Post-processing device and image forming apparatus

Abstract

To reduce loading failure of a medium in loading means compared to a case in which a gas is blown to the medium evenly in a width direction.SOLUTION: A post-processing device (U3) includes: discharge means (Rh) which discharges a medium (S); loading means (TRh) into which the discharged medium (S) is loaded; and blowing means (6) which is disposed below the discharge means (Rh) and blows the gas to the discharged medium (S) and in which an amount of the gas blown varies in a width direction intersecting with a discharge direction of the medium (S).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a post-processing device and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art In an image forming apparatus, the technique described in Patent Document 1 below is known as a technique for blowing gas onto a medium that is discharged.

[0003] Patent Document 1 describes a technology in which a sheet (S), which has been heated as it passes through a fixing device, is cooled by a suction fan (4) disposed inside the image forming device, and at the same time, a cooling unit (11) disposed outside the image forming device blows gas onto the sheet (S) from above to cool it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-52941 A ("0031"-"0045", Figures 2-5) Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has a technical object to suppress poor loading of media in a loading means, compared to a case where gas is blown uniformly onto the media in the width direction. [Means for solving the problem]

[0006] In order to solve the above technical problem, the post-processing device of the invention described in claim 1 comprises: An ejection means for ejecting the medium; A stacking means for stacking the discharged medium; a blowing means arranged below the discharge means for blowing gas toward the discharged medium, the blowing means having a difference in blowing amount in a width direction intersecting the discharge direction of the medium, the blowing means being arranged in a plurality of locations in the width direction and having a blowing port from which the gas is blown out; An opening / closing means capable of opening or closing the air outlet; Equipped with The opening / closing means is detachable from the blowing means, The above Opening and closing means By blocking some of the air outlets, the amount of air blown out is made different in the width direction. The opening and closing means is attached to close the blowing port according to the range in the width direction in which the blowing amount is to be reduced. It is characterized by:

[0007] The invention described in claim 2 is the post-processing device described in claim 1, the blowing means having a difference in blowing amount in the width direction so as to curve the discharged medium when viewed from the discharge direction of the medium; The present invention is characterized by comprising:

[0008] The invention described in claim 3 is the post-processing device described in claim 2, The amount of blowing out is larger at the center than at the ends in the width direction. It is characterized by:

[0009] The invention described in claim 4 is the post-processing device described in claim 3, The amount of blowing out is larger at the ends than at the center in the width direction. It is characterized by:

[0010] The invention described in claim 5 is the post-processing device described in claim 1, the blowing means having a difference in blowing amount with respect to the width direction so as to feed the medium toward one end side in the width direction; The present invention is characterized by comprising:

[0011] The invention described in claim 6 is the post-processing device described in claim 5, The amount of blowing out is larger at one end side in the width direction than at the other end side. It is characterized by:

[0012] The invention described in claim 7 is the post-processing device according to any one of claims 1 to 6, the blowing means being arranged in a plurality of locations in the width direction and having blowing ports from which gas is blown out; a transfer means arranged corresponding to each of the blowing ports and configured to transfer gas toward the blowing ports; Equipped with The amount of gas transferred by each of the transfer means is made different, and a difference is made in the amount of gas blown out in the width direction.

[0013] Claim 8 The invention described in claim 1 or 7 In the post-processing device according to the present invention, the opening / closing means being detachable from the blowing means by magnetic force; The present invention is characterized by comprising:

[0014] In order to solve the above technical problem, the image forming apparatus according to the invention described in claim 9 comprises: A recording means for recording an image on a medium; An ejection means for ejecting the medium on which the image is recorded; A stacking means for stacking the discharged medium; a blowing means arranged below the discharge means for blowing gas toward the discharged medium, the blowing means having a difference in blowing amount in a width direction intersecting the discharge direction of the medium, the blowing means being arranged in a plurality of locations in the width direction and having a blowing port from which the gas is blown out; An opening / closing means capable of opening or closing the air outlet; Equipped with The opening / closing means is detachable from the blowing means, The above Opening and closing means By blocking some of the air outlets, the amount of air blown out is made different in the width direction. The opening and closing means is attached to close the blowing port according to the range in the width direction in which the blowing amount is to be reduced. It is characterized by: Effect of the Invention

[0015] Claim 1 ,9 According to the invention described in the above, it is possible to suppress improper loading of the media on the loading means, compared to a case in which gas is blown uniformly onto the media in the width direction. According to the invention as recited in claims 1 and 9, by opening a part of the blowing port and closing the other part, it is possible to differentiate the blowing amount in the width direction. Furthermore, according to the invention as set forth in claims 1 and 9, the opening and closing means can be manually attached and detached to achieve a desired distribution of the blowing amount. According to the invention recited in claim 2, the contact area between the medium and the stacking means can be reduced by curving the discharged medium. According to the invention as recited in claim 3, the ejected medium can be curved in a convex shape, which can reduce scratches on the medium compared to when the medium is not curved in a convex shape.

[0016] According to the invention as recited in claim 4, the discharged medium can be curved in a concave shape, and the straightness of the medium can be improved compared to a case where the medium is not curved in a concave shape. According to the fifth and sixth aspects of the invention, the ejected medium can be fed toward one end, improving the consistency compared to the case where the medium is not fed. According to the invention described in claim 7, the amount of gas transferred by the transfer means arranged corresponding to the blowing openings can be made different in the width direction. 。

[0017] Claim 8 According to the invention described in the above, the opening and closing means can be attached and detached easily by hand, compared to a case in which the opening and closing means cannot be attached and detached by magnetic force. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is an overall explanatory diagram of an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a side view of the discharge port of the post-treatment device of the first embodiment. [Diagram 3]FIG. 3 is a perspective view of a main part of the discharge port portion of the post-processing device according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram of the blowing settings in Example 1, where FIG. 4A is an explanatory diagram when the air volume is large in the center, FIG. 4B is an explanatory diagram when the air volume is large at both ends, and FIG. 4C is an explanatory diagram when the air volume is large on the front side (one end side). [Diagram 5] FIG. 5 is an explanatory diagram of the media ejection state in a conventional configuration, with FIG. 5A being an explanatory diagram of the state where the front end of the media contacts the ejection tray, and FIG. 5B being an explanatory diagram of the state where the media has been ejected further from the state in FIG. 5A. [Figure 6] FIG. 6 is an explanatory diagram of the second embodiment, in which FIG. 6A is an explanatory diagram of a state in which the shutter is removed, and FIG. 6B is an explanatory diagram of a state in which the shutter is attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Next, examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples. In order to make the following explanation easier to understand, in the drawings, the front-to-back direction (width direction of the medium) is defined as the X-axis direction, the left-to-right direction (direction of medium transport) is defined as the Y-axis direction, and the up-down direction is defined as the Z-axis direction, and the directions or sides indicated by arrows X, -X, Y, -Y, Z, -Z are defined as the front, rear, right, left, upper, and lower, or the front side, rear side, right side, left side, upper side, and lower side, respectively. In addition, in the figures, a "·" inside a "○" means an arrow going from the back to the front of the page, and an "×" inside a "○" means an arrow going from the front to the back of the page. In the following description using the drawings, illustrations of components other than those necessary for the description are omitted as appropriate to facilitate understanding. EXAMPLES

[0020] (Explanation of Overall Configuration of Printer U in First Embodiment) FIG. 1 is an overall explanatory diagram of an image forming apparatus according to a first embodiment. In FIG. 1, a printer U as an example of an image forming apparatus according to a first embodiment of the present invention has a printer main body U1, a feeder unit U2 as an example of a supply device that supplies media to the printer main body U1, an operation unit UI operated by a user, and a finisher U3 as an example of a post-processing device that performs post-processing of media discharged from the printer main body U1.

[0021] (Description of Marking Configuration in Example 1) 1, the main body U1 of the printer includes a control unit (an example of a control means) C that controls the printer U, a communication unit (not shown) that receives image information transmitted from a print image server COM (an example of an information transmitting device) connected to the outside of the printer U via a dedicated cable (not shown), and a marking unit U1a (an example of a recording means) that records an image on a medium. A personal computer PC (an example of an image transmitting device) is connected to the print image server COM via a line such as a cable or a LAN (Local Area Network) and transmits information of an image to be printed by the printer U. The marking unit U1a has photoconductors Py, Pm, Pc, and Pk for each color, Y: yellow, M: magenta, C: cyan, and K: black, as an example of an image holding means, and a photoconductor Po for making an image glossy when printing a photographic image, etc. The photoconductors Py to Po have surfaces made of a photosensitive dielectric material.

[0022] In FIG. 1, around the black photoconductor Pk, arranged in the direction of rotation of the photoconductor Pk are a charger CCk as an example of a charging means, an exposure device ROSk as an example of a latent image forming means, a developer Gk as an example of a developing means, a primary transfer roll T1k as an example of a primary transfer means, and a photoconductor cleaner CLk as an example of a cleaning means for an image holding means. Similarly, around the other photoconductors Py, Pm, Pc, Po, there are arranged chargers CCy, CCm, CCc, CCo, exposure devices ROSy, ROSm, ROSc, ROSo, developers Gy, Gm, Gc, Go, primary transfer rolls T1y, T1m, T1c, T1o, and photoconductor cleaners CLy, CLm, CLc, CLo. Toner cartridges Ky, Km, Kc, Kk, and Ko, which are an example of a developer storage means, are detachably supported on the upper portion of the marking portion U1a. The toner cartridges Ky to Ko store developers to be replenished to the developing units Gy to Go.

[0023] An intermediate transfer belt B, which is an example of intermediate transfer means and an example of image holding means, is disposed below each of the photoconductors Py-Po. The intermediate transfer belt B is sandwiched between the photoconductors Py-Po and the primary transfer rolls T1y-T1o. The back surface of the intermediate transfer belt B is supported by a drive roll Rd, which is an example of drive means, a tension roll Rt, which is an example of tension applying means, a walking roll Rw, which is an example of meandering prevention means, a plurality of idler rolls Rf, which are an example of driven means, a backup roll T2a, which is an example of opposing means for secondary transfer, a plurality of retract rolls R1, which are an example of movable means, and the primary transfer rolls T1y-T1o. On the surface of the intermediate transfer belt B, a belt cleaner CLB as an example of a cleaning means for the intermediate transfer means is disposed near the drive roll Rd.

[0024] A secondary transfer roll T2b, which is an example of a secondary transfer member, is disposed opposite the backup roll T2a with the intermediate transfer belt B sandwiched therebetween. A contact roll T2c, which is an example of a contact means, is in contact with the backup roll T2a in order to apply a voltage of a polarity opposite to the charging polarity of the developer to the backup roll T2a. The backup roll T2a, the secondary transfer roll T2b, and the contact roll T2c constitute a secondary transfer device T2 as an example of a secondary transfer means of Example 1, and the primary transfer rolls T1y to T1o, the intermediate transfer belt B, the secondary transfer device T2, etc. constitute transfer devices T1, B, and T2 as an example of a transfer means of Example 1.

[0025] Below the secondary transfer device T2, a paper feed tray TR1 as an example of a storage means is provided. Recording sheets S as an example of a medium are stored in the paper feed tray TR1. A pickup roll Rp as an example of a take-out means and a handling roll Rs as an example of a handling means are arranged diagonally above the right of the paper feed tray TR1. A transport path SH along which the recording sheets S are transported extends from the handling roll Rs. A plurality of transport rolls Ra as an example of a transport means for transporting the recording sheets S downstream are arranged along the transport path SH. A deburring device Bt, which is an example of a means for removing unnecessary parts, is disposed downstream of the separation roll Rs. The deburring device Bt pinches the recording sheet S with a preset pressure and conveys it downstream to remove unnecessary parts from the edge of the recording sheet S, that is, to remove burrs.

[0026] A double feed detector Jk is disposed downstream of the deburring device Bt. The double feed detector Jk measures the thickness of the recording sheets S passing through and detects a state in which multiple recording sheets S are stacked on top of each other, i.e., a double feed. A correction roll Rc, which is an example of a position correction means, is disposed downstream of the double feed detection device Jk. The correction roll Rc corrects the inclination of the recording sheet S with respect to the transport direction, that is, the skew. A registration roll Rr is disposed downstream of the correction roll Rc as an example of an adjustment unit that adjusts the timing of conveying the recording sheet S to the secondary transfer device T2. Also, a sheet guide SG1 is disposed downstream of the registration roll Rr as an example of a medium guiding unit. The feeder unit U2 also has paper feed trays TR2 and TR3 configured similarly to the paper feed tray TR1, pickup roll Rp, handling roll Rs, and transport roll Ra, and the transport path SH from the paper feed trays TR2 and TR3 merges with the transport path SH of the printer main body U1 upstream of the double feed detection device Jk.

[0027] A plurality of conveyor belts HB, which are an example of a medium conveying means, are disposed downstream of the secondary transfer roll T2b in the conveying direction of the recording sheet S. A fixing device F, which is an example of a fixing means, is disposed downstream of the conveyor belt HB in the conveying direction of the recording sheet S. A de-curler Hd as an example of a curvature correcting means is disposed in the finisher U3 downstream of the fixing device F. The de-curler Hd applies pressure to the recording sheet S to correct the curvature, or so-called curl, of the recording sheet S. A transport path SH extends downstream of the decurler Hd toward a discharge tray TRh (an example of a loading means). Discharge rollers Rh (an example of a discharging means) are disposed at the downstream end of the transport path SH.

[0028] A reversing path SH2, which is an example of a transport path branching off from the transport path SH, is formed downstream of the decurler Hd. A first gate GT1, which is an example of a transport direction switching means, is disposed at the branch point between the transport path SH and the reversing path SH2. A plurality of switchback rolls Rb, which are an example of a forward and reverse rotatable conveying means, are arranged on the reverse path SH2. A connection path SH3, which is an example of a conveying path, is formed on the upstream side of the switchback rolls Rb, branching off from the upstream part of the reverse path SH2 and joining the conveying path SH downstream of the branching point with the reverse path SH2. A second gate GT2, which is an example of a conveying direction switching means, is arranged at the branching point between the reverse path SH2 and the connection path SH3.

[0029] A turn-back path SH4 for reversing, or switching back, the conveying direction of the recording sheet S is disposed downstream of the reversing path SH2 and below the fixing device F. A switch-back roll Rb, which is an example of a conveying means capable of rotating forward and backward, is disposed on the turn-back path SH4. A third gate GT3, which is an example of a conveying direction switching means, is disposed at the entrance of the turn-back path SH4. The transport path SH downstream of the return path SH4 merges with the transport path SH for the paper feed tray TR1.

[0030] (Marking action) When the printer U receives image information transmitted from the personal computer PC via the print image server COM, a job, which is an image forming operation, is started. When the job is started, the photoconductors Py-Po, the intermediate transfer belt B, etc. rotate. The photoconductors Py to Po are rotated by a driving source (not shown). A preset voltage is applied to the chargers CCy to CCo, which charge the surfaces of the photoconductors Py to Po. In response to a control signal from the control unit C, the exposure machines ROSy to ROSo output laser light Ly, Lm, Lc, Lk, and Lo as an example of light for writing a latent image, and write an electrostatic latent image on the charged surfaces of the photoconductors Py to Po. The developing units Gy to Go develop the electrostatic latent images on the surfaces of the photoconductors Py to Po into visible images. The toner cartridges Ky-Ko replenish the developer consumed in the development in the developing units Gy-Go.

[0031] A primary transfer voltage having a polarity opposite to the charge polarity of the developer is applied to the primary transfer rolls T1y to T1o, and the primary transfer rolls transfer the visible images on the surfaces of the photoconductors Py to Po onto the surface of the intermediate transfer belt B. The photoconductor cleaners CLy to CLo remove and clean the developer remaining on the surfaces of the photoconductors Py to Po after the primary transfer. When passing through the primary transfer area facing the photoconductors Py to Po, the intermediate transfer belt B has images transferred and stacked in the order of O, Y, M, C, and K, and passes through the secondary transfer area Q4 facing the secondary transfer device T2. In the case of a monochrome image, an image of only one color is transferred and sent to the secondary transfer area Q4.

[0032] The pickup roller Rp feeds out the recording sheet S from the paper feed trays TR1 to TR3 from which the recording sheet S is supplied, according to the size of the received image information, the designation of the recording sheet S, and the size and type of the stored recording sheet S. The separation roll Rs separates and separates the recording sheets S sent out from the pickup roll Rp one by one. The deburring device Bt applies a preset pressure to the recording sheet S passing therethrough to remove burrs. The double feed detection device Jk detects double feeding of the recording sheets S by detecting the thickness of the recording sheets S passing through. The correction roll Rc corrects the skew of the passing recording sheet S by bringing it into contact with a wall surface (not shown).

[0033] The registration roll Rr feeds the recording sheet S in time with the image on the surface of the intermediate transfer belt B being sent to the secondary transfer area Q4. The sheet guide SG1 guides the recording sheet S sent out by the registration roll Rr to the secondary transfer area Q4. In the secondary transfer device T2, a secondary transfer voltage having the same polarity as the charge polarity of the developer set in advance is applied to the backup roll T2a via the contact roll T2c, and the image on the intermediate transfer belt B is transferred to the recording sheet S. The belt cleaner CLB removes and cleans the developer remaining on the surface of the intermediate transfer belt B after the image has been transferred in the secondary transfer area Q4. The conveyor belt HB conveys the recording sheet S, onto which an image has been transferred by the secondary transfer device T2, downstream while holding the recording sheet S on its surface.

[0034] The fixing device F has a heating roll Fh as an example of a heating member and a pressure roll Fp as an example of a pressure member. A heater h as an example of a heat source is housed inside the heating roll Fh. The fixing device F heats and presses the recording sheet S passing through a fixing area Q5 where the heating roll Fh and the pressure roll Fp come into contact with each other, thereby fixing an unfixed image on the surface of the recording sheet S. The heating roll Fh and the pressure roll Fp constitute the fixing members Fp, Fh of the first embodiment. The decurler Hd applies pressure to the recording sheet S that has passed through the fixing device F to remove the curvature, or so-called curl, of the recording sheet S.

[0035] When double-sided printing is to be performed on the recording sheet S that has passed through the decurler Hd, the first gate GT1 is activated and the sheet is transported to the reversing path SH2, switched back at the return path SH4, and sent again through the transport path SH to the registration roll Rr, where printing is performed on the second side. When the recording sheet S is discharged onto the discharge tray TRh with the side on which the image is recorded facing up, that is, when the recording sheet S is discharged face-up, the recording sheet S is transported along the transport path SH and discharged onto the discharge tray TRh by the discharge roll Rh.

[0036] On the other hand, when the recording sheet S is discharged with the side on which the image is recorded facing down, that is, in the case of face-down discharge, the recording sheet S is once conveyed from the transport path SH to the reversing path SH2. Then, after the trailing end of the recording sheet S in the transport direction passes through the second gate GT2, the forward rotation of the switchback roll Rb is stopped. Then, the second gate GT2 switches, the switchback roll Rb rotates in the reverse direction, and the recording sheet S is transported along the connecting path SH3 to the discharge tray TRh. The discharged recording sheets S are stacked on the discharge tray TRh.

[0037] (Explanation of spray mechanism) FIG. 2 is a side view of the discharge port of the post-treatment device of the first embodiment. FIG. 3 is a perspective view of a main part of the discharge port portion of the post-processing device according to the first embodiment. 1 to 3, in the first embodiment, the discharge tray TRh is formed to be inclined downward in the direction of gravity as it approaches the downstream side in the sheet conveying direction. An end guide 1 as an example of a stopping means is disposed on the downstream end of the discharge tray TRh in the direction of gravity. In addition, a side guide 2 as an example of a stopping means is disposed on the back side (rear side) of the discharge tray TRh as an example of the other end in the width direction.

[0038] A blowing device 6 as an example of a blowing means is disposed below the discharge port 3 through which the sheet S discharged by the discharge roll Rh passes. The blowing device 6 has a housing 7 as an example of a case. The housing 7 in the first embodiment is formed in a hollow rectangular tube shape extending in the front-rear direction, which is the width direction of the sheet S. The housing 7 is formed with a plurality of blowing ports 8. The blowing ports 8 are disposed at intervals in the width direction of the sheet S. In the first embodiment, as an example, the blowing ports 8 are disposed up to positions corresponding to both ends of the maximum usable paper width. A fan 9 as an example of a gas transfer means is disposed below the housing 7. The fan 9 of the first embodiment draws in outside air and transfers it into the housing 7. Therefore, the gas drawn into the housing 7 is blown out from the outlet 8.

[0039] A shutter 11 as an example of an opening / closing means is disposed above the housing 7. The shutters 11 are disposed corresponding to the respective air outlets 8. The shutters 11 in the first embodiment are supported in a suspended state by a wire extending from a winding device 12 as an example of a moving means. The winding device 12 is controlled based on a control signal from the control unit C. In the first embodiment, when the winding device 12 loosens the wire, the shutter 11 descends due to gravity, and the shutter 11 moves to a blocking position where the air outlet 8 is blocked. When the winding device 12 winds up the wire, the shutter 11 rises, and the shutter 11 moves to an opening position where the air outlet 8 is opened.

[0040] Although the winding device 12 has been exemplified as a configuration for moving the shutter 11, the present invention is not limited to this. For example, it is possible to use a solenoid as a drive source for moving the shutter 11, and to move the shutter 11 by turning the solenoid on and off. In addition, it is also possible to combine a motor as an example of a drive source with a pinion gear and rack teeth as an example of a transmission mechanism to move the shutter 11. Furthermore, it is also possible to use hydraulic pressure or gas pressure to move the shutter 11. Furthermore, the shutter 11 is not limited to a configuration in which it moves up and down, and the movement direction can be any direction, such as movement along the width direction. In addition, it is preferable to provide a shutter 11 for each air outlet 8 individually. However, if there are a large number of air outlets 8, it is also possible to use a shutter or the like that can close two or more air outlets 8 together.

[0041] The control unit C of the first embodiment has an input / output interface I / O for inputting and outputting signals from and to the outside. The control unit C also has a ROM (read-only memory) in which programs and information for performing necessary processing are stored. The control unit C also has a RAM (random access memory) for temporarily storing necessary data. The control unit C also has a CPU (central processing unit) for performing processing according to the programs stored in the ROM or the like. Thus, the control unit C of the first embodiment is configured by a so-called microcomputer. The control unit C can realize various functions by executing programs stored in the ROM or the like.

[0042] FIG. 4 is an explanatory diagram of the blowing settings in Example 1, where FIG. 4A is an explanatory diagram when the air volume is large in the center, FIG. 4B is an explanatory diagram when the air volume is large at both ends, and FIG. 4C is an explanatory diagram when the air volume is large on the front side (one end side). The control unit C of the first embodiment controls the shutter 11 according to the range in the width direction in which the air volume (blowout volume) from the air outlet 8 is to be reduced, and moves the shutter 11 to the closed position. In FIG. 4, when the discharged medium is to be curved, the control unit C of the first embodiment closes some of the air outlets 8 with the shutter 11. In FIG. 4A, when the medium is to be curved in a convex shape as viewed from the discharge direction, the air outlets 8 (8a) at the ends in the width direction are closed and only the air outlets 8 (8b) at the center are opened, so that the air volume at the center is larger than at both ends. Also, in FIG. 4B, when the medium is to be curved in a concave shape as viewed from the discharge direction, the air outlets 8 (8b) at the center in the width direction are closed and only the air outlets 8 (8a) at the ends are opened, so that the air volume at the ends is larger than at the center.

[0043] In addition, in the control unit C of the first embodiment, when it is desired to send the sheet S in the width direction in the discharge tray TRh, a difference is provided in the air volume in the width direction according to the desired sending direction. In FIG. 4C, when it is desired to send the sheet S toward the side guide 2 on the right side (the rear side of the finisher U3) as viewed from the discharge direction, the air outlets 8a1 and 8b1 on the front side (one end side) are opened, and the air outlets 8a2 and 8b2 on the rear side (the other end side) are closed. In this way, it is possible to move the sheet S toward the rear side, and the side end of the sheet S is brought into contact with the side guide 2, so that the sheet S can be aligned and adjusted. Note that when it is desired to send the sheet S toward the front side, the combination of the air outlets 8 to be opened and closed is reversed. It should be noted that the user can select which of the forms shown in FIGS. 4A to 4C to use by inputting information from the operation unit UI.

[0044] (Function of Example 1) In the finisher U3 of the first embodiment having the above-mentioned configuration, the amount of gas blown onto the sheet S discharged toward the discharge tray TRh varies in the width direction. Therefore, as shown in Figs. 4A and 4B, the sheet S is discharged to the discharge tray TRh in a curved state or with one side of the sheet S floating. In particular, the front end of the sheet S in the discharge direction is likely to be curved or with one side floating. Therefore, when the front end of the sheet S in the discharge direction contacts and is stacked on the upper surface of the discharge tray TRh, the contact area is reduced compared to when the entire sheet S contacts the upper surface in the width direction. This reduces the frictional resistance of the sheet S.

[0045] FIG. 5 is an explanatory diagram of the media ejection state in a conventional configuration, with FIG. 5A being an explanatory diagram of the state where the front end of the media contacts the ejection tray, and FIG. 5B being an explanatory diagram of the state where the media has been ejected further from the state in FIG. 5A. In FIG. 5, in a conventional configuration where wind is not blown, when the front end of the sheet 01 in the conveying direction comes into contact with the discharge tray 02, almost the entire area in the width direction comes into contact with the discharge tray 02 as shown in FIG. 5A. Here, the type of sheet 01 may be thin paper or the like with low "stiffness" (so-called weak paper stiffness), or coated paper or the like with a high friction coefficient between the paper and the discharge tray. In this case, when the sheet 01 is further fed, as shown in FIG. 5B, the frictional force between the sheet 01 and the discharge tray 02 exceeds the "stiffness" of the sheet 01, and the sheet 01 may not move downstream and may buckle midway. If the sheet 01 buckles, this may lead to problems such as poor loading, such as the sheet 01 being bent midway, the sheet 01 being turned upside down, or the stacking order of the sheets 01 being disturbed.

[0046] In contrast, in the first embodiment, the amount of air blown onto the sheet S varies in the width direction. Therefore, as shown in FIGS. 4A to 4C, the contact area when the front end of the sheet S in the transport direction comes into contact with the discharge tray TRh is reduced. This reduces the frictional force between the front end of the sheet S in the discharge direction and the discharge tray TRh. Therefore, in the first embodiment, buckling of the sheet S is reduced compared to the conventional configuration. Therefore, in the first embodiment, it is possible to suppress the occurrence of stacking problems.

[0047] In addition, in Example 1, when the sheet S is curved convexly as shown in Figure 4A, the central portion of the sheet S in the width direction is less likely to come into contact with the surface of the discharge tray TRh, which makes it possible to suppress the occurrence of scratches on the sheet S. Furthermore, in the first embodiment, when the sheet S is curved in a concave shape as shown in Fig. 4B, a force is likely to be generated from both sides of the sheet S toward the center in the width direction. Therefore, the sheet S is less likely to move outward in the width direction, and the straightness of the sheet S can be improved. 4C, when one side of the sheet S in the width direction is lifted, the sheet S can be moved toward the side guide 2. This makes it possible to improve the alignment of the sheet S. Note that, in order to further improve the alignment, it is also possible to install a vibration device that vibrates the discharge tray TRh. EXAMPLES

[0048] Next, a second embodiment of the present invention will be described. In the description of the second embodiment, components corresponding to those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted. This embodiment 2 differs from the above-mentioned embodiment 1 in the following points, but is otherwise configured similarly to the above-mentioned embodiment 1.

[0049] FIG. 6 is an explanatory diagram of the second embodiment, in which FIG. 6A is an explanatory diagram of a state in which the shutter is removed, and FIG. 6B is an explanatory diagram of a state in which the shutter is attached. 6, in the spraying device 6 of the second embodiment, a shutter 11' is used as an example of an opening / closing member, instead of the shutter 11 and the winding device 12 of the first embodiment. The shutter 11' of the second embodiment has a main body 11a' and a fall prevention part 11b' extending leftward from the upper end of the main body 11a'. The main body 11a' is formed in a plate shape and is configured to face the air outlet 8 and be able to be closed. The shutter 11' in the second embodiment is made of a magnet, and the housing 7 is made of iron, which is an example of a magnetic material. Therefore, the shutter 11' can be attached to the housing 7 by magnetic force. Also, the user can remove the shutter 11' from the housing 7 by pulling it with his / her hand. In the second embodiment, the drop prevention part 11b' is also formed in a plate shape, and contacts the top surface of the housing 7 to help prevent the shutter 11' from falling off.

[0050] (Function of Example 2) In the blowing device 6 of the second embodiment having the above-mentioned configuration, a user can attach the shutter 11' to the air outlet 8 that he / she wants to close, and not attach the shutter 11' to the air outlet 8 that he / she wants to open (or remove the shutter 11' if it is attached), thereby making it possible to create a difference in air volume along the width direction. In the second embodiment, it is not necessary to provide a moving means such as the winding device 12 as in the first embodiment, and it is possible to reduce manufacturing costs, maintenance costs, and the like.

[0051] (Example of change) Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Modifications (H01) to (H010) of the present invention are illustrated below. (H01) In the above embodiment, the printer U is shown as an example of an image forming apparatus, but the present invention is not limited to this and may be configured as, for example, a copier, a fax, or a multifunction machine having multiple or all of these functions. Also, the present invention is not limited to an electrophotographic image forming apparatus and may be applied to any image forming apparatus such as an inkjet type or a thermal transfer type.

[0052] (H02) In the above embodiment, the printer U is configured to use five colors of developer, but this is not limited to this and can also be applied to, for example, a monochrome image forming device or a multi-color image forming device having four or less colors or six or more colors. (H03) In the above embodiment, an endless intermediate transfer belt B is exemplified as an example of an image holding means, but the present invention is not limited to this. For example, the present invention can be applied to a cylindrical intermediate transfer drum, a photosensitive drum, or a photosensitive belt. The present invention can also be applied to a configuration that does not have an intermediate transfer body and records an image directly from a photosensitive body onto a sheet S.

[0053] (H04) In the above embodiment, the number of air outlets 8 is not limited to the illustrated number, and can be increased or decreased according to the design and specifications. Although the air outlets 8 are arranged in the width direction, the air outlets 8 can be arranged offset in the vertical direction or a configuration having multiple air outlets 8 in the vertical direction is also possible. When air outlets are provided both at the top and bottom, it is possible to create a difference in air volume between the center and the ends in the width direction by closing the top and opening only the bottom at the ends in the width direction and leaving both the top and bottom open at the center in the width direction. Alternatively, it is possible to use a single elongated or slit-shaped air outlet extending along the width direction of the sheet S, and to close the portion where the air volume is to be reduced with the shutters 11, 11'. In this case, it is possible to finely adjust the air volume distribution continuously (linearly) compared to the stepwise adjustment as in the first and second embodiments. The number of slit-shaped air outlets is not limited to one, and it is also possible to configure a configuration in which multiple slit-shaped air outlets are provided at intervals in the width direction or height direction. In other words, the shape of the air outlet 8 is not limited to a round hole, and can be any shape such as an elongated hole or a square hole.

[0054] (H05) In the above embodiment, a configuration in which the air outlet 8 is completely closed or completely open to create a difference in air volume is exemplified, but the present invention is not limited to this. For example, it is possible to adjust the degree of blocking of the shutter 11 and adjust the opening area of ​​the air outlet 8 to create a difference in the air volume. Making the opening area adjustable allows for even finer adjustment of the air volume.

[0055] (H06) In the above embodiment, the combination of opening and closing the air outlets 8 is not limited to those exemplified in Figs. 4A to 4C. For example, it is also possible to open every other air outlet 8 in the width direction to curve the sheet S in a wavy shape. Curving in this way makes it possible to improve the straightness. In addition, when curving in a wavy shape, if there are a large number of air outlets 8, the pattern can be changed appropriately according to the desired curved shape, such as a pattern in which two air outlets are opened and two air outlets are closed along the width direction.

[0056] (H07) In the above-mentioned embodiment 2, the shutter 11' is attracted by magnetic force, but the present invention is not limited to this. It is also possible to adopt a configuration in which the shutter 11' is hooked by a combination of a claw and a hole, or a configuration in which the shutter 11' is attached and detached by fastening means such as a screw or a bolt. Also, it is also possible to adopt a configuration in which the shutter 11 of embodiment 1 is not provided with the winding device 12, but the user manually slides the shutter 11 to open and close the air outlet 8. (H08) In the above embodiment, the finisher U3 and the printer main body U1 are separate, but they can be integrated. Also, the spray device 6 can be installed in an image forming apparatus that does not have a finisher U3.

[0057] (H09) In the above embodiment, the shape of the housing 7 is not limited to a square cylinder, but may be any shape, such as a round cylinder. (H010) In the above embodiment, it is possible to provide individual fans for the air outlets 8 and control the rotation speed of each fan to control the air volume and create a difference in the air outlet volume in the width direction. Note that the present invention is not limited to providing a fan for each air outlet 8, and it is also possible to provide one fan for each of a plurality of air outlets 8 (for example, 2 to 3 air outlets). [Explanation of symbols]

[0058] 6...Blowing means, 8…Air outlet, 9...Transportation means, 11, 11'...opening and closing means, 12...Transportation, C…control means; Rh...Exhaust means, S...medium, TRh: loading means, U: Image forming device, U1a…recording means, U3...After-treatment device.

Claims

1. An ejection means for ejecting the medium; A stacking means for stacking the discharged medium; a blowing means arranged below the discharge means for blowing gas toward the discharged medium, the blowing means having a difference in blowing amount in a width direction intersecting the discharge direction of the medium, the blowing means being arranged in a plurality of locations in the width direction and having a blowing port from which the gas is blown out; An opening / closing means capable of opening or closing the air outlet; Equipped with The opening / closing means is detachable from the blowing means, The opening and closing means closes a part of the air outlets to provide a difference in the air outlet amount in the width direction, The opening and closing means is attached to close the blowing port according to the range in the width direction in which the blowing amount is to be reduced. A post-processing device comprising:

2. the blowing means having a difference in blowing amount in the width direction so as to curve the discharged medium when viewed from the discharge direction of the medium; The post-processing device according to claim 1 , further comprising:

3. The amount of blowing out is larger at the center than at the ends in the width direction. The post-processing device according to claim 2 .

4. The amount of blowing out is larger at the ends than at the center in the width direction. The post-processing device according to claim 3 .

5. the blowing means having a difference in blowing amount with respect to the width direction so as to feed the medium toward one end side in the width direction; The post-processing device according to claim 1 , further comprising:

6. The amount of blowing out is larger at one end side in the width direction than at the other end side. The post-processing device according to claim 5 .

7. the blowing means being arranged in a plurality of locations in the width direction and having blowing ports from which gas is blown out; a transfer means arranged corresponding to each of the blowing ports and configured to transfer gas toward the blowing ports; Equipped with 7. The post-processing device according to claim 1, wherein the transfer amounts of the gases transferred by the transfer means are made different, so that the blowing amounts are made different in the width direction.

8. the opening / closing means being detachable from the blowing means by magnetic force; 8. The post-processing device according to claim 1, further comprising:

9. A recording means for recording an image on a medium; An ejection means for ejecting the medium on which the image is recorded; A stacking means for stacking the discharged medium; a blowing means arranged below the discharge means for blowing gas toward the discharged medium, the blowing means having a difference in blowing amount in a width direction intersecting the discharge direction of the medium, the blowing means being arranged in a plurality of locations in the width direction and having a blowing port from which the gas is blown out; An opening / closing means capable of opening or closing the air outlet; Equipped with The opening / closing means is detachable from the blowing means, The opening and closing means closes a part of the air outlets to provide a difference in the air outlet amount in the width direction, The opening and closing means is attached to close the blowing port according to the range in the width direction in which the blowing amount is to be reduced.

1. An image forming apparatus comprising:

Images