Image forming apparatus

Abstract

The present application provides an image forming apparatus, which has a mechanism capable of reliably closing a cover member that opens and closes an opening portion of a fixing unit by an operator. The image forming apparatus (10) of the present application has an apparatus main body (1), a heating unit (5a), a fixing unit (5b), a first cover member (10a), an opening portion (100), a second cover member (102), a linkage mechanism (7), an operation portion (202), and an operation portion (201). The operation portion (202) is provided on a side surface of the apparatus main body (1) and operates to turn on or off a power supply. The operation portion (201) is provided on the first cover member and is capable of operating the operation portion in a state where the first cover member is arranged at a first closed position.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrophotographic image forming apparatus provided with a heating unit and a fixing unit. BACKGROUND

[0002] An electrophotographic image forming apparatus transfers a toner image from an image carrier to a sheet, and fixes the toner image to the sheet by a fixing device.

[0003] The fixing device is sometimes divided into a heating unit having a heater and a fixing unit having a fixing member and a pressure roller. The heater heats the fixing member.

[0004] Further, an image forming apparatus provided with a moving mechanism that moves the heating unit from a heating position to a retreat position is known. The image forming apparatus is provided with an opening portion for the fixing unit to enter and exit with respect to a device main body, and a cover member (opening and closing cover) for opening and closing the opening portion. The moving mechanism moves the heating unit from the heating position to the retreat position in conjunction with the opening operation of the cover member. When the cover member is positioned at an open position and the heating unit is retreated to the retreat position, an operator can pull out the fixing unit from the main body.

[0005] However, if the image forming apparatus is operated in a state where the cover member is open, there is a possibility that the image quality is reduced due to a temperature reduction of the fixing member on the opening portion side or dust entering from the opening portion. Further, there is a possibility that the image quality is reduced due to a positional displacement of the fixing unit. Generally, a mechanical or optical detection sensor is provided in order to detect the opening and closing of the cover member, and it is detected that the cover member is in an open state based on an output signal from the detection sensor. However, the provision of the detection sensor for detecting only the opening and closing of the cover member increases the number of components of the image forming apparatus and increases the manufacturing cost, and thus is not preferred. SUMMARY

[0006] An object of the present application is to provide an image forming apparatus provided with a mechanism that enables an operator to reliably close a cover member that opens and closes an opening portion of a fixing unit.

[0007] The image forming apparatus of the present application includes: an apparatus main body; a heating unit disposed inside the apparatus main body along a first direction, having a heater; a fixing unit disposed inside the apparatus main body along the first direction in a manner adjacent to a side of the heating unit, having a fixing member heated by the heater and a pressing member that applies a force to a sheet toward the fixing member; a first cover member supported to the apparatus main body in a manner rotatable between a first closed position that closes a side surface of a side of the apparatus main body in the first direction and a first open position that opens the side surface; an opening portion provided to the side surface, having an opening for attaching and detaching the fixing unit with respect to the apparatus main body; a second cover member provided to the side surface, supported to the apparatus main body in a manner rotatable between a second closed position that closes the opening portion and a second open position that opens the opening portion; a linkage mechanism that moves the heating unit between a reference position where an abutting portion of the heating unit abuts against the fixing unit and a retreat position further away from the fixing unit than the reference position in linkage with a rotation action of the second cover member between the second closed position and the second open position; an action portion provided to the side surface, performing an action to turn on or off a power supply; and an operation portion provided to the first cover member, causing the action portion to act in a state where the first cover member is disposed in the first closed position.

[0008] According to the present application, the cover member that opens and closes the opening portion of the fixing unit can be reliably closed by an operator without newly providing a sensor.

[0009] This specification suitably refers to the accompanying drawings by way of summarizing the contents of the concepts described in the following detailed description in a brief manner. The intention of this specification is not to limit the important features and essential features of the subject matter recited in the claims, and furthermore, is not to limit the scope of the subject matter recited in the claims. Furthermore, the subject matter recited in the claims is not limited to the embodiments that solve a part or all of the disadvantages recited in any part of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 FIG. 1 is a configuration diagram of an image forming apparatus of an embodiment.

[0011] Figure 2 FIG. 2 is a diagram showing a configuration of a main part of a fixing device in the image forming apparatus of the embodiment.

[0012] Figure 3 FIG. 3 is a front view of the fixing device and a linkage mechanism of a force application state in the image forming apparatus of the embodiment.

[0013] Figure 4is a front view of a fixing device and a linkage mechanism in a retreat state in an image forming apparatus of an embodiment.

[0014] Figure 5 is a perspective view of a front side of an image forming apparatus of an embodiment, showing a state in which a front cover is closed.

[0015] Figure 6 is a perspective view of a front side of an image forming apparatus of an embodiment, showing a state in which a front cover is opened.

[0016] Figure 7 is a perspective view of a front side of an image forming apparatus of an embodiment, showing a state in which a front cover and an inner cover are opened.

[0017] Figure 8 is a perspective view of a fixing unit and a peripheral portion of an inner cover in an image forming apparatus of an embodiment.

[0018] Figure 9 is a perspective view of a main body frame of an image forming apparatus of an embodiment.

[0019] Figure 10 is a plan view of a fixing device and a linkage mechanism in a retreat state in an image forming apparatus of an embodiment.

[0020] Figure 11 is a plan view of a fixing device and a linkage mechanism in a retreat state in an image forming apparatus of an embodiment.

[0021] Figure 12 is a block diagram showing a configuration of a control section of an image forming apparatus of an embodiment.

[0022] Figure 13 is a flowchart showing an example of a sequence of a cover state detection process performed by a control section of an image forming apparatus of an embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, an embodiment of the present application will be described with reference to the accompanying drawings. In addition, the following embodiment is an example of embodying the present application, and does not limit the technical scope of the present application.

[0024] [Configuration of image forming apparatus 10]

[0025] Figure 1 is a schematic view showing a configuration of an image forming apparatus 10 of the present embodiment. The image forming apparatus 10 performs a print process based on an electrophotographic method. The print process is a process of forming an image on a sheet 900 (refer to Figure 1 ). In addition, in the following description, the image forming apparatus 10 is assumed to be a multifunction peripheral that has a scanner function, a printer function, a copier function, and a facsimile function. Figure 1The state in which the image forming apparatus 10 is set as shown is defined as a reference to define the up-down direction D3, and the side closer to the user as the front side of the image forming apparatus 10 is defined as the front-rear direction Dl, and the left-right direction D2 or the width direction D2 is defined when the image forming apparatus 10 is viewed from the front. Figure 1 The state in which the image forming apparatus 10 is set as shown is defined as a reference to define the up-down direction D3, and the side closer to the user as the front side of the image forming apparatus 10 is defined as the front-rear direction Dl, and the left-right direction D2 or the width direction D2 is defined when the image forming apparatus 10 is viewed from the front.

[0026] As shown in FIG. 1, the image forming apparatus 10 includes a main body 1 (an example of an apparatus main body of the present application), a sheet body housing portion 2, a sheet body conveying device 3, a printing device 4, and a control portion 150 (an example of a heating control portion of the present application, refer to FIG. 2). Figure 1 The sheet body conveying device 3 and the printing device 4 are housed in the main body 1 as a housing. Figure 12

[0027] The sheet body housing portion 2 is capable of housing a plurality of sheet bodies 900. The sheet body conveying device 3 includes a sheet body feeding device 30 and a plurality of sets of conveying roller pairs 31.

[0028] The sheet body feeding device 30 feeds the sheet bodies 900 in the sheet body housing portion 2 one by one to a conveying passage 300. The conveying passage 300 is a passage for the sheet bodies 900.

[0029] The plurality of sets of conveying roller pairs 31 convey the sheet bodies 900 along the conveying passage 300. One set of conveying roller pairs 31a among the plurality of sets of conveying roller pairs 31 discharges the sheet bodies 900 on which images are formed from the conveying passage 300 to a paper discharge tray la.

[0030] The printing device 4 performs the printing process on the sheet bodies 900 conveyed along the conveying passage 300. The images formed on the sheet bodies 900 are toner images.

[0031] The printing device 4 includes a light scanning unit 40, one or more image forming portions 4x, a transfer device 45, and a fixing device 5. The image forming portion 4x includes a photosensitive drum 41, a charging device 42, a developing device 43, and a photosensitive drum cleaning device 44.

[0032] The charging device 42 charges the surface of the photosensitive drum 41. The light scanning unit 40 scans laser light on the surface of the charged photosensitive drum 41. Thus, the light scanning unit 40 forms an electrostatic latent image on the surface of the photosensitive drum 41.

[0033] The developing device 43 supplies toner to the surface of the photosensitive drum 41, thereby developing the electrostatic latent image into a toner image. The transfer device 45 transfers the toner image formed on the surface of the photosensitive drum 41 to the sheet body 900.

[0034] The transfer device 45 transfers the toner image to the sheet body 900 at a transfer position Pl in the conveying passage 300.

[0035] ​In the present embodiment, the printing device 4 is a serial color printing device provided with a plurality of image forming sections 4x. In addition, the transfer device 45 is provided with an intermediate transfer belt 450, a plurality of primary transfer devices 451, a secondary transfer device 452, and a belt cleaning device 453.

[0036] In Figure 1 In the example shown, the printing device 4 is provided with four image forming sections 4x corresponding to toners of four colors of yellow, magenta, cyan, and black. The transfer device 45 is provided with four primary transfer devices 451 corresponding to the four image forming sections 4x.

[0037] The intermediate transfer belt 450 is rotatably supported by a plurality of support rollers 454. One of the plurality of support rollers 454 is a drive roller that is rotated by a belt driving device not shown. Thus, the intermediate transfer belt 450 is rotated.

[0038] Each of the primary transfer devices 451 transfers the toner image formed on the surface of the photosensitive drum 41 in each of the image forming sections 4x to the surface of the intermediate transfer belt 450. Thus, a composite toner image in which toner images of the four colors are synthesized is formed on the surface of the intermediate transfer belt 450.

[0039] The intermediate transfer belt 450 carries the composite toner image and rotates. The secondary transfer device 452 transfers the composite toner image formed on the surface of the intermediate transfer belt 450 to the sheet 900 at a transfer position Pl.

[0040] The photosensitive drum cleaning device 44 removes primary waste toner from the surface of the photosensitive drum 41. The primary waste toner is toner that remains on the surface of the photosensitive drum 41 after passing through the primary transfer device 451.

[0041] The belt cleaning device 453 removes secondary waste toner from the surface of the intermediate transfer belt 450. The secondary waste toner is toner that remains on the surface of the intermediate transfer belt 450 after passing through the secondary transfer device 452.

[0042] The fixing device 5 heats and presses the composite toner image on the sheet 900 at a fixing position P2 in the conveyance path 300. Thus, the fixing device 5 fixes the composite toner image to the sheet 900. The fixing position P2 is a position located on the downstream side of the sheet conveyance direction with respect to the transfer position Pl.

[0043] Figure 2 is a view showing the configuration of the main part of the fixing device 5. As Figure 2As shown, the fixing device 5 is provided with a heater 51, a fixing belt 52 (an example of the fixing member of the present application), a fixing roller 520, a pressure roller 53 (an example of the pressure member of the present application), a temperature sensor 56 (an example of the temperature sensor of the present application), and a sheet separation member 57.

[0044] The fixing belt 52 is a flexible cylindrical member that houses the fixing roller 520. The fixing belt 52 is a fixing member that is heated by the heater 51.

[0045] The fixing roller 520 is a cylindrical member that supports the fixing belt 52 on the inside of the fixing belt 52. The fixing roller 520 has a cylindrical core portion 521 and an elastic portion 522 formed on the outer periphery of the core portion 521.

[0046] The fixing roller 520 is rotatably supported by the second support body 55 (see Figure 3 ). The fixing belt 52 is rotatable together with the fixing roller 520.

[0047] The fixing belt 52 has an electrically conductive base material, an elastic layer formed on the outer periphery of the base material, and a release layer formed on the outer periphery of the elastic layer.

[0048] The heater 51 is disposed in opposition to the outer peripheral surface of the fixing belt 52. In the present embodiment, the heater 51 is an electromagnetic induction heating type heating device, and is a heating device called a so-called IH heater. The heater 51 mainly heats the base material of the fixing belt 52 by electromagnetic induction. Note that the heater 51 is not limited to heating based on electromagnetic induction, and can heat the fixing belt 52 by other heating methods.

[0049] The heater 51 is connected to a control section 150 (see Figure 12 ). The control section 150 starts heating by the heater 51 by outputting a drive signal to the heater 51 when a prescribed start condition is satisfied, and controls the heater 51 to reach a predetermined fixing temperature (target temperature). Specifically, the control section 150 calculates the surface temperature of the fixing belt 52 based on a detection signal of the temperature sensor 56 described later, and controls the heater 51 so that the calculated temperature becomes the fixing temperature. In addition, the control section 150 stops the heating of the heater 51 by stopping driving the heater 51 when a prescribed stop condition is satisfied.

[0050] The pressure roller 53 is rotatably supported. The pressure roller 53 also has a cylindrical core portion 531 and an elastic portion 532 formed on the outer periphery of the core portion 531, like the fixing roller 520.

[0051] The pressure roller 53 is a pressure member that applies a sheet 900 to the fixing belt 52. In the present embodiment, the pressure roller 53 is supported by a second support body 55 (refer to Figure 3 ) to be described later in a state where an elastic portion 532 is pressure-bonded to the fixing belt 52.

[0052] The pressure roller 53 is driven to rotate by a drive device not shown. The fixing belt 52 and the fixing roller 520 rotate in conjunction with the pressure roller 53.

[0053] The fixing belt 52 heats the toner image formed on the sheet 900. The pressure roller 53 applies pressure to the toner image toward the sheet 900.

[0054] The sheet separation member 57 peels the sheet 900 from the fixing belt 52 when the sheet 900 is attached to the fixing belt 52.

[0055] The temperature sensor 56 is used to detect the temperature of the surface of the fixing belt 52. The temperature sensor 56 is provided at the periphery of the fixing unit 5b. The temperature sensor 56 is mounted to a bracket 55a (refer to Figure 2 ) supported by the second support body 55 (refer to Figure 3 ) to be described later, for example. The temperature sensor 56 is disposed at a position that is separated by a prescribed angle θ from the contact portion of the fixing belt 52 and the pressure roller 53, that is, the nip portion N10, on the upstream side in the rotation direction of the fixing belt 52. Thus, the temperature sensor 56 can detect the surface temperature of the fixing belt 52 before heat is taken away by the sheet 900 in the nip portion N10.

[0056] The temperature sensor 56 is a non-contact type temperature sensor. The non-contact type temperature sensor detects the surface temperature of an object (detection target object) by measuring electromagnetic waves such as infrared rays emitted from the object, and is a thermopile, for example. The temperature sensor 56 is configured so that the sensor head that detects the infrared rays opposes the outer peripheral surface of the fixing belt 52. The temperature sensor 56 is connected to the control portion 150 (refer to Figure 12 ). The detection signal output from the temperature sensor 56 is sent to the control portion 150, and the control portion 150 calculates the surface temperature of the fixing belt 52 based on the detection signal. In addition, the temperature sensor 56 can be any type of sensor, either non-contact type or contact type, as long as it is a sensor for detecting the surface temperature of the fixing belt 52.

[0057] Figure 3 and Figure 4 are diagrams that show the configuration of the fixing device 5. As Figure 3 and Figure 4As shown, the fixing device 5 of the present embodiment is divided into a heating unit 5a and a fixing unit 5b. The heating unit 5a is arranged in the inside of the main body 1 along the front-rear direction Dl. The fixing unit 5b is also arranged in the inside of the main body 1 along the front-rear direction Dl. In addition, the front-rear direction Dl corresponds to the first direction of the present application.

[0058] The heating unit 5a has a heater 51 and a first support 54. The fixing unit 5b has a fixing belt 52, a fixing roller 520, a pressure roller 53, and a second support 55.

[0059] The first support 54 is a member that supports the heater 51. The second support 55 is a member that supports the fixing belt 52, the fixing roller 520, and the pressure roller 53. The second support 55 supports the fixing belt 52 via the fixing roller 520.

[0060] In the present embodiment, the heating unit 5a is moved to a position (position shown) away from the fixing unit 5b, whereby the fixing unit 5b can be pulled out of the main body 1 (refer to Figure 4 ). Figure 11

[0061] Figure 5 Figure 6 is a perspective view showing the front side of the image forming apparatus 10. As shown, the main body 1 has a front cover 10a (an example of the first cover member of the present application). Figure 5 Figure 5 shows a state in which the front cover 10a is closed. The front cover 10a covers an opening 10b (refer to Figure 6 ) of the front side of the main body 1. In addition, the front cover 10a constitutes the outer appearance of the front of the image forming apparatus 10 in the closed state.

[0062] The front cover 10a is configured to be able to open and close the opening 10b. The front cover 10a is supported so as to be able to rotate with the vicinity of the lower edge portion of the opening 10b as a rotation support point. Therefore, the front cover 10a is able to rotate in a manner of tilting to the front side from the closed state. The front cover 10a is supported so as to be able to rotate between a first closed position (position shown) in which the opening 10b is closed and a first open position (position shown) in which the opening 10b is opened. If the front cover 10a is opened, a partition member 100 described later is exposed. Figure 5 Figure 6

[0063] As shown, in the main body 1, the partition member 100 is provided inside the front cover 10a. The partition member 100 is a plate-like member that partitions the inside of the main body 1 from the front side of the main body 1. In the present embodiment, the partition member 100 is provided in the vicinity of the right end portion in the main body 1. Figure 6

[0064] As shown, in the main body 1, the partition member 100 is provided inside the front cover 10a. The partition member 100 is a plate-like member that partitions the inside of the main body 1 from the front side of the main body 1. In the present embodiment, the partition member 100 is provided in the vicinity of the right end portion in the main body 1. Figure 7 ​​​​​​As shown, the partition member 100 has an opening portion 101 (an example of the opening portion of the present application) and an inner cover 102 (an example of the second cover member of the present application). Here, Figure 7 is a perspective view showing the front side of the image forming apparatus 10, showing a state in which the front cover 10a and the inner cover 102 are open.

[0065] The opening portion 101 has an opening for dismounting the fixing unit 5b with respect to the main body 1. That is, the opening portion 101 includes an opening located on one side (front side) of the front-rear direction D1 of the housing space of the fixing unit 5b. Inside the main body 1, the space on the inner side of the opening portion 101 is a housing space capable of dismountably housing the fixing unit 5b.

[0066] As shown in Figure 5 , a power source operation portion 201 (an example of the operation portion of the present application) is provided on the front cover 10a, which is operated to turn on or off the power source of the image forming apparatus 10. In addition, as shown in Figure 6 , an action member 202 (an example of the action portion of the present application) that acts when the power source is turned on or off is provided on the partition member 100. The action member 202 is a moving member that is supported so as to be movable between an on position at which an actuator provided on the main body 1 is pressed to make the contacts of the power switch (not shown) conductive, and an off position at which the actuator is separated from the power switch to cut off the contacts of the power switch.

[0067] The power source operation portion 201 is provided at a position corresponding to the action member 202. That is, the power source operation portion 201 is provided at a position opposite to the action member 202 in a state in which the front cover 10a is closed. Therefore, in a state in which the front cover 10a is closed, when the power source operation portion 201 is operated by an operator, the power source operation portion 201 presses the action member 202, and the action member 202 can be moved to the on position or the off position.

[0068] For example, in the configuration in which the front cover 10a and the inner cover 102 are provided separately, there is a case in which the inner cover 102 is in the open state even if the front cover 10a is closed. In this case, if the image forming apparatus 10 performs a printing operation, there is a possibility that the temperature of the portion of the fixing belt 52 on the side of the opening portion 101 decreases or dust enters from the opening portion 101, resulting in a decrease in image quality. In addition, there is a possibility that the positioning of the fixing unit 5b in the front-rear direction D1 is not performed and a positional deviation occurs, resulting in a decrease in image quality. On the other hand, in order to detect the opening and closing of the inner cover 102, by providing a mechanical or optical detection sensor, it is possible to detect a case in which the inner cover 102 is in the open state. However, the provision of a detection sensor for detecting only the opening and closing of the inner cover 102 results in an increase in the number of components of the image forming apparatus 10 and an increase in product cost, and thus is not preferable.

[0069] On the contrary, in the image forming apparatus 10 of the present embodiment, the inner cover 102 is provided in the partition member 100, and further, the front cover 10a is provided on the outer side thereof. Therefore, in the state in which the inner cover 102 is open, the front cover 10a cannot be closed. Further, if the front cover 10a is not closed, the power supply is not turned on even if the operator operates the power supply operation portion 201. Therefore, for example, even if the fixing unit 5b is reinstalled when the fixing unit 5b is maintained or replaced, and then the inner cover 102 is forgotten to be closed, the operator can easily find that the inner cover 102 is forgotten to be closed. Therefore, according to the image forming apparatus 10, even if the operator forgets to close the inner cover 102, the operator can reliably close the inner cover 102.

[0070] Figure 8 is a perspective view of the fixing unit 5b and the peripheral portion of the inner cover 102 in the image forming apparatus 10. As shown in Figure 8 , the main body 1 is provided with a main body frame 1x. The main body frame 1x forms a skeleton of the main body 1. The partition member 100 is attached to the main body frame 1x.

[0071] The main body frame 1x is configured by a combination of a plurality of metal pipes. The heating unit 5a and the fixing unit 5b are supported by the main body frame 1x. The fixing unit 5b is arranged adjacent to the side of the heating unit 5a. In the present embodiment, the fixing unit 5b is arranged on the right side of the heating unit 5a.

[0072] Figure 9 is a perspective view of the main body frame 1x. As shown in Figure 9 , the plurality of metal pipes configuring the main body frame 1x have two pillar portions 11 and two beam portions 12.

[0073] The two pillar portions 11 extend along the up-down direction D3 and are arranged at intervals in the front-rear direction D1. The up-down direction D3 is the longitudinal direction or the height direction.

[0074] In addition, as shown in Figure 8 Two pillar portions 11 are formed by extending in the up-and-down direction D3 at the side (right side) of the fixing unit 5b.

[0075] The front-and-rear direction D1 is also a direction along a center line of rotation of the fixing belt 52 and the pressure roller 53. In the present embodiment, the front-and-rear direction D1 is a depth direction of the image forming apparatus 10.

[0076] The inner cover 102 is supported by the main body 1 so as to be rotatable between a second closed position (position shown in Figure 8 ) in which the opening portion 101 is closed, and a second open position (position shown in Figure 7 ) in which the opening portion 101 is opened.

[0077] Figure 3 and Figure 10 indicates the fixing device 5 when the inner cover 102 is in the second closed position. Figure 4 and Figure 11 indicates the fixing device 5 when the inner cover 102 is in the second open position.

[0078] As shown in Figure 10 and Figure 11 In the present embodiment, the inner cover 102 has a first support shaft 102x at the upper end and the lower end of the left end portion thereof, respectively. The first support shaft 102x protrudes in a direction along the up-and-down direction D3. An axial hole (not shown) for the first support shaft 102x to pass through is formed in the upper edge portion and the lower edge portion of the opening portion 101, respectively. The inner cover 102 is supported by the first support shaft 102x by the first support shaft 102x being inserted into the axial hole. Thus, the inner cover 102 is rotatable about the first support shaft 102x in the direction indicated by an arrow D21 (refer to Figure 10 ). More specifically, the inner cover 102 is rotatable between the second closed position in which the opening portion 101 is closed, and the second open position in which the opening portion 101 is opened.

[0079] When the inner cover 102 is in the second closed position, the inner cover 102 is held in the second closed position by a lock mechanism (not shown). By releasing the lock of the lock mechanism, the inner cover 102 is rotatable from the second closed position to the second open position.

[0080] However, it is important to arrange the heater 51 at an appropriate position with respect to the fixing belt 52 in terms of improving the heating efficiency of the heater 51 on the fixing belt 52. The accuracy of the position of the heater 51 is particularly important in the case where an electromagnetic induction heating type heating device is employed as the heater 51.

[0081] In addition, in order to pull the fixing unit 5b out of the storage space inside the main body 1, the positioning mechanism of the heating unit 5a needs to have both approach and retraction functions.

[0082] The proximity function positions the heating unit 5a at a reference position close to the fixing unit 5b. The retraction function moves the heating unit 5a to a retraction position away from the fixing unit 5b.

[0083] Therefore, in order to accurately position the heating unit 5a at the reference position, the mechanical clearance of the positioning mechanism must not adversely affect the positioning of the heating unit 5a.

[0084] The image forming apparatus 10 includes a mechanism for precisely positioning the heating unit 5a and the fixing unit 5b at a target position. According to this embodiment, the positioning mechanism for positioning the heating unit 5a and the fixing unit 5b at the target position is implemented using a simple mechanism. The mechanism for positioning the heating unit 5a and the fixing unit 5b will be described below.

[0085] [Mechanism for positioning the heating unit 5a and the fixing unit 5b]

[0086] like Figure 9 As shown, the two support portions 11 include a first support portion 11a disposed on the front side of the image forming apparatus 10 and a second support portion 11b disposed on the rear side of the image forming apparatus 10.

[0087] like Figure 8 as well as Figure 9 As shown, the two beams 12 are in the heating unit 5a and the fixing unit 5b (see reference). Figure 3 The lower side of the ) is formed by extending along the left-right direction (width direction) D2, and is arranged at intervals in the front-back direction D1.

[0088] The two beam sections 12 are respectively connected to the two support sections 11. For example, the two beam sections 12 are respectively connected to the two support sections 11 by welding.

[0089] The two beam portions 12 include: a first beam portion 12a, disposed on the front side of the image forming apparatus 10; and a second beam portion 12b, disposed on the rear side of the image forming apparatus 10.

[0090] like Figure 3 As shown, the fixing unit 5b is disposed between the heating unit 5a and the two support columns 11.

[0091] The first support body 54 of the heating unit 5a is placed on the two beam portions 12 in a state of being supported on the two beam portions 12. Likewise, the second support body 55 of the fixing unit 5b is placed on the two beam portions 12 in a state of being supported on the two beam portions 12.

[0092] That is, neither the heating unit 5a nor the fixing unit 5b is fixed with respect to the main frame 1x by a fixing member such as a screw.

[0093] As shown in Figure 10 and Figure 11 , the heating unit 5a and the fixing unit 5b are placed on the two beam portions 12 in a state where their long side directions are along the front-rear direction D1.

[0094] The heating unit 5a and the fixing unit 5b are arranged in the left-right direction (width direction) D2. That is, the left-right direction D2 is the arrangement direction of the heating unit 5a and the fixing unit 5b. The left-right direction D2 is a width direction that intersects the front-rear direction D1.

[0095] As shown in Figure 3 and Figure 10 , the image forming apparatus 10 further includes an acting member 6 (an example of the acting member of the present application), a pressing spring 60 (an example of the unit urging member of the present application), and a linkage mechanism 7 (an example of the linkage mechanism of the present application). The acting member 6 and the pressing spring 60 are arranged inside the main body 1.

[0096] The acting member 6 is supported inside the main body 1 so as to be movable between a first position and a second position. The acting member 6 is movable along the left-right direction D2. Figure 3 and Figure 10 indicates a state in which the acting member 6 exists in the first position. Figure 4 and Figure 11 indicates a state in which the acting member 6 exists in the second position.

[0097] The acting member 6 sandwiches the pressing spring 60 between the heating unit 5a when existing in the first position (refer to Figure 3 ). That is, the first position is a position in which the acting member 6 is arranged in a manner of sandwiching the pressing spring 60 between the heating unit 5a, and the heating unit 5a is located at the reference position. The second position is a position that is farther to the side (left side) from the fixing unit 5b than the first position (refer to Figure 4 ). That is, the second position is a position in which the acting member 6 is arranged at a position that is farther to the side (left side) from the fixing unit 5b than the first position, and the heating unit 5a is located at the retreat position.

[0098] The pressing spring 60 is an elastic member. As shown in Figure 3As shown, the pressing spring 60 is arranged inside the main body 1 on the opposite side of the fixing unit 5b side with respect to the heating unit 5a. Specifically, the pressing spring 60 is arranged on the left side of the first support body 54 of the heating unit 5a. For example, the pressing spring 60 is supported by the protrusion portion 544 of the left end portion of the first support body 54 so as to be able to stretch and contract in the left-right direction D2.

[0099] The pressing spring 60 exerts a force on the first support body 54 toward the second support body 55 by the elastic force when the acting member 6 is in the first position. Figure 3 The first support body 54 is shown in a state in which the first support body 54 is pressed by the pressing spring 60 toward the second support body 55 by the elastic force.

[0100] The pressing spring 60 exerts a force F1 (refer to Figure 3 ) on the first support body 54 toward the second support body 55.

[0101] The first support body 54 has one or more ribs 541 that come into contact with the upper surfaces of the two beam portions 12. Similarly, the second support body 55 has a plurality of ribs 551 (refer to Figure 3 ) that come into contact with the upper surfaces of the two beam portions 12. The ribs 541 of the first support body 54 and the ribs 551 of the second support body 55 are provided in order to reduce the static friction.

[0102] The pressing spring 60 brings the first support body 54 into abutment with the second support body 55 by exerting a force on the first support body 54. Further, the pressing spring 60 brings the second support body 55 into abutment with the two pillar portions 11 by exerting a force on the first support body 54. That is, the pressing spring 60 exerts a force on the second support body 55 via the first support body 54.

[0103] As shown in Figure 3 and Figure 4 , the first support body 54 has a plurality of first fitting portions 542. Each first fitting portion 542 is formed in a recessed shape and opens in the side direction (right side in the present embodiment) of the first support body 54. Each first fitting portion 542 is provided at an end portion of the first support body 54 on the fixing unit 5b side. The first support body 54 has four first fitting portions 542 formed at intervals in the front-rear direction D1 and the up-down direction D3.

[0104] The second support body 55 has a plurality of second fitting portions 553. Each second fitting portion 553 is formed in a convex shape so as to be fitted into each first fitting portion 542. The second support body 55 has four second fitting portions 553 corresponding to the four first fitting portions 542.

[0105] As shown in Figure 3As shown, the inner surfaces of the recessed portions of the four first fitting portions 542 are in abutment with the four second fitting portions 553 by pressing the spring 60 to apply a force to the first support body 54. In the present embodiment, the inner surfaces of the four first fitting portions 542 are portions that are in abutment with the fixing unit 5b by the force received from the pressing spring 60, and are an example of the abutment portion of the present application. That is, the four first fitting portions 542 include the abutment portion.

[0106] In addition, by fitting the first fitting portion 542 into the second fitting portion 553, the relative movement of the first support body 54 and the second support body 55 in the up-down direction D3 is restricted.

[0107] In addition, it is also possible that the second support body 55 is provided with the first fitting portion 542, and the first support body 54 is provided with the second fitting portion 553.

[0108] In addition, as shown in Figure 3 and Figure 4 , the second support body 55 has a plurality of column abutment portions 552 that project toward the two pillar portions 11. The plurality of column abutment portions 552 are in abutment with the side surfaces of the two pillar portions 11.

[0109] The linkage mechanism 7 moves the heating unit 5a between the reference position and the retreat position in linkage with the turning action of the inner cover 102 when opening and closing the opening portion 101. Here, the reference position is a position at which an abutment portion of a portion of the heating unit 5a is in abutment with the fixing unit 5b. In addition, the retreat position is a position that is apart from the fixing unit 5b by a prescribed interval to the side (left side) from the reference position.

[0110] In the present embodiment, the linkage mechanism 7 moves the acting member 6 in the left-right direction D2 in linkage with the turning action of the inner cover 102. In addition, the inner cover 102 is turned by the operation of the operator.

[0111] The linkage mechanism 7 moves the acting member 6 from one of the first position and the second position to the other in linkage with the turning action of the inner cover 102.

[0112] The linkage mechanism 7 moves the acting member 6 from the first position (the position shown in Figure 10 ) to the second position (the position shown in Figure 11 ) when the inner cover 102 is turned from the second closed position (refer to Figure 3 ) to the second open position (refer to Figure 4 ).

[0113] Further, the linkage mechanism 7 moves the acting member 6 from the second position to the first position when the inner cover 102 is turned from the second open position to the second closed position.

[0114] When the acting member 6 moves from the first position to the second position, the heating unit 5a moves from the reference position to the retreat position in conjunction with the movement of the acting member 6 (refer to Figure 3 and Figure 4 ).

[0115] When the acting member 6 moves from the second position to the first position, the heating unit 5a moves from the retreat position to the reference position in conjunction with the movement of the acting member 6 (refer to Figure 3 and Figure 4 ).

[0116] Figure 3 and Figure 10 indicates a state in which the heating unit 5a is located at the reference position. Figure 4 and Figure 11 indicates a state in which the heating unit 5a is located at the retreat position.

[0117] The reference position is a position of the heating unit 5a in which the heating unit 5a abuts against the fixing unit 5b (refer to Figure 3 and Figure 10 ).

[0118] When the heating unit 5a is located at the reference position, the four first fitting portions 542 of the heating unit 5a abut against the four second fitting portions 553 of the fixing unit 5b.

[0119] The retreat position is a position of the heating unit 5a in which the heating unit 5a is away from the fixing unit 5b (refer to Figure 4 and Figure 11 ).

[0120] When the heating unit 5a moves from the reference position to the retreat position, the four first fitting portions 542 are away from the four second fitting portions 553 (refer to Figure 4 ).

[0121] In addition, the heating unit 5a is located at the reference position synonymously with the first support body 54 being located at the reference position. In addition, the heating unit 5a is located at the retreat position synonymously with the first support body 54 being located at the retreat position.

[0122] When the heating unit 5a is located at the retreat position, the fixing unit 5b can be pulled out from the inside of the main body 1 to a detachment direction D11 (refer to Figure 11 ). The fixing unit 5b has a handle portion (not shown) which is held by hand when pulled out from the inside of the main body 1. The fixing unit 5b is pulled out from the inside of the main body 1 without contacting the heating unit 5a. The detachment direction D11 is a direction along the front-rear direction D1.

[0123] When the fixing unit 5b is pulled out from the main body frame 1x, the fixing unit 5b is able to pass through the opening portion 101 of the partition member 100.

[0124] As shown in Figure 3 , if the heating unit 5a moves from the retreat position to the reference position, the four second fitting portions 553 are fitted into the four first fitting portions 542. Therefore, when the heating unit 5a exists in the reference position, the four first fitting portions 542 of the heating unit 5a abut against the four second fitting portions 553 of the fixing unit 5b.

[0125] The first support body 54 of the heating unit 5a has an engaged portion 543 which is engaged with a portion of the action member 6. In addition, the action member 6 has an engaging portion 62 which is able to be engaged with the engaged portion 543 of the first support body 54.

[0126] As shown in Figure 4 , in the middle of the movement of the action member 6 from the first position to the second position, the engaging portion 62 is engaged with the engaged portion 543.

[0127] When the action member 6 moves from the first position to the second position, the heating unit 5a is engaged with the engaged portion 62. Thereby, the heating unit 5a is forced by the engaging portion 62 from the action member 6 to move from the reference position to the retreat position (refer to Figure 4 ).

[0128] On the other hand, when the action member 6 moves from the second position to the first position along the left-right direction D2, the engagement of the engaging portion 62 with the engaged portion 543 is released.

[0129] After the engagement of the engaging portion 62 with the engaged portion 543 is released, when the action member 6 further moves to the first position, the action member 6 forces the first support body 54 of the heating unit 5a toward the fixing unit 5b via the pressing spring 60 (refer to Figure 3 ).

[0130] When the action member 6 moves from the second position to the first position, the heating unit 5a is forced by the pressing spring 60 from the action member 6 to move from the retreat position to the reference position (refer to Figure 3 ).

[0131] When the action member 6 exists in the first position, the four first fitting portions 542 of the heating unit 5a abut against the four second fitting portions 553 of the fixing unit 5b by the force from the pressing spring 60 (refer to Figure 3 ).

[0132] The heating unit 5a and the fixing unit 5b are positioned in the left-right direction D2 by being sandwiched between the pressing spring 60 and the two support portions 11. The four first fitting portions 542 are fitted into the second fitting portions 553, and the heating unit 5a is positioned at the reference position by abutting against the fixing unit 5b.

[0133] In addition, the pressing spring 60 applies a force to the heating unit 5a toward the fixing unit 5b by an elastic force. Thus, it is possible to avoid a mechanical play of the link mechanism 7 from adversely affecting the positioning of the heating unit 5a.

[0134] As shown in Figure 10 , in the present embodiment, the link mechanism 7 includes a link member 71, a tension spring 72, a first link member 73, and a second link member 74.

[0135] The link member 71 is supported so as to be movable along the front-rear direction D1 between a prescribed restriction position (position shown in Figure 10 ) and a prescribed release position (position shown in Figure 11 ). Figure 10 represents a state in which the link member 71 is present at the restriction position. Figure 11 represents a state in which the link member 71 is present at the release position.

[0136] In addition, the acting member 6 has a first protruding portion 61 protruding toward the opposite side with respect to the heating unit 5a side. The link member 71 has a second protruding portion 711 protruding toward the acting member 6 side.

[0137] The tension spring 72 is an elastic member that applies a force to the acting member 6 in a direction away from the fixing unit 5b. The tension spring 72 is an example of a retreat biasing member.

[0138] The force F2 (refer to Figure 4 ) of the tension spring 72 acting on the acting member 6 is greater than the static friction of the heating unit 5a with respect to the two beam portions 12.

[0139] The first link member 73 is linked to the link member 71 by a first link shaft 713. In the present embodiment, the link member 71 has an arm portion 712 extending toward the inner cover 102. The first link shaft 713 links the arm portion 712 and the first link member 73.

[0140] The second link member 74 is linked to the first link member 73 by a second link shaft 731. Further, the second link member 74 is linked to the inner cover 102 by a third link shaft 741.

[0141] The second link member 74 is supported by a second support shaft 740. The second link member 74 is rotatable about the second support shaft 740.

[0142] The first link member 73, the first link shaft 713, the second link shaft 731, the second link member 74, and the third link shaft 741 are a link mechanism that converts the rotational motion of the inner cover 102 to the linear motion of the link member 71.

[0143] By the action of the link mechanism, the link member 71 moves from the restriction position to the release position in conjunction with the turning action of the inner cover 102 from the second closed position to the second open position. Likewise, by the action of the link mechanism, the link member 71 moves from the release position to the restriction position in conjunction with the turning action of the inner cover 102 from the second open position to the second closed position.

[0144] The first protrusion 61 has a first inclined side surface 61a (refer to Figure 10 and Figure 11 ) that is formed so as to be inclined from the root portion toward the head portion. Likewise, the second protrusion 711 has a second inclined side surface 711a (refer to Figure 10 and Figure 11 ) that is formed so as to be inclined from the root portion toward the head portion.

[0145] When the link member 71 moves from the restriction position to the release position, the second inclined side surface 711a slides on the first inclined side surface 61a in a downward direction. The downward direction is a direction from the head portion toward the root portion of the first protrusion 61.

[0146] By the second inclined side surface 711a sliding on the first inclined side surface 61a in the downward direction, the acting member 6 moves from the first position to the second position under the force of the tension spring 72 (refer to Figure 11 ).

[0147] On the other hand, when the link member 71 moves from the release position to the restriction position, the second inclined side surface 711a slides on the first inclined side surface 61a in an upward direction. The upward direction is a direction from the root portion toward the head portion of the first protrusion 61.

[0148] By the second inclined side surface 711a sliding on the first inclined side surface 61a in the upward direction, the acting member 6 moves from the second position to the first position against the force of the tension spring 72 by the force received from the second protrusion 711 (refer to Figure 10 ).

[0149] In the present embodiment, the second inclined side surface 711a of the second protrusion 711 is an example of a sliding portion that comes into contact with the first inclined side surface 61a.

[0150] In addition, the first inclined side surface 61a is an example of a sliding portion that comes into contact with the second inclined side surface 711a.

[0151] That is, when the link member 71 moves from the restriction position to the release position, the first inclined side surface 61a slides on the second inclined side surface 711a in a downward direction. The downward direction in this case is a direction from the top of the second protruding portion 711 toward the root.

[0152] By the first inclined side surface 61a sliding on the second inclined side surface 711a in the downward direction, the acting member 6 moves from the first position to the second position under the force of the tension spring 72 (refer to Figure 11 ).

[0153] On the other hand, when the link member 71 moves from the release position to the restriction position, the first inclined side surface 61a slides on the second inclined side surface 711a in an upward direction. The upward direction in this case is a direction from the root of the second protruding portion 711 toward the top.

[0154] By the first inclined side surface 61a sliding on the second inclined side surface 711a in the upward direction, the acting member 6 moves from the second position to the first position against the force of the tension spring 72 by the force received from the second protruding portion 711 (refer to Figure 10 ).

[0155] In addition, the link mechanism 7 can also include a gear mechanism such as a rack and pinion mechanism. In this case, the link mechanism 7 also converts the turning action of the inner cover 102 into an action of moving the acting member 6 in the left-right direction D2.

[0156] In addition, the heating unit 5a and the fixing unit 5b are positioned in the up-down direction D3 by being placed on the two beam portions 12. The load of the heating unit 5a and the fixing unit 5b restricts the upward movement of the heating unit 5a and the fixing unit 5b.

[0157] In addition, the image forming apparatus 10 is also provided with a cover urging mechanism 8 mounted to the inner side surface of the inner cover 102 (refer to Figure 10 and Figure 11 ). In addition, the second support body 55 of the fixing unit 5b has a beam abutting portion 554 protruding downward from the lower surface (refer to Figure 3 , Figure 4 and Figure 8 ).

[0158] As shown in Figure 10 , the cover urging mechanism 8 is provided with a third spring 80, a spring box 81, and a cover portion 82.

[0159] The spring box 81 accommodates the third spring 80. The cover portion 82 is mounted so as to be movable with respect to the spring box 81. The third spring 80 is an example of an urging member having elasticity that urges the fixing unit 5b to the rear side.

[0160] When the inner cover 102 is in the second closed position, the third spring 80 is clamped between the inner cover 102 and the second support 55 of the fixing unit 5b. In this embodiment, the third spring 80 and the cover portion 82 are clamped between the inner cover 102 and the second support 55.

[0161] like Figure 10 As shown, the third spring 80, sandwiched between the inner cover 102 and the second support 55, exerts a force on the second support 55 in the installation direction D12 through its elasticity. The installation direction D12 is opposite to the removal direction D11.

[0162] Furthermore, utilizing the force exerted on the second support 55 by the third spring 80 when the inner cover 102 is in the second closed position, the beam abutment portion 554 abuts against the side of one of the two beam portions 12. In this embodiment, the beam abutment portion 554 abuts against the side of the second beam portion 12b.

[0163] The fixing unit 5b is positioned in the front-rear direction D1 by the action of the third spring 80 and the beam abutment 554.

[0164] Alternatively, the covering force mechanism 8 can also be installed on the second support 55 of the fixing unit 5b.

[0165] [Control Unit 150]

[0166] The control unit 150 comprehensively controls the image forming apparatus 10. The control unit 150 is an example of the heating control unit of the present invention, and controls the heater 51 of the heating unit 5a. Furthermore, the control unit 150 is an example of the judgment unit of the present invention.

[0167] like Figure 12 As shown, the control unit 150 includes a CPU 151, a ROM 152, a RAM 153, and an EEPROM 154 (registered trademark). The ROM 152 is a non-volatile storage device, the RAM 153 is a volatile storage device, and the EEPROM 154 is a non-volatile storage device. The RAM 153 and EEPROM 154 are used as temporary storage for various processes executed by the CPU 151. Additionally, a predetermined control program is stored in the ROM 152. In this embodiment, the control unit 150 performs arithmetic processing according to the control program via the CPU 151, and performs the cover state detection processing described later. Alternatively, the control unit 150 may also be constructed using integrated circuits (ASIC, DSP, etc.).

[0168] As described above, a heater 51 and a temperature sensor 56 are connected to the control unit 150. The control unit 150 controls the heater 51 based on the detection signal from the temperature sensor 56.

[0169] In the present embodiment, in a case where the front cover 10a is closed in a state where the inside cover 102 is not properly closed, thereby resulting in an uninstalled state where the fixing unit 5b is not properly installed in the fixing device 5, the control section 150 determines whether the inside cover 102 is properly closed by using the existing temperature sensor 56 (cover state detection processing). By performing the cover state detection processing, even if it is assumed that the front cover 10a is closed in an uninstalled state where the fixing unit 5b is not properly installed in the closing mode of the inside cover 102 is not sufficient, it is not necessary to additionally add a sensor, and it is possible to determine that the closing state of the inside cover 102 is not sufficient, and further determine that the fixing unit 5b is not properly installed in the uninstalled state. Therefore, it is possible to achieve a safe image forming apparatus 10 without performing an excessive heating operation due to heating by the heater 51 in the uninstalled state.

[0170] [Cover state detection processing]

[0171] Hereinafter, an example of the order of the cover state detection processing performed by the image forming apparatus 10 will be described with reference to the flowchart of FIG. 10. Here, S11, S12,... in FIG. 10 indicate the numbers of processing orders (steps). In addition, the cover state detection processing is performed in a case where the power of the image forming apparatus 10 is turned on in a state where the inside cover 102 is not properly closed and the fixing unit 5b is in an uninstalled state after the power is turned off and the fixing unit 5b is replaced. Figure 13 Figure 13 In a state where the closing mode of the inside cover 102 is not sufficient, if the power operation section 201 is operated after the front cover 10a is closed, the power of the image forming apparatus 10 is turned on from off (S11). By turning on the power from off, it is possible to determine that the front cover 10a has been closed. In addition, in a case where a cover sensor that detects the opening and closing state of the front cover 10a is provided, it is also possible to perform the processing after step S12 after the control section 150 confirms the closing state of the front cover 10a detected by the cover sensor after the power is turned on.

[0172] If the power is turned on, the control section 150 drives the heater 51, and heating by the heater 51 is started (S12).

[0173]

[0174] ​​In the next step S13, the control section 150 determines whether or not the predetermined set time has elapsed since the start of heating of the heater 51. Here, the set time is a time in which the detection temperature detected by the temperature sensor 56 becomes the predetermined reference temperature or more in the case where the heater 51 is heated in the state in which the fixing unit 5b is normally installed. In addition, the set time is a time in which the detection temperature detected by the temperature sensor 56 is lower than the reference temperature in the case where the heater 51 is heated in the non-installed state in which the fixing unit 5b is not normally installed. In addition, the reference temperature is an example of the threshold value defined in the present application.

[0175] If the set time has elapsed since the start of heating of the heater 51, the control section 150 calculates the temperature on the basis of the detection signal of the temperature sensor 56 (S14).

[0176] In the next step S15, the control section 150 determines whether or not the calculated temperature calculated in step S14 is the reference temperature or more.

[0177] In step S15, if it is determined that the calculated temperature is the reference temperature or more, the control section 150 determines that the inner cover 102 is normally closed and the fixing unit 5b is normally installed (S15). Thereafter, the series of processing is ended. In addition, in the case where the inner cover 102 is normally closed and the fixing unit 5b is normally installed, since the heating unit 5a is disposed at the reference position, the fixing belt 52 can be normally heated by the heater 51. Therefore, the calculated temperature becomes the reference temperature or more.

[0178] On the other hand, in step S15, if it is determined that the calculated temperature is lower than the reference temperature, the control section 150 determines that the inner cover 102 is not normally closed and the fixing unit 5b is not normally installed, and outputs an installation error (S17). Thereafter, the driving of the heater 51 is stopped (S18), and the series of processing is ended. In addition, in the case where the inner cover 102 is not normally closed, since the heating unit 5a is disposed at the retreat position, the distance from the heater 51 to the fixing belt 52 becomes long, the magnetic force generated by the heater 51 is difficult to reach the conductive base material of the fixing belt 52, the density of the magnetic lines of force of the conductive base material becomes small, and the fixing belt 52 cannot be raised to the reference temperature within the set time. Therefore, in the case where the calculated temperature is lower than the reference temperature, it can be determined that the inner cover 102 is not normally closed.

[0179] As described above, in the present embodiment, since the cover state detection processing is executed by the control section 150, it is not necessary to additionally add a sensor, and it is possible to determine whether or not the inner cover 102 is normally closed by using the existing temperature sensor 56.

[0180] [PATENT CLAIM] 1. An image forming apparatus comprising: a fixing unit including a heating unit and a fixing belt; a cover which is provided to be openable and closable with respect to the fixing unit; a temperature sensor which detects a temperature of the fixing belt; and a control section which determines whether or not the cover is normally closed on the basis of a detection signal of the temperature sensor. 2. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the state in which the cover is normally closed. 3. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the non-closed state in which the cover is not normally closed. 4. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the state in which the cover is normally closed. 5. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the non-closed state in which the cover is not normally closed. 6. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the state in which the cover is normally closed. 7. The image forming apparatus according to claim 1, wherein the control section determines whether or not the cover is normally closed on the basis of a detection temperature detected by the temperature sensor in the case where the heating unit is heated in the non-closed state in which the cover is not normally closed.

[0181] Hereinafter, the summary of the invention extracted from the above-described embodiments is described. In addition, each configuration and each processing function described in the following notes can be arbitrarily combined by selection.

[0182] <Note 1>

[0183] An image forming apparatus including:

[0184] an apparatus main body;

[0185] a heating unit (5a) disposed inside the apparatus main body along a first direction (D1) and having a heater;

[0186] a fixing unit (5b) disposed inside the apparatus main body along the first direction (D1) in a manner adjacent to a side of the heating unit, and having a fixing member heated by the heater and a pressing member that applies a sheet body to the fixing member;

[0187] a first cover member supported to the apparatus main body in a manner rotatable between a first closed position that closes a side of the apparatus main body on a side of the first direction and a first open position that opens the side;

[0188] an opening portion provided to the side and having an opening for attaching and detaching the fixing unit with respect to the apparatus main body;

[0189] a second cover member provided to the side and supported to the apparatus main body in a manner rotatable between a second closed position that closes the opening portion and a second open position that opens the opening portion;

[0190] a linkage mechanism that moves the heating unit between a reference position at which an abutting portion of the heating unit abuts against the fixing unit and a retreat position further away from the fixing unit than the reference position in linkage with a rotation action of the second cover member between the second closed position and the second open position;

[0191] an action portion provided to the side and performing an action to turn on or off a power supply; and

[0192] an operation portion provided to the first cover member and capable of causing the action portion to act in a state in which the first cover member is disposed in the first closed position.

[0193] <Note 2>

[0194] In the image forming apparatus described in Note 1, further comprising:

[0195] a temperature sensor capable of detecting a temperature of the fixing member;

[0196] a heating control section that performs a heating operation of heating the stopped heater in a case where the first cover member is turned from the first closed position to the first open position; and

[0197] a determination section that determines that the second cover member is open in a case where a detection temperature detected by the temperature sensor after the heating operation is performed is less than a prescribed threshold value.

[0198] <NOTE 3>

[0199] In the image forming apparatus described in Note 2,

[0200] the heating control section performs the heating operation within a predetermined set time, on condition that the first cover member is turned from the first closed position to the first open position,

[0201] the determination section determines whether the detection temperature is less than the threshold value after the set time elapses, and determines that the second cover member is open in a case where the detection temperature is less than the threshold value.

[0202] <NOTE 4>

[0203] In the image forming apparatus described in Note 2 or 3,

[0204] the heating control section stops driving the heater in a case where the determination section determines that the second cover member is open.

[0205] <NOTE 5>

[0206] In the image forming apparatus described in any one of Notes 1 to 4,

[0207] the linkage mechanism includes:

[0208] a unit urging member that is an elastic member arranged on an opposite side of the fixing unit side with respect to the heating unit inside the apparatus main body; and

[0209] an acting member arranged inside the apparatus main body and supported so as to be movable between a first position at which the unit urging member is interposed between the acting member and the heating unit and a second position farther from the fixing unit than the first position,

[0210] the heating unit is positioned at the reference position by an acting force received from the unit urging member when the acting member is present at the first position,

[0211] the action member has an engagement portion that engages with a portion of the heating unit when moving from the first position to the second position,

[0212] the linkage mechanism is configured to move the action member from the first position to the second position when the second cover member is rotated from the second closed position to the second open position, and the heating unit is moved from the reference position to the retreat position further away from the fixing unit during the movement of the action member by engaging with the engagement portion,

[0213] Furthermore, the linkage mechanism is configured to move the action member from the second position to the first position by the force of the unit urging member when the second cover member is rotated from the second open position to the second closed position.

[0214] <Note 6>

[0215] the image forming apparatus described in any one of Notes 1 to 5,

[0216] the heater is a heating device of an electromagnetic induction heating type.

[0217] The present application is not limited to the above, but is defined by the claims, and thus it is considered that the embodiments described in the specification are merely illustrative, and not limiting. Therefore, all modifications within the scope of the claims, and equivalents to the scope of the claims are included in the scope of the claims.

Claims

1. An image forming apparatus characterized by comprising: including: an apparatus main body; a heating unit configured inside the apparatus main body along a first direction, having a heater; a fixing unit configured inside the apparatus main body along the first direction in a manner adjacent to a side of the heating unit, having a fixing member heated by the heater and a pressing member that applies a sheet body to the fixing member; a first cover member supported to the apparatus main body in a manner rotatable between a first closed position that closes a side of a side of the apparatus main body and a first open position that opens the side; an opening portion provided to the side, having an opening for attaching and detaching the fixing unit with respect to the apparatus main body; a second cover member provided to the side, supported to the apparatus main body in a manner rotatable between a second closed position that closes the opening portion and a second open position that opens the opening portion; a linkage mechanism that moves the heating unit between a reference position at which an abutting portion of the heating unit abuts against the fixing unit and a retreat position further from the fixing unit than the reference position in linkage with a rotation action of the second cover member between the second closed position and the second open position; an action portion provided to the side, performing an action to turn on or off a power supply; an operation portion provided to the first cover member, capable of causing the action portion to act in a state in which the first cover member is disposed in the first closed position; a temperature sensor capable of detecting a temperature of the fixing member; a heating control portion that performs a heating action of causing the stopped heater to heat in a case in which the first cover member is rotated from the first closed position to the first open position; and a determination portion that determines that the second cover member is open in a case in which a detection temperature detected by the temperature sensor after the heating action is performed is less than a prescribed threshold value.

2. The image forming apparatus according to claim 1, wherein the heating control portion performs the heating action within a predetermined set time on condition that the first cover member is rotated from the first closed position to the first open position, the determination portion determines whether the detection temperature is less than the threshold value after the set time elapses, and determines that the second cover member is open in a case in which the detection temperature is less than the threshold value.

3. The image forming apparatus according to claim 2, wherein the heating control portion stops driving the heater in a case in which it is determined by the determination portion that the second cover member is open.

4. The image forming apparatus according to claim 1, wherein the linkage mechanism includes: a unit pressing member that is an elastic member configured inside the apparatus main body on an opposite side of the fixing unit with respect to the heating unit; and an acting member configured inside the apparatus main body, supported so as to be movable between a first position at which the unit pressing member is sandwiched between the acting member and the heating unit and a second position further from the fixing unit than the first position. ​ The heating unit is positioned at the reference position by an acting force received from the unit urging member when the acting member is present at the first position, The acting member has an engaging portion that engages with a portion of the heating unit when moving from the first position to the second position, The linkage mechanism is configured to move the acting member from the first position to the second position when the second cover member rotates from the second closed position to the second open position, and the heating unit moves from the reference position to the retreat position further away from the fixing unit than the reference position by engaging with the engaging portion during the movement of the acting member, Further, the linkage mechanism is configured to move the acting member from the second position to the first position by the acting force of the unit urging member when the second cover member rotates from the second open position to the second closed position.

5. The image forming apparatus according to claim 1, wherein The heater is a heating device of an electromagnetic induction heating type.

Images