Image forming device, control method and program

Abstract

To enable unlocking a locked state when an image forming device is in a specified state and to allow a user to easily and safely replace a replaceable unit.SOLUTION: There is provided an image forming device 1 in which a replaceable unit 6 is mounted on a mounting portion 7 inside the device and an image is formed on a recording medium 9 by operating the replaceable unit 6. The image forming device 1 comprises a holding portion 40 which holds in a state where the replaceable unit 6 is mounted on the mounting portion 7. The holding portion 40 enables the replaceable unit 6 to be removed from the mounting portion 7 when the image forming apparatus 1 is in a predetermined state. Further, the holding portion 40 holds the replaceable unit 6 in a state of not being removable from the mounting portion 7 when the image forming device 1 is not in a predetermined state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, a control method, and a program, and more particularly to a technique for replacing a replaceable unit installed inside the apparatus. [Background technology]

[0002] Image forming apparatuses such as MFPs (Multifunction Printers) are equipped with various replaceable units. For example, Patent Document 1 discloses a replaceable unit equipped with a lock lever and a cover that covers the lock lever. This conventional technology has a configuration that prevents a new replaceable unit from being incompletely installed in an image forming apparatus when replacing the replaceable unit. Specifically, this conventional technology employs a configuration in which the cover cannot be rotated to a position that covers the lock lever when the lock lever is in an unlocked state.

[0003] By making it possible to easily lock and unlock the replaceable unit using a lock lever or the like as described above, users of the image forming apparatus can easily replace the replaceable unit themselves, which has the advantage of reducing the number of times that a service technician needs to visit the installation site of the image forming apparatus. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2013-11822 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described conventional technology, a user can unlock the replaceable unit even when power is being supplied to the image forming apparatus or the replaceable unit, which can lead to problems such as electric shock if the user tries to unlock the replaceable unit and replace it while power is being supplied.

[0006] For example, an image forming apparatus includes an intermediate transfer unit as one of its replaceable units. In conventional image forming apparatuses, the intermediate transfer unit is fixed to a mounting portion of the apparatus body with screws. Therefore, replacement of the intermediate transfer unit is performed by a service technician visiting the image forming apparatus installation site. However, with the future population decline, replaceable units such as the intermediate transfer unit are required to be configured so that users can replace them themselves as needed, i.e., to prioritize the user experience. In such a configuration, it is essential to consider how users can safely replace the unit even when power is being supplied to the image forming apparatus or the replaceable unit.

[0007] The present invention has been made to solve the above-mentioned problems of the prior art, and aims to provide an image forming apparatus, a control method, and a program that can release a lock state when the image forming apparatus is in a predetermined state, and enable a user to easily and safely replace a replaceable unit by themselves. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the invention of claim 1 is an image forming device in which a replaceable unit is attached to an attachment section inside the device and an image is formed on a recording medium by operating the replaceable unit, the image forming device having a holding section that holds the replaceable unit attached to the attachment section, the holding section making the replaceable unit removable from the attachment section when the image forming device is in a predetermined state, and holding the replaceable unit in a state in which it cannot be removed from the attachment section when the image forming device is not in the predetermined state.

[0009] The invention of claim 2 is an image forming apparatus of claim 1, characterized in that the holding section is provided with a locking mechanism that locks the replaceable unit so that it cannot be removed from the mounting section, and the locking mechanism releases the locking state when the image forming apparatus is in the specified state, and maintains the locking state when the image forming apparatus is not in the specified state.

[0010] The invention according to claim 3 is the image forming apparatus according to claim 1 or 2, characterized in that the predetermined state is a state in which power supplied to the image forming apparatus is turned off.

[0011] The invention according to claim 4 is the image forming apparatus according to claim 1 or 2, characterized in that the predetermined state is a state in which power supplied to the replaceable unit is turned off.

[0012] The invention of claim 5 is an image forming apparatus of claim 2, further comprising a control unit that drives the locking mechanism and switches between the locked state and an unlocked state in which the locked state is released, and the control unit is configured to release the locked state by the locking mechanism when the image forming apparatus is in the specified state.

[0013] The invention according to claim 6 is the image forming apparatus according to claim 5, characterized in that the predetermined state is a state in which the control unit has received an instruction to replace the replaceable unit.

[0014] The invention of claim 7 is an image forming apparatus according to claim 5 or 6, further comprising a display unit that displays various information to the user, and the control unit displays guidance on the display unit to guide the user through the replacement operation of the replaceable unit.

[0015] The invention of claim 8 is an image forming apparatus of claim 1, 2, 5, or 6, characterized in that the replaceable unit is an intermediate transfer unit that carries and transports a toner image to be primarily transferred, and secondarily transfers the toner image to the recording medium at a predetermined position in the transport direction.

[0016] The invention of claim 9 is characterized in that, in the image forming apparatus of claim 8, it further comprises a fixing unit that fixes the toner image that has been secondarily transferred to the recording medium to the recording medium, and the specified state includes a state in which the power supplied to the fixing unit is off.

[0017] The invention of claim 10 is an image forming device in which a replaceable unit is attached to an attachment section inside the device and an image is formed on a recording medium by operating the replaceable unit, characterized in that it comprises: a holding section that holds the replaceable unit attached to the attachment section; a locking mechanism that is provided in the holding section and locks the replaceable unit so that it cannot be removed from the attachment section and releases the locked state when power supplied to the image forming device is turned off; and a control section that drives the locking mechanism to release the locked state when an instruction to replace the replaceable unit is received when power supplied to the image forming device is turned on.

[0018] The invention of claim 11 is an image forming apparatus of claim 10, characterized in that the replaceable unit is an intermediate transfer unit that carries and transports a toner image to be primarily transferred, and secondarily transfers the toner image to the recording medium at a predetermined position in the transport direction.

[0019] The invention of claim 12 is a control method for an image forming device that includes a replaceable unit that is attached to an attachment portion inside the device, a holding portion that holds the replaceable unit attached to the attachment portion, and a locking mechanism that is provided in the holding portion and locks the replaceable unit so that it cannot be removed from the attachment portion and releases the locked state when power supplied to the image forming device is turned off, and is characterized in that it has a configuration that includes a step of accepting an instruction to replace the replaceable unit when power supplied to the image forming device is on, and a step of driving the locking mechanism to release the locked state when the replacement instruction is accepted.

[0020] The invention of claim 13 is a program executed in an image forming device comprising: a replaceable unit that is attached to an attachment portion inside the device; a holding portion that holds the replaceable unit attached to the attachment portion; and a locking mechanism that is provided in the holding portion and locks the replaceable unit so that it cannot be removed from the attachment portion and releases the locked state when power supplied to the image forming device is turned off, and is characterized in that the program causes the image forming device to execute the steps of accepting an instruction to replace the replaceable unit and, when the replacement instruction is accepted, driving the locking mechanism to release the locked state. [Effects of the Invention]

[0021] According to the present invention, a configuration is realized in which the locked state can be released when the image forming apparatus is in a predetermined state, allowing the user to easily and safely replace the replaceable unit when the image forming apparatus is in the predetermined state. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 illustrates an example of the configuration of an image forming apparatus. [Figure 2] 2A and 2B are diagrams illustrating examples of how an intermediate transfer unit is attached to an image forming apparatus. [Figure 3] 10 is an enlarged view showing a holding portion provided on the mounting portion. FIG. [Figure 4] 10A and 10B are diagrams illustrating a state in which the pressing member presses the intermediate transfer unit while the protrusion is housed in the recess. [Figure 5] 10A and 10B are diagrams showing a locking mechanism provided in the holding portion. [Figure 6] FIG. 2 is a block diagram showing the functional configuration of a control unit. [Figure 7] 10 is a flowchart illustrating an example of a processing procedure performed by a control unit. [Figure 8] 10A and 10B are diagrams illustrating an example of the configuration of a locking mechanism in a second embodiment. [Figure 9] 10A and 10B are diagrams showing how the cover is attached to the partition wall. [Figure 10] FIG. 10 is a diagram illustrating a state in which the locked state by the locking mechanism is released. [Figure 11] 10A and 10B are diagrams illustrating an example of the configuration of a locking mechanism in a third embodiment. [Figure 12] FIG. 10 is a diagram illustrating a state in which the locked state by the locking mechanism is released. [Figure 13] 10A and 10B are diagrams illustrating an example of the configuration of a locking mechanism in a fourth embodiment. [Figure 14] FIG. 10 is a perspective view of a locking mechanism according to a fourth embodiment. [Figure 15] 10A and 10B are diagrams showing an operating member exposed through an opening in a partition wall. [Figure 16] FIG. 10 is a diagram illustrating a state in which the locked state by the locking mechanism is released. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Elements common to the embodiments described below are designated by the same reference numerals, and redundant description thereof will be omitted.

[0024] (First embodiment) First, a first embodiment of the present invention will be described. FIG. 1 is a diagram showing an example of the configuration of an image forming apparatus 1 according to one embodiment of the present invention. The XYZ three-dimensional coordinate system shown in FIG. 1 is a coordinate system in which the XY plane is the horizontal plane and the Z axis is the vertical direction, and is a coordinate system common to the coordinate systems shown in other drawings. The image forming apparatus 1 shown in FIG. 1 is configured as an MFP and has scanning and printing functions. The image forming apparatus 1 has a scanner unit 2 on the top of the apparatus body. The image forming apparatus 1 also has a printer unit 3 on the bottom of the apparatus body. The image forming apparatus 1 also has an operation panel 4 serving as a user interface on the front side of the apparatus body. Furthermore, the image forming apparatus 1 has a control unit 5 inside the apparatus body.

[0025] The scanner unit 2 includes an image reading unit 2a and an automatic document feeder unit 2b. When a scan job is executed in the image forming apparatus 1, the image reading unit 2a and the automatic document feeder unit 2b operate. The image reading unit 2a optically reads the image of a document set by a user and generates image data. The automatic document feeder unit 2b has a document placement tray 2c. The automatic document feeder unit 2b picks up documents placed on the document placement tray 2c one by one and automatically transports them to an image reading position by the image reading unit 2a. The image reading unit 2a works in conjunction with the document transport operation by the automatic document feeder unit 2b to read the image of the document as it passes the image reading position.

[0026] The printer unit 3 includes an image forming unit 3a and a paper feed conveying unit 3b. When a print job is executed in the image forming device 1, the image forming unit 3a and the paper feed conveying unit 3b operate. The paper feed conveying unit 3b includes multiple paper feed cassettes 11 arranged one above the other. The paper feed cassettes 11 store sheet-like recording media 9, such as printing paper. Each paper feed cassette 11 is provided with a pickup roller 12 and a paper feed roller 13. When a print job is executed in the image forming device 1, the paper feed conveying unit 3b drives the pickup roller 12 and paper feed roller 13 arranged in the paper feed cassette 11 specified by the user to feed the recording media 9 one sheet at a time toward a conveying path 14. The paper feed conveying unit 3b then conveys the recording media 9 along the conveying path 14. The image forming unit 3a, in conjunction with the conveying operation of the recording media 9 by the paper feed conveying unit 3b, transfers a toner image onto the recording media 9 as the recording media 9 passes a predetermined position.

[0027] The image forming section 3a includes an intermediate transfer unit 30 as one of the replaceable units 6 installed inside the image forming apparatus 1. The intermediate transfer unit 30 is a replaceable part in which a drive roller 31, a driven roller 32, an intermediate transfer belt 33, and a primary transfer roller 34 are integrally assembled. The intermediate transfer unit 30 holds the drive roller 31 and the driven roller 32 at a predetermined distance. The intermediate transfer belt 33 is an endless belt and is stretched between the drive roller 31 and the driven roller 32. The primary transfer roller 34 is held inside the intermediate transfer belt 33. Note that multiple primary transfer rollers 34 corresponding to the colors Y (yellow), M (magenta), C (cyan), and K (black) are arranged inside the intermediate transfer belt 33. When the intermediate transfer unit 30 is installed inside the image forming apparatus 1, the drive roller 31 is coupled to a rotary shaft driven by a motor inside the apparatus main body. The primary transfer roller 34 is also connected to a drive mechanism and a drive circuit inside the main body of the apparatus.

[0028] The image forming section 3a also includes a plurality of image forming units 20Y, 20M, 20C, and 20K below the intermediate transfer unit 30. Each of the image forming units 20Y, 20M, 20C, and 20K is disposed opposite a primary transfer roller 34 with the intermediate transfer belt 33 sandwiched therebetween. Each of the image forming units 20Y, 20M, 20C, and 20K generates a toner image of each color, Y, M, C, or K, and performs primary transfer onto the intermediate transfer belt 33. Toner bottles 21Y, 21M, 21C, and 21K for each color are attached above the intermediate transfer unit 30. These toner bottles 21Y, 21M, 21C, and 21K supply toner to the image forming units 20Y, 20M, 20C, and 20K for the corresponding color, respectively.

[0029] The image forming units 20Y, 20M, 20C, and 20K differ only in the color of toner they use. That is, the image forming units 20Y, 20M, 20C, and 20K share a common configuration. Specifically, each image forming unit 20Y, 20M, 20C, and 20K includes a photosensitive drum 22, a charger 23, an exposure unit 24, and a developing unit 25. The photosensitive drum 22 is a cylindrical image carrier having a photosensitive layer on its outer circumferential surface. The charger 23, the exposure unit 24, and the developing unit 25 are arranged along the outer circumferential surface of the photosensitive drum 22. The charger 23 charges the surface of the photosensitive drum 22 to a predetermined charge. The exposure unit 24 exposes the charged surface of the photosensitive drum 22 to light, forming an electrostatic latent image on the surface of the photosensitive drum 22. The developing unit 25 applies a developer containing toner to the surface of the photosensitive drum 22, thereby developing the electrostatic latent image with toner. The developing unit 25 develops the electrostatic latent image, thereby forming a toner image on the surface of the photosensitive drum 22. When this toner image comes into contact with the intermediate transfer belt 33, it is primarily transferred to the intermediate transfer belt 33 by a transfer voltage applied from the primary transfer roller 34.

[0030] The intermediate transfer unit 30 circulates the intermediate transfer belt 33 with the toner image thus primarily transferred carried on the intermediate transfer belt 33. The image forming units 20Y, 20M, 20C, and 20K primarily transfer the toner images of the respective colors onto the circulating intermediate transfer belt 33 in a superimposed manner, thereby forming a color image on the intermediate transfer belt 33. The intermediate transfer unit 30 secondarily transfers the color image at a predetermined position onto the surface of the recording medium 9 being transported along the transport path 14.

[0031] A timing roller 15, a secondary transfer roller 16, and a fixing unit 17 are provided on the conveyance path 14 for the recording medium 9. When the leading edge of the recording medium 9 reaches the position of the timing roller 15, the paper feed conveyance unit 3b temporarily stops conveying the recording medium 9. Then, the paper feed conveyance unit 3b drives the timing roller 15 to convey the recording medium 9 toward the secondary transfer roller 16, timing it to coincide with the time when the toner image carried on the intermediate transfer belt 33 reaches the position of the secondary transfer roller 16. When the recording medium 9 conveyed from the timing roller 15 comes into contact with the toner image carried on the intermediate transfer belt 33, the secondary transfer roller 16 applies a secondary transfer voltage, thereby secondarily transferring the toner image to the recording medium 9. The recording medium 9 with the transferred toner image is then conveyed to the fixing unit 17. The fixing unit 17 applies heat and pressure to the recording medium 9 to fix the toner image to the recording medium 9. The recording medium 9 with the image formed thereon is then ejected onto a tray 3c formed above the printer unit 3.

[0032] 2 is a diagram illustrating an example of how the intermediate transfer unit 30 is attached to the image forming apparatus 1. As shown in FIG. 2, the intermediate transfer unit 30 has a housing 35 that holds the drive roller 31, driven roller 32, intermediate transfer belt 33, and primary transfer roller 34 described above. Cylindrical protrusions 36 and 37 are provided on the side of the housing 35. In addition, a grip 38 is provided on the end of the housing 35, which is useful when removing the intermediate transfer unit 30 from the image forming apparatus 1.

[0033] An opening / closing door 1a is provided on the side of the image forming apparatus 1. By opening this opening / closing door 1a and unfolding the secondary transfer roller 16, the mounting portion 7 for the intermediate transfer unit 30 is opened. The mounting portion 7 is formed in the horizontal direction (Y direction) inside the image forming apparatus 1. Furthermore, both side surfaces 7a, 7b in the front-rear direction (X direction) of the mounting portion 7 are configured to engage with protrusions 36, 37 formed on the side surfaces of the housing 35 to guide the intermediate transfer unit 30 inside the apparatus main body. On both side surfaces 7a, 7b near the entrance of the mounting portion 7, there are provided holding portions 40 that hold the intermediate transfer unit 30 in a state where it is mounted in the mounting portion 7.

[0034] 3(a) and 3(b) are enlarged views of the holding portion 40 provided in the mounting portion 7. The holding portions 40 are provided symmetrically on both side surfaces 7a and 7b of the mounting portion 7 in the front-rear direction (X direction) inside the image forming apparatus 1. Note that FIGS. 3(a) and 3(b) illustrate the holding portion 40 formed on one side surface 7a of the mounting portion 7.

[0035] As shown in Figures 3(a) and 3(b), partition walls 18 and 19 are provided near the entrance of the mounting unit 7 to separate the mounting unit 7 from an inner space in which the internal mechanisms of the image forming apparatus 1 are installed. The partition walls 18 and 19 form a right angle with each other near the entrance of the mounting unit 7, i.e., the partition wall 18 is a wall parallel to the side surface of the image forming apparatus 1. The partition walls 18 and 19 are joined to each other to form an L-shaped wall in a plan view.

[0036] On the outside of the partition wall 19 (inside the mounting section 7), shelf-like guide sections 27, 28 are provided to engage with protrusions 36, 37 formed on the housing 35 of the intermediate transfer unit 30 and guide the intermediate transfer unit 30 in a horizontal position toward the depth direction (Y direction) of the mounting section 7. These two guide sections 27, 28 are at slightly different heights. For example, the guide section 27 provided on the front side of the entrance of the mounting section 7 is formed at a slightly higher position than the guide section 28 provided on the back side of the entrance of the mounting section 7. In addition, a recess 29 capable of accommodating the protrusion 36 is formed between the two guide sections 27, 28.

[0037] When the intermediate transfer unit 30 is attached to the attachment portion 7, the protrusion 36 on the front side is housed in the recess 29. The holding portion 40 holds the protrusion 36 of the intermediate transfer unit 30 in a state where it is housed in the recess 29. As a holding mechanism, the holding portion 40 is provided with a pressing member 50 that moves toward and away from the recess 29, and a lever member 41 that changes the attitude of the pressing member 50.

[0038] The lever member 41 is an L-shaped metal member that can be attached to and detached from the corner portion where the partition walls 18 and 19 are joined, and has a first plate portion 42 parallel to the XZ plane and a second plate portion 43 parallel to the YZ plane. The upper portion of the second plate portion 43 extends in the depth direction (Y direction) of the mounting portion 7, and is connected to a rod-shaped body 44a attached to one end of a compression coil spring 44. The second plate portion 43 also has an engagement arm 45 that extends in the depth direction (Y direction) of the mounting portion 7 below the portion to which the rod-shaped body 44a is connected. For example, the engagement arm 45 has engagement pieces 46 and 47 formed at two positions spaced a predetermined distance apart and protruding toward the inside of the mounting portion 7. The compression coil spring 44 biases the first plate portion 42 of the lever member 41 in a direction away from the partition wall 18.

[0039] The pressing member 50 has a generally L-shaped rotating arm 51. A base end of the rotating arm 51 is rotatably supported by a rotating shaft 52. The rotating arm 51 rotates around the rotating shaft 52. This causes the pressing member 50 to be displaced between a pressing position shown in FIG. 3(a) and a released position shown in FIG. 3(b).

[0040] 3(b), the path along which the protrusions 37, 36 enter or exit is opened along the guide portions 27, 28. Therefore, when the pressing member 50 is in the released position, the intermediate transfer unit 30 is detachable from the mounting portion 7.

[0041] 3A, the path along which the protrusions 37, 36 enter or exit is blocked along the guide portions 27, 28. Therefore, when the pressing member 50 is in the pressing position, the intermediate transfer unit 30 cannot be attached to or detached from the attachment portion 7.

[0042] 3A, when the lever member 41 is pressed in the direction of arrow F1 against the biasing force of the compression coil spring 44, the compression coil spring 44 is compressed, and the engagement arm 45 is displaced in the direction of arrow F1 to rotate the rotation arm 51. As a result, the pressing member 50 assumes the pressing position. At this time, the first plate portion 42 of the lever member 41 is in contact with the partition wall 18.

[0043] Furthermore, when the force pressing the lever member 41 is released, as shown in FIG. 3(b), the biasing force of the compression coil spring 44 moves the lever member 41 in the direction of arrow F2. At this time, the engagement arm 45 is displaced in the direction of arrow F2, causing the pivot arm 51 to pivot. As a result, the pressing member 50 assumes the release position. At this time, the first plate portion 42 of the lever member 41 is separated from the partition wall 18.

[0044] The holding section 40 configured as described above holds the pressing member 50 in a pressing position when the intermediate transfer unit 30 is attached to the attachment section 7, thereby preventing the intermediate transfer unit 30 from being removed from the attachment section 7. FIG. 4 is a diagram showing a state in which the pressing member 50 presses the intermediate transfer unit 30 while the protrusion 36 is housed in the recess 29. As shown in FIG. 4, the pressing member 50 holds the protrusion 36 of the intermediate transfer unit 30 in a pressed state against the recess 29, so that the intermediate transfer unit 30 remains attached to the attachment section 7.

[0045] 3(b) by a compression coil spring 44. Therefore, in order to maintain the state in which the pressing member 50 presses the protrusion 36 against the recess 29, it is necessary to maintain the first plate portion 42 of the lever member 41 in a state in which it is joined to the partition wall 18. Therefore, the holding portion 40 is provided with a locking mechanism 60 that maintains the first plate portion 42 of the lever member 41 in a state in which it is joined to the partition wall 18.

[0046] 5(a) and 5(b) are diagrams illustrating a locking mechanism 60 provided in the holder 40. The locking mechanism 60 is provided inside the image forming apparatus 1, surrounded by partition walls 18 and 19, in a space different from the mounting unit 7. The locking mechanism 60 includes two magnets 61 and 62 arranged inside the partition wall 18. Of the two magnets 61 and 62, one magnet 61 is adhesively fixed to the inside of the partition wall 18. The other magnet 62 is attached to a drive shaft 64 of a solenoid 63. The solenoid 63 retracts the drive shaft 64 when current is applied and pushes the drive shaft 64 when current is not applied. The magnet 62 is attached to the tip of the drive shaft 64. When the solenoid 63 is not driven, the magnet 62 is in close contact with the inside of the partition wall 18, as shown in FIG. 5(a). On the other hand, when the solenoid 63 is driven, the magnet 62 moves to a position a predetermined distance away from the partition wall 18 as shown in FIG. 5(b).

[0047] 5(a), when the solenoid 63 is not driven, the first plate portion 42 is joined to the partition wall 18 against the biasing force of the compression coil spring 44, and the magnetic forces of the two magnets 61, 62 hold the first plate portion 42 in a state joined to the partition wall 18. Therefore, the pressing member 50 holds the protrusion 36 of the intermediate transfer unit 30 pressed against the recess 29.

[0048] In contrast, when the solenoid 63 is driven and the magnet 62 moves away from the inside of the partition wall 18, the magnetic force acting on the first plate portion 42 decreases. At this time, the biasing force of the compression coil spring 44 becomes stronger than the magnetic force, and the first plate portion 42 moves away from the partition wall 18, as shown in FIG. 5(b). Accordingly, the pivoting arm 51 of the pressing member 50 rotates, and the pressing member 50 releases the pressing state of the protrusion 36.

[0049] In other words, the biasing force of the compression coil spring 44 is weaker than the magnetic force acting on the first plate portion 42 when the two magnets 61, 62 are in close contact with the inside of the partition wall 18, and is stronger than the magnetic force acting on the first plate portion 42 when only one magnet 61 is in close contact with the inside of the partition wall 18. Therefore, when the solenoid 63 is not driven, the locking mechanism 60 keeps the first plate portion 42 in a state where it is joined to the partition wall 18, maintaining a locked state in which the intermediate transfer unit 30 cannot be removed from the mounting portion 7. When the solenoid 63 is driven, the locking mechanism 60 moves one magnet 62 away from the partition wall 18 to release the locked state. Such operation of the solenoid 63 is controlled by the control unit 5.

[0050] The control unit 5 includes a hardware processor such as a CPU (not shown) and a storage unit such as a memory. A computer-readable program to be executed by the hardware processor is stored in advance in the storage unit. The hardware processor reads and executes the program to control the operation of each unit of the image forming apparatus 1. In particular, the control unit 5 in this embodiment drives the solenoid 63 of the locking mechanism 60 described above.

[0051] 6 is a block diagram showing the functional configuration of the control unit 5. When the hardware processor executes a program, the control unit 5 functions as a replacement detection unit 71, a replacement guide unit 72, and an unlocking unit 73, as shown in FIG.

[0052] The replacement detection unit 71 detects that it is time to replace the intermediate transfer unit 30. For example, the replacement detection unit 71 detects that it is time to replace the intermediate transfer unit 30 when the number of prints made by the image forming apparatus 1 reaches a predetermined number. When the replacement detection unit 71 detects that it is time to replace the intermediate transfer unit 30, it causes the replacement guide unit 72 to function.

[0053] The replacement guide section 72 guides the user on the replacement operation of the intermediate transfer unit 30. For example, the replacement guide section 72 guides the user on the replacement operation via the operation panel 4.

[0054] The operation panel 4 comprises a display unit 4a and an operation unit 4b. The display unit 4a is configured, for example, as a color LCD display, and displays various guidance screens. The operation unit 4b is configured, for example, as touch keys arranged on the screen of the display unit 4a, and accepts operations by the user.

[0055] The replacement guide unit 72 displays guidance on the display unit 4a of the operation panel 4 to guide the user through the replacement operation of the intermediate transfer unit 30. This guidance is composed of still images or video. For example, when displaying the guidance, the replacement guide unit 72 displays, as an initial screen, a screen including guidance indicating that the intermediate transfer unit 30 needs to be replaced and an operation button for selecting whether or not to start the replacement operation of the intermediate transfer unit 30. The initial screen allows the user to understand that the intermediate transfer unit 30 needs to be replaced. When performing the replacement operation of the intermediate transfer unit 30, the user operates the operation button on the initial screen to select starting the replacement operation. This operation is accepted by the replacement guide unit 72 as a replacement instruction. When accepting the replacement instruction, the replacement guide unit 72 advances the guidance and displays an image showing the procedure for the replacement operation of the intermediate transfer unit 30. When accepting the replacement instruction, the replacement guide unit 72 also instructs the unlocking unit 73 to unlock.

[0056] The unlocking unit 73 drives the solenoid 63. When the unlocking unit 73 does not receive an unlocking instruction from the replacement guide unit 72, it does not drive the solenoid 63. In this case, the holding unit 40 continues to be locked by the locking mechanism 60. In contrast, when the unlocking unit 73 receives an unlocking instruction from the replacement guide unit 72, it applies a current to the solenoid 63 and releases the locked state by the locking mechanism 60. This makes it possible to remove the intermediate transfer unit 30 from the attachment unit 7.

[0057] 7 is a flowchart showing an example of a processing procedure performed by the control unit 5. This processing is repeatedly executed by the control unit 5 at regular intervals. When this processing starts, the control unit 5 determines whether it is time to replace the intermediate transfer unit 30 (step S10). If it is not time to replace the intermediate transfer unit 30 (NO in step S10), the processing by the control unit 5 ends. On the other hand, if it is time to replace the intermediate transfer unit 30 (YES in step S10), the control unit 5 displays guidance on the display 4a of the operation panel 4 indicating that the intermediate transfer unit 30 should be replaced (step S11).

[0058] While the initial guidance screen is displayed, the control unit 5 determines whether or not a replacement instruction from the user has been received (step S12). If a replacement instruction has not been received (NO in step S12), the processing by the control unit 5 ends. At this time, the display of the guidance also ends.

[0059] When a replacement instruction is received from the user (YES in step S12), the control unit 5 cuts off power to the intermediate transfer unit 30 (step S13). The control unit 5 cuts off power to the intermediate transfer unit 30 and switches off the power supplied to the intermediate transfer unit 30, thereby ensuring safety when the user replaces the intermediate transfer unit 30. At this time, the control unit 5 may also cut off power to the fixing unit 17. The fixing unit 17 is disposed near the intermediate transfer unit 30, and receives a relatively large amount of power when it is in a powered state. Therefore, by switching off the power supplied to the fixing unit 17, safety can be improved when the user replaces the intermediate transfer unit 30.

[0060] Next, the control unit 5 drives the solenoid 63 to release the locked state by the locking mechanism 60 (step S14). As a result, the intermediate transfer unit 30 attached to the attachment portion 7 becomes removable from the attachment portion 7. Therefore, in this unlocked state, the user removes the intermediate transfer unit 30 from the attachment portion 7, and then attaches a new intermediate transfer unit 30 to the attachment portion 7.

[0061] Thereafter, the control unit 5 determines whether or not it has detected that the intermediate transfer unit 30 has been attached to the attachment unit 7 (step S15). For example, the attachment unit 7 is provided with a sensor for detecting that the intermediate transfer unit 30 has been attached. The control unit 5 uses the sensor to detect that the intermediate transfer unit 30 has been attached. When it detects that the intermediate transfer unit 30 has been attached (YES in step S15), the control unit 5 determines whether or not the attached intermediate transfer unit 30 is new (step S16). For example, the intermediate transfer unit 30 is equipped with a fuse for detecting whether it is new. The control unit 5 determines whether or not it is new by detecting the fuse via a drive circuit for the intermediate transfer unit 30. If the intermediate transfer unit 30 attached to the attachment unit 7 is new, the control unit 5 blows the fuse after detecting that it is new.

[0062] When it is detected that a new intermediate transfer unit 30 has been attached to the attachment portion 7 (YES in step S16), the control unit 5 stops driving the solenoid 63 and returns the locking mechanism 60 to the locked state (step S17). As a result, the intermediate transfer unit 30 attached to the attachment portion 7 cannot be removed from the attachment portion 7. Thereafter, the control unit 5 resumes supplying power to the intermediate transfer unit 30 (step S18).

[0063] As described above, the image forming apparatus 1 of this embodiment is configured to release the locked state of the locking mechanism 60 when the image forming apparatus 1 is in a predetermined state. Here, the predetermined state includes various states. For example, the predetermined state includes a state in which the control unit 5 receives an instruction to replace the intermediate transfer unit 30. The predetermined state also includes a state in which power supplied to the intermediate transfer unit 30 is turned off. The predetermined state also includes a state in which power supplied to the fixing unit 17 is turned off. When the image forming apparatus 1 is in a predetermined state, it releases the locked state of the locking mechanism 60, allowing the intermediate transfer unit 30 to be removed from the mounting portion 7. In contrast, when the image forming apparatus 1 is not in a predetermined state, it maintains the locked state of the locking mechanism 60, preventing the intermediate transfer unit 30 from being removed from the mounting portion 7. In other words, the image forming apparatus 1 is configured to release the locked state of the locking mechanism 60 only when the image forming apparatus 1 is in a predetermined state. Therefore, the image forming apparatus 1 is configured to allow the user to easily and safely replace the intermediate transfer unit 30.

[0064] (Second embodiment) Next, a second embodiment of the present invention will be described, which will explain an example of the configuration of a lock mechanism 60 that is different from that of the first embodiment.

[0065] 8 is a diagram showing an example of the configuration of a locking mechanism 60 in the second embodiment. As in the first embodiment, this locking mechanism 60 is provided inside the image forming apparatus 1 surrounded by partition walls 18 and 19, for example, and is arranged in a space different from the mounting unit 7. Also, as in the first embodiment, the locking mechanism 60 includes two magnets 61 and 62 arranged inside the partition wall 18.

[0066] Of the two magnets 61, 62, one magnet 61 is adhesively fixed to the inside of the partition wall 18. This magnet 61 is adhesively fixed to the outside of the partition wall 18 within the range of the area where the first plate portion 42 is located.

[0067] The other magnet 62 is attached to the inside of the partition wall 18 and to a slide member 82 that is slidable up and down. The slide member 82 slides up and down with the magnet 62 attached to the inside of the partition wall 18. One end of a tension coil spring 81 is connected to the top of the slide member 82. The other end of the tension coil spring 81 is connected to a support portion 18a provided on the inside of the partition wall 18. The slide member 82 also has a shaft portion 84 that protrudes to the outside of the partition wall 18 through a slit 86 provided in the partition wall 18. An operating portion 83 that can be operated by the user is attached to the tip of the shaft portion 84.

[0068] The tension coil spring 81 exerts a biasing force in a direction (Z direction) that pulls the slide member 82 upward. The biasing force of the tension coil spring 81 positions the shaft portion 84 at the upper end of the slit 86. At this time, the slide member 82 is positioned at the upper end of its sliding range inside the partition wall 18, and holds the magnet 62 within the range in which the first plate portion 42 is located.

[0069] Therefore, when the first plate portion 42 is joined to the partition wall 18 against the biasing force of the compression coil spring 44, the magnetic force of the two magnets 61, 62 acts on the first plate portion 42. This magnetic force holds the first plate portion 42 in a state where it is joined to the partition wall 18. As a result, the pressing member 50 holds the protrusion 36 of the intermediate transfer unit 30 in a state where it is pressed against the recess 29. In other words, the locking mechanism 60 puts the intermediate transfer unit 30 in a locked state where it cannot be removed from the mounting portion 7.

[0070] A cover 85 that surrounds the operating unit 83 is attached to the outside of the partition wall 18. Figures 9(a) and 9(b) are diagrams illustrating how the cover 85 is attached to the partition wall 18. When the slide member 82 is positioned at the top end of its sliding range, the operating unit 83 is located at the top end of the slit 86. The cover 85 is attached to the partition wall 18 so as to surround the operating unit 83 located at the top end of the slit 86. This cover 85 is detachable from the partition wall 18. For example, as shown in Figure 9(b), the partition wall 18 is provided with multiple mounting holes 18b. The cover 85 is an elastic U-shaped member molded from synthetic resin or the like. The cover 85 has multiple protrusions 85a at its tip. At least one of the multiple protrusions 85a is formed as a snap fit. The cover 85 is attached to the partition wall 18 by fitting the multiple protrusions 85a into multiple mounting holes 18b provided in the partition wall 18. The protrusions 85 a formed as snap fits engage with the inside of the partition wall 18 , thereby preventing the cover 85 from coming off the partition wall 18 .

[0071] The snap-fit ​​engagement of this cover 85 can be easily released by pinching and pressing the two parallel flat plate portions with the fingers. This allows the user to easily remove the cover 85 from the partition wall 18. By removing the cover 85 from the partition wall 18, the operating unit 83 becomes operable. The user can release the locked state established by the locking mechanism 60 by lowering the operating unit 83.

[0072] FIG. 10 illustrates a state in which the locking state by the locking mechanism 60 has been released. When the operating part 83 is pressed downward against the biasing force of the tension coil spring 81, the slide member 82 holding the magnet 62 moves downward along the slit 86 in response. The movement of the slide member 82 moves the magnet 62 out of the range of the area where the first plate part 42 is located. This reduces the magnetic force acting on the first plate part 42. The biasing force of the compression coil spring 44 then becomes stronger than the magnetic force attracting the first plate part 42 to the partition wall 18. This moves the first plate part 42 away from the partition wall 18, causing the pivot arm 51 of the pressing member 50 to pivot. As a result, the pressing member 50 releases the pressure on the protrusion 36, and the locking state by the locking mechanism 60 is released. Therefore, by lowering the operating part 83, the user can remove the intermediate transfer unit 30 from the mounting part 7. The same applies when the intermediate transfer unit 30 is attached to the attachment portion 7.

[0073] As described above, the image forming apparatus 1 of this embodiment enters a predetermined state in which the locked state can be released by removing the cover 85 of the operation unit 83. For example, if the cover 85 covering the operation unit 83 is not provided, the user can operate the operation unit 83 simply by opening the opening / closing door 1a. Therefore, if a jam occurs in the image forming apparatus 1, there is a possibility that the user will mistakenly operate the operation unit 83 to clear the jam. The cover 85 is attached to prevent such a user mistaken operation. For this reason, it is preferable to attach a message or the like to the surface of the cover 85 indicating that the cover 85 should only be removed when replacing the intermediate transfer unit 30.

[0074] (Third embodiment) Next, a third embodiment of the present invention will be described. In this embodiment, a configuration example will be described in which the lock mechanism 60 described in the second embodiment can be configured to prevent erroneous operation by the user without providing a cover 85.

[0075] 11 is a diagram showing an example of the configuration of a locking mechanism 60 in the third embodiment. As in the second embodiment, this locking mechanism 60 releases the locked state by causing a sliding member 82, which is located at the upper end of a slit 86, to slide downward using a tension coil spring 81. This locking mechanism 60 includes a stopper 67 that moves forward and backward to a position below the sliding member 82 by operation of a solenoid 63.

[0076] The solenoid 63 retracts the drive shaft 64 when current is applied, and pushes the drive shaft 64 out when current is not applied. One end of a swinging member 65 that swings around a rotation shaft 66 is connected to the tip of the drive shaft 64. The rotation shaft 66 supports the swinging member 65 at the center position in the longitudinal direction. The other end of the swinging member 65 is connected to a stopper 67. The stopper 67 is supported by a guide portion 68 so as to move back and forth in the horizontal direction (Y direction).

[0077] When the solenoid 63 retracts the drive shaft 64, the swinging member 65 advances the stopper 67 to a position below the slide member 82, as shown in FIG. 11 . At this time, if the user attempts to move the operation unit 83 downward, the slide member 82 interferes with the stopper 67. As a result, the user cannot move the operation unit 83 downward. In other words, the locking mechanism 60 maintains a locked state in which the intermediate transfer unit 30 cannot be removed from the mounting portion 7.

[0078] In contrast, when the solenoid 63 is in a state in which it pushes out the drive shaft 64, the swinging member 65 retracts the stopper 67 from the position below the slide member 82, as shown in FIG. 12. At this time, if the user attempts to move the operation portion 83 downward, the slide member 82 does not interfere with the stopper 67. Therefore, the slide member 82 moves downward inside the partition wall 18 in response to the user's operation. In other words, the locking mechanism 60 is released from the locked state, making it possible to remove the intermediate transfer unit 30 from the attachment portion 7.

[0079] When the power supply to the image forming apparatus 1 is turned off, no current is applied to the solenoid 63. Therefore, the locked state by the locking mechanism 60 is released. Therefore, the user can remove the intermediate transfer unit 30 from the mounting portion 7 by moving the operating portion 83 downward.

[0080] Furthermore, when power supply to the image forming apparatus 1 is started, the control unit 5 applies a current to the solenoid 63. Accordingly, the solenoid 63 retracts the drive shaft 64, causing the stopper 67 to enter a position below the slide member 82. As a result, the locking mechanism 60 enters a locked state in which the intermediate transfer unit 30 cannot be removed from the mounting portion 7.

[0081] Furthermore, as described in the first embodiment, when an instruction to replace the intermediate transfer unit 30 is received while power is being supplied to the image forming apparatus 1, the control unit 5 turns off the power supplied to the intermediate transfer unit 30 and stops the current to the solenoid 63. At this time, the control unit 5 may also cut off the power supply to the fixing unit 17 and switch off the power supplied to the fixing unit.

[0082] When the current is stopped, the solenoid 63 retracts the stopper 67 from below the slide member 82. Therefore, the user can release the locked state by the locking mechanism 60 by moving the operation part 83 downward. When the locked state by the locking mechanism 60 is released, the intermediate transfer unit 30 becomes removable from the attachment part 7.

[0083] As described above, the image forming apparatus 1 of this embodiment, like the first embodiment, is configured to be able to release the locked state of the locking mechanism 60 when in a predetermined state. Here, the predetermined state includes various states. For example, the predetermined state includes a state in which the control unit 5 receives an instruction to replace the intermediate transfer unit 30. The predetermined state also includes a state in which power supplied to the image forming apparatus 1 is off. The predetermined state also includes a state in which power supplied to the intermediate transfer unit 30 is off. The predetermined state also includes a state in which power supplied to the fixing unit 17 is off. The image forming apparatus 1 releases the locked state of the locking mechanism 60 when in a predetermined state, thereby enabling the intermediate transfer unit 30 to be removed from the mounting portion 7. In contrast, when the image forming apparatus 1 is not in a predetermined state, the image forming apparatus 1 maintains the locked state of the locking mechanism 60, thereby preventing the intermediate transfer unit 30 from being removed from the mounting portion 7. In other words, the image forming apparatus 1 is configured to release the locked state of the locking mechanism 60 only when in a predetermined state. Therefore, the image forming apparatus 1 is configured so that the user can easily and safely replace the intermediate transfer unit 30.

[0084] Furthermore, this image forming apparatus 1 can prevent the operation unit 83 from being operated by mistake when it is not in a predetermined state. Therefore, this image forming apparatus 1 does not need to be provided with the cover 85 described in the second embodiment. However, the cover 85 described in the second embodiment may also be provided in this embodiment.

[0085] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described, which will explain an example of the configuration of a lock mechanism 60 that is different from those of the first to third embodiments.

[0086] Fig. 13 is a diagram showing an example of the configuration of a locking mechanism 60 in the fourth embodiment. Fig. 14 is a perspective view of the locking mechanism 60. As in the first embodiment, the locking mechanism 60 is provided inside the image forming apparatus 1, surrounded by partition walls 18 and 19, and is arranged in a space different from the mounting unit 7. The locking mechanism 60 also includes a magnet 62 arranged inside the partition wall 18. The magnet 62 exerts the combined magnetic force of the two magnets 61 and 62 described in the first to third embodiments.

[0087] The magnet 62 is attached to a rotating member 91 inside the partition wall 18. The rotating member 91 is composed of a rotating plate and a cam member, and is rotatably supported by a rotating shaft 92. A plate-shaped shielding portion 93 is formed on the rotating member 91 at a position opposite to the position where the magnet 62 is attached. This shielding portion 93 moves in the circumferential direction of the rotating member 91 as the rotating member 91 rotates. An optical position detection sensor 94 is disposed on the path along which the shielding portion 93 moves. This position detection sensor 94 detects the rotational position of the rotating member 91 by detecting the shielding portion 93. For example, when the magnet 61 is located closest to the partition wall 18, the shielding portion 93 is located at a position detected by the position detection sensor 94. At this time, the position detection sensor 94 detects that the rotating member 91 is in the reference position.

[0088] The upper end of the rotating shaft 92 is rotatably supported by a bearing portion 18c provided inside the partition wall 18. A disk-shaped operating member 95 is provided below the rotating member 91 on the rotating shaft 92. A part of the operating member 95 is exposed to the outside of the partition wall 18 through an opening 18d provided in the partition wall 18.

[0089] 15 is a diagram showing the operating member 95 exposed from the opening 18d of the partition wall 18. As shown in FIG. 15, a circumferential portion of the operating member 95 is exposed from the opening 18d of the partition wall 18. Therefore, the user can rotate the operating member 95 from outside the partition wall 18. When the operating member 95 rotates, the rotation shaft 92 and the rotation member 91 rotate accordingly.

[0090] Furthermore, a gear 96 is attached to the lower end of the rotating shaft 92. This gear 96 meshes with a gear 98 attached to a rotating shaft 97a of a motor 97. Therefore, when the motor 97 rotates the rotating shaft 97a, the rotating shaft 92 rotates. As the rotating shaft 92 rotates, the rotating member 91 also rotates.

[0091] The control unit 5 drives the motor 97 based on the rotational position of the rotating member 91 detected by the position detection sensor 94. For example, the control unit 5 enables the locking state by the locking mechanism 60 to be released when the image forming apparatus 1 is in a predetermined state, and allows the locking state by the locking mechanism 60 to continue when the image forming apparatus 1 is not in the predetermined state.

[0092] For example, when the power supplied to the image forming apparatus 1 is in an on state, the control unit 5 drives the motor 97 so that the rotational position of the rotating member 91 detected by the position detection sensor 94 remains at the reference position. In other words, the control unit 5 drives the motor 97 so that the locking state of the locking mechanism 60 continues. At this time, if the user attempts to rotate the operating member 95, the control unit 5 controls the motor 97 to drive in the direction opposite to the operating rotation direction so that the rotating member 91 remains at the reference position. Therefore, when the user attempts to rotate the operating member 95, a resistance force from the motor 97 acts on the operating member 95. Therefore, the user cannot rotate the operating member 95, and the locking mechanism 60 maintains the locked state.

[0093] In contrast, when the power supplied to the image forming apparatus 1 is turned off, the control unit 5 stops functioning and no current flows through the motor 97. In this case, the control unit 5 can release the locked state established by the lock mechanism 60. In other words, when the user attempts to rotate the operation member 95, the control unit 5 does not apply resistance force from the motor 97, thereby allowing the operation member 95 to be rotated. When the operation member 95 rotates, the rotation member 91 rotates.

[0094] 16 is a diagram showing a state in which the rotating member 91 rotates and the locked state by the locking mechanism 60 is released. As shown in FIG. 16, as the rotating member 91 rotates, the magnet 62 moves away from the position closest to the inside of the partition wall 18. As a result, the magnetic force acting on the first plate portion 42 decreases, and the first plate portion 42 moves away from the partition wall 18 due to the biasing force of the compression coil spring 44, and the locked state by the pressing member 50 is released. This makes it possible to remove the intermediate transfer unit 30 from the mounting portion 7.

[0095] When the user replaces the intermediate transfer unit 30 and the power supplied to the image forming apparatus 1 is turned on, the control unit 5 drives the motor 97 to return the rotating member 91 to the above-mentioned reference position. As a result, the locking mechanism 60 returns to a locked state in which the intermediate transfer unit 30 cannot be removed from the mounting portion 7.

[0096] Furthermore, when the power supplied to the image forming apparatus 1 is on and an instruction to replace the intermediate transfer unit 30 is received from the operation panel 4, the control unit 5 drives the motor 97 to move the rotating member 91 from the reference position. This rotates the rotating member 91, moving the magnet 62 away from the position closest to the inside of the partition wall 18, as shown in FIG. 16 . As a result, the magnetic force acting on the first plate 42 decreases, and the biasing force of the compression coil spring 44 moves the first plate 42 away from the partition wall 18, releasing the lock state established by the pressing member 50. This allows the intermediate transfer unit 30 to be removed from the mounting portion 7. When the user replaces the intermediate transfer unit 30, the control unit 5 drives the motor 97 to return the rotating member 91 to the reference position. This causes the locking mechanism 60 to return to the locked state in which the intermediate transfer unit 30 cannot be removed from the mounting portion 7, as shown in FIG. 13 .

[0097] Furthermore, when the power supplied to the image forming apparatus 1 is on, the control unit 5 preferably switches off the power supplied to the intermediate transfer unit 30 when driving the motor 97 to move the rotating member 91 from the reference position. In this case, the control unit 5 drives the motor 97 to move the rotating member 91 from the reference position, provided that the power supply to the intermediate transfer unit 30 is cut off. This ensures safety when the intermediate transfer unit 30 is replaced.

[0098] Furthermore, when the power supplied to the image forming apparatus 1 is on, the control unit 5 preferably switches off the power supplied to the fixing unit 17 when driving the motor 97 to move the rotating member 91 from the reference position. In this case, the control unit 5 drives the motor 97 to move the rotating member 91 from the reference position, provided that the power supply to the fixing unit 17 is cut off. This ensures safety when replacing the intermediate transfer unit 30.

[0099] As described above, the image forming apparatus 1 of this embodiment, like the first embodiment, is configured to release the lock state of the lock mechanism 60 when the image forming apparatus 1 is in a predetermined state. Here, the predetermined state includes various states. For example, the predetermined state includes a state in which the control unit 5 receives an instruction to replace the intermediate transfer unit 30. The predetermined state also includes a state in which power supplied to the image forming apparatus 1 is off. The predetermined state also includes a state in which power supplied to the intermediate transfer unit 30 is off. The predetermined state also includes a state in which power supplied to the fixing unit 17 is off. The image forming apparatus 1 releases the lock state of the lock mechanism 60 when the image forming apparatus 1 is in a predetermined state, thereby enabling the intermediate transfer unit 30 to be removed from the mounting portion 7. In contrast, when the image forming apparatus 1 is not in a predetermined state, the image forming apparatus 1 maintains the lock state of the lock mechanism 60, preventing the intermediate transfer unit 30 from being removed from the mounting portion 7. In other words, the image forming apparatus 1 is configured to release the lock state of the lock mechanism 60 only when the image forming apparatus 1 is in a predetermined state, thereby enabling the intermediate transfer unit 30 to be replaced easily and safely.

[0100] In this embodiment, a circumferential portion of the operating member 95 is exposed from the opening 18d of the partition wall 18. Therefore, in the image forming apparatus 1 of this embodiment, a cover 85 similar to that of the second embodiment may be attached to the partition wall 18 to prevent the user from easily operating the operating member 95 exposed from the partition wall 18.

[0101] (Variation) The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the contents described in the above embodiments. In other words, various modifications can be applied to the above embodiments.

[0102] For example, in the first to third embodiments, a configuration example was described in which two magnets 61, 62 are used to maintain the first plate portion 42 joined to the partition wall 18. However, the locking mechanism 60 described in each of the first to third embodiments can also be realized using one magnet 62, as in the fourth embodiment.

[0103] In the above embodiment, an example has been described in which permanent magnets are used as the magnets 61 and 62. However, the magnets 61 and 62 are not limited to permanent magnets and may be electromagnets. When electromagnets are used as the magnets 61 and 62, the control unit 5 can maintain or release the locked state by switching on and off the power supply to the electromagnets. This has the advantage of making it easier to realize the configuration of the locking mechanism 60.

[0104] In the above-described embodiment, the intermediate transfer unit 30 is exemplified as an example of a replaceable unit 6. However, various replaceable units 6 other than the intermediate transfer unit 30 are mounted in the image forming apparatus 1. For example, the fixing unit 17 and the image forming units 20Y, 20M, 20C, and 20K are also replaceable units 6. Furthermore, for example, the toner bottles 21Y, 21M, 21C, and 21K are also replaceable units 6. The configuration of the holding unit 40 described in each of the above-described embodiments can also be applied to these various replaceable units 6. Therefore, the replaceable unit 6 to which the present invention is applied is not limited to the intermediate transfer unit 30.

[0105] In the above embodiment, an example has been described in which a program executed by the hardware processor of the control unit 5 is pre-recorded in the image forming apparatus 1. However, such a program can be traded independently. Therefore, the image forming apparatus 1 may be configured to acquire a program from an external source and store it in the control unit 5. In this case, the program may be provided in a downloadable format via a network such as the Internet. Alternatively, the program may be provided in a format recorded on a computer-readable, non-transitory recording medium such as a CD-ROM or USB memory. [Explanation of symbols]

[0106] 1. Image forming device 4 Operation panel 4a Display section 4b Operation section 5. Control section 6 Replaceable Units 7 Mounting part 9. Recording Media 17 Fuser unit 30 Intermediate transfer unit 40 Holding part 60 Locking mechanism

Claims

1. An image forming apparatus in which a replaceable unit is mounted in a mounting portion inside the apparatus, and an image is formed on a recording medium by operating the replaceable unit, a holding portion that holds the replaceable unit in a state where the replaceable unit is attached to the attachment portion, The image forming apparatus is characterized in that the holding section makes the replaceable unit removable from the mounting section when the image forming apparatus is in a predetermined state, and holds the replaceable unit in a state where it cannot be removed from the mounting section when the image forming apparatus is not in the predetermined state.

2. The image forming apparatus according to claim 1, characterized in that the holding section is provided with a locking mechanism that locks the replaceable unit so that it cannot be removed from the mounting section, and the locking mechanism releases the locking state when the image forming apparatus is in the specified state, and maintains the locking state when the image forming apparatus is not in the specified state.

3. 3. The image forming apparatus according to claim 1, wherein the predetermined state is a state in which power supplied to the image forming apparatus is turned off.

4. 3. The image forming apparatus according to claim 1, wherein the predetermined state is a state in which power supplied to the replaceable unit is turned off.

5. a control unit that drives the lock mechanism and switches between the locked state and a released state in which the locked state is released; Further provided with 3. The image forming apparatus according to claim 2, wherein the control unit releases the locked state set by the lock mechanism when the image forming apparatus is in the predetermined state.

6. 6. The image forming apparatus according to claim 5, wherein the predetermined state is a state in which the control unit has received an instruction to replace the replaceable unit.

7. A display unit that displays various information to the user; Further provided with 7. The image forming apparatus according to claim 5, wherein the control unit displays guidance on the display unit to guide the user through the replacement operation of the replaceable unit.

8. 7. The image forming apparatus according to claim 1, 2, 5, or 6, wherein the replaceable unit is an intermediate transfer unit that carries and transports a toner image to be primarily transferred, and secondarily transfers the toner image onto the recording medium at a predetermined position in the transport direction.

9. a fixing unit that fixes the toner image that has been secondarily transferred onto the recording medium onto the recording medium; Further provided with 9. The image forming apparatus according to claim 8, wherein the predetermined state includes a state in which power supplied to the fixing unit is turned off.

10. An image forming apparatus in which a replaceable unit is mounted in a mounting portion inside the apparatus, and an image is formed on a recording medium by operating the replaceable unit, a holding portion that holds the replaceable unit in a state where the replaceable unit is attached to the attachment portion; a locking mechanism provided in the holding portion, which locks the replaceable unit so that it cannot be removed from the mounting portion, and which releases the locking mechanism when power supplied to the image forming apparatus is turned off; a control unit that, when receiving a replacement instruction for the replaceable unit while power supplied to the image forming apparatus is on, drives the lock mechanism to release the locked state; An image forming apparatus comprising:

11. 11. The image forming apparatus according to claim 10, wherein the replaceable unit is an intermediate transfer unit that carries and transports a toner image to be primarily transferred, and secondarily transfers the toner image onto the recording medium at a predetermined position in the transport direction.

12. a replaceable unit that is attached to a mounting portion inside the device; a holding portion that holds the replaceable unit in a state where the replaceable unit is attached to the attachment portion; a locking mechanism provided in the holding portion, which locks the replaceable unit so that it cannot be removed from the mounting portion, and which releases the locking mechanism when power supplied to the image forming apparatus is turned off; A control method for an image forming apparatus comprising: receiving an instruction to replace the replaceable unit when power supplied to the image forming apparatus is on; a step of driving the locking mechanism to release the locked state when the replacement instruction is received; A control method comprising:

13. a replaceable unit that is attached to a mounting portion inside the device; a holding portion that holds the replaceable unit in a state where the replaceable unit is attached to the attachment portion; a locking mechanism provided in the holding portion, which locks the replaceable unit so that it cannot be removed from the mounting portion, and which releases the locking mechanism when power supplied to the image forming apparatus is turned off; A program executed in an image forming apparatus comprising: receiving an instruction to replace the replaceable unit; a step of driving the locking mechanism to release the locked state when the replacement instruction is received; A program characterized by executing the following.

Images