Drying device and image forming system

Abstract

This prevents the temperature of the heating element from rising due to malfunction of the control unit, and reliably prevents the inside of the drying device from becoming too high. [Solution] The drying device 3 comprises a housing 30 with an openable and closable cover member 34, a locking mechanism 40 that can restrict the opening of the cover member 34, a detection unit 50 that detects the release of the lock by the locking mechanism 40, a heater 68 that is provided inside the housing 30 and whose temperature rises when electricity is applied, a control unit 80 that controls the application of electricity to the heater 68 and the operation of the locking mechanism 40, and a protection circuit 100 that cuts off the flow of electricity to the heater 68 when the detection unit 50 detects the release of the lock.

Description

[Technical Field]

[0001] The present invention relates to a drying device and an image forming system, and more particularly to a technique for cutting off power to a heating member. [Background technology]

[0002] 2. Description of the Related Art In an apparatus having a heating element inside a housing, techniques are known for preventing a user from coming into contact with the heating element at a high temperature in order to ensure the safety of the user.

[0003] For example, Patent Document 1 discloses a technology in which the temperature of a drying promotion unit inside a housing is acquired from a temperature sensor, and if the acquired temperature exceeds a predetermined threshold, the opening operation of a cover member provided on the housing is restricted, and if the acquired temperature is below the predetermined threshold, the restriction on the opening operation of the cover member is lifted.

[0004] Patent document 2 discloses a technology in which the internal temperature of a housing having a heating unit inside is obtained from a temperature detection unit, and when the internal temperature exceeds a predetermined temperature, the outer cover is locked to prevent it from being opened, and when the internal temperature is below the predetermined temperature, the outer cover is unlocked to allow it to be opened. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-41598 [Patent Document 2] Japanese Patent Publication No. 2022-148189 Summary of the Invention [Problem to be solved by the invention]

[0006] In the techniques disclosed in Patent Documents 1 and 2, when the device is in a powered state and the processor that controls the power supply to the heating element is operating normally, there is no risk of the heating element heating up, for example, when a user reaches into the housing to clear a paper jam. However, there are cases where the processor malfunctions due to thermal runaway or the like, causing the heating element to heat up by mistake.

[0007] The present invention has been made in view of the above circumstances, and has an object to prevent the temperature of the heating member from rising due to malfunction of the control unit, and to reliably prevent the temperature inside the drying device from rising to a high temperature. [Means for solving the problem]

[0008] A drying device according to one aspect of the present invention includes a housing with an openable and closable cover member, a locking mechanism that can restrict the opening of the cover member, a heating element provided inside the housing and whose temperature increases when electricity is applied, a control unit that controls the application of electricity to the heating element and the operation of the locking mechanism, a detection unit that detects the release of the lock by the locking mechanism, and a cut-off mechanism that cuts off the flow of electricity to the heating element when the detection unit detects the release of the lock.

[0009] 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]

[0010] According to the present invention, when the cover member is unlocked, the power supply to the heating member is forcibly cut off, which prevents the temperature of the heating member from rising due to a malfunction of the control unit, thereby reliably preventing the temperature inside the drying device from becoming too high. [Brief explanation of the drawings]

[0011] [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 diagram illustrating the configuration of a housing. [Figure 4] FIG. 10 is a diagram showing the state of the locking mechanism when the lock is released. [Figure 5] 10A and 10B are diagrams illustrating the state of the locking mechanism when the cover member is locked. [Figure 6] FIG. 2 is a diagram illustrating a configuration of a detection unit. [Figure 7] FIG. 2 is a simplified front view showing part of the configuration of the drying mechanism. [Figure 8] FIG. 2 is a diagram showing the configuration of a heater circuit and a protection circuit. [Figure 9] 10 is a flowchart illustrating a lock control process. [Figure 10] 10 is a flowchart showing a paper jam resolution process. [Figure 11] FIG. 10 is a diagram showing a state when the heating part is raised. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Configuration of image forming system 1] An image forming system 1 including a drying device 3 according to one embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the image forming system 1 includes an image forming apparatus 2 and a drying device 3. The image forming apparatus 2 forms an image by ejecting ink onto paper P. The drying device 3 heats and dries the ink ejected onto paper P.

[0013] Below, the up-down direction is defined based on a typical installation state, as shown in Figure 1. In addition, in a typical installation state, the front side where the user stands during operation is defined as the front side, and the front-to-back direction is defined as the front. The direction perpendicular to the up-down and front-to-back directions is defined as the left-to-right direction, and the left and right sides are defined based on the direction the user faces during operation.

[0014] [Configuration of image forming device 2] 1, the image forming apparatus 2 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.

[0015] 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.

[0016] 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.

[0017] 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 3.

[0018] 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.

[0019] 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.

[0020] 2, the image forming apparatus 2 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.

[0021] The processor is, for example, a central processing unit (CPU), a micro processing unit (MPU), or an application specific integrated circuit (ASIC).

[0022] The control unit 18 functions as a control unit 19 when the processor executes 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 2. Note that the control unit 19 may be configured by a logic circuit, or may be realized by a plurality of control units, regardless of the operation based on the control program.

[0023] 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.

[0024] The storage unit 20 is a storage device such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive). The storage unit 20 stores various control programs for realizing general operations of the image forming apparatus 2, along with various data.

[0025] The drying device 3 is connected to the interface unit 21. The interface unit 21 includes a terminal for electrically connecting to the drying device 3.

[0026] The communication unit 22 includes a communication module such as a LAN (Local Area Network) board, etc. The control unit 19 performs data communication via the communication unit 22 with an external device such as a PC (Personal Computer) 22A connected to the network.

[0027] Each part of the image forming apparatus 2 is connected to a power supply, and each part of the image forming apparatus 2 operates when power is supplied from the power supply.

[0028] [Configuration of Drying Device 3] (Housing 30) As shown in Fig. 1, the drying device 3 includes a housing 30. An entrance 30A is formed on the side of the housing 30 facing the image forming device 2 (i.e., the right side), and an exit 30B is formed on the left side. A discharge tray 31 is provided below the exit 30B on the left side of the housing 30. A pair of discharge rollers 32 for discharging the paper P to the exit tray 31 is provided near the exit 30B.

[0029] As shown in Fig. 3, an opening 33 is formed in the front of the housing 30. The housing 30 is provided with a cover member 34 for covering the opening 33. The cover member 34 is a plate-shaped member, and is attached to the housing 30 via a hinge 35 fixed near the left end of the opening 33 in the housing 30. The cover member 34 is configured to be able to open and close the opening 33 by rotating around the hinge 35.

[0030] (locking mechanism 40) 4 and 5, the drying device 3 includes a locking mechanism 40 that can restrict the opening of the cover member 34. The locking mechanism 40 includes a hole 41, a lever member 42, and an actuator 43. The hole 41 is a notch formed in the upper end surface near the upper right corner of the cover member 34. The lever member 42 and the actuator 43 are provided inside the housing 30.

[0031] The lever member 42 is a rod-shaped member that is rotatable about a rotation shaft 44 that is provided at approximately the center in the longitudinal direction. The lever member 42 is provided on the front end side of the rotation shaft 44. The rotation shaft 44 is provided near the upper right corner of the cover member 34 so as to extend in the front-to-rear direction. A protrusion 45 that protrudes toward the hole 41 is provided on the left end of the lever member 42.

[0032] The actuator 43 is a drive unit operated by a solenoid. The actuator 43 includes a variable member 46 whose position varies in the up and down direction. The variable member 46 is connected to the right end of the lever member 42. When the control unit 80 shown in FIG. 2 energizes the actuator 43, the variable member 46 is pulled downward (in the direction of arrow A1). As a result, the lever member 42 rotates together with the rotating shaft 44 in a direction in which the protrusion 45 moves away from the hole 41, and takes the unlocked position shown in FIG. 4 in which the protrusion 45 is not fitted in the hole 41.

[0033] On the other hand, when the control unit 80 stops the supply of electricity to the actuator 43, the fluctuating member 46 is pushed upward (in the direction of arrow A2). As a result, the lever member 42 rotates together with the rotation shaft 44 in a direction in which the protrusion 45 approaches the hole 41, and assumes the locked position shown in Fig. 5 in which the protrusion 45 is fitted into the hole 41. In other words, the position of the fluctuating member 46 changes depending on whether the cover member 34 is locked or unlocked.

[0034] (Detection unit 50) 6, the drying device 3 includes a detection unit 50 for detecting the release of the lock by the locking mechanism 40. The detection unit 50 includes a PI (Photo Interrupter) sensor 51 and a shielding plate 52. The PI sensor 51 includes a light-emitting element 51A and a light-receiving element 51B that are disposed facing each other so that the shielding plate 52 passes between them. The shielding plate 52 is, for example, a fan-shaped plate-like member that is provided at the longitudinal rear end of the rotation shaft 44 that rotates together with the lever member 42.

[0035] The detection unit 50 is configured to output an ON signal when it detects the shielding plate 52 (here, when the cover member 34 is locked), and to output an OFF signal when it does not detect the shielding plate 52 (here, when the cover member 34 is unlocked).

[0036] In this way, the detection unit 50 detects the release of the lock by indirectly detecting the position of the variable member 46 by detecting the rotation of the rotation shaft 44. Note that the detection unit 50 is not limited to a PI sensor as long as it is a sensor that can detect the position of the variable member 46, and may be, for example, a mechanical sensor configured to physically detect contact with the variable member 46.

[0037] (Drying mechanism 60) 1 and 7, the drying device 3 includes a drying mechanism 60 and a temperature sensor 70 inside a housing 30. The drying mechanism 60 includes a conveying unit 61 and a heating unit 62. The conveying unit 61 conveys the paper P. The heating unit 62 heats the paper P being conveyed by the conveying unit 61.

[0038] Specifically, the conveying unit 61 includes a conveying belt 63, a driving roller 64A, a driven roller 64B, a conveying support plate 65, and a plurality of suction fans 66. The conveying belt 63 is an endless belt that is stretched over the driving roller 64A and the driven roller 64B. The driving roller 64A rotates counterclockwise on the page by being driven by a first driving motor of the driving unit 83 shown in FIG.

[0039] The conveyor belt 63 rotates counterclockwise on the paper surface, driven by the rotation of the drive roller 64A. The driven roller 64B rotates counterclockwise on the paper surface, driven by the rotation of the conveyor belt 63. The conveyor belt 63 conveys the paper P conveyed from the image forming device 2 via the carry-in entrance 30A toward the discharge exit 30B. The paper P conveyed toward the discharge exit 30B is discharged by the discharge roller pair 32 through the discharge exit 30B onto the discharge tray 31.

[0040] The transport support plate 65 is provided inside the transport belt 63 so that its upper surface contacts the inner peripheral surface of the transport belt 63. The length of the transport support plate 65 in the paper width direction is formed to be approximately the same as the length of the transport belt 63 in the paper width direction. Here, the paper width direction refers to the direction perpendicular to the paper transport direction. The transport belt 63 and the transport support plate 65 have a large number of ventilation holes formed therein.

[0041] The plurality of suction fans 66 are provided inside the conveyor belt 63. When the plurality of suction fans 66 are driven by the control unit 80, the paper P on the conveyor belt 63 is sucked through the numerous air holes. As a result, the paper P is conveyed while being adsorbed onto the conveyor belt 63.

[0042] The heating unit 62 includes a housing 67 and a plurality of heaters 68. The housing 67 is provided above the conveyor belt 63. The housing 67 is a box-shaped member that is open at the bottom. The housing 67 is configured to be movable up and down by an elevation mechanism connected to a second drive motor of the drive unit 83.

[0043] The heaters 68 are heating elements whose temperature rises when energized. The heaters 68 are rod-shaped or strip-shaped, and are, for example, halogen heaters, carbon heaters, or infrared heaters. The heaters 68 are fixed in a row within the housing 67 at intervals in the paper transport direction, with their longitudinal direction aligned with the paper width direction.

[0044] The heaters 68 heat the paper P on the conveyor belt 63 from above the conveyor belt 63. When heated by the heaters 68, the water content of the ink on the paper P evaporates, and the pigment of the ink is fixed onto the paper P.

[0045] (Temperature sensor 70) 7, the temperature sensor 70 is provided near the drying mechanism 60. The temperature sensor 70 measures the temperature near the drying mechanism 60 and outputs the measured temperature to the control unit 81 shown in FIG.

[0046] (cooling mechanism) 1 again, the drying device 3 includes an air-cooling fan 36 inside the housing 30. The air-cooling fan 36 is provided below the drying mechanism 60 and blows air from below toward the drying mechanism 60 to cool the drying mechanism 60. The drying device 3 may further include an exhaust mechanism that exhausts air inside the housing 30 to the outside.

[0047] 2 again, the drying device 3 includes a control unit 81, a storage unit 82, a drive unit 83, and an interface unit 84. The control unit 81 includes a processor, RAM, ROM, etc. The processor is, for example, a CPU, an MPU, or an ASIC, etc.

[0048] The control unit 81 functions as a control unit 80 by the processor executing a control program stored in the ROM or the storage unit 82. The control unit 80 controls the operation of each unit of the drying device 3. For example, the control unit 80 controls the supply of electricity to the heater 68 and the operation of the locking mechanism 40.

[0049] The control unit 80 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.

[0050] The control unit 81 is electrically connected to the cooling fan 36 , the actuator 43 , the suction fan 66 , the heater 68 , the temperature sensor 70 , the memory unit 82 , the drive unit 83 , and the interface unit 84 .

[0051] The storage unit 82 is a storage device such as an SSD or an HDD. The storage unit 82 stores various control programs for realizing general operations of the drying device 3, along with various data.

[0052] The drive unit 83 includes a plurality of drive motors. The drive unit 83 drives each drive motor to rotate the drive roller 64A, raise and lower the housing 67, or rotate the pair of discharge rollers 32.

[0053] The image forming apparatus 2 is connected to the interface section 84. The interface section 84 includes a terminal for electrically connecting with the image forming apparatus 2.

[0054] Each part of the drying device 3 is connected to a power source, and each part of the drying device 3 operates when power is supplied from the power source.

[0055] (heater circuit 90) 8, the drying device 3 includes a heater circuit 90 that allows a control unit 80 to control the supply of electricity to the heater 68. The heater circuit 90 includes a power supply line L1 that supplies power from a commercial power source 91 to the heater 68. The power supply line L1 connects the commercial power source 91, the heater 68, an SSR (Solid State Relay) 92, and a relay circuit 93 in series in this order.

[0056] The SSR 92 is connected to a FET (Field Effect Transistor) 94 via a signal line L2. The FET 94 switches on and off the conduction of the power supply line L1 by switching on and off the SSR 92 and the relay circuit 93. The control unit 81 is connected to the FET 94 via a signal line L3. The control unit 80 controls the supply of electricity to the heater 68 via the signal line L3.

[0057] Specifically, when the control unit 80 outputs a high signal S1 to the FET 94 via the signal line L3, the FET 94 switches on the SSR 92 and the relay circuit 93. This brings the power supply line L1 into conduction, and the heater 68 lights up.

[0058] When the control unit 80 outputs a LOW signal S2 to the FET 94 via the signal line L3, the FET 94 switches off the SSR 92 and the relay circuit 93. This cuts off the electrical continuity of the power supply line L1, and the heater 68 turns off.

[0059] (Protection circuit 100) In this embodiment, the drying device 3 includes a protection circuit 100 as a cutoff mechanism that cuts off power to the heater 68 when the detection unit 50 detects that the lock has been released. The protection circuit 100 includes an NPN bipolar transistor 101 that is connected to the signal line L3 via the signal line L4.

[0060] The bipolar transistor 101 is connected to the PI sensor 51 via a signal line L5. The bipolar transistor 101 is also grounded via a signal line L6. When the PI sensor 51 outputs an OFF signal S3 via the signal line L5 (i.e., when the cover member 34 is unlocked), the bipolar transistor 101 turns on, bringing the heater circuit 90 and the protection circuit 100 into conduction. In this way, the protection circuit 100 grounds the signal line L3.

[0061] On the other hand, when the PI sensor 51 outputs an ON signal S4 via the signal line L5 (i.e., when the cover member 34 is locked), the bipolar transistor 101 is turned off, cutting off the electrical continuity between the heater circuit 90 and the protection circuit 100. In this case, the control unit 80 can input a high signal S1 or a low signal S2 to the FET 94 via the signal line L3.

[0062] [Operation] Hereinafter, the operation of the image forming system 1 when a paper jam occurs will be described with reference to FIGS.

[0063] In the following description, when the drying device 3 is powered on, the control unit 80 outputs a LOW signal S2 to the FET 94 via the signal line L3 to turn off the heater 68. Also, it is assumed that the cover member 34 is in an unlocked state and the control unit 80 is not activating the PI sensor 51. In this case, the conduction between the heater circuit 90 and the protection circuit 100 is cut off.

[0064] In this situation, when the control unit 19 of the image forming apparatus 2 receives image data and an instruction to execute a print job from the PC 22A via the communication unit 22, it operates the image forming unit 12, the transport unit 13, the paper feed unit 14, the transport mechanism 15, etc. to execute a printing process for forming an image indicated by the received image data on the paper P. The control unit 19 also sends an instruction to start a drying process to the drying device 3 via the interface unit 21.

[0065] When the control unit 80 of the drying device 3 receives an instruction to start the drying process via the interface unit 84, it drives the first drive motor to rotate the drive roller 64A counterclockwise on the paper, thereby rotating the conveying belt 63 and the driven roller 64B counterclockwise on the paper.

[0066] The control unit 80 further switches the signal output to the FET 94 via the signal line L3 from a low signal S2 to a high signal S1, thereby turning on the heater 68 and driving the suction fan 66 to start blowing air. This starts the drying process for heating and drying the ink on the paper P being transported by the transport unit 61.

[0067] 9, and determines whether the temperature measured by the temperature sensor 70 is below a predetermined reference temperature (step S10). The reference temperature is not particularly limited as long as it is a temperature that is predetermined as a high temperature, but here it is assumed that 50°C is set.

[0068] Until the temperature measured by the temperature sensor 70 reaches the reference temperature, the control unit 80 determines that the measured temperature is below the reference temperature (YES in step S10), maintains the power supply to the actuator 43, rotates the lever member 42 to a position where it assumes the unlocked posture shown in Figure 4, and maintains the cover member 34 in the unlocked state (step S11).

[0069] When the temperature measured by temperature sensor 70 reaches the reference temperature due to the temperature rise of heater 68, control unit 80 determines that the measured temperature is not below the reference temperature (NO in step S10), stops the supply of electricity to actuator 43, and rotates lever member 42 to a position where it assumes the locked posture shown in Fig. 5, thereby locking cover member 34 (step S12). After processing step S11 or step S12, control unit 80 returns to processing step S10.

[0070] When the control unit 80 starts the drying process, it also starts the paper jam resolution process shown in Figure 10 and repeats the process of determining that a paper jam has not occurred (NO in step S20) and the process of determining that an instruction to end the drying process has not been received (NO in step S21) until it detects the occurrence of a paper jam based on the detection results of a paper detection sensor located near the conveyor belt 63, for example, or until it receives an instruction to end the drying process.

[0071] If the control unit 80 receives an instruction to end the drying process from the image forming device 2 that has finished the printing process via the interface unit 84 without detecting the occurrence of a paper jam (YES in step S21), the control unit 80 ends the paper jam resolution process, turns off the heater 68, and stops driving the first drive motor and the suction fan 66, thereby ending the drying process. The control unit 80 also ends the lock control process.

[0072] On the other hand, for example, if the paper detection sensor does not output a non-detection of paper P within a predetermined time after detecting paper P, the control unit 80 determines that a paper jam has occurred (YES in step S20) and activates the PI sensor 51 (step S22).

[0073] At this time, the lever member 42 is in the locked position, so the PI sensor 51 outputs the ON signal S4 via the signal line L5, and the bipolar transistor 101 is turned off, maintaining the state in which the conduction between the heater circuit 90 and the protection circuit 100 is interrupted.

[0074] After the process of step S22, the control unit 80 switches the signal output to the FET 94 via the signal line L3 from the High signal S1 to the Low signal S2, thereby turning off the heater 54 (step S23).

[0075] After processing step S23, the control unit 80 stops driving the first drive motor of the drive unit 83 and the suction fan 66, thereby stopping the suction transport of the paper P (step S24). After processing step S24, the control unit 80 drives the second drive motor of the drive unit 83 and causes the lifting mechanism to raise the heating unit 62, thereby moving the heating unit 62 from the normal position to a retracted position away from the transport unit 61 (step S25).

[0076] 11, a space SP is formed between the conveying section 61 and the heating section 62 for the user to insert their hand and remove the paper P. After the process of step S25, the control section 80 starts cooling the conveying belt 63 by driving the cooling fan 36 to start the air blowing operation (step S26). After the process of step S26, the control section 80 ends the paper jam resolution process.

[0077] When the heater 68 is turned off and the air-cooling fan 36 is blowing air, the internal temperature of the housing 30 is cooled and the temperature measured by the temperature sensor 70 becomes lower than the reference temperature (YES in step S10), the control unit 80 starts to apply electricity to the actuator 43, rotates the lever member 42 to a position where it assumes the unlocked posture shown in Figure 4, and puts the cover member 34 in the unlocked state (step S11).

[0078] When the lever member 42 assumes the unlocked position, the PI sensor 51 outputs an OFF signal S3 via the signal line L5, which turns on the bipolar transistor 101 and connects the heater circuit 90 and the protection circuit 100 to each other, thereby grounding the signal line L3.

[0079] In this situation, suppose that an abnormality occurs in the processor of the control unit 81, causing the control unit 80 to malfunction and switch the signal output to the FET 94 via the signal line L3 from a low signal S2 to a high signal S1. However, because the signal line L3 is grounded, the high signal S1 is not input to the FET 94, and the heater 68 does not light up.

[0080] Therefore, even if the control unit 80 is outputting a high signal S1 due to a malfunction, the user can open the cover member 34 and reach into the space SP to remove the paper P without the heater 68 being turned on.

[0081] For example, when the paper P is removed and the paper detection sensor outputs a non-detection of the paper P (i.e., when the paper jam is resolved), the control unit 80 drives the second drive motor of the drive unit 83 to lower the heating unit 62 using the lifting mechanism, thereby returning the heating unit 62 from the retracted position to the normal position. The control unit 80 also stops driving the cooling fan 36. The control unit 80 then ends the lock control process.

[0082] According to the above embodiment, the drying device 3 includes a housing 30 having an openable and closable cover member 34, a locking mechanism 40 that can restrict the opening of the cover member 34, a detection unit 50 that detects the release of the lock by the locking mechanism 40, a heater 68 that is provided inside the housing 30 and whose temperature rises when electricity is applied, a control unit 80 that controls the application of electricity to the heater 68 and the operation of the locking mechanism 40, and a protection circuit 100 that cuts off the flow of electricity to the heater 68 when the detection unit 50 detects the release of the lock.

[0083] As a result, when the cover member 34 is unlocked, power to the heater 68 is forcibly cut off, thereby preventing the heater 68 from rising in temperature due to malfunction of the control unit 80. Therefore, the heater 68 can be reliably turned off when the user accesses the inside of the housing 30.

[0084] Furthermore, according to the above embodiment, the detection unit 50 detects the release of the lock by detecting the position of the movable member 46. This makes it possible to more reliably detect the release of the lock compared to the case where the control unit 80 monitors the power supply control of the lock mechanism 40.

[0085] Furthermore, according to the above embodiment, the control unit 80 controls the supply of electricity to the heater 68 via the signal line L3, and the protection circuit 100 grounds the signal line L3 to cut off the supply of electricity to the heater 68. This makes it possible to cut off the supply of electricity to the heater 68 more reliably.

[0086] Furthermore, according to the above embodiment, the control unit 80 causes the locking mechanism 40 to lock the cover member 34 when the temperature detected by the temperature sensor 70 exceeds a predetermined reference temperature, and causes the locking mechanism 40 to unlock when the temperature detected by the temperature sensor 70 is below the reference temperature. This allows the heater 68 to be shut off more reliably when the user accesses the inside of the housing 30.

[0087] Furthermore, according to the above embodiment, in the drying device 3, the conveying unit 61 conveys the paper P, and the heater 68 heats the paper P conveyed by the conveying unit 61. As a result, when a paper jam occurs, the heater 68 can be reliably shut off when the user opens the cover member 34 to access the vicinity of the heater 68 and remove the paper.

[0088] Furthermore, according to the above embodiment, the image forming system 1 includes the image forming device 2 and the drying device 3. This allows ink-based image formation to be performed with high safety.

[0089] (Other variations) In the above embodiment, the bipolar transistor 101 is of the NPN type, but the present invention is not limited to such an embodiment, and it may be of the PNP type.

[0090] The configuration and processing of the embodiment described above using FIGS. 1 to 11 are merely one embodiment of the present invention, and the present invention is not limited to these configurations and processing. [Explanation of symbols]

[0091] 1. Image forming system 2. Image forming device 3 Drying equipment 30 Case 34 Cover member 40 Locking mechanism 46 Variable parts 50 Detection unit 61 Conveyor 68 Heater 70 Temperature Sensor 80 Control Unit 100 protection circuit

Claims

1. a housing having an openable and closable cover member; a locking mechanism capable of restricting the opening of the cover member; a heating element provided inside the housing, the temperature of which increases when current is applied; a control unit that controls the energization of the heating member and the operation of the locking mechanism; a detection unit that detects the release of the lock by the lock mechanism; a cut-off mechanism that cuts off power to the heating member when the detection unit detects that the lock has been released.

2. the locking mechanism includes a variable member whose position changes between when the cover member is locked and when the cover member is unlocked, The drying device according to claim 1 , wherein the detection unit detects the release of the lock by detecting a position of the variable member.

3. the control unit controls the supply of electricity to the heating member via a signal line; The drying device according to claim 1 , wherein the cutoff mechanism cuts off the current to the heating member by grounding the signal line.

4. Further provided is a temperature sensor that detects the temperature inside the housing, The control unit When the temperature detected by the temperature sensor exceeds a predetermined reference temperature, the locking mechanism locks the cover member; The drying device according to claim 1 , wherein the locking mechanism is caused to release the lock when the temperature detected by the temperature sensor is lower than the reference temperature.

5. a conveying unit provided inside the housing and configured to convey paper; The drying device according to claim 1 , wherein the heating member heats the paper being transported by the transport section.

6. 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