Sheet dryer and image formation device

Abstract

To provide a sheet dryer capable of inhibiting deterioration of a conveyor belt which conveys a sheet to be dried, and to provide an image formation device.SOLUTION: A dryer 3 includes: an endless conveyor belt 32 configured to convey a sheet with an ink image formed thereon which is placed on an outer peripheral surface; a dry unit 23 which is provided facing an outer periphery surface of the conveyor belt 32 and heats the sheet conveyed by the conveyor belt 32; and a cooling part 24 which cools the conveyor belt 32 at the outer side of a heating area R1 where the conveyor belt 32 and the dry unit 23 face each other in a traveling direction D1 of the conveyor belt 32.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sheet drying device and an image forming apparatus. [Background technology]

[0002] An image forming apparatus capable of forming an image by an inkjet method includes a sheet drying device that heats and dries a sheet after an ink image is formed on the sheet. For example, a sheet drying device is known that holds the leading edge of a sheet to be dried and pulls the sheet downstream in the sheet conveying direction, thereby conveying the sheet while sliding it against an adsorption plate (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-39820 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the sheet drying device, a sheet to be dried may be placed on a conveyor belt and conveyed. In the configuration including the conveyor belt, the conveyor belt may be deteriorated by heat from a heater used to heat the sheet placed on the conveyor belt.

[0005] An object of the present invention is to provide a sheet drying device and an image forming apparatus capable of suppressing deterioration of a conveyor belt that conveys a sheet to be dried. [Means for solving the problem]

[0006] A sheet drying device according to one aspect of the present invention includes a conveyor belt, a heater, and a cooling section. The conveyor belt is endless and conveys a sheet on which an ink image has been formed, the sheet being placed on its outer circumferential surface. The heater is provided opposite the outer circumferential surface of the conveyor belt and heats the sheet conveyed by the conveyor belt. The cooling section cools the conveyor belt outside a heating region where the conveyor belt and the heater face each other in the running direction of the conveyor belt.

[0007] An image forming apparatus according to another aspect of the present invention includes the sheet drying device described above. Effect of the Invention

[0008] According to the present invention, it is possible to suppress deterioration of the conveyor belt that conveys the sheet to be dried. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the system configuration of an image forming apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of the drying device of the image forming apparatus according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing the configuration of a cooling unit of the image forming apparatus according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the configuration of the cooling unit of the image forming apparatus according to the first embodiment of the present invention. [Diagram 5] FIG. 5 is a block diagram showing a system configuration of an image forming apparatus according to the second embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing the configuration of a drying device of an image forming apparatus according to the second embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing the configuration of a cooling unit of an image forming apparatus according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of the present invention, and is not intended to limit the technical scope of the present invention.

[0011] [First embodiment] First, with reference to FIG. 1, a configuration of an image forming apparatus 100 according to a first embodiment of the present invention will be described.

[0012] The image forming apparatus 100 is an inkjet printer that forms an image on a sheet by an inkjet method. Note that the image forming apparatus 100 may also be a fax machine, a copier, a multifunction machine, or the like that is capable of forming an image by an inkjet method.

[0013] As shown in FIG. 1, the image forming apparatus 100 includes a paper feed section 1, an image forming section 2, a drying device 3, an operation display section 4, and a control section 5.

[0014] The paper feed section 1 supplies sheets on which an image is to be formed to the image forming section 2. The paper feed section 1 includes a paper feed cassette and a paper feed unit.

[0015] The image forming unit 2 uses an inkjet system to form an ink image on a sheet supplied by the paper feed unit 1. The image forming unit 2 has four line heads that eject C (cyan), M (magenta), Y (yellow), and K (black) inks onto the sheet. The sheet on which the ink image has been formed by the image forming unit 2 is transported to a drying device 3.

[0016] The drying device 3 dries the sheet on which the ink image has been formed by the image forming unit 2. The sheet on which the ink image has been formed and dried by the drying device 3 is discharged to a discharge tray (not shown).

[0017] The operation display unit 4 is a user interface of the image forming apparatus 100. The operation display unit 4 includes a display unit and an operation unit. The display unit displays various information in response to control instructions from the control unit 5. For example, the display unit is a liquid crystal display. The operation unit inputs various information to the control unit 5 in response to user operations. For example, the operation unit is a touch panel.

[0018] The control unit 5 performs overall control of the image forming apparatus 100. As shown in FIG. 1, the control unit 5 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various arithmetic processing. The ROM 12 is a non-volatile storage device in which information such as a control program for causing the CPU 11 to execute various processing is stored in advance. The RAM 13 is a volatile or non-volatile storage device used as a temporary storage memory (work area) for various processing executed by the CPU 11. The CPU 11 executes various control programs stored in advance in the ROM 12. This performs overall control of the image forming apparatus 100.

[0019] [Configuration of Drying Equipment 3] Next, the configuration of the drying device 3 will be described with reference to Figs. 2 to 4. Fig. 2 is a cross-sectional view showing the configuration of the drying device 3 placed on the installation surface of the image forming apparatus 100. Fig. 3 is a view of the conveyor belt 32 as viewed from the upstream side of the sheet conveyance path X1. Fig. 4 is a view of the conveyor belt 32 as viewed from the downstream side of the sheet conveyance path X1. In Fig. 2, the sheet conveyance path X1 is indicated by a two-dot chain line with an arrow.

[0020] As shown in FIG. 2, the drying device 3 includes a housing 21, a sheet conveying section 22, a drying unit 23, and a cooling section 24.

[0021] The housing 21 houses the sheet conveying section 22, the drying unit 23, and the cooling section 24. The housing 21 is formed in a substantially rectangular parallelepiped shape. The drying device 3 does not necessarily have to include the housing 21. In this case, the drying device 3 may be provided in a housing that houses the image forming section 2 and the like.

[0022] The sheet conveying section 22 conveys the sheet on which the ink image has been formed, conveyed from the image forming section 2, along a conveying path X1 (see FIG. 2) to the discharge tray. The conveying path X1 is a path along a horizontal plane. In the drying device 3, the sheet is conveyed in a position along the horizontal plane.

[0023] As shown in FIG. 2, the sheet transport section 22 includes a first transport roller pair 31, a transport belt 32, a drive roller 33, a driven roller , and a second transport roller pair .

[0024] The first transport roller pair 31 is provided at the most upstream side of the transport path X1 shown in Fig. 2. The first transport roller pair 31 transports the sheet on which the ink image has been formed, which has been transported from the image forming unit 2, to the downstream side of the transport path X1.

[0025] The conveyor belt 32 is endless and conveys a sheet on which an ink image has been formed, which is placed on the outer peripheral surface. The conveyor belt 32 is provided downstream of the first conveyor roller pair 31 in the conveyor path X1 shown in FIG. 2. The conveyor belt 32 is stretched by a drive roller 33 and a driven roller 34. As shown in FIG. 2, the drive roller 33 and the driven roller 34 are provided at an interval along the conveyor path X1. The drive roller 33 and the driven roller 34 are both hollow rollers. The conveyor belt 32 is stretched along the conveyor path X1 by being stretched by the drive roller 33 and the driven roller 34.

[0026] For example, the conveyor belt 32 has a belt body made of a metal such as stainless steel in a mesh shape, and a coating layer formed on the outer circumferential surface of the belt body. The coating layer is made of a heat-resistant material such as silicon, polyimide, or fluorine-based resin.

[0027] The driving roller 33 rotates by receiving a driving force supplied from a motor (not shown). As a result, the conveyor belt 32 stretched around the driving roller 33 travels in a travel direction D1 shown in Fig. 2. Therefore, the sheet on which the ink image has been formed and placed on the outer circumferential surface of the conveyor belt 32 is conveyed along a conveying path X1.

[0028] A number of intake holes are provided on the outer peripheral surface of the conveyor belt 32. A support plate along a horizontal plane that supports the inner peripheral surface of the conveyor belt 32 and an intake device that sucks air above the conveyor belt 32 through a number of intake holes formed in the support plate and a number of intake holes formed on the outer peripheral surface of the conveyor belt 32 are provided inside the conveyor belt 32. When the intake device is driven, a sheet on which an ink image has been formed and which is placed on the outer peripheral surface of the conveyor belt 32 is adsorbed to the outer peripheral surface of the conveyor belt 32. The conveyor belt 32 conveys the sheet adsorbed to the outer peripheral surface along a conveying path X1.

[0029] The drying unit 23 is provided to face the outer circumferential surface of the conveyor belt 32, and heats the sheet conveyed by the conveyor belt 32. The drying unit 23 is an example of the heater of the present invention.

[0030] 2, the drying unit 23 is provided above the conveyor belt 32. For example, the drying unit 23 includes a heat source that radiates infrared rays in response to power supply, a reflector above the heat source that reflects the infrared rays radiated from the heat source downward, and a hot air fan above the reflector that blows air downward. The drying unit 23 heats the sheet by blowing hot air from above the conveyor belt 32 to the sheet conveyed by the conveyor belt 32. Note that the configuration of the drying unit 23 is not limited to the above, and it is sufficient if the drying unit 23 is capable of heating the sheet conveyed by the conveyor belt 32.

[0031] Incidentally, in a configuration in which a sheet to be dried is placed on and transported on a transport belt 32, as in the drying device 3, the heat of the drying unit 23 may cause the transport belt 32 to deteriorate.

[0032] In contrast, in the image forming apparatus 100 according to the first embodiment of the present invention, as described below, it is possible to suppress deterioration of the conveyor belt 32 that conveys the sheet to be dried.

[0033] The cooling section 24 cools the conveyor belt 32 outside a heating region R1 (see FIG. 2) where the conveyor belt 32 and the drying unit 23 face each other in the running direction D1 of the conveyor belt 32.

[0034] As shown in FIGS. 2 to 4, the cooling unit 24 includes five blower fans 41 (41A to 41E), five first temperature sensors 42 (42A to 42E), and five second temperature sensors 43 (43A to 43E).

[0035] Each of the blower fans 41 is provided facing the outer circumferential surface of the conveyor belt 32. As shown in Figs. 2 to 4, each of the blower fans 41 is provided below the conveyor belt 32 facing the outer circumferential surface of the conveyor belt 32. Each of the blower fans 41 blows air toward the outer circumferential surface of the conveyor belt 32 in response to power supply. Air from outside the housing 21 is supplied to each of the blower fans 41 via an air intake port (not shown) formed in the housing 21.

[0036] Each of the first temperature sensors 42 detects the temperature of the conveyor belt 32 outside the heating region R1 (see FIG. 2) in the traveling direction D1 and outside the cooling region R2 (see FIG. 2) where the conveyor belt 32 and the blower fan 41 face each other. As shown in FIGS. 2 to 4, each of the first temperature sensors 42 is provided below the conveyor belt 32 and faces the outer circumferential surface of the conveyor belt 32. Also, as shown in FIG. 2, each of the first temperature sensors 42 is provided downstream of the cooling region R2 in the traveling direction D1. For example, each of the first temperature sensors 42 is a non-contact infrared temperature sensor. Each of the first temperature sensors 42 may be a contact temperature sensor.

[0037] Each of the second temperature sensors 43 detects the temperature of the conveyor belt 32 outside the heating region R1 (see FIG. 2) and outside the cooling region R2 (see FIG. 2) in the traveling direction D1. As shown in FIGS. 2 to 4, each of the second temperature sensors 43 is provided below the conveyor belt 32 and faces the outer circumferential surface of the conveyor belt 32. Also, as shown in FIG. 2, each of the second temperature sensors 43 is provided upstream of the cooling region R2 in the traveling direction D1. For example, each of the second temperature sensors 43 is a non-contact infrared temperature sensor. Note that each of the second temperature sensors 43 may be a contact temperature sensor.

[0038] 3 and 4, the blower fan 41, the first temperature sensor 42, and the second temperature sensor 43 are provided corresponding to each of a plurality of divided regions R10 (R11 to R15) arranged in the width direction D2 of the conveyor belt 32 and set on the outer circumferential surface of the conveyor belt 32. The width direction D2 is a direction perpendicular to the traveling direction D1.

[0039] Specifically, the blower fan 41A, the first temperature sensor 42A, and the second temperature sensor 43A are provided corresponding to the divided region R11. That is, the blower fan 41A, the first temperature sensor 42A, and the second temperature sensor 43A are provided facing the divided region R11. The first temperature sensor 42A and the second temperature sensor 43A detect the temperature of the conveyor belt 32 on both outer sides of the cooling region R2 corresponding to the blower fan 41A in the traveling direction D1.

[0040] The blower fan 41B, the first temperature sensor 42B, and the second temperature sensor 43B are provided corresponding to the divided region R12. That is, the blower fan 41B, the first temperature sensor 42B, and the second temperature sensor 43B are provided facing the divided region R12. The first temperature sensor 42B and the second temperature sensor 43B detect the temperature of the conveyor belt 32 on both outer sides of the cooling region R2 corresponding to the blower fan 41B in the traveling direction D1.

[0041] The blower fan 41C, the first temperature sensor 42C, and the second temperature sensor 43C are provided corresponding to the divided region R13. That is, the blower fan 41C, the first temperature sensor 42C, and the second temperature sensor 43C are provided facing the divided region R13. The first temperature sensor 42C and the second temperature sensor 43C detect the temperature of the conveyor belt 32 on both outer sides of the cooling region R2 corresponding to the blower fan 41C in the traveling direction D1.

[0042] The blower fan 41D, the first temperature sensor 42D, and the second temperature sensor 43D are provided corresponding to the divided region R14. That is, the blower fan 41D, the first temperature sensor 42D, and the second temperature sensor 43D are provided facing the divided region R14. The first temperature sensor 42D and the second temperature sensor 43D detect the temperature of the conveyor belt 32 on both outer sides of the cooling region R2 corresponding to the blower fan 41D in the traveling direction D1.

[0043] The blower fan 41E, the first temperature sensor 42E, and the second temperature sensor 43E are provided corresponding to the divided region R15. That is, the blower fan 41E, the first temperature sensor 42E, and the second temperature sensor 43E are provided facing the divided region R15. The first temperature sensor 42E and the second temperature sensor 43E detect the temperature of the conveyor belt 32 on both outer sides of the cooling region R2 corresponding to the blower fan 41E in the traveling direction D1.

[0044] For example, five blower fans 41 are arranged side by side along the width direction D2. Furthermore, five first temperature sensors 42 are arranged side by side along the width direction D2. Furthermore, five second temperature sensors 43 are arranged side by side along the width direction D2. Note that the five blower fans 41 do not have to be arranged side by side along the width direction D2. Furthermore, the five first temperature sensors 42 do not have to be arranged side by side along the width direction D2. Furthermore, the five second temperature sensors 43 do not have to be arranged side by side along the width direction D2.

[0045] [Configuration of control unit 5] Next, the configuration of the control unit 5 will be described in more detail with reference to FIG.

[0046] 1, the control unit 5 includes a drive control unit 51 and a detection processing unit 52. An apparatus including the drying device 3 and the control unit 5 is an example of the sheet drying device of the present invention.

[0047] Specifically, an operation control program for causing the CPU 11 to function as each of the above-mentioned functional units is stored in advance in the ROM 12 of the control unit 5. The CPU 11 executes the operation control program stored in the ROM 12 to function as each of the above-mentioned functional units.

[0048] The operation control program may be recorded on a computer-readable recording medium such as a CD, a DVD, or a flash memory, and may be read from the recording medium and stored in a non-volatile storage device such as a flash memory provided in image forming apparatus 100. Some or all of the functional units included in control unit 5 may be configured with electronic circuits. The operation control program may be a program for causing a plurality of processors to function as each functional unit included in control unit 5.

[0049] The drive control unit 51 controls the drive of the blower fan 41 based on the temperature of the conveyor belt 32 detected by the first temperature sensor .

[0050] Specifically, the drive control unit 51 executes drive control of the blower fan 41 based on the temperature detected by the first temperature sensor 42 for each divided region R10.

[0051] That is, the drive control unit 51 executes drive control of the blower fan 41A based on the detection result by the first temperature sensor 42A. The drive control unit 51 also executes drive control of the blower fan 41B based on the detection result by the first temperature sensor 42B. The drive control unit 51 also executes drive control of the blower fan 41C based on the detection result by the first temperature sensor 42C. The drive control unit 51 also executes drive control of the blower fan 41D based on the detection result by the first temperature sensor 42D. The drive control unit 51 also executes drive control of the blower fan 41E based on the detection result by the first temperature sensor 42E. This makes it possible to suppress the temperature of the outer circumferential surface of the conveyor belt 32 from varying in the width direction D2, compared to a configuration in which the drive of five blower fans 41 is controlled based on the detection result by one first temperature sensor 42.

[0052] For example, the drive control unit 51 adjusts the amount of power supplied to the blower fan 41 based on the difference between the temperature of the conveyor belt 32 detected by the first temperature sensor 42 and a preset target temperature. This adjusts the amount of air sent by the blower fan 41 in accordance with the detection result by the first temperature sensor 42. Note that the drive control unit 51 may switch between supplying power to the blower fan 41 and not supplying power based on the determination result of whether or not the temperature of the conveyor belt 32 detected by the first temperature sensor 42 exceeds the target temperature.

[0053] The detection processing unit 52 detects an abnormality in the blower fan 41 based on the difference between the temperature detected by the first temperature sensor 42 and the temperature detected by the second temperature sensor 43.

[0054] Specifically, the detection processing unit 52 executes abnormality detection of the blower fan 41 based on the difference between the temperature detected by the first temperature sensor 42 and the temperature detected by the second temperature sensor 43 for each divided region R10.

[0055] That is, the detection processing unit 52 executes abnormality detection of the blower fan 41A based on the difference between the temperature detected by the first temperature sensor 42A and the temperature detected by the second temperature sensor 43A. The detection processing unit 52 also executes abnormality detection of the blower fan 41B based on the difference between the temperature detected by the first temperature sensor 42B and the temperature detected by the second temperature sensor 43B. The detection processing unit 52 also executes abnormality detection of the blower fan 41C based on the difference between the temperature detected by the first temperature sensor 42C and the temperature detected by the second temperature sensor 43C. The detection processing unit 52 also executes abnormality detection of the blower fan 41D based on the difference between the temperature detected by the first temperature sensor 42D and the temperature detected by the second temperature sensor 43D. The detection processing unit 52 also executes abnormality detection of the blower fan 41E based on the difference between the temperature detected by the first temperature sensor 42E and the temperature detected by the second temperature sensor 43E. This makes it possible to detect abnormalities in each of the blower fans 41 individually.

[0056] For example, when the difference between the temperature detected by the first temperature sensor 42 and the temperature detected by the second temperature sensor 43 while the blower fan 41 is in operation is less than a predetermined reference value, the detection processing unit 52 detects an abnormality in the blower fan 41. The reference value may be set according to the amount of power supplied to the blower fan 41 (the amount of air blown by the blower fan 41).

[0057] For example, when an abnormality is detected in any of the blower fans 41, the detection processing unit 52 causes the operation display unit 4 to display a message to that effect.

[0058] In this manner, in the image forming apparatus 100, the conveyor belt 32 is cooled by the cooling section 24. This makes it possible to suppress deterioration of the conveyor belt 32 due to the heat of the drying unit 23.

[0059] The number of divided regions R10 set on the outer circumferential surface of the conveyor belt 32 is not limited to five, and may be any number.

[0060] Furthermore, the drying device 3 does not necessarily have to include the first temperature sensor 42. In this case, the drive control unit 51 may control the drive of the blower fan 41 based on the temperature of the conveyor belt 32 detected by the second temperature sensor 43.

[0061] [Second embodiment] Hereinafter, an image forming apparatus 200 according to a second embodiment of the present invention will be described with reference to Fig. 5 to Fig. 7. Fig. 6 is a cross-sectional view showing the configuration of a drying device 3 placed on an installation surface of the image forming apparatus 200. Fig. 7 is a view of a conveyor belt 32 as viewed from the upstream side of a sheet conveying path X1.

[0062] The image forming apparatus 200 differs from the image forming apparatus 100 in the configurations of the drying device 3 and the control unit 5. The other configurations are common between the image forming apparatus 100 and the image forming apparatus 200.

[0063] Specifically, as shown in Figures 5 and 6, the cooling section 24 of the drying device 3 is equipped with a water cooling device 61, a first temperature sensor 62, and a second temperature sensor 63 instead of the blower fan 41, the first temperature sensor 42, and the second temperature sensor 43.

[0064] 5, the control unit 5 includes a drive control unit 71 and a detection processing unit 72 instead of the drive control unit 51 and the detection processing unit 52.

[0065] The water cooling device 61 circulates cooling water along a circulation path passing through the hollow driven roller 34 around which the conveyor belt 32 is tensioned. The driven roller 34 is an example of the tension roller of the present invention.

[0066] As shown in FIG. 6 and FIG. 7, the water cooling device 61 includes a first circulation path 81, a second circulation path 82, a pump 83, and a radiator 84. The first circulation path 81 is an internal space of the hollow driven roller 34. The first circulation path 81 is formed along the axis of the driven roller 34, and penetrates the driven roller 34 along the axis. The second circulation path 82 is a flow path of the cooling water from one end of the first circulation path 81 to the other end of the first circulation path 81 via the pump 83 and the radiator 84. For example, the second circulation path 82 is formed by a resin tube or the like. The first circulation path 81 and the second circulation path 82 form the circulation path through which the cooling water circulates. The pump 83 circulates the cooling water in the circulation path in a circulation direction D3 shown in FIG. 7. The radiator 84 cools the cooling water flowing through the second circulation path 82.

[0067] In the water cooling device 61, the pump 83 is driven, and the cooling water cooled by the radiator 84 is supplied to the first circulation path 81 in the driven roller 34. As a result, the conveyor belt 32 in contact with the driven roller 34 is cooled.

[0068] The first temperature sensor 62 detects the temperature of the conveyor belt 32 outside the heating region R1 (see FIG. 6) in the running direction D1 and outside the contact region R3 (see FIG. 6) where the conveyor belt 32 and the driven roller 34 contact each other. As shown in FIG. 6 and FIG. 7, the first temperature sensor 62 is provided on the upper side of the conveyor belt 32, facing the outer circumferential surface of the conveyor belt 32. Also, as shown in FIG. 6, the first temperature sensor 62 is provided downstream of the contact region R3 in the running direction D1 and upstream of the heating region R1. Also, the first temperature sensor 62 is provided facing the outer side of the placement region on the outer circumferential surface of the conveyor belt 32 where the sheet is placed. That is, the first temperature sensor 62 is provided facing one end of the outer circumferential surface of the conveyor belt 32 in the width direction D2 (see FIG. 7). For example, the first temperature sensor 62 is a non-contact infrared temperature sensor.

[0069] The second temperature sensor 63 detects the temperature of the conveyor belt 32 outside the heating region R1 (see FIG. 6) and outside the contact region R3 (see FIG. 6) in the traveling direction D1. As shown in FIGS. 6 and 7, the second temperature sensor 63 is provided below the conveyor belt 32, facing the outer circumferential surface of the conveyor belt 32. Also, as shown in FIG. 6, the second temperature sensor 63 is provided upstream of the contact region R3 in the traveling direction D1. For example, the second temperature sensor 63 is provided facing the outer side of the placement region on the outer circumferential surface of the conveyor belt 32. That is, the second temperature sensor 63 is provided facing one end of the outer circumferential surface of the conveyor belt 32 in the width direction D2 (see FIG. 7). For example, the second temperature sensor 63 is a non-contact infrared temperature sensor.

[0070] The first temperature sensor 62 and the second temperature sensor 63 detect the temperature of the conveyor belt 32 on both outer sides of the contact area R3 in the traveling direction D1.

[0071] The drive control unit 71 controls the drive of the water cooling device 61 based on the temperature of the conveyor belt 32 detected by the first temperature sensor 62 .

[0072] For example, the drive control unit 71 adjusts the flow rate of the cooling water by the pump 83 based on the difference between the temperature of the conveyor belt 32 detected by the first temperature sensor 62 and the target temperature. The drive control unit 71 may switch between driving and not driving the pump 83 based on the determination result of whether or not the temperature of the conveyor belt 32 detected by the first temperature sensor 62 exceeds the target temperature.

[0073] The detection processor 72 detects an abnormality in the water-cooling device 61 based on the difference between the temperature detected by the first temperature sensor 62 and the temperature detected by the second temperature sensor 63 .

[0074] For example, when the difference between the temperature detected by the first temperature sensor 62 and the temperature detected by the second temperature sensor 63 while the pump 83 is operating is less than the reference value, the detection processing unit 72 detects an abnormality in the water-cooling device 61. The reference value may be set according to the flow rate of the cooling water caused by the pump 83.

[0075] For example, when an abnormality in the water-cooling device 61 is detected, the detection processing unit 72 causes the operation display unit 4 to display a message to that effect.

[0076] In this manner, in the image forming apparatus 200, the conveyor belt 32 is cooled by the cooling section 24, similarly to the image forming apparatus 100. Therefore, deterioration of the conveyor belt 32 due to the heat of the drying unit 23 can be suppressed.

[0077] The sheet conveying section 22 of the drying device 3 may include a hollow tension roller for tensioning the conveying belt 32, in addition to the driving roller 33 and the driven roller 34. In this case, the water-cooling device 61 may circulate the cooling water along a path passing through the tension roller.

[0078] Furthermore, the drying device 3 does not need to include the first temperature sensor 62. In this case, the drive control unit 71 may control the drive of the water-cooling device 61 based on the temperature of the conveyor belt 32 detected by the second temperature sensor 63.

[0079] [Notes on the invention] The following will provide an overview of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0080] <Appendix 1> A sheet drying device comprising: an endless conveyor belt that conveys a sheet after an ink image is formed on the sheet and is placed on its outer peripheral surface; a heater that faces the outer peripheral surface of the conveyor belt and heats the sheet conveyed by the conveyor belt; and a cooling section that cools the conveyor belt outside a heating area where the conveyor belt and the heater face each other in the running direction of the conveyor belt.

[0081] <Appendix 2> 2. The sheet drying device according to claim 1, wherein the cooling section includes a blower fan provided opposite to an outer circumferential surface of the conveyor belt.

[0082] <Appendix 3> The sheet drying device described in Appendix 2 includes a temperature sensor that detects the temperature of the conveyor belt outside the heating area in the traveling direction and outside a cooling area where the conveyor belt and the blower fan face each other, and a drive control unit that controls the drive of the blower fan based on the temperature of the conveyor belt detected by the temperature sensor.

[0083] <Appendix 4> The sheet drying device described in Appendix 3, wherein the blower fan and the temperature sensor are provided corresponding to each of a plurality of divided areas arranged in the width direction of the conveyor belt and set on the outer peripheral surface of the conveyor belt, and the drive control unit performs drive control of the blower fan based on the temperature detected by the temperature sensor for each of the divided areas.

[0084] <Appendix 5> The sheet drying device described in Appendix 3 or 4, further comprising: a pair of temperature sensors that detect the temperature of the conveying belt on both outer sides of the cooling area in the traveling direction; and a detection processing unit that detects an abnormality in the blower fan based on a difference between a temperature detected by a first temperature sensor of one of the pair of temperature sensors and a temperature detected by a second temperature sensor of the other of the pair of temperature sensors.

[0085] <Appendix 6> The sheet drying device described in Appendix 5, wherein the blower fan and the pair of temperature sensors are provided corresponding to each of a plurality of divided areas arranged in the width direction of the conveying belt set on the outer peripheral surface of the conveying belt, and the detection processing unit performs abnormality detection of the blower fan based on the difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor for each divided area.

[0086] <Appendix 7> The sheet drying apparatus according to claim 1, wherein the cooling section includes a water cooling device that circulates cooling water along a circulation path that passes through a hollow tension roller that tensions the conveyor belt.

[0087] <Appendix 8> The sheet drying device described in Appendix 7 includes a temperature sensor that detects the temperature of the conveying belt outside the heating area in the traveling direction and outside a contact area where the conveying belt and the tension roller are in contact, and a drive control unit that controls the drive of the water cooling device based on the temperature of the conveying belt detected by the temperature sensor.

[0088] <Appendix 9> The sheet drying device described in Appendix 8, comprising a pair of temperature sensors that detect the temperature of the conveying belt on both outsides of the contact area in the traveling direction, and a detection processing unit that detects an abnormality in the water cooling device based on the difference between the temperature detected by a first temperature sensor of one of the pair of temperature sensors and the temperature detected by a second temperature sensor of the other of the pair of temperature sensors.

[0089] <Appendix 10> An image forming apparatus comprising the sheet drying device according to any one of claims 1 to 9. [Explanation of symbols]

[0090] 1 Paper feed section 2 Image forming section 3 Drying equipment 4 Operation display section 5. Control section 21 Case 22 Sheet transport section 23 Drying unit 24 Cooling section 32 Conveyor belt 33 Drive roller 34 Driven roller 41 Blower fan 42 First temperature sensor 43 Second temperature sensor 51 Drive control unit 52 Detection processing section 61 Water cooling system 62 First temperature sensor 63 Second temperature sensor 71 Drive control unit 72 Detection processing section 100 Image forming device 200 Image forming device

Claims

1. an endless conveyor belt for conveying a sheet on which an ink image has been formed and which is placed on an outer peripheral surface of the conveyor belt; a heater provided opposite to an outer peripheral surface of the conveyor belt and configured to heat the sheet conveyed by the conveyor belt; a cooling unit that cools the conveyor belt outside a heating area where the conveyor belt and the heater face each other in a running direction of the conveyor belt; A sheet drying device comprising:

2. The cooling unit includes a blower fan provided opposite to an outer circumferential surface of the conveyor belt. The sheet drying apparatus according to claim 1.

3. a temperature sensor that detects a temperature of the conveyor belt outside the heating area in the traveling direction and outside a cooling area where the conveyor belt and the blower fan face each other; a drive control unit that controls the drive of the blower fan based on the temperature of the conveyor belt detected by the temperature sensor; The sheet drying apparatus according to claim 2 .

4. the blower fan and the temperature sensor are provided corresponding to each of a plurality of divided regions arranged in a width direction of the conveyor belt, the divided regions being set on an outer peripheral surface of the conveyor belt, the drive control unit executes drive control of the blower fan based on the temperature detected by the temperature sensor for each of the divided regions. The sheet drying apparatus according to claim 3.

5. a pair of temperature sensors for detecting a temperature of the conveyor belt on both outer sides of the cooling area in the traveling direction; a detection processing unit that detects an abnormality in the blower fan based on a difference between a temperature detected by a first temperature sensor of the pair of temperature sensors and a temperature detected by a second temperature sensor of the other of the pair of temperature sensors; The sheet drying apparatus according to claim 3 .

6. the blower fan and the pair of temperature sensors are provided corresponding to each of a plurality of divided regions arranged in a width direction of the conveyor belt on an outer peripheral surface of the conveyor belt, the detection processing unit detects an abnormality in the blower fan based on a difference between a temperature detected by the first temperature sensor and a temperature detected by the second temperature sensor for each of the divided regions. The sheet drying apparatus according to claim 5.

7. The cooling unit includes a water cooling device that circulates cooling water along a circulation path that passes through a hollow tension roller that tensions the conveyor belt. The sheet drying apparatus according to claim 1.

8. a temperature sensor for detecting a temperature of the conveyor belt outside the heating area in the traveling direction and outside a contact area where the conveyor belt contacts the tension roller; a drive control unit that controls the drive of the water cooling device based on the temperature of the conveyor belt detected by the temperature sensor; The sheet drying apparatus according to claim 7 .

9. a pair of temperature sensors for detecting a temperature of the conveyor belt on both outer sides of the contact area in the traveling direction; a detection processing unit that detects an abnormality in the water-cooling device based on a difference between a temperature detected by a first temperature sensor of the pair of temperature sensors and a temperature detected by a second temperature sensor of the other of the pair of temperature sensors; The sheet drying apparatus according to claim 8 .

10. The sheet drying device according to any one of claims 1 to 9, Image forming device.

Images