Sheet drying device, sheet processing device, and image forming apparatus

Abstract

To enable a sheet coated with a liquid containing an antibacterial agent to be effectively dried.SOLUTION: A sheet drying device 7 receives and conveys a sheet 9 coated with a liquid W containing an antibacterial agent, and dries the sheet 9. The sheet drying device 7 includes a circulating moving body (heating rollers 61, 71 or heating belts 130, 140) which is disposed in a conveyance path 13 of the sheet 9, circulates and moves in accordance with conveyance of the sheet in a state where a surface heated to a predetermined temperature is brought into contact with the sheet 9 conveyed along the conveyance path 13 to dry the sheet.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sheet drying device, a sheet processing device, and an image forming apparatus, and more particularly to a technique for drying a sheet coated with a liquid containing an antibacterial agent. [Background technology]

[0002] Conventionally, there is known an image forming apparatus equipped with an antibacterial agent applicator that applies a liquid containing an antibacterial agent to both sides of a sheet (for example, Patent Document 1). In this image forming apparatus, the antibacterial agent applicator is disposed downstream of a fixing unit that fixes a toner image on the sheet. The antibacterial agent applicator receives a sheet that has been fixed in the fixing unit, and applies a liquid containing an antibacterial agent to both sides of the sheet while the sheet is being transported along a transport path.

[0003] When the antibacterial agent applicator described above is installed in an office-type image forming apparatus, the sheet is coated with a liquid containing an antibacterial agent by the antibacterial agent applicator and then immediately discharged onto the discharge tray. In this case, the transport path from when the liquid is applied to when the sheet is discharged is short, so the liquid applied to the sheet may not dry sufficiently, and the sheet may be discharged while still damp. If the sheet is damp when discharged onto the discharge tray, the user will feel uncomfortable when handling the sheet. Therefore, it is preferable that the antibacterial agent-coated sheet be discharged onto the discharge tray in a sufficiently dry state.

[0004] One possible way to quickly dry the sheet is to provide a mechanism for blowing hot air onto the sheet. However, blowing hot air onto the sheet dissipates heat both inside and outside the device. Dissipating heat inside the device can cause electronic components mounted inside the device to malfunction. Dissipating heat outside the device can also cause the surroundings of the image forming device to become hot, resulting in discomfort for the user. Furthermore, blowing hot air onto the sheet can blow away the antibacterial agent before it can penetrate the sheet, resulting in the problem of not being able to properly apply the antibacterial agent to the sheet. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-70377 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a sheet drying device, a sheet processing device, and an image forming device that can effectively dry sheets coated with a liquid containing an antibacterial agent. [Means for solving the problem]

[0007] In order to achieve the above object, the invention of claim 1 is a sheet drying device that receives and transports a sheet coated with a liquid containing an antibacterial agent, and dries the sheet, characterized in that it is configured to include a circulating moving body that is arranged in a sheet transport path and dries the sheet by circulating as the sheet is transported, with its surface heated to a predetermined temperature in contact with the sheet transported along the transport path.

[0008] The invention according to claim 2 is the sheet drying device according to claim 1, characterized in that the circulating body is constituted by a heating roller or a heating belt.

[0009] The invention of claim 3 is characterized in that, in the sheet drying device of claim 1, it further comprises a temperature detection unit that detects the surface temperature of the circulating body, and a control unit that controls the surface temperature of the circulating body based on the temperature detected by the temperature detection unit.

[0010] The invention according to claim 4 is the sheet drying device according to claim 3, wherein the control unit adjusts the contact pressure of the circulating body against the sheet.

[0011] The invention of claim 5 is characterized in that, in the sheet drying device of claim 4, the control unit acquires information about the sheet being transported along the transport path and adjusts the surface temperature or contact pressure of the circulating body based on the information.

[0012] The invention of claim 6 is a sheet drying device of claim 4, further comprising a moisture content detection unit that detects the moisture content of the sheet that has passed through the contact position with the circulating body, and the control unit is configured to change the surface temperature or contact pressure of the circulating body when the moisture content exceeds a predetermined amount.

[0013] The invention of claim 7 is characterized in that, in the sheet drying device of claim 3, the circulating body can be moved away to a position where it does not contact the sheet transported along the transport path, and the control unit moves the circulating body away from the sheet when the liquid is not applied to the sheet transported along the transport path.

[0014] The invention according to claim 8 is the sheet drying device according to claim 1, further comprising a liquid removing member that removes the liquid adhering to the surface of the circulating body.

[0015] The invention of claim 9 is a sheet drying device of claim 3, further comprising a moisture content detection unit that detects the moisture content of the sheet that has passed through the contact position with the circulating body, and the control unit is configured to reduce the sheet conveying speed when the moisture content exceeds a predetermined amount.

[0016] The invention of claim 10 is a sheet processing apparatus characterized by comprising an antibacterial agent application device that is installed in a sheet transport path and applies a liquid containing an antibacterial agent to the sheet, and a sheet drying device described in any of claims 1 to 9 that is positioned downstream of the antibacterial agent application device in the transport path.

[0017] The invention according to claim 11 is the sheet processing apparatus according to claim 10, further comprising a heat insulating wall provided between the antibacterial agent applying device and the sheet drying device.

[0018] The invention of claim 12 is characterized in that, in the sheet processing device of claim 10, the antibacterial agent application device comprises a tank for storing a liquid containing an antibacterial agent, a temperature measurement unit for measuring the temperature of the liquid in the tank, and a cooling member for cooling the liquid in the tank when the temperature measured by the temperature measurement unit is above a predetermined temperature.

[0019] The invention of claim 13 is an image forming apparatus comprising an apparatus main body that forms an image on a sheet and a sheet processing apparatus according to claim 10, wherein the sheet processing apparatus is provided inside the apparatus main body.

[0020] The invention of claim 14 is an image forming apparatus comprising an apparatus main body that forms an image on a sheet and a sheet processing apparatus according to claim 10, wherein the sheet processing apparatus is provided outside the apparatus main body.

[0021] The invention of claim 15 is an image forming apparatus of claim 13 or 14, characterized in that the apparatus main body comprises a tray for loading sheets to be coated with a liquid containing an antibacterial agent, a fixing unit for fixing the toner image transferred to the sheet to the sheet, and a paper feed unit for transporting the sheets loaded on the tray downstream of the fixing unit and feeding them into the sheet processing apparatus.

[0022] The invention of claim 16 is an image forming apparatus comprising: a conveying path for conveying a sheet; an image forming unit that transfers toner onto a sheet conveyed along the conveying path to form a toner image; a fixing unit provided downstream of the image forming unit that fixes the toner image transferred to the sheet in the image forming unit to the sheet; an antibacterial agent application unit provided downstream of the fixing unit that applies a liquid containing an antibacterial agent to the sheet on which the toner image has been fixed; and a control unit that controls the conveyance of the sheet along the conveying path, wherein the control unit reverses the conveying direction of the sheet after the liquid has been applied by the antibacterial agent application unit and conveys the sheet into the fixing unit, and heats the sheet in the fixing unit to dry the sheet on which the liquid has been applied. [Effects of the Invention]

[0023] According to the present invention, it is possible to effectively dry a sheet to which a liquid containing an antibacterial agent has been applied. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a conceptual diagram illustrating an overall configuration of an image forming apparatus. [Figure 2] FIG. 2 is an enlarged view of the sheet processing apparatus; [Figure 3] FIG. 10 is a diagram showing a mechanism for circulating a liquid. [Figure 4] FIG. 10 is a diagram showing the state of the sheet drying section when a sheet passes through. [Figure 5] FIG. 2 is a block diagram showing a control mechanism of an image forming apparatus equipped with a sheet processing apparatus. [Figure 6] FIG. 10 is a diagram showing table information that is referenced to determine the application amount. [Figure 7] FIG. 10 is a diagram showing table information referenced to determine a target temperature and a contact pressure. [Figure 8] 10 is a flowchart showing a processing procedure performed by a control unit of the antibacterial agent application device. [Figure 9]4 is a flowchart showing a processing procedure performed by a control unit of the sheet drying device. [Figure 10] FIG. 2 is an enlarged view showing the internal configuration of the sheet drying device. [Figure 11] FIG. 2 is an enlarged view showing the internal configuration of the sheet drying device. [Figure 12] 1 is a conceptual diagram illustrating an overall configuration of an image forming apparatus. [Figure 13] 1A to 1C are diagrams illustrating a process of drying a sheet on which a liquid has been applied in an image forming apparatus. [Figure 14] 1 is a conceptual diagram illustrating an overall configuration of an image forming apparatus. [Figure 15] 1 is a conceptual diagram illustrating an overall configuration of an image forming apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Elements common to the embodiments described below are designated by the same reference numerals, and redundant description thereof will be omitted.

[0026] (First embodiment) FIG. 1 is a conceptual diagram showing the overall configuration of an image forming apparatus 1 according to one embodiment of the present invention. This image forming apparatus 1 is configured as, for example, an MFP (Multifunction Peripheral) and has multiple functions, such as a scanning function and a printing function. The image forming apparatus 1 has a scanner unit 2 at the top of the apparatus main body 1a. The scanner unit 2 optically reads an image of a document set by a user and generates image data. The image forming apparatus 1 has an operation panel 3 at the front side of the scanner unit 2. The operation panel 3 is a user interface used by a user when using the image forming apparatus 1. The operation panel 3 displays an operation screen that can be operated by the user and accepts operations by the user. The image forming apparatus 1 also has a printer unit 4 at the bottom of the apparatus main body 1a. The printer unit 4 forms an image on a sheet and outputs it.

[0027] The device main body 1a has a body space 8 between the scanner unit 2 and the printer unit 4. The printer unit 4 discharges a sheet on which an image has been formed into the body space 8. The image forming device 1 is equipped with a sheet processing device 5 provided in the body space 8. The sheet processing device 5 applies an antibacterial agent to the sheet discharged from the printer unit 4.

[0028] 1, the printer unit 4 includes a paper feed conveyance unit 10 and an image forming unit 20. The printer unit 4 also includes a control unit 19 that controls the overall operation of the image forming apparatus 1.

[0029] The paper feed conveyance unit 10 feeds a sheet 9 from one of a plurality of paper feed trays 10a, 10b, and 10c, and conveys the sheet 9 along a conveyance path 13 formed inside the printer unit 4. The plurality of paper feed trays 10a, 10b, and 10c may each store different types of sheets 9, or may store the same type of sheets 9. Each of the paper feed trays 10a, 10b, and 10c is provided with a pickup roller 11 and a paper feed roller 12. The paper feed conveyance unit 10 drives the pickup roller 11 and paper feed roller 12 provided in one paper feed tray designated by the user, and feeds the sheet 9 toward the conveyance path 13. The paper feed conveyance unit 10 conveys the sheet 9 sent to the conveyance path 13 in the direction of arrow F1.

[0030] The conveying path 13 is provided with a sheet detecting unit 14, timing rollers 15, a secondary transfer roller 16, a fixing unit 17, and a paper discharge roller 18.

[0031] The sheet detection unit 14 is a sensor that detects the type of sheet 9 when the sheet 9 passes a predetermined position on the conveying path 13. For example, the sheet detection unit 14 detects the basis weight of the sheet 9 being conveyed. The sheet detection unit 14 may also detect physical properties of the sheet other than basis weight. The detection result by the sheet detection unit 14 is output to the control unit 19. The control unit 19 controls the fixing temperature in the fixing unit 17, etc., based on the detection result by the sheet detection unit 14. The control unit 19 also sends information about the sheet obtained from the sheet detection unit 14 to the sheet processing device 5.

[0032] The timing roller 15 is composed of a pair of rollers. The timing roller 15 is a roller that adjusts the timing at which the sheet 9 is sent to the secondary transfer position by the secondary transfer roller 16. When the leading edge of the sheet 9 fed from the paper feed trays 10a, 10b, and 10c reaches the position of the timing roller 15, the paper feed conveying unit 10 temporarily stops the conveyance of the sheet 9. The paper feed conveying unit 10 then drives the timing roller 15 in accordance with the timing at which the image that has been primarily transferred onto the intermediate transfer belt 22 in the image forming unit 20 is conveyed to the secondary transfer position, and conveys the sheet 9 toward the secondary transfer roller 16. The image is secondarily transferred onto the sheet 9 sent out from the timing roller 15 as it passes through the secondary transfer position by the secondary transfer roller 16. The sheet 9 onto which the image has been secondarily transferred then proceeds toward the fixing unit 17.

[0033] The image forming section 20 includes image forming units 21Y, 21M, 21C, and 21K corresponding to the colors yellow (Y), magenta (M), cyan (C), and black (K), respectively, and an intermediate transfer belt 22.

[0034] The image forming unit 21Y is a unit that forms a Y-color image. The image forming unit 21Y includes an image carrier 25, which is composed of a photosensitive drum or the like, a charger 26, an exposure device 27, and a developing device 28. The image carrier 25 has a photosensitive layer on the surface of a cylindrical body and rotates in a predetermined direction (clockwise). The charger 26, the exposure device 27, and the developing device 28 are arranged around the image carrier 25. The charger 26 charges the surface of the image carrier 25 to a predetermined charge. The exposure device 27 exposes the charged surface of the image carrier 25 based on image data, thereby forming an electrostatic latent image on the surface of the image carrier 25. The developing device 28 supplies a developer containing toner to the surface of the image carrier 25 and develops the electrostatic latent image with toner. As a result, an image (toner image) corresponding to the image data is formed on the surface of the image carrier 25. The other image forming units 21M, 21C, and 21K have the same configuration as image forming unit 21Y, and differ only in the color of toner that they supply to image carrier 25. In other words, multiple image forming units 21Y, 21M, 21C, and 21K having the same configuration are arranged at predetermined intervals in the horizontal direction.

[0035] The intermediate transfer belt 22 is an endless belt disposed above the image forming units 21Y, 21M, 21C, and 21K. The intermediate transfer belt 22 is stretched over a drive roller 23 disposed opposite the secondary transfer roller 16 and a driven roller 24 disposed a predetermined distance horizontally from the drive roller 23. As the drive roller 23 is driven to rotate counterclockwise, the intermediate transfer belt 22 circulates in the direction indicated by arrow F2. The intermediate transfer belt 22 comes into contact with the secondary transfer roller 16 at the position of the drive roller 23.

[0036] Primary transfer rollers 29 are provided inside the intermediate transfer belt 22 at positions facing each of the image forming units 21Y, 21M, 21C, and 21K. The primary transfer rollers 29 press the intermediate transfer belt 22 against the surfaces of the image carriers 25 of each of the image forming units 21Y, 21M, 21C, and 21K. In this state, a predetermined voltage is applied to the primary transfer rollers 29. As a result, the images (toner images) formed on the surfaces of the image carriers 25 are primarily transferred onto the intermediate transfer belt 22. Each of the image forming units 21Y, 21M, 21C, and 21K primarily transfers each of the Y, M, C, and K images onto the intermediate transfer belt 22 in order, superimposing them on top of each other. As a result, a color image is formed on the surface of the intermediate transfer belt 22. The image transferred onto the intermediate transfer belt 22 is secondarily transferred onto the sheet 9 at the position of the secondary transfer roller 16.

[0037] The fixing unit 17 applies heat and pressure to the sheet 9 onto which the image has been secondarily transferred, thereby fixing the image to the sheet 9. The fixing unit 17 includes a heating roller 17a and a pressure roller 17b. The heating roller 17a and the pressure roller 17b are cylindrical circulating bodies that rotate in opposite directions. The heating roller 17a and the pressure roller 17b contact each other to form a nip. The heating roller 17a and the pressure roller 17b sandwich the sheet 9 in the nip and apply heat and pressure. The surface temperature of the heating roller 17a is heated by the control unit 19 to a fixing temperature appropriate for the type of sheet 9 (e.g., basis weight). The toner transferred to the sheet 9 is melted by the heating roller 17a, and the melted toner is fixed to the sheet 9 by the pressure of the pressure roller 17b. The sheet 9 with the image fixed in the fixing unit 17 is discharged into the body space 8 of the device main body 1a via the paper discharge roller 18. The sheet 9 discharged from the printer unit 4 is carried into the sheet processing device 5 and conveyed inside the sheet processing device 5.

[0038] The sheet processing device 5 applies an antibacterial treatment to the sheet 9 discharged from the printer unit 4 in the body space 8 of the device main body 1a by applying a liquid containing an antibacterial agent to the sheet 9 and drying the liquid. The sheet processing device 5 includes an antibacterial agent applicator 6 and a sheet drying device 7. The antibacterial agent applicator 6 is located upstream of the sheet drying device 7 in the conveying direction of the sheet 9. The antibacterial agent applicator 6 receives the sheet 9 discharged from the printer unit 4 and conveys the sheet 9 toward the downstream sheet drying device 7. The antibacterial agent applicator 6 applies the liquid containing the antibacterial agent to both the front and back sides of the sheet 9 as the conveyed sheet 9 passes a predetermined position. The sheet drying device 7 receives the sheet 9 to which the liquid containing the antibacterial agent has been applied by the antibacterial agent applicator 6 and conveys the sheet 9 toward the downstream side. The sheet drying device 7 dries the liquid applied to the sheet 9 while the sheet 9 is being conveyed, allowing the antibacterial agent to penetrate into the sheet 9.

[0039] Fig. 2 is an enlarged view of the sheet processing device 5. As shown in Fig. 2, the sheet processing device 5 is installed in a state where an antibacterial agent applicator 6 and a sheet drying device 7 are adjacent to each other in a body space 8. Inside the antibacterial agent applicator 6 and the sheet drying device 7, a conveying path 13 for conveying a sheet 9 is formed.

[0040] The antibacterial agent applicator 6 receives the sheet 9 through an inlet 31 and conveys the sheet 9 along the conveying path 13. The antibacterial agent applicator 6 has a guide 32 for guiding the sheet 9 along the conveying path 13. The antibacterial agent applicator 6 includes an applicator 30 that applies a liquid containing an antibacterial agent to the sheet 9 being conveyed along the conveying path 13. The applicator 30 applies the liquid containing the antibacterial agent to both sides of the sheet 9 while the sheet 9 is being conveyed along the conveying path 13. In other words, the applicator 30 can apply the liquid containing the antibacterial agent to the sheet 9 without stopping the conveyance of the sheet 9. For example, the antibacterial agent is stored in a tank 40, which is a storage tank, as a liquid W diluted with water, alcohol, or the like. The applicator 30 pumps up the liquid W stored in the tank 40 and applies the liquid W to both sides of the sheet 9.

[0041] The coating unit 30 has an upper coating unit 30a and a lower coating unit 30b. The upper coating unit 30a is disposed above the transport path 13 and coats the upper surface of the sheet 9 with the liquid W. The lower coating unit 30b is disposed below the transport path 13 and coats the lower surface of the sheet 9 with the liquid W.

[0042] The upper application section 30a has an upper tray 41, a draw-up roller 43, an intermediate roller 44, a supply roller 45, a draining roller 46, and an application roller 34. The upper tray 41 stores the liquid W drawn up from the tank 40. The draw-up roller 43 is partially immersed in the liquid W in the upper tray 41. The draw-up roller 43 holds and draws up the liquid W on its surface by rotating in a predetermined direction. The intermediate roller 44 is in contact with the draw-up roller 43 and the supply roller 45. The intermediate roller 44 rotates while holding the liquid W drawn up by the draw-up roller 43 on its surface, and supplies the liquid W to the supply roller 45 at a position where it comes into contact with the supply roller 45. The supply roller 45 rotates in contact with the application roller 34, and supplies the liquid W supplied from the intermediate roller 44 to the application roller 34. The application roller 34 is configured to rotate in contact with the upper surface of the sheet 9 being transported along the transport path 13. The application roller 34 is supplied with the liquid W on its surface, and therefore, by rotating in contact with the upper surface of the sheet 9, the application roller 34 can apply the liquid W to the upper surface of the sheet 9. The draining roller 46 comes into contact with the supply roller 45 and removes a portion of the liquid W held on the surface of the supply roller 45.

[0043] The lower application section 30b includes a lower tray 42, a supply roller 47, a draining roller 48, and an application roller 35. The lower tray 42 stores the liquid W circulated from the upper tray 41. A portion of the supply roller 47 is immersed in the liquid W in the lower tray 42. The supply roller 47 retains and draws up the liquid W on its surface by rotating in a predetermined direction. The supply roller 47 rotates in contact with the application roller 35 and supplies the liquid W drawn up from the lower tray 42 to the application roller 35. The application roller 35 is configured to rotate in contact with the underside of the sheet 9 conveyed along the conveyance path 13. The application roller 35 receives the liquid W on its surface, and can apply the liquid W to the underside of the sheet 9 by rotating in contact with the underside of the sheet 9. The draining roller 48 contacts the supply roller 47 and removes a portion of the liquid W retained on the surface of the supply roller 47.

[0044] FIG. 3 is a diagram showing a mechanism for circulating the liquid W from the tank 40 to the upper tray 41 and the lower tray 42 in the application unit 30. FIG. 3 shows the liquid circulation mechanism as seen from the conveyance direction of the sheet 9. The upper tray 41 and the lower tray 42 extend in a horizontal direction perpendicular to the conveyance direction of the sheet 9. A horizontal space X through which the sheet 9 passes is formed between the upper tray 41 and the lower tray 42. The sheet 9 is conveyed through the horizontal space X, and the liquid W is applied to the sheet 9 during the conveyance. This liquid circulation mechanism includes a pump 81 and liquid circulation paths 82, 83, and 84. The liquid W stored in each of the upper tray 41 and the lower tray 42 is maintained at an appropriate amount by the liquid circulation mechanism.

[0045] The liquid circulation path 82 supplies the liquid W from the tank 40 to the upper tray 41. A pump 81 is provided in the liquid circulation path 82. The pump 81 pumps the liquid W from the tank 40 into the liquid circulation path 82, thereby supplying it to the upper tray 41 via the liquid circulation path 82. The liquid circulation path 83 is a circulation path that supplies the liquid W from the upper tray 41 to the lower tray 42. One end of the liquid circulation path 83 is connected to the bottom of the upper tray 41, and the other end is connected to the top of the lower tray 42. The liquid circulation path 84 is a circulation path that returns the liquid W from the lower tray 42 to the tank 40. One end of the liquid circulation path 84 is connected to the bottom of the lower tray 42, and the other end is open to the top of the tank 40.

[0046] The amount (level) of the liquid W stored in the upper tray 41 and the lower tray 42 is controlled by the rotation speed of the pump 81. That is, the amount of liquid W pumped out by driving the pump 81 is stored in the upper tray 41 and the lower tray 42. The movement of the liquid W from the upper tray 41 to the lower tray 42 and the movement of the liquid W from the lower tray 42 to the tank 40 is due to the weight of the liquid W itself.

[0047] Returning to FIG. 2 , the antibacterial agent application device 6 includes a control unit 39 that controls the operation of the application unit 30 described above. The control unit 39 applies an appropriate amount of liquid W to both sides of the sheet 9 by controlling the upper application unit 30a, the lower application unit 30b, and the pump 81. For example, the control unit 39 acquires information about the sheet 9 from the control unit 19 of the image forming apparatus 1. The information about the sheet 9 is detected by the sheet detection unit 14 and includes information about the basis weight of the sheet 9. The control unit 39 determines the application amount of liquid W according to the type of sheet 9 based on the information about the sheet 9. The control unit 39 then drives the application unit 30 to apply the determined amount of liquid W to the sheet 9. The sheet 9, to which the antibacterial agent-containing liquid W has been applied by the application unit 30, is transported from the discharge port 33 to the downstream sheet drying device 7.

[0048] The antibacterial agent application device 6 also includes a temperature measurement unit 37 for measuring the temperature of the liquid W in the tank 40, and a cooling fan 36 for cooling the liquid W in the tank 40. The sheet drying device 7, located downstream of the antibacterial agent application device 6, heats and dries the sheet 9 to which the antibacterial agent-containing liquid W has been applied. Therefore, the temperature of the liquid W stored in the tank 40 may rise due to the influence of heat from the sheet drying device 7. The control unit 39 drives the cooling fan 36 to cool the liquid W when the temperature of the liquid W measured by the temperature measurement unit 37 reaches or exceeds a predetermined temperature. This makes it possible to suppress a rise in the temperature of the liquid W stored in the tank 40.

[0049] The upper application unit 30a can be raised and lowered by a drive unit (not shown). When applying the liquid W to the sheet 9, the upper application unit 30a descends to a predetermined position so that the liquid W can be applied to the sheet 9 being transported along the transport path 13. On the other hand, when the liquid W is not being applied to the sheet 9, the upper application unit 30a ascends to hold the application roller 34 at an upper position away from the transport path 13. This prevents the application roller 34 from coming into contact with the upper surface of the sheet 9 being transported along the transport path 13, preventing the liquid W from adhering to the sheet 9.

[0050] The lower application unit 30b can also be raised and lowered by a drive unit (not shown). When applying the liquid W to the sheet 9, the lower application unit 30b rises to a predetermined position and is able to apply the liquid W to the sheet 9 being transported along the transport path 13. On the other hand, when the liquid W is not being applied to the sheet 9, the lower application unit 30b descends and holds the application roller 35 at a lower position away from the transport path 13. This prevents the application roller 35 from coming into contact with the underside of the sheet 9 being transported along the transport path 13, preventing the liquid W from adhering to the sheet 9.

[0051] The sheet drying device 7 receives the sheet 9 through an inlet 51 and conveys the sheet 9 along the conveying path 13. The sheet drying device 7 has a guide 52 for guiding the sheet 9 along the conveying path 13. The sheet drying device 7 also has a sheet drying section 50 and a control section 56. The sheet drying section 50 has an upper drying section 50a arranged above the conveying path 13 and a lower drying section 50b arranged below the conveying path 13.

[0052] The upper drying section 50a includes a heating roller 61, an elevation drive unit 66, a temperature detection unit 64, and a liquid removal member 65. The heating roller 61 is capable of contacting the upper surface of the sheet 9 transported along the transport path 13. The heating roller 61 is a circulating moving body that rotates in a predetermined rotational direction to circulate the roller surface. The heating roller 61 contacts the upper surface of the sheet 9 with its surface heated to a predetermined temperature and rotates in the rotational direction as the sheet 9 is transported. A heat source 63 such as a heater is provided on a rotation shaft 62 of the heating roller 61. The heat source 63 heats the surface of the heating roller 61 to a predetermined temperature from inside the heating roller 61. Note that there may be multiple heat sources 63 provided on the rotation shaft 62, or there may be only one. The heating roller 61 heats the sheet 9 by rotating in contact with the upper surface of the sheet 9, thereby drying the liquid W applied to the sheet 9.

[0053] Both ends of the heating roller 61 are held by a lifting / lowering drive unit 66. The lifting / lowering drive unit 66 adjusts the contact pressure of the heating roller 61 with the sheet 9. The lifting / lowering drive unit 66 can also raise the heating roller 61 to a position where it does not come into contact with the sheet 9 being transported along the transport path 13. The lifting / lowering drive unit 66 is driven by the control unit 56.

[0054] The temperature detection unit 64 is a temperature sensor that detects the surface temperature of the heating roller 61. The temperature detection unit 64 detects the surface temperature of the heating roller 61 at a position immediately before the heating roller 61 comes into contact with the sheet 9. The control unit 56 acquires the surface temperature of the heating roller 61 detected by the temperature detection unit 64, and controls the heat source 63 so that the surface temperature of the heating roller 61 becomes a predetermined temperature.

[0055] The liquid removal member 65 is a member that removes the liquid W adhering to the surface of the heating roller 61. For example, the liquid removal member 65 may be configured as a sponge roller. Alternatively, the liquid removal member 65 may be configured to contact the surface of the heating roller 61 when the type of sheet 9 is a specific type and to be spaced apart from the surface of the heating roller 61 when the type is not the specific type. A specific type refers to a sheet that is difficult for the liquid W to penetrate, such as coated paper, glossy paper, or cardboard. When the sheet 9 is a specific type, the amount of liquid W adhering to the surface of the heating roller 61 increases. Therefore, the liquid W adhering to the surface of the heating roller 61 may re-adhere to the surface of the sheet 9 due to the rotation and circulation of the heating roller 61. To prevent this, the control unit 56 brings the liquid removal member 65 into contact with the surface of the heating roller 61 when the sheet 9 is a specific type, thereby removing the liquid W adhering to the surface of the heating roller 61. The liquid removal member 65 may be in constant contact with the surface of the heating roller 61.

[0056] The lower drying section 50b includes a heating roller 71, an elevation drive unit 76, a temperature detection unit 74, and a liquid removal member 75. The heating roller 71 is capable of contacting the underside of the sheet 9 transported along the transport path 13. The heating roller 71 is a circulating moving body that rotates in a predetermined rotational direction to circulate the roller surface. The heating roller 71 contacts the underside of the sheet 9 with its surface heated to a predetermined temperature and rotates in the rotational direction as the sheet 9 is transported. A heat source 73 such as a heater is provided on a rotation shaft 72 of the heating roller 71. The heat source 73 heats the surface of the heating roller 71 to a predetermined temperature from inside the heating roller 71. Note that there may be multiple heat sources 73 provided on the rotation shaft 72, or there may be only one. The heating roller 71 heats the sheet 9 by rotating in contact with the underside of the sheet 9, thereby drying the liquid W applied to the sheet 9.

[0057] Both ends of the heating roller 71 are held by a lifting / lowering drive unit 76. The lifting / lowering drive unit 76 adjusts the contact pressure of the heating roller 71 with the sheet 9. The lifting / lowering drive unit 76 can also lower the heating roller 71 to a position where it does not come into contact with the sheet 9 being transported along the transport path 13. The lifting / lowering drive unit 76 is driven by the control unit 56.

[0058] Temperature detection unit 74 is a temperature sensor that detects the surface temperature of heating roller 71. Temperature detection unit 74 detects the surface temperature of heating roller 71 at a position immediately before heating roller 71 comes into contact with sheet 9. Control unit 56 acquires the surface temperature of heating roller 71 detected by temperature detection unit 74, and controls heat source 73 so that the surface temperature of heating roller 71 becomes a predetermined temperature.

[0059] The liquid removal member 75 is a member that removes the liquid W adhering to the surface of the heating roller 71. For example, the liquid removal member 75 may be configured as a sponge roller. Alternatively, the liquid removal member 75 may be configured to contact the surface of the heating roller 71 when the type of sheet 9 is a specific type and to be spaced apart from the surface of the heating roller 71 when the type is not the specific type. A specific type refers to a sheet that is difficult for the liquid W to penetrate, such as coated paper, glossy paper, or cardboard. When the sheet 9 is a specific type, the amount of liquid W adhering to the surface of the heating roller 71 increases. Therefore, the liquid W adhering to the surface of the heating roller 71 may re-adhere to the surface of the sheet 9 due to the rotation and circulation of the heating roller 71. To prevent this, the control unit 56 brings the liquid removal member 75 into contact with the surface of the heating roller 71 when the sheet 9 is a specific type, thereby removing the liquid W adhering to the surface of the heating roller 71. The liquid removal member 75 may be in constant contact with the surface of the heating roller 71.

[0060] 2, a moisture content detection unit 54 and a paper discharge roller 53 are provided downstream of the sheet drying unit 50. The moisture content detection unit 54 is a sensor that detects the moisture content of the sheet 9 that has passed through the sheet drying unit 50. The paper discharge roller 53 discharges the sheet 9 from a discharge port 55 onto a paper discharge tray 57.

[0061] The sheet drying apparatus 7 also includes a heat shield wall 58 on the wall where the inlet 51 is provided. The heat shield wall 58 is made of a heat insulating material and is disposed on the entire wall separating the sheet drying apparatus 7 and the antibacterial agent application apparatus 6, excluding the inlet 51. Therefore, the heat shield wall 58 prevents heat from the sheet drying section 50 from being transferred to the adjacent antibacterial agent application apparatus 6, preventing the internal temperature of the antibacterial agent application apparatus 6 from rising excessively. However, because the inlet 51 is not blocked by the heat shield wall 58, a certain amount of high-temperature atmosphere inevitably enters the antibacterial agent application apparatus 6 through the inlet 51. If the temperature of the liquid W in the tank 40 rises due to such a high-temperature atmosphere, the cooling fan 36 in the antibacterial agent application apparatus 6 is activated. The heat shield wall 58 may itself be provided as a partition separating the sheet drying apparatus 7 and the antibacterial agent application apparatus 6.

[0062] FIG. 4 shows the state of the sheet drying unit 50 when a sheet 9 passes through. FIG. 4(a) shows the state of the sheet drying unit 50 when a sheet 9 coated with liquid W passes through. When the sheet 9 coated with liquid W passes through, the heating rollers 61 and 71 come into contact with each other to form a nip. That is, the lifting / lowering drive unit 66 lowers the heating roller 61, and the lifting / lowering drive unit 76 raises the heating roller 71, so that the heating rollers 61 and 71 come into contact with each other at a predetermined contact pressure. The surface temperatures of the heating rollers 61 and 71 are maintained at a predetermined temperature according to the type of sheet 9. Furthermore, the heating rollers 61 and 71 are driven to rotate by a motor (not shown) at a rotational speed synchronized with the conveying speed of the sheet 9.

[0063] The sheet 9 coated with the liquid W is subjected to a heat treatment by the heating rollers 61, 71 as it passes through the nip between the heating rollers 61, 71. This heat treatment dries the liquid W coated on the sheet 9. The sheet 9 then passes through the nip with the liquid W dried. The antibacterial agent remains on the sheet 9 after the liquid W has dried. That is, the sheet drying unit 50 dries the sheet 9 coated with the liquid W by bringing the surfaces of the heating rollers 61, 71, which have been heated to a predetermined temperature, into contact with the sheet 9 and circulating the roller surfaces as the sheet 9 is transported.

[0064] Such a sheet drying section 50 does not blow hot air onto the sheet 9. Therefore, the amount of heat dissipated inside or outside the image forming apparatus 1 can be kept small. In addition, the antibacterial agent is not blown away by the hot air before it penetrates into the sheet 9. Therefore, the sheet drying section 50 can effectively dry the sheet 9 to which the liquid W containing the antibacterial agent has been applied.

[0065] FIG. 4(b) shows the state of the sheet drying unit 50 when a sheet 9 that has not been coated with liquid W passes through. When liquid W has not been coated on the sheet 9, the lifting / lowering drive unit 66 raises the heating roller 61, and the lifting / lowering drive unit 76 lowers the heating roller 71. As a result, as shown in FIG. 4(b), the heating rollers 61 and 71 retract from the conveying path 13. At this time, the heat sources 63 and 73 of the heating rollers 61 and 71 are not driven. The sheet 9 that has not been coated with liquid W passes through the space formed between the two heating rollers 61 and 71 and is conveyed downstream of the conveying path 13. In other words, when liquid W has not been coated on the sheet 9, the sheet drying unit 50 does not perform a drying process on the sheet 9.

[0066] 5 is a block diagram showing a control mechanism of the image forming apparatus 1 equipped with the sheet processing device 5. The image forming apparatus 1 is equipped with a control unit 19, a storage unit 103, a temperature sensor 104, a panel control unit 105, a fixing unit 17, an image forming unit 20, a paper feed and conveyance unit 10, a sheet detection unit 14, a communication interface 101, and a connection interface 102. The control unit 19 is connected to each unit via a bus and controls the operation of each unit.

[0067] The communication interface 101 is an interface that connects the image forming apparatus 1 to a network such as a LAN (Local Area Network) and communicates with external devices. The connection interface 102 is an interface that connects to each of the antibacterial agent application device 6 and the sheet drying device 7 of the sheet processing apparatus 5 and communicates with them. The memory unit 103 is a non-volatile memory device configured, for example, as a hard disk drive (HDD) or a solid state drive (SSD). The temperature sensor 104 is a sensor that detects the environmental temperature around the image forming apparatus 1. The panel control unit 105 controls the operation panel 3. For example, the panel control unit 105 changes the screen displayed on the operation panel 3 based on instructions from the control unit 19, and outputs operation information to the control unit 19 based on user operations detected by the operation panel 3.

[0068] The control unit 19 includes a CPU 19a, a ROM 19b, and a RAM 19c. The CPU 19a is a hardware processor that executes computer-readable programs. The ROM 19b is a non-volatile memory that stores the programs executed by the CPU 19a. The RAM 19c is a volatile memory that stores temporary data generated by the CPU 19a executing the programs, and is used as a work area for the CPU 19a. The CPU 19a reads and executes the programs from the ROM 19b, thereby allowing the control unit 19 to control the operation of each unit in the image forming apparatus 1.

[0069] In the case of a print job, the control unit 19 drives the paper feed conveyance unit 10, the image forming unit 20, and the fixing unit 17 to control the operation of forming an image on the sheet 9. When the sheet detection unit 14 detects the basis weight of the sheet 9, the control unit 19 determines the fixing temperature in the fixing unit 17 based on the basis weight of the sheet 9, and controls the fixing unit 17. For example, the fixing temperature of the fixing unit 17 is set to approximately 180 to 200° C. based on the basis weight of the sheet 9. Furthermore, the control unit 19 may change the subsequent conveyance speed of the sheet 9 based on the basis weight of the sheet 9.

[0070] If a setting to perform antibacterial treatment on the sheet 9 is made in the print job, the control unit 19 instructs the antibacterial agent applying device 6 and the sheet drying device 7 to perform antibacterial treatment when the execution of the print job starts. At this time, the control unit 19 transmits the detection result by the sheet detection unit 14 to the antibacterial agent applying device 6 and the sheet drying device 7 as information on the sheet 9. The control unit 19 also transmits the environmental temperature detected by the temperature sensor 104 to the antibacterial agent applying device 6 and the sheet drying device 7. Furthermore, the control unit 19 transmits the conveying speed of the sheet 9 to the antibacterial agent applying device 6 and the sheet drying device 7.

[0071] The antibacterial agent application device 6 includes a connection interface 110, a control unit 39, an upper application unit 30a, a lower application unit 30b, a pump 81, a temperature measurement unit 37, and a fan drive unit 112. The connection interface 110 is an interface that connects to each of the image forming apparatus 1 and the sheet drying device 7 and communicates with them. The fan drive unit 112 drives the cooling fan 36.

[0072] The control unit 39 conveys the sheet 9 by matching the conveying speed of the sheet 9 in the antibacterial agent application device 6 with the conveying speed in the image forming apparatus 1. When the control unit 39 receives an instruction from the image forming apparatus 1 to perform antibacterial treatment, it determines the amount of liquid W to be applied to the sheet 9. The control unit 39 determines the amount of liquid W to be applied based on information obtained from the image forming apparatus 1. The information obtained by the control unit 39 from the image forming apparatus 1 includes information about the sheet 9 and the environmental temperature. The control unit 39 determines the amount of liquid W to be applied based on this information.

[0073] FIG. 6 shows table information referenced to determine the application amount. FIG. 6(a) shows table information for determining the application amount based on the basis weight of the sheet 9 and the ambient temperature. By referencing the table information shown in FIG. 6(a), the control unit 39 can determine the application amount when applying the liquid W to the sheet 9 based on the basis weight of the sheet 9 and the ambient temperature. For example, if the basis weight is 100 g or more and the ambient temperature is less than 15°C, the control unit 39 determines an amount of the liquid W that is larger than normal as the application amount. In other cases, the control unit 39 determines a normal application amount. Note that a relationship other than the table information shown in FIG. 6(a) may be adopted as the relationship between the application amount and the basis weight and the ambient temperature.

[0074] FIG. 6(b) shows table information for determining the application amount based on the conveying speed of the sheet 9 and the ambient temperature. By referring to the table information shown in FIG. 6(b), the control unit 39 can determine the application amount of the liquid W to be applied to the sheet 9 based on the conveying speed of the sheet 9 and the ambient temperature. For example, if the conveying speed of the sheet 9 is slower than normal and the ambient temperature is less than 15°C, the control unit 39 determines an application amount of the liquid W that is larger than normal. In other cases, the control unit 39 determines a normal application amount. Note that a relationship other than the table information shown in FIG. 6(b) may be adopted as the relationship between the application amount and the conveying speed and the ambient temperature.

[0075] When the control unit 39 determines the amount of liquid W to be applied, it drives the pump 81, the upper application unit 30a, and the lower application unit 30b to apply the liquid W to the sheet 9 transported from the image forming apparatus 1. Furthermore, when the control unit 39 determines the amount of liquid W to be applied, it notifies the sheet drying device 7 of the determined amount of application. Furthermore, the control unit 39 constantly monitors the temperature of the liquid W measured by the temperature measurement unit 37, and when the temperature of the liquid W becomes equal to or higher than a predetermined temperature, it drives the fan drive unit 112 to operate the cooling fan 36 to cool the liquid W. Note that the cooling member that cools the liquid W is not limited to the cooling fan 36.

[0076] Furthermore, when the image forming apparatus 1 instructs the control unit 39 not to perform antibacterial treatment, the control unit 39 raises the upper applicator 30a and lowers the lower applicator 30b, causing the upper applicator 30a and the lower applicator 30b to retreat from the conveyance path 13. Therefore, the sheet 9 is conveyed downstream without being coated with the liquid W.

[0077] The sheet drying device 7 includes a connection interface 120, a control unit 56, an upper drying unit 50a, a lower drying unit 50b, and a moisture content detection unit 54. The connection interface 120 is an interface that connects to each of the image forming device 1 and the antibacterial agent application device 6 and communicates with them.

[0078] The control unit 56 conveys the sheet 9 by matching the conveying speed of the sheet 9 in the sheet drying device 7 with the conveying speed in the image forming apparatus 1. When the image forming apparatus 1 instructs to perform antibacterial treatment, the control unit 56 determines the target temperature of the heating rollers 61, 71 and the contact pressure of the heating rollers 61, 71. The control unit 56 determines the target temperature and contact pressure based on information acquired from the image forming apparatus 1 and information acquired from the antibacterial agent application device 6. The information acquired from the image forming apparatus 1 includes information about the sheet 9 and the environmental temperature. Furthermore, the information acquired from the antibacterial agent application device 6 includes the amount of liquid W to be applied. The control unit 56 determines the target temperature and contact pressure based on this information.

[0079] FIG. 7 shows table information referenced to determine the target temperature and contact pressure. FIG. 7(a) shows table information for determining the target temperature and contact pressure based on the basis weight, ambient temperature, and coating amount. By referencing the table information shown in FIG. 7(a), the control unit 56 can determine the target temperature and contact pressure of the heating rollers 61 and 71 based on the basis weight, ambient temperature, and coating amount. For example, the control unit 39 determines the target temperature of the heating rollers 61 and 71 to 100°C or 110°C, which is lower than the fixing temperature of the fixing unit 17. By setting the surface temperature of the heating rollers 61 and 71 to a temperature lower than the fixing temperature of the fixing unit 17, remelting of the toner fixed to the sheet 9 is prevented. Furthermore, by setting the temperature of the heating rollers 61 and 71 to 100°C or higher, the control unit 56 can evaporate the moisture contained in the liquid W and dry the sheet 9. Furthermore, the control unit 56 determines the contact pressure to be either a normal pressure or a pressure stronger than the normal pressure.

[0080] 7(b) shows table information for determining the target temperature and contact pressure based on the conveying speed, ambient temperature, and coating amount. By referring to the table information shown in FIG. 7(b), the control unit 56 can determine the target temperature and contact pressure of the heating rollers 61 and 71 based on the basis weight, ambient temperature, and coating amount.

[0081] After determining the target temperature and contact pressure, the control unit 56 drives the upper drying unit 50a and the lower drying unit 50b. Then, the control unit 56 sandwiches the sheet 9 conveyed from the antibacterial agent application device 6 between the heating rollers 61 and 71, heats it, and dries the liquid W applied to the sheet 9.

[0082] The control unit 56 also monitors the moisture content of the sheet 9 detected by the moisture content detection unit 54. If the moisture content of the sheet 9 that has passed through the drying position by the upper drying unit 50a and the lower drying unit 50b is equal to or less than a predetermined value, the control unit 56 discharges the sheet 9 to the discharge tray 57 at the same conveying speed. On the other hand, if the moisture content of the sheet 9 exceeds the predetermined value, the control unit 56 reduces the conveying speed of the sheet 9. By reducing the conveying speed of the sheet 9, the heated sheet 9 is dried more rapidly. Therefore, the sheet 9 can be sufficiently dried by the time it is completely discharged to the discharge tray 57.

[0083] Furthermore, when the moisture content of the sheet 9 detected by the moisture content detection unit 54 exceeds a predetermined value, the control unit 56 may change the surface temperature or contact pressure of the heating rollers 61, 71. For example, increasing the surface temperature of the heating rollers 61, 71 can accelerate the drying of the sheet 9. In addition, increasing the contact pressure of the heating rollers 61, 71 with respect to the sheet 9 can also accelerate the drying of the sheet 9. Therefore, when the drying of the sheet 9 is insufficient, the control unit 56 may change the surface temperature or contact pressure of the heating rollers 61, 71 so as to increase it.

[0084] Next, the processing procedure in the antibacterial agent application device 6 will be described. FIG. 8 is a flowchart showing the processing procedure performed by the control unit 39 of the antibacterial agent application device 6. When the control unit 39 starts this processing, it determines whether or not execution of a job is to be started in the image forming apparatus 1 (step S10). If execution of a job is not to be started (NO in step S10), the processing by the control unit 39 ends. On the other hand, if execution of a job is to be started (YES in step S10), the control unit 39 determines whether or not the job is to apply an antibacterial agent to the sheet 9 (step S11). If the job is not to apply an antibacterial agent to the sheet 9 (NO in step S11), the control unit 39 releases the application rollers 34 and 35 from contact with each other and moves them away from the conveyance path 13 (step S12). As a result, the liquid W containing the antibacterial agent is not applied to the sheet 9 being conveyed through the antibacterial agent application device 6.

[0085] On the other hand, if the job is to apply an antibacterial agent to the sheet 9 (YES in step S11), the control unit 39 acquires information for determining the amount of liquid W to be applied (step S13). Then, the control unit 39 determines the amount of liquid W to be applied by referring to the table information in FIG. 6(a) or 6(b) (step S13). That is, the control unit 39 determines the amount of liquid W to be applied based on the type of sheet 9, the conveying speed, the ambient temperature, etc. After determining the amount of liquid W to be applied, the control unit 39 outputs the determined amount of liquid W to the sheet drying device 7 (step S15). This allows the sheet drying device 7 to perform a drying process according to the amount of liquid W applied to the sheet 9.

[0086] Next, based on the determined application amount, control unit 39 drives pump 81, upper application unit 30a, and lower application unit 30b to start the operation of applying liquid W to sheet 9 (step S16). As a result, when sheet 9 discharged from image forming apparatus 1 passes through antibacterial agent application device 6, liquid W containing an antibacterial agent is applied to both sides of sheet 9.

[0087] The control unit 39 also detects the temperature of the liquid W stored in the tank 40 (step S17) and determines whether the temperature of the liquid W is equal to or higher than a predetermined temperature (step S18). As a result, if the temperature of the liquid W is equal to or higher than the predetermined temperature (YES in step S18), the control unit 39 drives the cooling fan 36 to start the operation of cooling the liquid W. If the temperature of the liquid W is lower than the predetermined temperature (NO in step S18), the control unit 39 does not perform the cooling operation. If the cooling fan 36 is currently being driven, the control unit 39 stops the driving of the cooling fan 36.

[0088] Next, the control unit 39 determines whether or not the execution of the job has finished (step S20). If the execution of the job has not finished (NO in step S20), the process by the control unit 39 returns to step S13 and repeats the above-mentioned process. On the other hand, if the execution of the job has finished (YES in step S20), the process by the control unit 39 ends.

[0089] Next, the processing procedure in the sheet drying device 7 will be described. FIG. 9 is a flowchart showing the processing procedure performed by the control unit 56 of the sheet drying device 7. When the control unit 56 starts this processing, it determines whether or not execution of a job is to be started in the image forming apparatus 1 (step S30). If execution of a job is not to be started (NO in step S30), the processing by the control unit 56 ends. On the other hand, if execution of a job is to be started (YES in step S30), the control unit 56 determines whether or not the job is to apply an antibacterial agent to the sheet 9 (step S31). If the job is not to apply an antibacterial agent to the sheet 9 (NO in step S31), the control unit 56 releases the contact of the heating rollers 61 and 71 and causes them to retract from the conveying path 13 (step S32). As a result, the sheet 9 conveyed through the sheet drying device 7 is not subjected to a drying process.

[0090] On the other hand, if the job is to apply an antibacterial agent to the sheet 9 (YES in step S31), the control unit 56 acquires information for determining the target temperature and contact pressure of the heating rollers 61 and 71 (step S33). Then, the control unit 56 references the table information in FIG. 7(a) or 7(b) to determine the target temperature of the heating rollers 61 and 71 (step S35). The control unit 56 also determines the contact pressure of the heating rollers 61 and 71 (step S36). That is, the control unit 56 determines the target temperature and contact pressure based on the type of sheet 9, the conveying speed, the ambient temperature, the amount of application, etc.

[0091] When the target temperature and contact pressure are determined, the control unit 56 drives the upper drying unit 50a and the lower drying unit 50b based on the determined target temperature and contact pressure, and starts an operation to dry the liquid W applied to the sheet 9 (step S37). As a result, when the sheet 9 applied with the liquid W passes through the sheet drying device 7, a process of drying the liquid W on the sheet 9 is performed.

[0092] Furthermore, the control unit 56 detects the moisture content of the sheet 9 downstream of the sheet drying unit 50 (step S38). The control unit 56 determines whether the sheet 9 is sufficiently dried based on the detected moisture content (step S39). For example, if the detected moisture content exceeds a predetermined value, the control unit 56 determines that the sheet 9 is not sufficiently dried. If the sheet 9 is not sufficiently dried (YES in step S39), the control unit 56 reduces the conveying speed of the sheet 9 (step S40). At this time, the control unit 56 preferably instructs the image forming apparatus 1 and the antibacterial agent applying device 6 to reduce the conveying speed of the sheet 9. This reduces the conveying speed of subsequent sheets 9 conveyed during the job execution, allowing the subsequent sheets 9 to be sufficiently dried.

[0093] Next, the control unit 56 determines whether or not the execution of the job has finished (step S41). If the execution of the job has not finished (NO in step S41), the process by the control unit 56 returns to step S33 and repeats the above-mentioned process. On the other hand, if the execution of the job has finished (YES in step S41), the process by the control unit 56 ends.

[0094] As described above, the image forming apparatus 1 of this embodiment includes a sheet processing apparatus 5 having an antibacterial agent applicator 6 and a sheet drying apparatus 7 disposed in the body space 8 of the apparatus main body 1a. The antibacterial agent applicator 6 applies antibacterial agent-containing liquid W to both sides of the sheet 9 discharged from the image forming apparatus 1. The sheet drying apparatus 7 receives the sheet 9 coated with antibacterial agent-containing liquid W and dries the sheet 9 while it is being transported. The sheet drying apparatus 7 includes heating rollers 61 and 71, which are circulating bodies. The heating rollers 61 and 71 circulate along the transport path 13, bringing their surfaces, heated to a predetermined temperature, into contact with the sheet 9 as it is transported, thereby drying the sheet 9. In other words, the sheet drying apparatus 7 can satisfactorily dry the sheet 9 coated with liquid W without blowing hot air onto the sheet 9.

[0095] (Second embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, an example of the configuration of a sheet drying device 7 different from that of the first embodiment will be described.

[0096] FIG. 10 is an enlarged view showing the internal configuration of the sheet drying device 7. The sheet drying device 7 has a first path 85 and a second path 86 branched from the conveying path 13 for conveying the sheet 9. A guide member 87 is provided at the branching point of the first path 85 and the second path 86. The guide member 87 is a flap-shaped member that swings around a swing axis at its base end to open either the first path 85 or the second path 86 and close the other. By this movement, the guide member 87 guides the sheet 9 conveyed from the antibacterial agent applying device 6 to either the first path 85 or the second path 86. The guide member 87 is controlled by the control unit 56.

[0097] The sheet drying section 50 is arranged on the first path 85. This sheet drying section 50 has the same configuration as in the first embodiment, and performs a drying process on the sheet 9 transported on the first path 85. On the other hand, the sheet drying section 50 is not arranged on the second path 86. Therefore, the drying process is not performed on the sheet 9 transported on the second path 86. The first path 85 and the second path 86 merge again downstream of the sheet drying section 50 to form a single transport path 13.

[0098] When the job is to apply an antibacterial agent to the sheet 9, the control unit 56 drives the guide member 87 to guide the sheet 9 conveyed from the antibacterial agent application device 6 to the first path 85. The control unit 56 also drives the sheet drying unit 50 to perform a drying process on the sheet 9 conveyed along the first path 85.

[0099] On the other hand, when the job does not involve applying an antibacterial agent to the sheet 9, the control unit 56 drives the guide member 87 to guide the sheet 9 conveyed from the antibacterial agent applying device 6 to the second path 86. The sheet 9 guided along the second path 86 is not subjected to a drying process. Therefore, the sheet drying unit 50 does not need to retract the upper drying section 50a and the lower drying section 50b from the first path 85. In other words, by providing the first path 85 and the second path 86, the sheet drying device 7 has the advantage of being able to shorten the stroke for driving the upper drying section 50a and the lower drying section 50b up and down.

[0100] In addition, the configuration of this embodiment other than the above-mentioned points may be the same as the configuration described in the first embodiment.

[0101] (Third embodiment) Next, a third embodiment of the present invention will be described, which illustrates an example of the configuration of the sheet drying unit 50 that is different from that of the first embodiment.

[0102] 11 is an enlarged view showing the internal configuration of the sheet drying device 7. In this sheet drying section 50, a lower drying section 50b and an upper drying section 50a are provided at different positions on the conveying path 13 of the sheet 9. For example, the lower drying section 50b is disposed upstream of the upper drying section 50a on the conveying path 13.

[0103] The lower drying section 50b includes a heating belt 130 configured as an endless belt as a circulating member. The heating belt 130 is stretched between a rotating roller 132 and a pressure pad 133 that are spaced apart in the vertical direction. As the rotating roller 132 rotates in a predetermined direction, the heating belt 130 circulates in the predetermined direction between the rotating roller 132 and the pressure pad 133. For example, a heat source 134 such as a heater is provided inside the pressure pad 133. The heat source 134 heats the heating belt 130 from inside the pressure pad 133. The heat source 134 may be provided inside the rotating roller 132 instead of inside the pressure pad 133.

[0104] A roller 135 is disposed above the pressure pad 133 across the conveyance path 13 for the sheet 9. The roller 135 comes into contact with the heating belt 130 held by the pressure pad 133, forming a nip portion that holds the sheet 9 therebetween.

[0105] Both ends of the rotary roller 132 and the pressure pad 133 are held by a holding portion 131. The holding portion 131 is driven to move up and down in the vertical direction, and is capable of adjusting the contact pressure between the heating belt 130 and the roller 135.

[0106] The upper drying section 50a includes a heating belt 140 configured as an endless belt as a circulating member. The heating belt 140 is stretched between a rotating roller 142 and a pressure pad 143 that are spaced apart in the vertical direction. As the rotating roller 142 rotates in a predetermined direction, the heating belt 140 circulates in the predetermined direction between the rotating roller 142 and the pressure pad 143. For example, a heat source 144 such as a heater is provided inside the pressure pad 143. The heat source 144 heats the heating belt 140 from inside the pressure pad 143. The heat source 144 may be provided inside the rotating roller 142 instead of inside the pressure pad 143.

[0107] A roller 145 is disposed below the pressure pad 143 across the conveyance path 13 for the sheet 9. The roller 145 comes into contact with the heating belt 140 held by the pressure pad 143, forming a nip portion that holds the sheet 9 therebetween.

[0108] Both ends of the rotary roller 142 and the pressure pad 143 are held by a holding portion 141. The holding portion 141 is driven to move up and down in the vertical direction, and is capable of adjusting the contact pressure between the heating belt 140 and the roller 145.

[0109] When a sheet 9 coated with the liquid W is conveyed to the sheet drying unit 50, the sheet drying unit 50 dries the lower surface of the sheet 9 by sandwiching the sheet 9 between the lower drying unit 50b and the roller 135 and circulating the heating belt 130. The sheet drying unit 50 also dries the upper surface of the sheet 9 by sandwiching the sheet 9 between the upper drying unit 50a and the roller 145 and circulating the heating belt 140. The control unit 56 controls the surface temperatures of the heating belts 130 and 140 based on the temperatures detected by the temperature detection units 74 and 64. The control unit 56 also adjusts the contact pressure of the heating belts 130 and 140 against the sheet 9. Therefore, the sheet drying unit 50 can dry the sheet 9 without blowing hot air onto the sheet 9.

[0110] In addition, the configuration of this embodiment other than the above-mentioned points may be the same as the configuration described in the first or second embodiment.

[0111] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. In this embodiment, a fixing unit 17 of the image forming apparatus 1 is also used as the sheet drying device 7.

[0112] 12 is a conceptual diagram showing the overall configuration of an image forming apparatus 1 of this embodiment. In this image forming apparatus 1, an antibacterial agent application device 6 is disposed in a body space 8 of an apparatus main body 1a. This image forming apparatus 1 does not have a sheet drying device 7 in the body space 8. Therefore, a paper output tray 57 is disposed adjacent to the antibacterial agent application device 6 and holds sheets 9 discharged from the antibacterial agent application device 6. When conveying the sheets 9 along a conveying path 13, the antibacterial agent application device 6 can switch the conveying direction.

[0113] FIG. 13 is a diagram showing a process of drying a sheet 9 coated with liquid W in the image forming apparatus 1. In the case of a job to coat the sheet 9 with an antibacterial agent, the image forming apparatus 1 transports the sheet 9, on which an image has been fixed by the fixing unit 17, into the antibacterial agent coating device 6, and as shown in FIG. 13( a), the antibacterial agent coating device 6 coats both sides of the sheet 9 with liquid W. After coating the entire surface of the sheet 9 with liquid W, the antibacterial agent coating device 6 reverses the conveyance direction of the sheet 9. That is, the antibacterial agent coating device 6 conveys the sheet 9 coated with liquid W toward the upstream fixing unit 17. At this time, the image forming apparatus 1 reverses the rotation direction of the paper discharge roller 18. The image forming apparatus 1 also reverses the rotation directions of the heating roller 17a and the pressure roller 17b of the fixing unit 17.

[0114] As a result, the sheet 9 coated with Liquid W is transported to the fixing unit 17 as shown in FIG. 13(b). The fixing unit 17 performs a heat treatment on the entire surface of the sheet 9 coated with Liquid W by circulating the rollers in the rotation direction while sandwiching the sheet 9 between a heating roller 17a and a pressure roller 17b. As a result, the sheet 9 coated with Liquid W is dried in the fixing unit 17. Furthermore, it is preferable that the heating roller 17a of the fixing unit 17 heats the sheet 9 not at the fixing temperature when the image is fixed to the sheet 9, but at a temperature lower than the fixing temperature.

[0115] When the entire surface of the sheet 9 is dried in the fixing unit 17, the image forming apparatus 1 reverses the rotation direction of the heating roller 17a and the pressure roller 17b again. The image forming apparatus 1 also reverses the rotation direction of the paper discharge roller 18. As a result, the sheet 9 is transported again toward the antibacterial agent applicator 6. When the antibacterial agent applicator 6 receives the dried sheet 9, it retracts the upper applicator 30a and the lower applicator 30b from the transport path 13 and allows the sheet 9 to pass without being coated with the liquid W. As a result, the sheet 9 on which the liquid W has dried is discharged onto the paper discharge tray 57, as shown in FIG. 13(c).

[0116] In this manner, in this embodiment, the fixing unit 17 of the image forming apparatus 1 is utilized as the above-described sheet drying device 7. Therefore, there is no need to provide a dedicated sheet drying device 7 as in the above-described embodiments. Furthermore, even in a configuration in which the antibacterial agent application device 6 is installed in the body space 8 of the image forming apparatus 1, the image forming apparatus 1 can discharge the sheet 9 in a sufficiently dried state.

[0117] Note that the configuration of this embodiment other than the above-described points may be the same as the configuration described in any of the first to third embodiments. In particular, the control when the fixing unit 17 dries the sheet 9 can be applied to the control described in the first embodiment.

[0118] (Fifth embodiment) Next, a fifth embodiment of the present invention will be described. The above embodiment illustrates a configuration in which the sheet processing device 5 is disposed inside the device body 1a of the image forming device 1, i.e., in the body space 8. In contrast, this embodiment illustrates a configuration in which the sheet processing device 5 is disposed adjacent to the outside of the device body 1a of the image forming device 1, rather than inside the device body 1a.

[0119] 14 is a conceptual diagram showing the overall configuration of the image forming apparatus 1 of this embodiment. This image forming apparatus 1 includes a sheet processing apparatus 5 installed adjacent to the outside of the apparatus main body 1a. Similar to the first embodiment, this sheet processing apparatus 5 includes an antibacterial agent application device 6 and a sheet drying device 7. Therefore, the sheet processing apparatus 5 can apply a liquid W containing an antibacterial agent to a sheet 9 on which an image has been formed in the image forming apparatus 1, and discharge the liquid W to a paper output tray 57 in a dried state.

[0120] The image forming apparatus 1 also includes an intermediary conveying device 150 for conveying the sheet 9 discharged into the body space 8 of the apparatus main body 1a to the sheet processing device 5. The intermediary conveying device 150 is installed in the body space 8 of the apparatus main body 1a, receives the sheet 9 discharged from the apparatus main body 1a, and carries the sheet 9 into the sheet processing device 5.

[0121] Even when the sheet processing device 5 is installed outside the device main body 1a in this way, the sheet processing device 5 is provided with the sheet drying device 7, so that the sheet 9 coated with the liquid W can be dried and discharged. This eliminates the need to lengthen the conveying path 13 inside the sheet processing device 5. This has the advantage that the device size of the sheet processing device 5 can be reduced.

[0122] The configuration of this embodiment other than the above-mentioned points may be the same as that described in any of the first to fourth embodiments.

[0123] (Sixth embodiment) Next, a sixth embodiment of the present invention will be described. In the above embodiment, a case where the liquid W is applied to the sheet 9 in conjunction with the image forming operation in the image forming apparatus 1 is exemplified. In this embodiment, an image forming apparatus 1 will be described that can execute a job in which the liquid W is applied to the sheet 9 and dried, without performing the image forming operation.

[0124] 15 is a conceptual diagram showing the overall configuration of the image forming apparatus 1 of this embodiment. This image forming apparatus 1 is provided with a paper feed unit 160 above a fixing unit 17 that feeds sheets 9 to be coated with the liquid W. The paper feed unit 160 is provided with, for example, a tray 161 that holds sheets 9 to be coated with the liquid W. An image may already be formed on the sheets 9 that are held on the tray 161.

[0125] The paper feed unit 160 also has a paper feed roller 162 that feeds the sheet 9 placed on the tray 161, and a conveyance path 163 that conveys the sheet 9. The conveyance path 163 merges downstream with the conveyance path 13 along which the sheet 9 on which an image has been formed is conveyed. The paper feed roller 162 feeds the sheet 9 placed on the tray 161, conveys the sheet 9 along the conveyance path 163 and the conveyance path 13, and sends it to the sheet processing device 5.

[0126] The sheet processing device 5 is disposed in the body space 8 of the image forming device 1, and includes an antibacterial agent application device 6 and a sheet drying device 7. The sheet processing device 5 applies a liquid W containing an antibacterial agent to the sheet 9 fed by the paper feed roller 162, dries the liquid W, and then discharges it.

[0127] Therefore, the image forming apparatus 1 of this embodiment can execute a job of applying an antibacterial agent to the sheet 9 by setting the sheet 9 to be applied with the liquid W on the tray 161. Therefore, the image forming apparatus 1 can apply the antibacterial agent to the sheet 9 without forming an image on the sheet 9.

[0128] The configuration of this embodiment other than the above-mentioned points may be the same as that described in any of the first to fifth embodiments.

[0129] (Variation) The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications are possible.

[0130] For example, in the above embodiment, a configuration example has been described in which the sheet processing device 5 is incorporated into the image forming apparatus 1. However, the sheet processing device 5 may be realized as a standalone device without being incorporated into the image forming apparatus 1. The same applies to the above-mentioned sheet drying device 7. In other words, the sheet drying device 7 may not be incorporated into the sheet processing device 5, but may be realized as a standalone device.

[0131] Furthermore, if the moisture content detection unit 54 detects that the sheet 9 is not sufficiently dried after the sheet drying device 7 has performed the drying process on the sheet 9, control different from that in the above embodiment may be performed. For example, if the control unit 56 detects that the sheet 9 is not sufficiently dried, the control unit 56 may reverse the conveying direction of the sheet 9 and perform control to repeatedly perform the drying process using the heating rollers 61, 71 or the heating belts 130, 140. [Explanation of symbols]

[0132] 1. Image forming device 5. Sheet processing device 6 Antibacterial agent application device 7 Sheet drying device 9 sheets 13 Transport path 17 Fixing section 20 Image forming unit 36 Cooling fan (cooling component) 37 Temperature measurement section 40 Tank 54 Moisture content detector 56 Control Unit 58 Heat shield wall 61, 71 Heating roller (circulating moving body) 64,74 Temperature detection unit 65,75 Liquid removal member W liquid

Claims

1. A sheet drying device that receives and transports a sheet coated with a liquid containing an antibacterial agent, and dries the sheet, A sheet drying device characterized by comprising a circulating moving body that is arranged in a sheet conveying path and dries the sheet by circulating as the sheet is conveyed, with its surface heated to a predetermined temperature in contact with the sheet being conveyed along the conveying path.

2. 2. The sheet drying apparatus according to claim 1, wherein the circulating member is a heating roller or a heating belt.

3. a temperature detection unit that detects the surface temperature of the circulating body; a control unit that controls a surface temperature of the circulating body based on the temperature detected by the temperature detection unit; The sheet drying device according to claim 1, further comprising:

4. The sheet drying device according to claim 3 , wherein the control unit adjusts a contact pressure of the circulating body against the sheet.

5. The sheet drying device according to claim 4 , wherein the control unit acquires information about the sheet being transported along the transport path, and adjusts the surface temperature or the contact pressure of the circulating member based on the information.

6. a moisture content detection unit that detects the moisture content of the sheet that has passed through a contact position with the circulating body; Further provided with The sheet drying apparatus according to claim 4 , wherein the control unit changes a surface temperature or a contact pressure of the circulating body when the moisture content exceeds a predetermined amount.

7. the circulating body is movable to a position where it does not come into contact with the sheet being transported along the transport path, The sheet drying device according to claim 3 , wherein the control unit separates the circulating body from the sheet when the liquid is not applied to the sheet being transported along the transport path.

8. a liquid removal member for removing the liquid adhering to the surface of the circulating body; The sheet drying device according to claim 1, further comprising:

9. a moisture content detection unit that detects the moisture content of the sheet that has passed through a contact position with the circulating body; Further provided with The sheet drying device according to claim 3 , wherein the control unit reduces a conveying speed of the sheet when the moisture content exceeds a predetermined amount.

10. an antibacterial agent application device that is installed in a sheet conveyance path and applies a liquid containing an antibacterial agent to the sheet; the sheet drying device according to claim 1, which is disposed downstream of the antibacterial agent applying device in the conveying path; A sheet processing apparatus comprising:

11. a heat insulating wall provided between the antibacterial agent application device and the sheet drying device; The sheet processing apparatus according to claim 10, further comprising:

12. The antibacterial agent application device is a tank for storing a liquid containing an antibacterial agent; a temperature measuring unit for measuring the temperature of the liquid in the tank; a cooling member that cools the liquid in the tank when the temperature measured by the temperature measuring unit is equal to or higher than a predetermined temperature; The sheet processing apparatus according to claim 10, further comprising:

13. an apparatus body for forming an image on a sheet; The sheet processing apparatus according to claim 10; Equipped with The image forming apparatus is characterized in that the sheet processing apparatus is provided inside the apparatus main body.

14. an apparatus body for forming an image on a sheet; The sheet processing apparatus according to claim 10; Equipped with The image forming apparatus is characterized in that the sheet processing device is provided outside the apparatus main body.

15. The device body includes: a tray for loading sheets to which a liquid containing an antibacterial agent is to be applied; a fixing unit that fixes the toner image transferred onto the sheet; a paper feed unit that conveys the sheets stacked on the tray downstream of the fixing unit and sends them to the sheet processing device; 15. The image forming apparatus according to claim 13, further comprising:

16. a conveying path for conveying a sheet; an image forming unit that transfers toner onto a sheet transported along the transport path to form a toner image; a fixing unit provided downstream of the image forming unit and configured to fix the toner image transferred onto the sheet by the image forming unit; an antibacterial agent application unit provided downstream of the fixing unit and configured to apply a liquid containing an antibacterial agent to the sheet on which the toner image has been fixed; a control unit that controls conveyance of the sheet in the conveyance path; Equipped with The control unit reverses the conveying direction of the sheet after the liquid has been applied by the antibacterial agent application unit, transports the sheet into the fixing unit, and heats the sheet in the fixing unit to dry the sheet on which the liquid has been applied.

Images