Post-processing device and image forming apparatus

Abstract

A post-processing device and an image forming apparatus are provided. The post-processing device includes: an ejection member that ejects a medium; a loading member that loads the ejected medium; and a blowing member that is disposed below the ejection member and blows a gas toward the ejected medium, and the blowing direction of the gas is different according to the kind of the medium.

Description

Technical Field

[0001] This disclosure relates to a post-processing apparatus and an image forming apparatus. Background Technology

[0002] In image forming apparatuses, the technique of blowing gas onto the discharged medium is well known in the past, as described in the following Japanese Patent Publication.

[0003] Japanese Patent Application Publication No. 2016-52941 (“0031”-“0045”) Figure 2 Figure 5 illustrates the following technique: the sheet S, which has been heated by passing through the fixing device, is cooled by a suction fan 4 disposed inside the image forming apparatus, and is also cooled by a cooling unit 11 disposed outside the image forming apparatus by blowing gas from above the sheet S. Summary of the Invention

[0004] The technical problem disclosed herein is to suppress poor loading of the medium on the loading component, compared to the case where the gas is blown in the same direction regardless of the type of medium.

[0005] According to a first aspect of this disclosure, a post-processing apparatus is provided, comprising: a discharge component for discharging a medium; a loading component for loading the discharged medium; and a blowing component disposed below the discharge component and blowing gas toward the discharged medium, wherein the blowing component blows gas in different directions depending on the type of medium.

[0006] According to the second aspect of this disclosure, the post-processing device includes: the blowing component, which, when the medium is a pre-defined lightweight medium, sets the blowing direction of the gas downwards compared to when the medium is not the lightweight medium.

[0007] According to the third aspect of this disclosure, the post-processing device includes: the blowing component, which, when the medium is the lightweight medium, sets the blowing direction of the gas to be lower than horizontal.

[0008] According to the fourth aspect of this disclosure, the post-processing device includes: the blowing component, which sets the blowing direction of the gas downward when the rigidity of the medium is weaker than the predetermined strength, compared with the case where the rigidity is greater than or equal to the predetermined strength.

[0009] According to the fifth aspect of this disclosure, the post-processing device includes: the blowing component, which sets the blowing direction of the gas to be lower than horizontal when the rigidity of the medium is weaker than the predetermined strength.

[0010] According to the sixth aspect of this disclosure, the post-processing device includes: the blowing component, which has a plurality of nozzles arranged in the width direction relative to the medium and has blowing ports for blowing gas, and the orientation of the blowing ports of the blowing component is movable in the vertical direction.

[0011] According to the seventh aspect of this disclosure, the post-processing apparatus includes: a moving component that moves the orientation of the nozzle in a vertical direction; and a control component that controls the moving component to move the orientation of the nozzle to an orientation corresponding to the type of medium.

[0012] According to the eighth aspect of this disclosure, the post-processing device includes: a lifting knob component that moves the orientation of the spray nozzle.

[0013] According to a ninth aspect of this disclosure, an image forming apparatus is provided, comprising: a recording component for recording an image on a medium; a discharge component for discharging the medium on which the image is recorded; a loading component for loading the discharged medium; and a blowing component disposed below the discharge component and blowing gas toward the discharged medium, wherein the blowing component blows gas in different directions depending on the type of medium.

[0014] (Effect)

[0015] According to the first or ninth scheme, compared with the case where the gas is blown in the same direction regardless of the type of medium, poor loading of the medium on the loading component can be suppressed.

[0016] According to the second or third scheme, poor loading can be suppressed compared to the case where the blowing direction is the same as that for light media and ordinary paper.

[0017] According to the fourth or fifth scheme, compared with the case where the blowing direction is the same when the medium is weak and strong, poor loading can be suppressed.

[0018] According to the sixth scheme, the orientation of the blowing component can be moved to adjust the orientation of the gas being blown.

[0019] According to the seventh scheme, the direction of the gas blowing can be automatically adjusted using a control component.

[0020] According to the eighth scheme, the direction of the gas blowing can be manually adjusted by operating the lifting knob. Attached Figure Description

[0021] Figure 1 This is an overall explanatory diagram of the image forming apparatus of Embodiment 1.

[0022] Figure 2 This is a side view of the discharge port portion of the post-processing device in Embodiment 1.

[0023] Figure 3 This is a perspective view of the main part of the discharge port section of the post-processing device in Example 1.

[0024] Figure 4 This is an explanatory diagram of the interior of the blow-attach device in Example 1.

[0025] Figure 5A and Figure 5B This is an explanatory diagram showing the orientation of the nozzle in Example 1. Figure 5A The illustration is for the case of ordinary paper. Figure 5B This is an explanatory diagram for the case of thin paper.

[0026] Figure 6A and Figure 6B This is an illustration of the discharge status of the medium in the previous structure. Figure 6A This diagram illustrates the state of the medium's tip contacting the discharge tray. Figure 6B From Figure 6A The diagram illustrates the state of the medium being discharged.

[0027] Figure 7A and Figure 7B This is an explanatory diagram illustrating the function of ordinary paper in Example 1. Figure 7A This is an explanatory diagram showing the state of the device after exiting the outlet and before grounding. Figure 7B This is an illustration of the state after grounding.

[0028] Figure 8 This is an explanatory diagram for the case of thin paper, illustrating an example of continuously blowing gas onto the rear end of the thin paper.

[0029] Figure 9 This is an explanatory diagram of Example 2, which is the same as that of Example 1. Figure 3 The corresponding diagram. Detailed Implementation

[0030] Next, specific embodiments that are implementations of this disclosure will be described with reference to the accompanying drawings, but this disclosure is not limited to the following embodiments.

[0031] In addition, for ease of understanding of the following explanations, in the attached figures, the front-back direction (the width direction of the medium) is set as the X-axis direction, the left-right direction (the transport direction of the medium) is set as the Y-axis direction, and the up-down direction is set as the Z-axis direction. The directions or sides indicated by the arrows X, -X, Y, -Y, Z, and -Z are respectively set as front, back, right, left, top, bottom, or front side, back side, right side, left side, top side, and bottom side.

[0032] Furthermore, in the diagram, the symbol “·” in “○” refers to an arrow pointing from the back side of the paper to the front side, and the symbol “×” in “○” refers to an arrow pointing from the front side of the paper to the back side.

[0033] In addition, in the following description using the accompanying drawings, for ease of understanding, illustrations other than those of the components required for the description have been appropriately omitted.

[0034] [Example 1]

[0035] (Description of the overall structure of printer U in Example 1)

[0036] Figure 1 This is an overall explanatory diagram of the image forming apparatus of Embodiment 1.

[0037] Figure 1 In this embodiment, the printer U, as an example of the image forming apparatus of Embodiment 1 of the present disclosure, includes: a printer body U1; a feeder unit U2, as an example of a supply device, which supplies media to the printer body U1; an operation unit U1 for operation by a user; and a finisher U3, as an example of a post-processing device, which performs post-processing on the media discharged from the printer body U1.

[0038] (Description of the printing (marking) structure in Example 1)

[0039] Figure 1 The printer body U1 includes the following components: a control unit (an example of a control unit) C, which controls the printer U; a communication unit (not shown), connected to the outside of the printer U via a dedicated cable (not shown), which receives image information sent from a print image server COM, an example of an information transmission device; and a printing unit U1a, an example of a recording unit, which records images on a medium. The print image server COM is connected to a personal computer PC, an example of an image transmission device, which is connected via a cable or a local area network (LAN) and sends information about the image to be printed by the printer U.

[0040] The printing unit U1a includes, as an example, photosensitive materials Py, Pm, Pc, and Pk for yellow (Y), magenta (M), cyan (C), and black (K), respectively, as image holding components; and a photosensitive material Po, used to give images a glossy finish when printing photographic images, etc. The surfaces of photosensitive materials Py to Po contain a photosensitive dielectric.

[0041] Figure 1In this device, around the black photoreceptor Pk, along the rotation direction of the photoreceptor Pk, are arranged an electric charge CCk (an example of an electric charge component), an exposure unit ROSk (an example of an exposure unit), a developer Gk (an example of a developing unit), a primary transfer roller T1k (an example of a primary transfer component), and a photoreceptor cleaner CLk (an example of a cleaning component for an image holding component).

[0042] Around the other photoreceptors Py, Pm, Pc, and Po, there are also similarly arranged electrical appliances CCy, CCM, CCc, CCo, exposure unit ROSy, ROSm, ROSc, and ROSo, developer Gy, Gm, Gc, and Go, primary transfer roller T1y, T1m, T1c, and T1o, and photoreceptor cleaners CLy, CLm, CLc, and CLo.

[0043] At the upper part of the printing unit U1a, toner cartridges Ky, Km, Kc, Kk, and Ko, which serve as examples of developer storage components, are detachably supported. Toner cartridges Ky to Ko contain developer that is supplied to the developer units Gy to Go.

[0044] Below each photoreceptor Py to photoreceptor Po, as an example of an intermediate transfer component, an intermediate transfer belt B, as an example of an image holding component, is arranged. The intermediate transfer belt B is sandwiched between the photoreceptors Py to Po and the primary transfer rollers T1y to T1o. The back side of the intermediate transfer belt B is supported by a drive roller Rd, as an example of a drive component; a tension roller Rt, as an example of a tension imparting component; a walking roller Rw, as an example of a serpentine prevention component; multiple idle rollers Rf, as an example of a driven component; a backup roller T2a, as an example of a counter-rotating component for secondary transfer; multiple retract rollers R1, as an example of a movable component; and the primary transfer rollers T1y to T1o.

[0045] On the surface of the intermediate transfer belt B, near the drive roller Rd, there is a belt cleaner CLB, which is an example of a cleaning component for the intermediate transfer component.

[0046] As an example of a secondary transfer component, the secondary transfer roller T2b is positioned facing the support roller T2a, sandwiching the intermediate transfer belt B. Furthermore, in order to apply a voltage to the support roller T2a that is of the same polarity as the polarity of the developer, as an example of a contact component, a contact roller T2c contacts the support roller T2a.

[0047] The secondary transfer device T2, which is an example of a secondary transfer component in Embodiment 1, is composed of the support roller T2a, the secondary transfer roller T2b, and the contact roller T2c. The transfer device T1, the transfer device B, and the transfer device T2, which are examples of transfer components in Embodiment 1, are composed of the primary transfer rollers T1y to T1o, the intermediate transfer belt B, and the secondary transfer device T2.

[0048] Below the secondary transfer unit T2, there is a paper feed tray TR1, which serves as a receiving component. A recording sheet S, serving as a medium, is received on the paper feed tray TR1. To the upper right of the paper feed tray TR1, a pickup roll Rp, serving as a take-up component, and a combing roll Rs, serving as a combing component, are arranged. A transport path SH extends from the combing roll Rs to transport the recording sheet S. Along the transport path SH, multiple transport rollers Ra, serving as transport components, are arranged to transport the recording sheet S to the downstream side.

[0049] Downstream of the carding roller Rs, a burr removal device Bt is provided as an example of a component for removing excess material. The burr removal device Bt clamps the recording sheet S with a preset pressure and transports it downstream to remove excess material from the edges of the recording sheet S, i.e., burr removal.

[0050] Downstream of the burr removal device Bt, a stacking detection device Jk is installed. The stacking detection device Jk measures the thickness of the passing recording sheet S to detect the overlapping state of multiple recording sheets S, i.e., stacking.

[0051] Downstream of the stacking detection device Jk, a correction roller Rc is provided as an example of an attitude correction component. The correction roller Rc corrects the tilt of the recording sheet S relative to the transport direction, i.e., the so-called skew.

[0052] Downstream of the correction roller Rc, a registration roller Rr is provided as an example of an adjustment component, which adjusts the conveying time of the recording sheet S to the secondary transfer unit T2. Furthermore, downstream of the registration roller Rr, a sheet guide SG1 is provided as an example of a media guiding component.

[0053] In addition, the feeder unit U2 is also equipped with a paper feed tray TR2, a paper feed tray TR3, etc., which are configured in the same way as the paper feed tray TR1 or the pickup roller Rp, combing roller Rs, and conveying roller Ra. The conveying path SH starting from the paper feed tray TR2 and the paper feed tray TR3 converges to the conveying path SH of the printer body U1 on the upstream side of the stacking detection device Jk.

[0054] In contrast to the secondary transfer roller T2b, a plurality of conveyor belts HB, which serve as media conveying components, are arranged downstream of the recording sheet S in the conveying direction.

[0055] In contrast to the conveyor belt HB, a fixing device F, which is an example of a fixing component, is arranged on the downstream side of the recording film S in the conveying direction.

[0056] Downstream of the fixing unit F, the finishing unit U3 is equipped with a decurler Hd, which is an example of a bend correction component. The decurler Hd applies pressure to the recording sheet S to correct the bend, i.e., the curl, of the recording sheet S.

[0057] Downstream of the curl eliminator Hd, a conveying path SH extends toward a discharge tray TRh, which serves as an example of a loading component. At the downstream end of the conveying path SH, a discharge roller Rh, which serves as an example of a discharge component, is disposed.

[0058] Downstream of the curl eliminator Hd, a reversing path SH2, branching off from the conveying path SH, is formed as an example of a conveying path. At the branch point between the conveying path SH and the reversing path SH2, a first brake GT1, serving as an example of a conveying direction switching component, is arranged.

[0059] In the reversing path SH2, multiple switchback rolls Rb are arranged as examples of reversible conveying components. Upstream of the switchback rolls Rb, a connecting path SH3 is formed as an example of a conveying path. The connecting path SH3 branches off from the upstream portion of the reversing path SH2 and merges downstream of the branch point between the conveying path SH2 and the reversing path SH2. At the branch point between the reversing path SH2 and the connecting path SH3, a second gate GT2 is arranged as an example of a conveying direction switching component.

[0060] Downstream of the reversing path SH2, below the fixing unit F, is a return path SH4 for reversing the transport direction of the recording sheet S, also known as retraction. The return path SH4 includes a return roller Rb, an example of a reversible transport component. Furthermore, at the entrance of the return path SH4, a third gate GT3, an example of a transport direction switching component, is provided.

[0061] In addition, the downstream conveying route SH of the turnaround route SH4 merges into the conveying route SH of the paper supply pallet TR1.

[0062] (Printing process)

[0063] In the printer U, when image information sent from a personal computer PC is received via a print image server COM, an image forming operation begins. When the operation begins, photoreceptors Py to Po or the intermediate transfer belt B rotate.

[0064] Photoreceptors Py to Po are rotated by a drive source (not shown).

[0065] The capacitors CCy and CCo apply a preset voltage to charge the surfaces of the photoreceptors Py and Po.

[0066] Exposure machines ROSy to ROSo output lasers Ly, Lm, Lc, Lk, and Lo as examples of light used to write latent images, based on control signals from the control unit C, and write electrostatic latent images on the charged surfaces of photoreceptors Py to Po.

[0067] The developer Gy to developer Go develop the electrostatic latent image on the surface of the photoreceptor Py to the photoreceptor Po into a visible image.

[0068] Toner cartridges Ky to Ko replenish the developer consumed during development in the developer units Gy to Go.

[0069] The primary transfer rollers T1y to T1o are subjected to a primary transfer voltage with opposite polarity to the polarity of the developer, transferring the visible image of the surface of the photoreceptor Py to the surface of the intermediate transfer belt B.

[0070] The photoreceptor cleaner CLy~CLo removes the developer residue left on the surface of the photoreceptor Py~Po after a single transfer, thus cleaning it.

[0071] The intermediate transfer belt B transfers and stacks images in the order of O, Y, M, C, K as it passes through the primary transfer area facing photoreceptors Py to Po, and then passes through the secondary transfer area Q4 facing the secondary transfer unit T2. In the case of a monochrome image, only one color image is transferred and sent to the secondary transfer area Q4.

[0072] The pickup roller Rp feeds the recording sheet S from the paper supply trays TR1 to TR3, which supply the recording sheet S, according to the size of the received image information or the specification of the recording sheet S, as well as the size or type of the recording sheet S being stored.

[0073] The carding roller Rs separates and cards the recording sheets S sent out by the pickup roller Rp one by one.

[0074] The burr removal device Bt applies a preset pressure to the passing recording sheet S to remove burrs.

[0075] The stacking detection device Jk detects the thickness of the passing recording sheet S, thereby detecting the stacking of the recording sheet S.

[0076] The correction roller Rc corrects the skew by bringing the passing recording sheet S into contact with a wall surface (not shown).

[0077] The image on the surface of the intermediate transfer belt B is sent to the secondary transfer area Q4 by the registration roller Rr to deliver the recording sheet S.

[0078] The sheet guide SG1 guides the recording sheet S, which is fed by the registration roller Rr, to the secondary transfer area Q4.

[0079] The secondary transfer unit T2 applies a pre-set secondary transfer voltage with the same polarity as the developer to the support roller T2a via the contact roller T2c, transferring the image of the intermediate transfer belt B to the recording sheet S.

[0080] The cleaner CLB removes the developer residue left on the surface of the intermediate transfer belt B after the image has been transferred in the secondary transfer area Q4.

[0081] The conveyor belt HB holds the recording sheet S, on which the image has been transferred by the secondary transfer unit T2, on its surface and conveys it to the downstream side.

[0082] The fixing device F includes a heating roller Fh, which is an example of a heating member, and a pressure roller Fp, which is an example of a pressure member. Inside the heating roller Fh, a heater h, which is an example of a heat source, is housed. The fixing device F applies pressure and heats the recording sheet S in the fixing area Q5, which is in contact with the pressure roller Fp via the heating roller Fh, to fix the unfixed image on the surface of the recording sheet S. The heating roller Fh and the pressure roller Fp constitute the fixing member Fp and fixing member Fh of Embodiment 1.

[0083] The curl eliminator Hd applies pressure to the recording sheet S passing through the fixing unit F to remove the curvature, or so-called curl, of the recording sheet S.

[0084] In the case of double-sided printing, the first gate GT1 operates, and the recording sheet S, which has passed through the curl eliminator Hd, is conveyed to the reversing path SH2, retracted by the return path SH4, and then sent back to the registration roller Rr via the conveying path SH for printing on the second side.

[0085] The recording sheet S, which is discharged to the discharge tray TRh, is conveyed in the conveying path SH in the case where the surface on which the image is recorded is the upper surface, that is, in the case of so-called face-up discharge, and is discharged to the discharge tray TRh by the discharge roller Rh.

[0086] On the other hand, when the recording sheet S is discharged with the image-recorded side facing down, i.e., in the case of face-down discharge, it is temporarily moved from the transport path SH to the reversing path SH2. Furthermore, after the rear end of the recording sheet S passes the second gate GT2 in the transport direction, the forward rotation of the return roller Rb stops. Then, the second gate GT2 switches, the return roller Rb reverses, and the recording sheet S is transported in the connecting path SH3 to the discharge tray TRh.

[0087] The recording sheet S to be discharged is loaded into the discharge tray TRh.

[0088] (Explanation of the blow-attach mechanism)

[0089] Figure 2 This is a side view of the discharge port portion of the post-processing device in Embodiment 1.

[0090] Figure 3 This is a perspective view of the main part of the discharge port section of the post-processing device in Example 1.

[0091] exist Figures 1-3 In Embodiment 1, the discharge tray TRh is formed inclined downwards in the gravity direction as it moves downstream in the sheet conveying direction. At the downstream end of the discharge tray TRh in the gravity direction, an end guide 1, as an example of a stopping member, is disposed. Furthermore, at the inner (rear) side of the discharge tray TRh, as an example of a stopping member, a side guide 2, is disposed. Below the discharge outlet 3 through which the sheet S discharged by the discharge roller Rh passes, a blowing device 6, as an example of a blowing member, is disposed. The blowing device 6 has a housing 7, as an example of a frame. The housing 7 of Embodiment 1 is formed as a hollow square tube extending in the width direction (front-back direction) of the sheet S. Multiple guide grooves 8, as an example of guide members, are formed on the housing 7. Multiple guide grooves 8 are arranged at intervals relative to the width direction of the sheet S. In Example 1, the guide groove 8 is positioned to correspond to the two ends of the largest usable paper width.

[0092] Figure 4 This is an explanatory diagram of the interior of the blow-attach device in Example 1.

[0093] Figure 3 , Figure 4 Inside the housing 7, a movable nozzle 9 is disposed as an example of an adjustment component. The movable nozzle 9 is formed as a hollow cylinder extending in the width direction. The movable nozzle 9 is supported in a rotatable manner relative to the housing 7. On the movable nozzle 9, a blowhole 9a is formed corresponding to each guide groove 8. Furthermore, on the lower part of the movable nozzle 9, a plurality of air vents 9b are formed at intervals in the width direction.

[0094] Below the housing 7, a fan 11 is disposed as an example of a gas delivery component. The fan 11 of Embodiment 1 draws in outside gas and delivers it into the housing 7. Inside the housing 7, a seal 12 is disposed as an example of a sealing component. The seal 12 is configured to suppress (seal, prevent) gas leakage, thereby directing the gas drawn in by the fan 11 into the interior of the movable nozzle 9. Therefore, the gas drawn in by the fan 11 is ejected from the nozzle 9a through the vent 9b.

[0095] Driven by a motor 13, which is an example of a moving component, the drive is transmitted to the axial end of the movable nozzle 9 via a gear (not shown). The motor 13 is controlled by a control unit (controller) C, which is an example of a control component.

[0096] Furthermore, as an example of a moving component, a motor 13 and a gear are shown, but the invention is not limited to this. For example, a structure can be adopted in which the position of the movable nozzle 9 is moved in two stages by using a solenoid or a spring to open and close the solenoid. In addition, as a moving component, a structure can also be adopted in which the movable nozzle 9 is moved by hydraulic or pneumatic pressure.

[0097] The control unit C in Embodiment 1 has an input / output interface (I / O) for inputting / outputting signals to and from external sources. Furthermore, the control unit C has a read-only memory (ROM) storing programs and information for performing necessary processing. It also has random access memory (RAM) for temporarily storing required data. Finally, the control unit C has a central processing unit (CPU) for performing processing corresponding to the programs stored in the ROM, etc. Therefore, the control unit C in Embodiment 1 comprises a so-called microcomputer. By executing programs stored in the ROM, the control unit C can perform various functions.

[0098] In Example 1, the control unit C controls the motor 13 and adjusts the orientation of the nozzle 9a according to the type of sheet S. In Example 1, as an example, the type of sheet S used is determined based on its basis weight (weight per unit area). For example, if the basis weight of sheet S is less than 60 g / m², which is considered a first threshold, then... 2 If the sheet material S is greater than 90 g / m³, which is considered a second threshold, then the sheet material S is classified as thin paper. 2 In the case of […], sheet S is classified as thick paper. Therefore, when the paper basis weight is 60 [g / m²], 2 ~90[g / m 2 In the case of [missing information], it is classified as ordinary paper. Furthermore, the specific basis weight of the paper is not limited to the values ​​shown and can be varied according to design or specifications.

[0099] Figure 5A and Figure 5B This is an explanatory diagram showing the orientation of the nozzle in Example 1. Figure 5A The illustration is for the case of ordinary paper. Figure 5B This is an explanatory diagram for the case of thin paper.

[0100] When the sheet S is ordinary paper, in Example 1, the control unit C controls the motor 13 to move the nozzle 9a to a predetermined first position. In Example 1, as an example, ... Figure 5A As shown, the first position is set along the horizontal orientation.

[0101] When the sheet S is thin paper, in Embodiment 1, the control unit C controls the motor 13 to orient the nozzle 9a downwards compared to the case of ordinary paper. In Embodiment 1, when the sheet S is thin paper, as... Figure 5B As shown, the nozzle 9a is moved to a predetermined second position. In Example 1, as one example, ... Figure 5B As shown, the second position is set to be downwards than horizontal. Additionally, in Example 1, the second position is set to be parallel to the upper surface of the discharge tray TRh.

[0102] In addition, when using thin paper, the fan 11 can be controlled to reduce the airflow compared to ordinary paper.

[0103] When the sheet S is thick paper, the control unit C in Embodiment 1 moves the nozzle 9a to the same first position as for ordinary paper. Alternatively, in the case of thick paper, the orientation of the nozzle 9a can be left unchanged, and the fan 11 can be stopped to set the airflow to zero.

[0104] (The function of Example 1)

[0105] Figure 6A and Figure 6B This is an illustration of the media discharge situation in a conventional structure. Figure 6A This is an illustration of the state where the front end of the medium contacts the discharge tray. Figure 6B From Figure 6A The diagram illustrates the state of the medium being discharged.

[0106] In the finisher U3 of embodiment 1, which includes the structure described above, the sheet S discharged toward the discharge tray TRh is blown with gas using the blowing device 6.

[0107] Figure 6A and Figure 6B In the same way as in previous structures, in a structure without blowing air, when the front end of sheet 01 in the conveying direction contacts the discharge tray 02, as... Figure 6A As shown, the material falls into the discharge tray 02 and contacts the upstream side in the conveying direction. Therefore, the angle 06 between the imaginary line 05 connecting the grounding position 03 and the discharge port 04 and the upper surface of the discharge tray 02 becomes relatively large. Here, there are cases where the sheet 01 is made of thin paper or similar materials with low "rigidity" (so-called soft paper), or coated paper or similar materials with a high coefficient of friction between the paper and the discharge tray. In this case, when the sheet 01 is further fed in, it is possible that... Figure 6B As shown, the friction between sheet 01 and discharge tray 02 exceeds the "rigidity" of sheet 01, causing sheet 01 to not move downstream and instead bend longitudinally midway. When sheet 01 bends longitudinally, it can cause problems such as sheet 01 bending midway, sheet 01 flipping over, or sheet 01 being loaded in the wrong order, resulting in improper loading.

[0108] Figure 7A and Figure 7B This is an explanatory diagram illustrating the function of ordinary paper in Example 1. Figure 7A This is an explanatory diagram showing the state of the device after exiting the outlet and before grounding. Figure 7B This is an illustration of the state after grounding.

[0109] In contrast, in Example 1, when gas is blown onto sheet S, the front end of sheet S tends to float in the conveying direction. This front end of sheet S then contacts the upper surface of the discharge tray TRh further downstream in the conveying direction. Therefore, the angle 23 formed by the imaginary line 22 connecting the grounding position 21 and the discharge port 3 and the upper surface of the discharge tray TRh is greater than... Figure 6A The situation is less severe. Therefore, the direction in which the frictional force acts (along the upper surface of the discharge tray TRh) is close to the long side direction of sheet S (the discharge direction of sheet S), making it difficult for sheet S to bend longitudinally. Thus, the occurrence of poor loading of sheet S is suppressed.

[0110] In the finisher U3 of Example 1, when the sheet S is thin paper, the direction of the blow nozzle 9a is set downwards. With lightweight thin paper, when blown in the same airflow direction as ordinary paper, the sheet S tends to float and is difficult to fall onto the discharge tray TRh. As the sheet S continues to float, its position may deviate in the discharge direction or width direction, potentially worsening the integrity of the sheet S.

[0111] In contrast, in Example 1, when the sheet S is thin paper, the airflow is downward, and compared to the case where the airflow is not downward, the sheet S is less likely to float continuously, thus suppressing the deterioration of integration. Furthermore, when the sheet S is lightweight thin paper, even with downward airflow, the front end in the conveying direction can float sufficiently, allowing the position contacting the upper surface of the discharge tray TRh to be located on the downstream side of the conveying direction, just like with ordinary paper.

[0112] Figure 8 This is an explanatory diagram for the case of thin paper, illustrating an example of continuously blowing gas onto the rear end of the thin paper.

[0113] Furthermore, when the sheet S is thin paper, if gas is blown onto the rear end in a direction that is not in the wind direction, such as Figure 8 As shown, it is possible for the rear end to tilt upwards. In this state, when a subsequent sheet S2 is loaded, the front end of the subsequent sheet S2 in the transport direction may be positioned lower than the rear end of the preceding sheet S1. Therefore, the loading order of the sheets S may be disordered during the discharge of the pallet TRh. In contrast, in Example 1, when the sheet S is thin paper, the airflow direction is downwards, the tilting of the rear end of the sheet S is suppressed, and the disorder of the loading order is also suppressed.

[0114] Furthermore, in the sizing device U3 of Embodiment 1, the airflow direction is not downwards in the case of thick paper. Thick paper is highly rigid and difficult to bend longitudinally. Therefore, even without downward airflow, poor loading is unlikely. Moreover, for highly rigid thick paper, longitudinal bending is unlikely even without gas adsorption, i.e., even if fan 11 is stopped and no gas is adsorbed. Therefore, fan 11 can be stopped in the case of thick paper. Thus, in the case of thick paper, when fan 11 is stopped, it is easy to suppress the power required to operate fan 11, and the risk of time-related wear or failure of fan 11 is also suppressed, thereby reducing maintenance costs.

[0115] [Example 2]

[0116] Next, Embodiment 2 of this disclosure will be described. In the description of Embodiment 2, the structural elements corresponding to the structural elements of Embodiment 1 will be marked with the same symbols, and their detailed descriptions will be omitted.

[0117] The second embodiment differs from the first embodiment in the following respects, but is otherwise constructed in the same manner as the first embodiment.

[0118] Figure 9 This is an explanatory diagram of Example 2, which is the same as that of Example 1. Figure 3 The corresponding diagram.

[0119] Figure 9 In the blowing device 6 of Embodiment 2, instead of a moving part such as the motor 13 as in Embodiment 1, a lifting knob 31 is provided as an example of a lifting knob part. Therefore, when the user pinches the lifting knob 31 and rotates it, the orientation of the blow nozzle 9a can be adjusted.

[0120] (The function of Example 2)

[0121] In the blow-on apparatus 6 of Embodiment 2, which includes the aforementioned structure, the user can manually and freely adjust the orientation of the blow-on nozzle 9a. Therefore, fine adjustments can be made by operating the lifting knob 31 according to the setting environment of the image forming apparatus, the type of sheet S used by the user, the temperature and humidity of the day, and other environmental conditions.

[0122] Furthermore, in Embodiment 2, there is no need to install moving parts such as motor 13 as in Embodiment 1, which can reduce manufacturing or maintenance costs.

[0123] (Example of Change)

[0124] The embodiments of this disclosure have been described in detail above, but this disclosure is not limited to the described embodiments. Various modifications can be made within the scope of the spirit of this disclosure as set forth in the claims. Modifications (H01) to (H08) of this disclosure are illustrated below.

[0125] (H01) In the embodiments described, a printer U is exemplified as an image forming apparatus, but it is not limited to this. For example, it may also include a copier, a fax machine (Facsimile, FAX), or a multifunction printer having the aforementioned multiple or all of the functions. Moreover, it is not limited to an image forming apparatus of the electronic photograph method, and can be applied to any image forming apparatus of the inkjet method or thermal transfer method.

[0126] (H02) In the embodiment described, a structure using a five-color developer is exemplified as printer U, but it is not limited thereto. For example, it can also be applied to a monochrome image forming apparatus or a multi-color image forming apparatus with four or fewer colors or six or more colors.

[0127] (H03) In the embodiments described, an annular intermediate transfer belt B is illustrated as an example of an image holding component, but it is not limited to this. For example, it can also be applied to a cylindrical intermediate transfer drum, a photoreceptor drum, or a photoreceptor belt. Moreover, it can also be applied to a structure that does not have an intermediate transfer body and records the image directly from the photoreceptor to the sheet S.

[0128] (H04) In the embodiment described, the number of nozzles 9a is not limited to the illustrated number and can be increased or decreased depending on the design or specifications. Furthermore, while the illustrated nozzles 9a are arranged along the width direction, a configuration offset along the vertical direction or a structure with multiple nozzles 9a along the vertical direction is also possible. Additionally, a single elongated (slit-like) nozzle extending along the width direction of the sheet S can also be used. Moreover, the slit-like nozzle is not limited to a single one and multiple nozzles can be spaced apart in the width or height direction. That is, the shape of the nozzle is not limited to a circular hole and can be any shape such as an elongated hole or a square hole.

[0129] (H05) In the embodiment described, a structure in which the nozzle 9a moves together is shown, but it is not limited to this. A structure in which the nozzle 9a moves individually may also be used. In this case, for example, at the end in the width direction where gas is prone to leak along the width direction, a fine adjustment may be made to make it more upward compared to the central part.

[0130] Furthermore, fans 11 can be individually installed for each nozzle 9a, and the rotation speed of each fan can be controlled to control the airflow and create a difference in the amount of airflow in the width direction. Alternatively, the fan 11 can be configured such that the rotation speed remains constant, and an opening / closing member (shutter) is used at the nozzle 9a to narrow the opening area of ​​the nozzle 9a (partially blocking the nozzle 9a) in the case of thin paper, or to completely block the nozzle 9a in the case of thick paper.

[0131] (H06) In the embodiment described, the shape of the housing 7 is not limited to a square tube, and can also be any shape such as a cylinder. Furthermore, a structure in which the movable nozzle 9 rotates is illustrated, but it is not limited to this. For example, a structure in which the entire housing 7 moves to change the direction of the gas blowing can also be adopted.

[0132] (H07) In the embodiment described, the finishing unit U3 and the printer body U1 are shown as having independent structures, but they can also be integrated. Furthermore, the blowing device 6 can also be provided in the image forming apparatus where the finishing unit U3 is not installed.

[0133] (H08) In the embodiments described, examples of media include thin paper, ordinary paper, and thick paper based on the basis weight, but the examples are not limited to these. For example, based on the "rigidity" of the medium, a distinction can be made between media with high "rigidity" and those with low "rigidity." In media with low "rigidity," the same treatment as for thin paper in the embodiments can be applied, and in media with high "rigidity," the same treatment as for ordinary paper or thick paper in the embodiments can be applied. Furthermore, in the case of coated paper with a high coefficient of friction on the surface, the same treatment as for ordinary paper can be applied, or in the case of resin-made overhead projector (OHP) sheets, the same treatment as for thick paper can be applied. The type of medium can be determined by any parameter other than the basis weight, such as surface characteristics or material.

Claims

1. A post-processing apparatus, comprising: Discharge component, discharge medium; Loading components, used to load the discharged medium; as well as A blowing component is disposed below the discharge component and blows gas toward the discharged medium. The blowing component blows gas in different directions depending on the type of medium. When the medium is a pre-defined lightweight medium, the blowing component blows gas in a downward direction compared to when the medium is not the lightweight medium. When the medium is the lightweight medium, the blowing component blows gas in a direction that is even lower than horizontal.

2. The post-processing apparatus according to claim 1, comprising: When the rigidity of the medium is weaker than the predetermined strength, the blowing component sets the gas blowing direction downward compared to the case where the rigidity is greater than or equal to the predetermined strength.

3. The post-processing apparatus according to claim 2, comprising: When the rigidity of the medium is weaker than the predetermined strength, the blowing component sets the gas blowing direction to be lower than horizontal.

4. The post-processing apparatus according to any one of claims 1 to 3, comprising: The blowing component has multiple nozzles arranged in the width direction relative to the medium and has blowing nozzles for blowing gas, and the orientation of the blowing nozzles of the blowing component can be moved in the vertical direction.

5. The post-processing apparatus according to claim 4, comprising: The moving component causes the orientation of the nozzle to move in the vertical direction; as well as A control unit controls the moving component to move the orientation of the nozzle to an orientation corresponding to the type of medium.

6. The post-processing apparatus according to claim 4, comprising: The lifting knob component moves the orientation of the blow nozzle.

7. An image forming apparatus, comprising: Recording components record images on a medium; The discharge component discharges the medium containing the recorded image; Loading components, used to load the discharged medium; as well as A blowing component is disposed below the discharge component and blows gas toward the discharged medium. The blowing component blows gas in different directions depending on the type of medium. When the medium is a pre-defined lightweight medium, the blowing component blows gas in a downward direction compared to when the medium is not the lightweight medium. When the medium is the lightweight medium, the blowing component blows gas in a direction that is even lower than horizontal.

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