0057] When the sheet post-processing device 1 is powered on ("START" in FIG. 7), the post-processing control unit 12 starts rotating the cooling fan 17 (step S101).

[0058] Next, upon receiving a command for a post-processing job, post-processing control unit 12 determines whether post-processing using processing tray 15 is required (step S102). If post-processing using processing tray 15 is not required (No in step S102), post-processing control unit 12 proceeds to step S105, where it continues to rotate cooling fan 17 without transporting the sheet onto processing tray 15, and performs other post-processing.

[0059] On the other hand, in step S102, if post-processing using the processing tray 15 is required (Yes in step S102), the post-processing control unit 12 determines whether the stapling unit 112 is at the second post-processing position Ps2 (step S103). If the stapling unit 112 is at the second post-processing position Ps2 (Yes in step S103), the post-processing control unit 12 proceeds to step S105, continues to rotate the cooling fan 17, and performs post-processing using the processing tray 15.

[0060] On the other hand, in step S103, if the stapler 112 is not at the second post-processing position Ps2 (No in step S103), the post-processing control unit 12 stops the rotation of the cooling fan 17 during the sheet pull-in operation of pulling the sheets onto the processing tray 15 (step S104). Then, the post-processing control unit 12 performs stapling (post-processing) on ​​the sheet stack on the processing tray 15 (step S105).

[0061] Then, when the post-processing is completed, the process returns to step S101, and the post-processing control unit 12 causes the cooling fan 17 to resume rotation.

[0062] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and various modifications can be made without departing from the spirit of the invention.

[0063] For example, in the above embodiment, the post-processing unit that is disposed adjacent to the processing tray 15, moves, and performs post-processing on the sheets stacked on the processing tray 15 is the staple unit 112, but the present invention is not limited to such a device. The post-processing unit may be a device that has a function different from that of the staple unit 112. [Industrial Applicability]

[0064] The present invention can be used in a sheet post-processing device of an image forming apparatus. [Explanation of symbols]

[0065] 1 Sheet post-processing device 4 First sheet transport section 11 Post-processing section 12 Post-processing control unit 15 Processing tray 17 Cooling fan 31 1st outlet 32 First discharge roller pair 33 First output tray (output tray) 112 Stapling section (post-processing section) 112D Staple unit moving mechanism (moving mechanism) 201 Image forming device 301 Image Forming System Dc Sheet transport direction Ps2 Second post-processing position (post-processing position)

Claims

1. a processing tray on which sheets to be post-processed are stacked; a conveying unit that conveys the sheet to the processing tray; a post-processing section that performs the post-processing on the sheets stacked on the processing tray; a discharge tray disposed downstream of the processing tray in a sheet conveying direction and onto which the sheet is discharged; a cooling fan that blows air so that the air flows over the processing tray; a control unit that controls operations of the conveying unit, the post-processing unit, and the cooling fan; Equipped with The sheet post-processing device, wherein the control unit stops rotation of the cooling fan during a sheet drawing operation of drawing the sheet conveyed by the conveying unit onto the processing tray.

2. The sheet post-processing device according to claim 1 , wherein the control unit continues to rotate the cooling fan when the sheet is discharged onto the discharge tray without performing the sheet pulling operation.

3. a moving mechanism that moves the post-processing unit to a post-processing position between the processing tray and the cooling fan, The sheet post-processing device according to claim 1 , wherein the control unit continues to rotate the cooling fan when the movement mechanism moves the post-processing unit to the post-processing position before the sheet pulling operation is performed.

4. 2. The sheet post-processing device according to claim 1, wherein the post-processing section is a staple section that staples a sheet bundle formed by stacking a plurality of the sheets on the processing tray to bind the sheet bundle.

5. an image forming device that forms an image on a sheet; a sheet post-processing device according to any one of claims 1 to 4, which performs the post-processing on the sheet on which an image has been formed in the image forming apparatus; An image forming system comprising:

Images