Drying device and image forming system

Abstract

To detect abnormality of a heater by a simple configuration without increasing cost.SOLUTION: The drying device 2 includes a conveyance belt 30, a conveyance support plate 40, a heater 50, a sealed metal tube 60, a pressure sensor 70, an air-cooling fan 80, and a control unit 26. The sealed metal tube 60 is provided on the conveyance support plate 40 so as to face the heater 50 and so that one end portion in the longitudinal direction is located at a position away from the heater 50. The pressure sensor 70 is provided at one end in the longitudinal direction of the sealed metal tube 60. The air-cooling fan 80 blows air to one end in the longitudinal direction of the sealed metal tube 60. The controller 26 determines the presence or absence of an abnormality of the heater 50 based on the detection result of the pressure sensor 70.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a drying device and an image forming system, and more particularly to a technique for detecting an abnormality in a heater. [Background technology]

[0002] A drying device is known that uses a heater to dry ink on paper on which an image has been formed by an inkjet printer. Techniques for detecting the temperature of the heater in such a drying device are known.

[0003] For example, Patent Document 1 discloses a technique for detecting the temperature of a drying area by a thermistor provided above a halogen lamp and facing the halogen lamp.

[0004] Patent Document 2 discloses a technique for detecting the surface temperature of a heating roller by two temperature sensors provided near both ends of the heating roller in the axial direction.

[0005] Patent Documents 3 and 4 disclose techniques for detecting the temperature of a heat roller using a first infrared sensor provided above one widthwise end of the heat roller and a second infrared sensor provided above the other widthwise end of the heat roller. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-96727 [Patent Document 2] Patent Publication No. 2021-30516 [Patent Document 3] Patent Publication No. 2021-79663 [Patent Document 4] Patent Publication No. 2021-146601 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, in order to accurately detect the heater temperature, it is desirable to place a sensor near the heater, as in the techniques disclosed in Patent Documents 1 to 4. However, there are cases where the temperature near the heater exceeds the allowable temperature of the semiconductor element that constitutes the sensor. In such cases, the sensor may be damaged, making it unable to accurately detect the heater temperature, which may result in malfunctions such as component melting or fire.

[0008] One possible method for placing the sensor closer to the heater is to use a sensor made of a highly heat-resistant material, but this method has the drawbacks of making it difficult to select the sensor and increasing costs.

[0009] The technology disclosed in Patent Document 1 uses an intake fan to cool the halogen lamp in order to prevent the temperature around the halogen lamp from rising. However, this method requires the installation of a separate intake fan, which makes the configuration more complicated and does not solve the above problem if a malfunction occurs in the intake fan.

[0010] The present invention has been made in view of the above circumstances, and has as its object to detect an abnormality in a heater with a simple configuration without increasing costs. [Means for solving the problem]

[0011] A drying device according to one aspect of the present invention comprises an endless conveying belt that conveys paper along a predetermined paper conveying direction, a conveying support plate that is provided inside the conveying belt so that its upper surface contacts the inner surface of the conveying belt, a heater that is provided above the conveying belt, a sealed metal tube that is provided on the conveying support plate opposite the heater and has one longitudinal end that is positioned away from the heater, a pressure sensor that is provided at one longitudinal end of the sealed metal tube and detects the pressure inside the sealed metal tube, an air-cooling fan that blows air toward one longitudinal end of the sealed metal tube, and a control unit that determines whether or not there is an abnormality in the heater based on the detection results of the pressure sensor.

[0012] An image forming system according to another aspect of the present invention includes an image forming apparatus that ejects ink onto paper to form an image, and the drying device described above. [Effects of the Invention]

[0013] According to the present invention, the presence or absence of a heater abnormality is determined using the pressure inside the sealed metal tube detected by the pressure sensor. This allows the pressure sensor to be located away from the area heated by the heater, and measurements can be performed while the pressure sensor is cooled to below the allowable temperature of the semiconductor. Therefore, compared to when a temperature sensor is installed near the heated area, heater abnormalities can be detected with a simpler configuration and without increasing costs. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an image forming system. [Figure 2] FIG. 2 is a block diagram showing the internal configuration of the image forming apparatus and the drying device. [Figure 3] FIG. 2 is a simplified front view showing part of the configuration of the drying mechanism. [Figure 4] FIG. 2 is a top view showing the positional relationship between a heater and a pressure sensor. [Figure 5] FIG. 4 is a side view showing the positional relationship between a heater, a pressure sensor, and an air-cooling fan. [Figure 6] FIG. 1 is a diagram illustrating an example of a pressure sensor. [Figure 7] 10 is a flowchart showing an abnormality detection process. [Figure 8] FIG. 10 is a diagram showing an example of a first warning screen. [Figure 9] FIG. 10 is a diagram showing an example of a second warning screen. DETAILED DESCRIPTION OF THE INVENTION

[0015] [Configuration of image forming system 100] An image forming system 100 according to one embodiment of the present invention will be described below with reference to the drawings. As shown in Figures 1 and 2, the image forming system 100 includes an image forming apparatus 1 and a drying apparatus 2.

[0016] [Configuration of image forming apparatus 1] 1, the image forming apparatus 1 is an inkjet recording apparatus and includes an image reading unit 11, an image forming unit 12, a transport unit 13, a paper feed unit 14, a transport mechanism 15, a display unit 16, and an operation unit 17.

[0017] The image reading unit 11 reads an original document using a moving original document method or a fixed original document method to generate image data. The image forming unit 12 forms a color image by ejecting ink droplets from line heads corresponding to the colors yellow, magenta, cyan, and black onto a sheet of paper P conveyed by a conveying unit 13. Note that the sheet of paper P is not limited to paper media and may be, for example, an overhead projector (OHP) sheet.

[0018] The transport unit 13 transports the paper P fed by the paper feed unit 14 by adsorbing it to the transport belt 13A. The paper feed unit 14 pulls out the paper P stored in a paper feed cassette or a manual feed tray using a pickup roller and feeds the paper to the transport path T.

[0019] The transport mechanism 15 includes a plurality of transport roller pairs 15A, a discharge roller pair 15B, and a transport motor. The transport mechanism 15 rotates the transport roller pairs 15A and the discharge roller pair 15B by driving the transport motor, transporting the paper P along the transport path T and sending it out toward the drying device 2.

[0020] The display unit 16 is a display device configured by a liquid crystal display, an organic EL (organic light-emitting diode) display, etc. The display unit 16 displays various screens.

[0021] The operation unit 17 includes a plurality of hard keys such as a start key, etc. The operation unit 17 also includes a touch panel that is placed over the display unit 16. A user's instructions are input to the operation unit 17.

[0022] 2, the image forming apparatus 1 further includes a control unit 18, a storage unit 20, an interface unit 21, and a communication unit 22. The control unit 18 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like.

[0023] The processor is, for example, a central processing unit (CPU), a micro processing unit (MPU), or an application specific integrated circuit (ASIC).

[0024] The control unit 18 functions as a control unit 19 by the processor executing a control program stored in the ROM or storage unit 20. The control unit 19 controls the operation of each unit of the image forming apparatus 1.

[0025] The control unit 19 may be configured by a logic circuit, and may be realized by a plurality of control units, without relying on the operation based on the control program.

[0026] The control unit 18 is electrically connected to the image reading unit 11, the image forming unit 12, the conveying unit 13, the paper feeding unit 14, the conveying mechanism 15, the display unit 16, the operation unit 17, the memory unit 20, the interface unit 21, and the communication unit 22.

[0027] The storage unit 20 is a storage device such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive), etc. The storage unit 20 stores various control programs for realizing general operations of the image forming apparatus 1, together with various data.

[0028] The drying device 2 is connected to the interface unit 21. The interface unit 21 includes a plurality of terminals for electrically connecting to the drying device 2.

[0029] The communication unit 22 includes a communication module such as a LAN (Local Area Network) board. The control unit 19 performs data communication via the communication unit 22 with an external device such as a PC (Personal Computer) 22A connected via a network.

[0030] Each part of the image forming apparatus 1 is connected to a power source, and each part of the image forming apparatus 1 operates when power is supplied from the power source.

[0031] [Configuration of Drying Device 2] 1, the drying device 2 includes a housing 23 having an inlet 23A formed on a first side surface facing the image forming device 1 and an outlet 23B formed on a second side surface opposite the first side surface. An outlet tray 23C is provided below the outlet 23B on the second side surface of the housing 23.

[0032] The drying device 2 includes a drying mechanism 200 and a discharge roller pair 24 inside a housing 23. The drying mechanism 200 heats and dries the ink ejected onto the paper P. The discharge roller pair 24 discharges the paper P from a discharge port 23B to a discharge tray 23C.

[0033] [Drying mechanism 200] Next, the detailed configuration of the drying mechanism 200 will be described with reference to Figures 3 to 5. As shown in Figures 3 to 5, the drying mechanism 200 includes a conveyor belt 30, a conveyor support plate 40, a heater 50, a sealed metal tube 60, a pressure sensor 70, and an air-cooling fan 80.

[0034] The conveyor belt 30 is an endless belt that is stretched over a drive roller 32A and a driven roller 32B. The drive roller 32A is driven by a drive motor to rotate counterclockwise on the paper. The conveyor belt 30 rotates counterclockwise on the paper in response to the rotation of the drive roller 32A. The driven roller 32B rotates counterclockwise on the paper in response to the rotation of the conveyor belt 30.

[0035] The conveyor belt 30 conveys the paper P conveyed from the image forming apparatus 1 through the carry-in entrance 23A in the paper conveyance direction X1 toward the carry-out exit 22B. Hereinafter, the direction perpendicular to the paper conveyance direction X1 will be referred to as the "paper width direction X2."

[0036] The transport support plate 40 is provided inside the transport belt 30 so that its upper surface contacts the inner peripheral surface of the transport belt 30. The length of the transport support plate 40 in the paper width direction X2 is formed to be approximately the same as the length of the transport belt 30 in the paper width direction X2. The transport belt 30 and the transport support plate 40 have a large number of ventilation holes formed therein.

[0037] A plurality of suction fans 34 are provided inside the conveyor belt 30. When the plurality of suction fans 34 are driven, the paper P on the conveyor belt 30 is sucked through the numerous air holes. As a result, the paper P on the conveyor belt 30 is conveyed in the paper conveying direction X1 while being adsorbed onto the conveyor belt 30.

[0038] A plurality of heaters 50 are provided above the conveyor belt 30. Each heater 50 is formed in a rod or strip shape, and is, for example, a halogen heater, a carbon heater, or an infrared heater. The heaters 50 are arranged at intervals in the paper conveyance direction X1, with their longitudinal direction aligned with the paper width direction X2.

[0039] The heaters 50 heat the paper P on the conveyor belt 30 from above the conveyor belt 30. When heated by the heaters 50, the water content of the ink on the paper P evaporates, and the pigment of the ink is fixed onto the paper P.

[0040] A plurality of sealed metal tubes 60 are provided on the conveyance support plate 40. The sealed metal tubes 60 are arranged opposite the heaters 50 at intervals in the paper conveyance direction X1, with their longitudinal directions aligned along the paper width direction X2.

[0041] The longitudinal length of each sealed metal tube 60 is formed to be greater than the length of the conveyor belt 30 and the conveyor support plate 40 in the paper width direction X2. As shown in Figures 4 and 5, the sealed metal tube 60 is arranged so that one longitudinal end thereof protrudes outside the conveyor belt 30 and the conveyor support plate 40 and is located away from the heater 50.

[0042] The pressure sensor 70 is provided at one longitudinal end of the sealed metal tube 60. The pressure sensor 70 detects the pressure inside the sealed metal tube 60. There are no particular limitations on the type of pressure sensor 70 as long as it is a sensor that can detect the pressure inside the sealed metal tube 60, and an example of the pressure sensor 700 is shown in FIG. 6. The pressure sensor 700 includes a diaphragm membrane 701 provided on the inner wall of the sealed metal tube 60, and a strain detection sensor 702 that detects deformation of the diaphragm membrane 701.

[0043] When the pressure inside the sealed metal tube 60 increases with an increase in the internal temperature of the sealed metal tube 60, a pressure difference occurs between the inside and outside of the sealed metal tube 60, causing the diaphragm membrane 701 to deform in the direction X3 outside the sealed metal tube 60. The resistor of the strain detection sensor 702 outputs an electrical signal corresponding to the change in resistance value according to the strain of the diaphragm membrane 701.

[0044] 5, an air-cooling fan 80 is provided above one longitudinal end of each sealed metal tube 60. Each air-cooling fan 80 blows air toward one longitudinal end of each sealed metal tube 60, thereby air-cooling one longitudinal end of each sealed metal tube 60. This cools the temperature of one longitudinal end of each sealed metal tube 60 so that it is below the allowable temperature of the semiconductor that makes up the pressure sensor 70.

[0045] 2, the drying device 2 further includes a control unit 25, a memory unit 27, a drive unit 28, and an interface unit 29. The control unit 25 includes a processor, RAM, ROM, etc. The processor is, for example, a CPU, an MPU, or an ASIC, etc.

[0046] The control unit 25 functions as a control unit 26 by the processor executing a control program stored in the ROM or memory unit 27. The control unit 26 controls the operation of each part of the drying device 2. The control unit 26 also executes an abnormality detection process to determine whether or not there is an abnormality in the heater 50 based on the detection result of the pressure sensor 70.

[0047] The control unit 26 may be configured by a logic circuit, rather than by operations based on the control program, or may be configured to be realized by a plurality of control units.

[0048] The control unit 25 is electrically connected to the memory unit 27, the drive unit 28, the interface unit 29, the suction fan 34, the heater 50, the pressure sensor 70, and the air-cooling fan 80.

[0049] The storage unit 27 is a storage device such as an SSD or an HDD. The storage unit 27 stores, together with various data, various control programs for realizing general operations of the drying device 2. The storage unit 27 stores, as one of the various control programs, a detection program for executing the abnormality detection process according to this embodiment.

[0050] The drive unit 28 includes a plurality of drive motors. The drive unit 28 drives each of the drive motors to rotate the pair of discharge rollers 24 and the drive roller 32A.

[0051] The image forming apparatus 1 is connected to the interface section 29. The interface section 29 includes a plurality of terminals for electrically connecting with the image forming apparatus 1.

[0052] Each part of the drying device 2 is connected to a power source, and each part of the drying device 2 operates when power is supplied from the power source.

[0053] [Operation] Hereinafter, the operation of the image forming system 100 when the abnormality detection process is executed will be described with reference to FIGS.

[0054] When the control unit 19 of the image forming apparatus 1 receives image data and an instruction to execute a print job from the PC 22A via the communication unit 22, the control unit 19 operates the image forming unit 12, the transport unit 13, the paper feed unit 14, and the transport mechanism 15 to execute a printing process for forming an image indicated by the received image data on the paper P. The control unit 19 also transmits an instruction to start a drying process to the drying device 2 via the interface unit 21.

[0055] When the control unit 26 of the drying device 2 receives an instruction to start the drying process via the interface unit 29, it drives the drive motor to rotate the drive roller 32A counterclockwise on the paper, thereby rotating the conveying belt 30 and the driven roller 32B counterclockwise on the paper.

[0056] The control unit 26 also turns on the heater 50 and drives the suction fan 34 to start the air blowing operation, thereby starting the drying process for heating and drying the ink on the paper P while suction-transporting the paper P on the transport belt 30.

[0057] When the control unit 26 turns on the heater 50, it starts executing the abnormality detection process shown in Figure 7 and repeats the process of determining that a predetermined time (e.g., 10 seconds) has not elapsed since the heater 50 was turned on (NO in step S10) until the predetermined time has elapsed.

[0058] When, for example, 10 seconds have passed since the heater 50 was turned on, the control unit 26 determines that a predetermined time has passed (YES in step S10) and acquires the pressure p inside each sealed metal tube 60 based on the detection results of each pressure sensor 70 (step S11).

[0059] After the process of step S11, the control unit 26 uses the acquired pressures p to calculate the temperature T of each sealed metal tube 60 based on the equation of state of an ideal gas shown in the following formula (1) (step S12).

[0060] [Number 1] pV=nRT…Equation (1)

[0061] In equation (1), p is pressure, V is gas volume (ml), n is gas amount (mol), T is absolute temperature, and R is molar gas constant. Here, since the inside of the sealed metal tube 60 is sealed, the volume V, amount of substance n, and molar gas constant R are constant values. Therefore, once the control unit 26 acquires the pressure p detected by the pressure sensor 70, it can calculate the temperature T of each sealed metal tube 60 based on equation (1).

[0062] (1) When all temperatures T are within the range of the reference temperature Ts When all heaters 50 are operating normally in their normal positions, the temperature rise rates of all heaters 50 are approximately the same, and the calculated values ​​of each temperature T are within a range of a reference temperature Ts defined by a predetermined lower limit value (e.g., 90°C) and a predetermined upper limit value (e.g., 110°C).

[0063] In this case, the control unit 26 determines that none of the calculated temperatures T exceeds the reference temperature Ts (NO in step S13), and also determines that none of the calculated temperatures T is below the reference temperature Ts (NO in step S14), and terminates the abnormality detection process.

[0064] When the printing process is completed, the control unit 19 of the image forming apparatus 1 transmits an instruction to end the drying process to the drying device 2 via the interface unit 21. When the control unit 26 of the drying device 2 receives the instruction to end the drying process via the interface unit 29, it turns off the heater 50 and stops driving the drive motor and the suction fan 34, thereby completing the drying process.

[0065] (2) When the calculated temperature T exceeds the range of the reference temperature Ts For example, suppose that the heater 50 located third from the upstream side in the paper transport direction X1 (hereinafter referred to as the "third heater 50") is not fixed properly and has moved to a position closer to the transport belt 30 than the predetermined normal position.

[0066] In such a case, the amount of energy supplied to the sealed metal tube 60 facing the third heater 50 (hereinafter referred to as the "third sealed metal tube 60") becomes excessive compared to normal, so the temperature of the third sealed metal tube 60 rises faster than that of the other sealed metal tubes 60 and becomes very high.

[0067] If the control unit 26 calculates the temperature T of the third sealed metal tube 60 to be, for example, 140°C, it determines that there is a temperature T that exceeds the reference temperature Ts (YES in step S13), turns off the heater 50, and stops driving the drive motor and suction fan 34, thereby stopping the execution of the drying process (step S15).

[0068] After the process of step S15, control unit 26 transmits a display instruction for first warning screen 800 shown in Fig. 8 to image forming apparatus 1 via interface unit 29 (step S16). After the process of step S16, control unit 26 proceeds to the process of step S14.

[0069] When the control unit 19 of the image forming apparatus 1 receives the display instruction via the interface unit 29, it causes the display unit 16 to display a first warning screen 800. The control unit 19 causes the display unit 15 to display, on the first warning screen 800, information 801 for identifying the third heater 50 and information 802 indicating the cause of the temperature T of the third sealed metal tube 60 exceeding the reference temperature Ts.

[0070] (3) When the calculated temperature T is below the range of the reference temperature Ts For example, it is assumed that the fifth heater 50 counting from the upstream side in the paper transport direction X1 (hereinafter referred to as the "fifth heater 50") is not lit due to a malfunction such as a broken wire.

[0071] In such a case, the amount of energy supplied to the sealed metal tube 60 facing the fifth heater 50 (hereinafter referred to as the "fifth sealed metal tube 60") is less than normal, so the rate of temperature rise of the fifth sealed metal tube 60 is slower than that of the other sealed metal tubes 60, and the fifth sealed metal tube 60 becomes colder.

[0072] If the control unit 26 calculates the temperature T of the fifth sealed metal tube 60 to be, for example, 70°C, it determines that the temperature T is lower than the reference temperature Ts (YES in step S14), and stops the execution of the drying process in the same manner as described above (step S17).

[0073] After the process of step S17, control unit 26 transmits a display instruction for second warning screen 900 shown in Fig. 9 to image forming apparatus 1 via interface unit 29 (step S18). After the process of step S18, control unit 26 ends the abnormality detection process.

[0074] When the control unit 19 of the image forming apparatus 1 receives the display instruction via the interface unit 29, it causes the display unit 16 to display a second warning screen 900. The control unit 19 causes the display unit 15 to display, on the second warning screen 900, information 901 for identifying the fifth heater 50 and information 902 indicating the cause why the temperature T of the fifth sealed metal tube 60 is lower than the reference temperature Ts.

[0075] According to the above embodiment, the control unit 26 determines whether or not there is an abnormality in the heater 50, using the pressure inside the sealed metal tube 60 detected by the pressure sensor 70. This allows the pressure sensor 70 to be located away from the area heated by the heater 50, and makes it possible to perform measurements while cooling the pressure sensor 70 so that it is below the allowable temperature of the semiconductor. Therefore, compared to when a temperature sensor is provided near the heated area, an abnormality in the heater 50 can be detected with a simpler configuration and without increasing costs.

[0076] Furthermore, according to the above embodiment, a plurality of heaters 50 are provided above the conveying belt 30, a plurality of sealed metal tubes 60 are provided on the conveying support plate 40 so as to face each heater 50, and a pressure sensor 70 is provided at one longitudinal end of each sealed metal tube 60.

[0077] This allows the ink to dry efficiently, and since abnormalities can be detected for each heater, recovery from abnormalities can be made even easier. Also, since the shape of each sealed metal tube 60 is not particularly limited as long as it is the same (it can be cylindrical or rectangular), design freedom is increased and placement and replacement are made easier.

[0078] Furthermore, according to the above embodiment, the control unit 26 calculates the temperature T of the sealed metal tube 60 using the pressure detected by the pressure sensor 70, and if the calculated temperature T exceeds the reference temperature Ts, detects an abnormality related to the position of the heater 50, and if the calculated temperature T is less than the reference temperature Ts, detects an abnormality related to the lighting of the heater 50.

[0079] This makes it possible to not only detect an abnormality in the heater 50 but also identify the cause of the abnormality with a simple configuration.

[0080] Furthermore, according to the above embodiment, the image forming system 100 includes the image forming apparatus 1 and the drying apparatus 2. This allows ink-based image formation to be performed with high safety.

[0081] (Other variations) In the above embodiment, one cooling fan 80 is provided for each sealed metal tube 60, but the present invention is not limited to such an embodiment. For example, two or more cooling fans 80 may be provided for each sealed metal tube 60. This further reduces the risk of damage to the pressure sensor 70, thereby further improving the reliability of detecting abnormalities in the heater 50.

[0082] In the above embodiment, the sealed metal pipe 60 is provided in a part of the conveyor support plate 40, but the present invention is not limited to such an embodiment. For example, the entire conveyor support plate 40 may be formed of the sealed metal pipe 60. This allows a single pressure sensor 70 to detect an abnormality in the heater 50, thereby enabling an abnormality in the heater 50 to be detected with an even simpler configuration and without increasing costs.

[0083] In the above embodiment, the sealed metal tube 60 is formed to extend in the paper width direction X2 without being divided, but the present invention is not limited to such an embodiment. For example, the sealed metal tube 60 may extend in the paper width direction X2 and be divided into two pieces with respect to the paper width direction X2. In this way, by comparing the values ​​of the pressure sensors 70 provided in each of the two divided sealed metal tubes 60, it becomes possible to detect the degree of movement of the heater 50 in the paper width direction X2.

[0084] The configuration and processing of the embodiment described above using FIGS. 1 to 9 are merely one embodiment of the present invention, and the present invention is not limited to these configurations and processing. [Explanation of symbols]

[0085] 1. Image forming device 2 Drying equipment 26 Control Unit 30 conveyor belt 40 Transport support plate 50 Heater 60 Sealed metal tube 70 Pressure Sensor 80 Cooling fan 100 Image forming system

Claims

1. an endless conveyor belt that conveys paper in a predetermined paper conveyance direction; a conveyor support plate provided inside the conveyor belt so that an upper surface of the conveyor support plate contacts an inner peripheral surface of the conveyor belt; a heater provided above the conveyor belt; a sealed metal tube that is provided on the conveying support plate so as to face the heater and have one longitudinal end spaced apart from the heater, and that has a sealed interior; a pressure sensor provided at one end of the sealed metal tube in the longitudinal direction and configured to detect a pressure inside the sealed metal tube; an air-cooling fan that blows air toward one longitudinal end of the sealed metal tube; a control unit that determines whether or not there is an abnormality in the heater based on the detection result of the pressure sensor.

2. A plurality of the heaters are provided above the conveyor belt, a plurality of the sealed metal pipes are provided on the conveying support plate so as to face the plurality of heaters, respectively; The drying device according to claim 1 , wherein the pressure sensor is provided at one longitudinal end of each of the plurality of sealed metal tubes.

3. The control unit Calculating the temperature of the sealed metal tube using the pressure detected by the pressure sensor; If the calculated temperature exceeds a predetermined reference temperature, an abnormality related to the position of the heater is detected; The drying device according to claim 1 , wherein an abnormality related to the lighting of the heater is detected when the calculated temperature is lower than the reference temperature.

4. an image forming device that ejects ink onto paper to form an image; An image forming system comprising the drying device according to claim 1.

Images