Image forming apparatus

Abstract

To provide an image forming apparatus that can suppress the dropping of a fixing device from a support portion.SOLUTION: An image forming apparatus includes: an apparatus main body having an opening portion; an opening / closing member supported to be openable and closable between a closed position and an open position with respect to the apparatus main body; a fixing device supported to be attachable to and detachable from the apparatus main body via the opening portion and applying heat and pressure to a sheet to fix a toner image to the sheet; and a moving unit provided in the apparatus main body and capable of moving the fixing device from a first position toward a second position different from the first position. Movement of the fixing device from the first position to the second position is restricted in a state in which the opening / closing member is located at the closed position, and movement of the moving unit from the first position to the second position is allowed in a state in which the opening / closing member is located at the open position. The moving unit has a support portion that supports the fixing device located at the second position such that the fixing device is attachable and detachable, and a restricting portion that restricts the dropping of the fixing device supported by the support portion from the support portion.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms a toner image on a sheet. [Background technology]

[0002] Conventionally, an image forming apparatus has been proposed that includes a pair of arm members rotatably mounted on the apparatus body and a fixing device held at the tip of the arm members (see Patent Document 1). The fixing device is configured to be movable between an internal mounting position and a temporary holding position that is closer to the opening of the apparatus body than the internal mounting position by rotating the pair of arm members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-047806 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the fixing device described in Patent Document 1 may fall off the pair of arm members if a strong external force acts on the fixing device. For example, when processing a jammed sheet held in the fixing device, the fixing device may fall off the arm members if the user pulls on the sheet.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can prevent a fixing device from falling off a support portion. [Means for solving the problem]

[0006] The present invention is an image forming apparatus that forms a toner image on a sheet, comprising: an apparatus main body having an opening; an opening / closing member that is supported on the apparatus main body so as to be openable and closable between a closed position that covers the opening and an open position that opens the opening; a fixing device that is detachably supported on the apparatus main body via the opening and that fixes the toner image to the sheet by applying heat and pressure to the sheet; and a moving unit that is provided on the apparatus main body and is capable of moving the fixing device from a first position to a second position different from the first position, wherein when the opening / closing member is positioned at the closed position, movement of the fixing device from the first position to the second position is restricted, and when the opening / closing member is positioned at the open position, movement of the fixing device by the moving unit is permitted from the first position to the second position, and the moving unit has a support portion that detachably supports the fixing device that is positioned at the second position, and a regulating portion that restricts the fixing device supported on the support portion from falling off the support portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent the fixing device from falling off the support portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing an image forming apparatus. [Figure 2] FIG. 4 is a perspective view showing a state in which the fixing device is detached from the moving unit. [Figure 3] FIG. 2 is a cross-sectional view showing the image forming apparatus with the door open. [Figure 4] FIG. 4 is a cross-sectional view showing the image forming apparatus in a state where the fixing device is raised to a second position. [Figure 5] FIG. 4 is a cross-sectional view showing the image forming apparatus in a state where a transfer unit and a tray unit are pulled out from an opening portion. [Figure 6] 1A is a perspective view showing the image forming apparatus with the door open, and FIG. 1B is a perspective view showing the fixing device positioned at the second position. [Figure 7]1A is an enlarged perspective view showing the restricting member and locking member on the left side, and FIG. 1B is an enlarged perspective view showing the restricting member, locking member, and release lever on the right side. [Figure 8] FIG. 10 is a perspective view showing a state in which the locking member has moved to a removal allowing position. [Figure 9] FIG. 10 is a cross-sectional view showing a state in which a pressing rib of the door presses against a locking member. [Figure 10] FIG. 10 is a cross-sectional view showing how the top surface of the door presses against the restricting member. [Figure 11] FIG. 10 is a perspective view showing a state in which a jammed sheet held in the fixing device is cleared. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Overall structure] The image forming apparatus 1 according to the present embodiment is an electrophotographic full-color laser beam printer.

[0010] The term "image forming apparatus" includes printers, copiers, facsimiles, and multifunction peripherals, and refers to devices that form images on sheets used as recording media based on image information input from an external PC or image information read from a document. In addition to the main body having the image forming function, an image forming apparatus may be connected to accessory devices such as optional feeders, image readers, and sheet processing devices, and the entire system connected to such accessory devices is also considered a type of image forming apparatus. The term "sheet" also includes paper such as paper sheets and envelopes, plastic film such as overhead projector sheets (OHP), cloth, etc.

[0011] 1, the image forming apparatus 1 has an apparatus main body 1A having an opening 9, and a door 20 as an opening / closing member supported on the apparatus main body 1A so as to be openable and closable between a closed position that covers the opening 9 and an open position that exposes the opening 9. The door 20 is configured to be rotatable about a rotation shaft 20b. The frame and exterior of the apparatus main body 1A and the door 20 can be collectively referred to as a main frame 10.

[0012] The apparatus main body 1A houses an image forming unit 70 that forms an image on a sheet S, a feeding unit 30, a fixing device 80, a discharge unit 130, and a moving unit 140 (described later). The image forming unit 70 has a transfer unit 40, a tray unit 50 arranged above the transfer unit 40, and a scanner 2 arranged above the tray unit 50.

[0013] The tray unit 50 has a tray 51 that can be pulled out relative to the apparatus main body 1A, and four process cartridges PY, PM, PC, and PK that form toner images of four colors, yellow (Y), magenta (M), cyan (C), and black (K). The four process cartridges PY, PM, PC, and PK are placed on the tray 51. The tray 51 has a tray handle 52 that can be gripped by the user.

[0014] The four process cartridges PY, PM, PC, and PK have the same configuration except for the colors of the images they form. Therefore, only the configuration and image forming process of the process cartridge PY will be described, and descriptions of the process cartridges PM, PC, and PK will be omitted.

[0015] The process cartridge PY has a photosensitive drum 61, a charging roller 62, and a developing roller 71. The photosensitive drum 61 is configured by coating the outer periphery of an aluminum cylinder with an organic photoconductive layer, and is rotated by a drive motor (not shown). The rotation axes of the photosensitive drum 61, the developing roller 71, and the charging roller 62 are parallel to one another.

[0016] The transfer unit 40 includes a drive roller 46, a tension roller 47, and an intermediate transfer belt 41 wound around the drive roller 46 and the tension roller 47. Primary transfer rollers 42Y, 42M, 42C, and 42K are provided inside the intermediate transfer belt 41. A secondary transfer roller 45 is provided opposite the drive roller 46 so as to sandwich the intermediate transfer belt 41, and the intermediate transfer belt 41 and the secondary transfer roller 45 form a transfer nip that transfers an image onto the conveyed sheet S. An optical sensor 44 is provided in the image forming unit 70 to detect the toner image transferred onto the intermediate transfer belt 41. The directions of the rotation axes of the primary transfer rollers 42Y, 42M, 42C, and 42K, the drive roller 46, the tension roller 47, and the secondary transfer roller 45 are parallel to one another.

[0017] The feeding unit 30 is provided at the bottom of the image forming apparatus 1, and has a cassette 31 for loading sheets S, and a pickup roller 32 for feeding the sheets S supported by the cassette 31. The cassette 31 is configured to be detachable from the apparatus main body 1A on the same side as the opening 9. The discharge unit 130 has a pair of discharge rollers 131, and a discharge tray 1f on which the sheets S discharged by the pair of discharge rollers 131 are loaded.

[0018] The fixing device 80 has a fixing section 81 that fixes a toner image on a sheet to the sheet by applying heat and pressure to the sheet, a guide member 5, and a pair of reversing rollers 132. The fixing section 81 has a heating roller 83 as a heating unit incorporating a heater (not shown), and a pressure roller 84, and a fixing nip that holds the sheet S between the heating roller 83 and the pressure roller 84. The guide member 5 is configured to be rotatable between a discharge position where the sheet S is guided toward the discharge path 1d and a reversing position where the sheet S is guided toward the reversing path 1e.

[0019] Next, we will explain the image forming operation of the image forming apparatus 1 configured as above. The image forming apparatus 1 has a control unit 3 connected to an external host device 110. Based on an image signal received from the external host device 110 or a reading unit, the control unit 3 controls the scanner 2 so that a laser beam corresponding to the image signal is irradiated onto the photosensitive drum 61 of the process cartridge PY. The external host device 110 is, for example, a personal computer, an image reader, or a facsimile machine.

[0020] At this time, the surface of the photosensitive drum 61 is uniformly charged to a predetermined polarity and potential by the charging roller 62, and an electrostatic latent image is formed on the surface by irradiating it with laser light from the scanner 2. The electrostatic latent image formed on the photosensitive drum 61 is developed by the developing roller 71, and a yellow (Y) toner image is formed on the photosensitive drum 61.

[0021] The developing roller 71 is configured so as to be able to come into contact with or separate from the photosensitive drum 61. When the image forming apparatus 1 is not performing an image forming operation, the developing roller 71 is separated from the photosensitive drum 61, thereby extending the lifespan of the photosensitive drum 61 and the developing roller 71.

[0022] Similarly, the scanner 2 irradiates the photosensitive drums of the process cartridges PM, PC, and PK with laser light, forming magenta (M), cyan (C), and black (K) toner images on the respective photosensitive drums. The toner images of each color formed on the respective photosensitive drums are transferred to the intermediate transfer belt 41 by primary transfer rollers 42Y, 42M, 42C, and 42K, and are then transported to the transfer nip by the intermediate transfer belt 41, which is rotated by a drive roller 46. The image formation process for each color is performed at a timing to overlap the upstream toner image that has been primarily transferred onto the intermediate transfer belt 41. Residual toner remaining on the photosensitive drum 61 is removed by a cleaning blade.

[0023] In parallel with this image forming process, the sheet S stored in the cassette 31 of the feeding unit 30 is sent to the conveying path 1c by the pickup roller 32. Then, the sheet S has its skew corrected by a pair of registration rollers 4 provided on the conveying path 1c, and is conveyed at a predetermined conveying timing in accordance with the timing of image transfer at the transfer nip.

[0024] Then, the full-color toner image on the intermediate transfer belt 41 is transferred to the sheet S at the transfer nip by a secondary transfer bias applied to the secondary transfer roller 45. Any residual toner remaining on the intermediate transfer belt 41 is removed by a cleaning blade 43A provided in the cleaning unit 43. The sheet S onto which the toner image has been transferred is subjected to predetermined heat and pressure by a heating roller 83 and a pressure roller 84 of the fixing device 80, thereby melting and fixing (fixing) the toner. The sheet S that has passed through the fixing device 80 is guided by a guide member 5 to a discharge path 1d or a reversing path 1e.

[0025] When a single-sided print job for printing an image on only one side is input, the guide member 5 is positioned at the discharge position, and the sheet S is guided to the discharge path 1d. The sheet S guided to the discharge path 1d is discharged outside the apparatus by a pair of discharge rollers 131, and is stacked on the discharge tray 1f.

[0026] When a double-sided print job for forming images on both sides of a sheet S is input, the sheet S, on whose first side an image has been formed by the transfer nip, is guided to a reversing path 1e by a guide member 5 positioned at a reversing position. A pair of reversing rollers 132 provided in the reversing path 1e reverses after the trailing edge of the sheet S passes the guide member 5, causing the sheet S to switch back. During this time, the guide member 5 moves to a discharge position, and the switched-back sheet S is guided by the guide member 5 to a double-sided conveying path 20a.

[0027] The sheet S guided to the double-sided conveying path 20a is conveyed to the conveying path 1c by a plurality of conveying roller pairs, and an image is formed on the second side at the transfer nip. Then, after the toner image is fixed on the sheet S by the fixing device 80 as described above, the sheet S is discharged onto the discharge tray 1f by the discharge roller pair 131.

[0028] [Outline of mobile unit configuration] Next, a schematic configuration of the moving unit 140 will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the moving unit 140 with the fixing device 80 removed.

[0029] The moving unit 140 is disposed between a right side plate and a left side plate (not shown) that constitute part of the main frame 10, and as shown in FIG. 2, has a support section 90 and an elevator section 100. The elevator section 100 has an arm unit disposed on one side of the fixing device 80 in the longitudinal direction LD, and an arm unit disposed on the other side of the fixing device 80 in the longitudinal direction LD. These two arm units have the same configuration, and the following description will only cover the arm unit on one side (the right side) of the fixing device 80 in the longitudinal direction LD. The longitudinal direction LD is perpendicular to the vertical direction VD and parallel to the horizontal direction.

[0030] As shown in FIGS. 2 and 4, the arm unit includes arms 101aR, 101bR, and 101cR, and biasing members 102aR and 102bR that bias the arms 101aR, 101bR, and 101cR. The arms 101aR, 101bR, and 101cR form a link mechanism. In this embodiment, the biasing members 102aR and 102bR are formed of coil springs, but are not limited thereto. For example, the biasing members 102aR and 102bR may be formed of other springs such as leaf springs, or the biasing members 102aR and 102bR may be formed of multiple types of springs.

[0031] The support section 90 has a metal frame 91 and a shaft member 92 extending in the longitudinal direction LD. The metal frame 91 is formed in a roughly U-shape in a plan view, and by connecting the metal frame 91 to the shaft member 92, the entire support section 90 is formed in a rectangular shape. This improves the rigidity of the support section 90. The support section 90 is connected to the lifting section 100 and moves up and down together with the lifting section 100. The support section 90 supports the bottom surface of the fixing device 80. In other words, the support section 90 supports the fixing device 80 from below in a detachable manner.

[0032] When the door 20 is in the closed position, the fixing device 80 is housed inside the image forming apparatus 1 as shown in FIG. 1, and is located at a first position where the fixing device 80 can fix a toner image onto a sheet S during an image forming operation. The moving unit 140 can move the fixing device 80 to a second position shown in FIG. 6(b) while supporting the fixing device 80 with the support portion 90. Hereinafter, the position of the moving unit 140 when the door 20 is in the closed position will be referred to as the housed position, and the position of the moving unit 140 where the fixing device 80 can be supported when the door 20 is in the closed position will be referred to as the support position. That is, the moving unit 140 is configured to be able to rise from the housed position (the position shown in FIG. 1) to the support position (the position shown in FIG. 2) by the biasing forces of the biasing members 102aR, 102bR, etc.

[0033] [Moving the transfer unit and tray unit] Next, the movement of the transfer unit 40 and the tray unit 50 will be described with reference to Figures 3 to 5. Figure 3 is a cross-sectional view showing the image forming apparatus 1 with the door 20 open. Figure 4 is a cross-sectional view showing the image forming apparatus 1 with the fixing device 80 raised to the second position. Figure 5 is a cross-sectional view showing the image forming apparatus 1 with the transfer unit 40 and the tray unit 50 pulled out of the opening 9.

[0034] As shown in FIG. 3, when the door 20 is opened, the opening 9 of the apparatus main body 1A is opened. When the door 20 is moved to the open position, the fixing device 80 is exposed to the outside of the image forming apparatus 1 through the opening 9. In particular, as shown in FIGS. 1 to 3, the door 20 has a side surface 20c that forms one side of the image forming apparatus 1 and a top surface 20d that forms part of the top surface of the image forming apparatus 1, and is formed in a generally L-shape overall. That is, when the door 20 is moved to the open position, the space above the fixing device 80 that was covered by the top surface 20d of the door 20 in the closed position is opened. This allows the fixing device 80 to move upward from the first position to the second position. In other words, when the door 20 is in the closed position, movement of the fixing device 80 from the first position to the second position is restricted, and when the door 20 is in the open position, movement of the fixing device 80 from the first position to the second position is permitted. In this embodiment, the fixing device 80 located at the first position does not overlap with the door 20 located at the closed position when viewed in the longitudinal direction LD, and the fixing device 80 located at the second position at least partially overlaps with the door 20 located at the open position when viewed in the longitudinal direction LD.

[0035] Furthermore, by opening the door 20 from the closed position to the open position, the opening 9 is opened, and the conveying path 1c and the duplex conveying path 20a are exposed. This allows a sheet S that has jammed in the conveying path 1c or the duplex conveying path 20a to be processed. The door 20 also rotatably supports a secondary transfer frame 25 that supports a secondary transfer roller 45. By rotating the secondary transfer frame 25 with the door 20 in the open position, the duplex conveying path 20a can be opened widely.

[0036] 4, when the moving unit 140 rises from the storage position to the support position, the fixing device 80 moves to the second position, and the space below the fixing device 80 becomes open. As a result, the transfer unit 40 and the tray unit 50, which serve as image forming units for forming a toner image on a sheet, can be attached to and detached from the apparatus main body 1A through the opening 9 and the space below the fixing device 80.

[0037] As long as the moving unit 140 is raised to the support position, the transfer unit 40 and the tray unit 50 can be attached to and detached from the apparatus main body 1A, even when the fixing device 80 is attached to the support part 90. In other words, when the fixing device 80 is in the second position, the transfer unit 40 and the tray unit 50 are configured to be attachable and detachable to and from the apparatus main body 1A through the opening 9. The transfer unit 40 and the tray unit 50 are pulled out or attached to the apparatus main body 1A in the cross direction ID that crosses both the vertical direction VD and the longitudinal direction LD. The cross direction ID and the longitudinal direction LD are directions parallel to the horizontal plane.

[0038] 5, when the transfer unit 40 and the tray unit 50 are pulled out to the outside of the apparatus main body 1A, the process cartridges PY, PM, PC, and PK are detachable from the tray 51. This allows the process cartridges PY, PM, PC, and PK to be replaced. The transfer unit 40 can also be replaced.

[0039] In this way, the fixing device 80, the transfer unit 40, and the tray unit 50 are all configured to be detachable from the door 20 side of the image forming apparatus 1. Therefore, when attaching or detaching the fixing device 80, the transfer unit 40, and the tray unit 50, they can be accessed from one side of the image forming apparatus 1, improving usability and saving space when installing the image forming apparatus 1. Furthermore, the cassette 31 is also configured to be detachable from the same side as the opening 9 with respect to the apparatus main body 1A, improving usability and saving space.

[0040] On the other hand, the fixing device 80 located at the first position overlaps with the movement trajectory of the transfer unit 40 and the tray unit 50 when they are attached to or detached from the device main body 1A. This allows for a reduction in the size of the image forming apparatus 1. Note that, in this embodiment, the transfer unit 40 and the tray unit 50 are configured to be attachable and detachable to the device main body 1A independently of each other, but they may also be configured to be attachable and detachable to the device main body 1A as a single unit.

[0041] [Attaching and detaching the fixing unit] Next, the attachment and detachment operation of the fixing device 80 will be described with reference to FIGS. 2 and 6(a) to 10. FIG. 6(a) is a perspective view showing the image forming apparatus 1 with the door 20 open. FIG. 6(b) is a perspective view showing the fixing device 80 in the second position. FIG. 7(a) is an enlarged perspective view showing the left-side restricting member 111L and locking member 112L, and FIG. 7(b) is an enlarged perspective view showing the right-side restricting member 111R, locking member 112R, and release lever 113. FIG. 8 is a perspective view showing the locking members 112L and 112R moved to the removal permitting position. FIG. 9 is a cross-sectional view showing the pressing rib 21 of the door 20 pressing the locking members 112L and 112R. FIG. 10 is a cross-sectional view showing the top surface 20d of the door 20 pressing the restricting members 111L and 111R.

[0042] First, the procedure for removing the fixing device 80 from the support portion 90 of the moving unit 140 will be described. As shown in FIG. 6(a), the user first moves the door 20 from the closed position to the open position. Here, the fixing device 80 is provided with a fixing locking member (not shown), and the fixing locking member engages with a locked portion (not shown) provided on the device main body 1A, thereby holding the fixing device 80 in the first position. In other words, when the fixing locking member of the fixing device 80 is engaged with the locked portion of the device main body 1A, the moving unit 140 is restricted from rising from the storage position to the support position. For example, when clearing a jam in the conveying path 1c or the duplex conveying path 20a, the user can clear the jam in the state shown in FIG. 6(a).

[0043] 6(a)(b) and 7(a)(b), a restricting member 111L and a locking member 112L are provided on one side (left side) in the longitudinal direction LD of the moving unit 140. A restricting member 111R, a locking member 112R, and a release lever 113 are provided on the other side (right side) in the longitudinal direction LD of the moving unit 140. The restricting members 111L and 111R, the locking members 112L and 112R, and the release lever 113 are supported rotatably with respect to the shaft member 92. That is, the restricting members 111L and 111R, the locking members 112L and 112R, and the release lever 113 are rotatable relative to one another around the same shaft member 92.

[0044] The restricting members 111L, 111R are shaped to cover the locking members 112L, 112R, respectively. Engaging claws 112La, 112Ra that elastically deform with a predetermined force are provided on the side surfaces of the locking members 112L, 112R, which serve as removal restricting portions. The restricting members 111L, 111R are each provided with protrusions 111La, 111Ra that the engaging claws 112La, 112Ra can overcome with a predetermined force. When the engaging claws 112La, 112Ra are engaged with the protrusions 111La, 111Ra, the locking members 112L, 112R rotate integrally with the restricting members 111L, 111R, respectively.

[0045] On the other hand, when the user rotates the locking members 112L, 112R, the locking members 112L, 112R can rotate relative to the regulating members 111L, 111R while disengaging the engagement claws 112La, 112Ra from the protrusions 111La, 111Ra. As shown in FIGS. 7(a) and 7(b) and 9, claw portions 115L, 115R are provided at the tips of the regulating members 111L, 111R, respectively. Furthermore, as shown in FIG. 2, the fixing device 80 is provided with recesses 116L, 116R into which the claw portions 115L, 115R can engage. The engagement of the claw portions 115L, 115R with the recesses 116L, 116R restricts the upward movement of the fixing device 80. That is, in a state where the claws 115L and 115R are engaged with the recesses 116L and 116R, the fixing device 80 supported by the support portion 90 is restricted from being removed from the support portion 90.

[0046] The regulating members 111L, 111R are movable between a removal restricting position where the claws 115L, 115R engage with the recesses 116L, 116R and a removal allowing position where the claws 115L, 115R are separated from the recesses 116L, 116R. That is, the regulating members 111L, 111R restrict the fixing device 80 from being removed from the support part 90 at the removal restricting position, and allow the fixing device 80 to be removed from the support part 90 at the removal allowing position.

[0047] 7(a), the restriction member 111L is held in an upright position by the restriction spring 114. For example, the restriction spring 114 as a biasing member is made up of a torsion coil spring whose coil portion is supported by the shaft member 92, one end of which engages with the restriction member 111L and the other end of which engages with the metal frame 91.

[0048] The restricting member 111R is similarly held in an upright position by a restricting spring (not shown). In this embodiment, the restricting members 111L and 111R are configured to be rotatable about the shaft member 92 independently of each other, but this is not limiting. For example, the restricting members 111L and 111R may be configured to rotate integrally, in which case only one restricting spring is required. The home position is a position where no external force acts on the restricting members 111L and 111R and the restricting members 111L and 111R are held in an upright position by the restricting spring 114. When the restricting members 111L and 111R are located in the home position and the engaging claws 112La and 112Ra are engaged with the projections 111La and 111Ra, the locking members 112L and 112R are located in the removal restricting position.

[0049] The regulating members 111L and 111R located at the home position face the fixing device 80 placed on the support portion 90 in the cross direction ID, and regulate the fixing device 80 from falling off from the support portion 90. More specifically, the regulating members 111L and 111R as regulating portions regulate the fixing device 80 from falling off from the support portion 90 toward the door 20 located at the open position.

[0050] 4, when the moving unit 140 is located at the support position, the regulating members 111L, 111R protrude above the upper surface 1g of the apparatus main body 1A. That is, when the moving unit 140 is located at the support position, at least a portion of the regulating members 111L, 111R is located above the upper surface 1g of the apparatus main body 1A. Furthermore, when the moving unit 140 is located at the support position, at least a portion of the regulating members 111L, 111R is located above the upper end 84a of the pressure roller 84. By configuring the regulating members 111L, 111R in this manner, it is possible to prevent the fixing device 80 from falling off the support part 90 even if a strong force is applied to the fixing device 80.

[0051] Furthermore, since the regulating members 111L and 111R protrude above the upper surface 1g of the apparatus main body 1A, as will be described later, when attaching the fixing device 80 to the support part 90, the user can intuitively recognize the position to attach the fixing device 80. This improves the ease of attachment and detachment and usability of the fixing device 80.

[0052] 7(b), release lever 113 is configured to be rotatable in the vertical direction by the user, and the user can operate release lever 113 to move the above-mentioned fixing lock member (not shown) of fixing device 80. The fixing lock member is movably supported on a frame member of fixing device 80 between a restricted position and an allowed position, and is biased to the restricted position by a biasing member (not shown).

[0053] At the restricting position, the fixing locking member engages with the locked portion of the apparatus main body 1A, thereby restricting the movement of the fixing device 80 from the first position to the second position, i.e., the upward movement of the moving unit 140. At the allowing position, the fixing locking member is disengaged from the locked portion, thereby allowing the fixing device 80 to move from the first position to the second position. When the user operates the release lever 113, the fixing locking member moves from the restricting position to the release position.

[0054] 6(a) and 6(b), when the door 20 is opened from the closed position to the open position and the release lever 113 is operated by the user, the fixing lock member of the fixing device 80 moves from the restricting position to the allowing position, and the lifting operation of the moving unit 140 begins. As a result, the moving unit 140 rises from the stored position to the supporting position, and the fixing device 80 rises from the first position to the second position.

[0055] Next, the user rotates the locking members 112L, 112R from the removal restricting position to the removal allowing position, as shown in Fig. 8. This causes the claw portions 115L, 115R of the locking members 112L, 112R to move away from the recesses 116L, 116R (see Fig. 2) of the fixing device 80, making it possible to remove the fixing device 80 from the support part 90.

[0056] In this state, the user can remove the fixing device 80 from the support part 90 by lifting the gripping parts 117L, 117R provided on the upper surface of the fixing device 80. Since the fixing device 80 is simply placed on the metal frame 91 and the shaft member 92 of the support part 90, the fixing device 80 can be easily removed from the support part 90 by simply lifting the fixing device 80.

[0057] When moving unit 140 is raised to the support position, gripping portions 117L and 117R are located above upper surface 1g of apparatus main body 1A, which allows the user to easily lift fixing device 80, improving operability.

[0058] 2, when the fixing device 80 is removed from the support part 90, the support part 90 is visible. Furthermore, the metal frame 91 and the shaft member 92 of the support part 90 extend in the longitudinal direction LD over substantially the entire length of the fixing device 80, allowing the user to intuitively recognize the position where the fixing device 80 is to be placed. Furthermore, when the fixing device 80 is removed from the support part 90, the moving unit 140 is held in the support position, so the support part 90 is located near the opening 9, improving the visibility of the support part 90.

[0059] For example, when a consumable part of the fixing device 80 reaches the end of its life, the fixing device 80 is replaced. When attaching a new fixing device 80 to the support part 90, the user places their fingers on the gripping parts 117L, 117R and moves the fixing device 80 from above toward the support part 90. At this time, if the locking members 112L, 112R are in the removal restriction position, the lower surface of the fixing device 80 comes into contact with the locking members 112L, 112R.

[0060] 9, the locking members 112L, 112R are each provided with a tapered surface 115a, and the locking members 112L, 112R are moved to the removal permitting position when the fixing device 80 presses the tapered surface 115a. Therefore, the fixing device 80 can be attached to the support part 90 even when the locking members 112L, 112R are in the removal restricting position.

[0061] In this embodiment, the engagement of the engagement claws 112La, 112Ra with the projections 111La, 111Ra allows the locking members 112L, 112R to remain in the removal restriction position.

[0062] The user then pushes the fixing device 80 or the moving unit 140 downward, thereby moving the fixing device 80 downward until its movement is restricted by the locked portion. When the fixing locking member provided on the fixing device 80 engages with the locked portion of the device main body 1A, the fixing device 80 is in the first position. This allows the user to intuitively determine to which position to push the fixing device 80 down. Then, the user closes the door 20, completing the replacement of the fixing device 80.

[0063] 9, a pressing rib 21 is provided on the surface of door 20 facing fixing device 80. The pressing ribs 21 are provided at positions corresponding to the left and right locking members 112L, 112R. For example, consider a case where the user closes door 20 with the engagement between engagement claws 112La, 112Ra and protrusions 111La, 111Ra released and the locking members 112L, 112R remaining in the removal restriction position.

[0064] At this time, just before the door 20 reaches the closed position, the left and right pressing ribs 21 press the locking members 112L, 112R. Then, when the door 20 reaches the closed position, the locking members 112L, 112R are pressed by the pressing ribs 21 and rotate to the removal restriction position, and the locking members 112L, 112R lock the fixing device 80. As a result, the fixing device 80 is reliably locked to the support part 90, and the fixing device 80 can be reliably held in the first position with the door 20 closed.

[0065] 10, consider a case in which the door 20 is closed from the open position to the closed position with the moving unit 140 located at the support position and the fixing device 80 removed from the support portion 90 of the moving unit 140. Because the regulating members 111L and 111R are supported rotatably about the shaft member 92, they are pressed against the discharge tray 1f by the door 20 while the door 20 is moving from the open position to the closed position. This causes the regulating members 111L and 111R to rotate about the shaft member 92. This prevents damage to the regulating members 111L and 111R. The door 20 can also be moved to the closed position even when the fixing device 80 is not placed on the support portion 90 of the moving unit 140.

[0066] [Clearing jams in the fixing unit] Next, a method for clearing a jammed sheet S in the fixing device 80 will be described with reference to Fig. 11. Fig. 11 is a perspective view showing how a jammed sheet S held in the fixing device 80 is cleared.

[0067] 11 , when removing the sheet S held in the fixing nip of the fixing device 80, the fixing device 80 is raised to the second position using the same procedure as for removing the fixing device 80 described above. Then, the sheet S held in the fixing nip can be selected to be pulled downward or pulled upward and toward the user. When pulling the sheet S downward, the user pulls the sheet S downward while leaving the fixing device 80 placed on the support section 90.

[0068] On the other hand, when pulling the sheet S upward and toward the user, the user first opens the openable cover 118 provided on the fixing device 80. This allows the user to access close to the fixing nip of the fixing device 80. When the user pulls the sheet S upward and toward the user, a force acts on the fixing device 80 upward in the vertical direction VD and toward the user in the cross direction ID via the sheet S.

[0069] However, the fixing device 80 is positioned in the cross direction ID by the regulating members 111L, 111R, and is positioned in the vertical direction VD by the support portion 90 and the claw portions 115L, 115R of the locking members 112L, 112R. As a result, even when a jammed sheet S held in the fixing device 80 is cleared, the regulating members 111L, 111R and the locking members 112L, 112R prevent the fixing device 80 from falling off the support portion 90 toward the door 20, which is in the open position.

[0070] 9, when the door 20 is closed, the fixing device 80 is locked by the regulating members 111L and 111R. Therefore, when a jam of the sheet S held in the fixing device 80 is cleared, the regulating members 111L and 111R can be prevented from being separated from the fixing device 80. The jam clearance can be performed not only when the fixing device 80 is located in the second position, but also when the fixing device 80 is located in the first position. Even in this case, the regulating members 111L and 111R and the locking members 112L and 112R prevent the fixing device 80 from falling off the support portion 90 toward the door 20 located in the open position.

[0071] Furthermore, in this embodiment, the fixing device 80 is exposed upward through the opening 9 by being moved upward by the moving unit 140. The lifting operation of the fixing device 80 is performed in a substantially vertically upward direction, so the movement distance is shorter than, for example, when the fixing device 80 is moved upward by rotating it. This reduces the time required to replace the fixing device 80 or clear a jam, and improves the ease of attaching and detaching the fixing device 80 and the ease of clearing a jam.

[0072] Furthermore, the regulating members 111L and 111R are disposed outside the cover 118 of the fixing device 80 in the longitudinal direction LD. Therefore, the regulating members 111L and 111R can be designed without considering restrictions on the conveyance path of the sheet S, thereby improving design freedom. For example, the regulating members 111L and 111R can be placed close to the fixing device 80, which can prevent the fixing device 80 from shifting in position. Furthermore, with the fixing device 80 placed on the support section 90, the opening angle of the cover 118 can be increased, which can improve the workability when removing a sheet S that has jammed in the fixing nip.

[0073] Furthermore, the regulation member 111R as the second regulation member is disposed at a different position in the longitudinal direction LD from the regulation member 111L as the first regulation member. More specifically, the distance D1 between the regulation members 111L and 111R is longer than the width of the largest sheet size usable in the image forming apparatus 1. In other words, the regulation members 111L and 111R are disposed outside the area through which the sheet can pass in the longitudinal direction LD. Therefore, the regulation members 111L and 111R do not interfere with the sheet S that is pulled by the user, improving jam clearance.

[0074] As described above, when the fixing device 80 is located at the second position, the restricting members 111L, 111R and the locking members 112, 112R can prevent the fixing device 80 from falling off the support portion 90. This can reduce damage to the fixing device 80. Furthermore, even if a jammed sheet S is pulled while being held in the fixing device 80, the fixing device 80 is prevented from falling off the support portion 90, which can improve jam clearing performance.

[0075] <Other embodiments> In the above embodiment, the pair of regulating members 111L and 111R is provided in the moving unit 140, but this is not limiting. For example, the moving unit 140 may be provided with one regulating member or three or more regulating members.

[0076] In addition, in the above-described embodiment, the moving unit 140 is provided with a pair of locking members 112L, 112R, but this is not limiting. For example, the moving unit 140 may be provided with one locking member or three or more locking members.

[0077] In the above-described embodiment, the restricting members 111L and 111R and the locking members 112L and 112R prevent the fixing device 80 from falling off the support portion 90, but this is not limiting. For example, the locking members 112L and 112R may be omitted, and the restricting members 111L and 111R may prevent the fixing device 80 from falling off the support portion 90. Furthermore, the restricting members 111L and 111R may be omitted, and the locking members 112L and 112R may prevent the fixing device 80 from falling off the support portion 90.

[0078] In the above-described embodiment, the restricting members 111L, 111R and the locking members 112L, 112R are rotatably supported by the same shaft member 92, but this is not limiting. For example, the locking members 112L, 112R may be rotatably supported by the restricting members 111L, 111R, respectively.

[0079] In the above embodiment, the second position of the fixing device 80 is above the first position, but this is not limiting. For example, the fixing device 80 may be moved horizontally from the first position to the second position, or may be moved diagonally downward.

[0080] Furthermore, in the above-described embodiment, the lifting / lowering unit 100 has a link mechanism composed of multiple arms, but this is not limited to this. For example, the lifting / lowering unit 100 may be configured to have a rack portion, and to raise and lower the support portions 90, 190 by meshing the rack portion with a pinion gear provided on the support portions 90, 190. Alternatively, a pinion gear may be provided on the support portions 90, 190, and a rack member may be provided on the lifting / lowering unit 100. In this manner, the configuration of the lifting / lowering unit 100 is not limited.

[0081] In the above embodiment, the fixing device 80 includes the heating roller 83 and the pressure roller 84, but is not limited to this. For example, a heating unit including a heater such as a ceramic heater and a fixing film heated by the heater may be used instead of the heating roller 83. Also, a fixing belt having a heat-generating layer that generates heat by induction heating may be used instead of the heating roller 83.

[0082] In the above-described embodiment, the photosensitive drum 61, the charging roller 62, and the developing roller 71 are provided in the process cartridges (PY to PK), but this is not limiting. That is, the photosensitive drum 61, the charging roller 62, and the developing roller 71 may be provided in either the process cartridge or the tray 51.

[0083] In the above embodiment, the door 20 is provided to be rotatable about the rotation shaft 20b, but this is not limiting. For example, instead of the door 20, a cover that is slidable or removable relative to the apparatus main body 1A may be provided.

[0084] The disclosure of the present embodiment also includes the following configuration examples and method examples. (Configuration 1) In an image forming apparatus for forming a toner image on a sheet, a device body having an opening; an opening / closing member supported by the device body so as to be openable and closable between a closed position that covers the opening and an open position that opens the opening; a fixing device that is detachably supported on the device body via the opening and applies heat and pressure to the sheet to fix the toner image to the sheet; a moving unit provided in the apparatus body and capable of moving the fixing device from a first position to a second position different from the first position, the fixing device is restricted from moving from the first position to the second position when the opening / closing member is located at the closed position, and is allowed to move from the first position to the second position by the moving unit when the opening / closing member is located at the open position; the moving unit has a support portion that detachably supports the fixing device located at the second position, and a restriction portion that restricts the fixing device supported by the support portion from falling off the support portion. An image forming apparatus characterized by: (Configuration 2) the support portion extends in the longitudinal direction of the fixing device and supports the fixing device from below; 2. The image forming apparatus according to claim 1, (Configuration 3) the fixing device positioned at the first position does not overlap the opening / closing member positioned at the closed position when viewed in the longitudinal direction of the fixing device, the fixing device positioned at the second position at least partially overlaps the opening / closing member positioned at the closed position when viewed in the longitudinal direction of the fixing device; 3. The image forming apparatus according to claim 1, wherein: (Configuration 4) The second position is a position higher than the first position. 4. The image forming apparatus according to any one of configurations 1 to 3. (Configuration 5) the restricting portion restricts the fixing device from falling off the support portion toward the opening / closing member positioned at the open position. 5. The image forming apparatus according to any one of configurations 1 to 4. (Configuration 6) the regulating portion has a first regulating member that faces the fixing device in a cross direction that crosses both a longitudinal direction and a vertical direction of the fixing device, and a second regulating member that is disposed at a position different from the first regulating member in the longitudinal direction and faces the fixing device in the cross direction. 6. The image forming apparatus according to any one of configurations 1 to 5. (Configuration 7) a distance between the first regulating member and the second regulating member in the longitudinal direction is longer than the width of a sheet of a maximum size that can be used in the image forming apparatus; 7. The image forming apparatus according to configuration 6, (Configuration 8) the fixing device has an openable and closable cover, the restricting portion is disposed outside the cover in the longitudinal direction of the fixing device; 8. The image forming apparatus according to any one of configurations 1 to 7. (Configuration 9) The restricting portion is rotatably supported by the support portion. 9. The image forming apparatus according to any one of configurations 1 to 8. (Configuration 10) the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, When the opening / closing member is moved from the open position to the closed position in a state where the moving unit is located at the support position and the fixing device is detached from the support portion of the moving unit, the restricting portion is pressed by the opening / closing member and rotates. 10. The image forming apparatus according to configuration 9, (Configuration 11) a biasing member configured to bias the restricting portion toward a position facing the fixing device positioned at the second position, the restricting portion restricting the fixing device supported by the support portion from falling off the support portion; 11. The image forming apparatus according to configuration 9 or 10. (Configuration 12) the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, At least a part of the restricting portion is located above an upper surface of the device body when the moving unit is located at the support position. 12. The image forming apparatus according to any one of configurations 1 to 11. (Configuration 13) the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, the fixing device includes a heating unit capable of heating a toner image on a sheet, and a pressure roller that holds the sheet together with the heating unit; At least a part of the regulating portion is located above an upper end of the pressure roller when the moving unit is located at the support position. 13. The image forming apparatus according to any one of configurations 1 to 12. (Configuration 14) the moving unit has a removal restriction portion that engages with the fixing device supported by the support portion to restrict the fixing device from being removed from the support portion; 14. The image forming apparatus according to any one of configurations 1 to 13. (Configuration 15) the removal restriction portion is movable between a removal restriction position where it engages with the fixing device to restrict the fixing device from being removed from the support portion, and a removal permission position where it is separated from the fixing device to allow the fixing device to be removed from the support portion. 15. The image forming apparatus according to configuration 14. (Configuration 16) the removal restriction portion is pressed by the opening / closing member when the opening / closing member moves from the open position toward the closed position, and thereby moves to the removal restriction position. 16. The image forming apparatus according to configuration 15. (Configuration 17) The removal restriction portion is rotatably supported by the support portion. 17. The image forming apparatus according to any one of configurations 14 to 16. (Configuration 18) The restriction portion and the removal restriction portion are supported rotatably around the same shaft member. 18. The image forming apparatus according to any one of configurations 14 to 17. (Configuration 19) further comprising an image forming unit for forming a toner image on the sheet; the image forming unit is configured to be detachable from the apparatus main body through the opening when the fixing device is moved to the second position by the moving unit. 19. The image forming apparatus according to any one of configurations 1 to 18. [Explanation of symbols]

[0085] 1: image forming apparatus / 1A: apparatus body / 1g: top surface / 9: opening / 20: opening / closing member (door) / 40, 50: image forming section (transfer unit, tray unit) / 80: fixing device / 83: heating unit (heating roller) / 84: pressure roller / 84a: upper end / 90: support section / 92: shaft member / 111L: regulating section, first regulating member (regulating member) / 111R: regulating section, second regulating member (regulating member) / 112L, 112R: removal regulating section (locking member) / 114: urging member (regulating spring) / 118: cover / 140: moving unit / D1: distance / ID: cross direction / LD: longitudinal direction / VD: vertical direction

Claims

1. In an image forming apparatus for forming a toner image on a sheet, a device body having an opening; an opening / closing member supported by the device body so as to be openable and closable between a closed position that covers the opening and an open position that opens the opening; a fixing device that is detachably supported on the device body via the opening and applies heat and pressure to the sheet to fix the toner image to the sheet; a moving unit provided in the apparatus main body and capable of moving the fixing device from a first position to a second position different from the first position, the fixing device is restricted from moving from the first position to the second position when the opening / closing member is located at the closed position, and is allowed to move from the first position to the second position by the moving unit when the opening / closing member is located at the open position; the moving unit has a support portion that detachably supports the fixing device located at the second position, and a restriction portion that restricts the fixing device supported by the support portion from falling off the support portion. An image forming apparatus characterized by:

2. the support portion extends in the longitudinal direction of the fixing device and supports the fixing device from below; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. the fixing device positioned at the first position does not overlap the opening / closing member positioned at the closed position when viewed in the longitudinal direction of the fixing device, the fixing device positioned at the second position at least partially overlaps the opening / closing member positioned at the closed position when viewed in the longitudinal direction of the fixing device; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. The second position is a position higher than the first position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. the restricting portion restricts the fixing device from falling off the support portion toward the opening / closing member positioned at the open position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. the regulating portion includes a first regulating member that faces the fixing device in a cross direction that crosses both a longitudinal direction and a vertical direction of the fixing device, and a second regulating member that is disposed at a position different from the first regulating member in the longitudinal direction and faces the fixing device in the cross direction.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

7. a distance between the first regulating member and the second regulating member in the longitudinal direction is longer than the width of a sheet of a maximum size that can be used in the image forming apparatus; 7. The image forming apparatus according to claim 6, wherein the image forming apparatus is a recording medium.

8. the fixing device has an openable and closable cover, the restricting portion is disposed outside the cover in the longitudinal direction of the fixing device; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. The restricting portion is rotatably supported by the support portion.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, When the opening / closing member is moved from the open position to the closed position in a state where the moving unit is located at the support position and the fixing device is detached from the support portion of the moving unit, the restricting portion is pressed by the opening / closing member and rotates.

10. The image forming apparatus according to claim 9,

11. a biasing member configured to bias the restricting portion toward a position facing the fixing device positioned at the second position, the restricting portion restricting the fixing device supported by the support portion from falling off the support portion; 10. The image forming apparatus according to claim 9,

12. the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, At least a part of the restricting portion is located above an upper surface of the device body when the moving unit is located at the support position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

13. the moving unit is movable between a storage position where the opening / closing member is located when the opening / closing member is located at the closed position and a support position where the moving unit can support the fixing device located at the second position, the fixing device includes a heating unit capable of heating a toner image on a sheet, and a pressure roller that holds the sheet together with the heating unit; At least a part of the regulating portion is located above an upper end of the pressure roller when the moving unit is located at the support position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

14. the moving unit has a removal restriction portion that engages with the fixing device supported by the support portion to restrict the fixing device from being removed from the support portion; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

15. the removal restriction portion is movable between a removal restriction position where it engages with the fixing device to restrict the fixing device from being removed from the support portion, and a removal permission position where it is separated from the fixing device to allow the fixing device to be removed from the support portion.

15. The image forming apparatus according to claim 14.

16. the removal restriction portion is pressed by the opening / closing member when the opening / closing member moves from the open position toward the closed position, and thereby moves to the removal restriction position.

16. The image forming apparatus according to claim 15.

17. The removal restriction portion is rotatably supported by the support portion.

15. The image forming apparatus according to claim 14.

18. The restriction portion and the removal restriction portion are supported rotatably around the same shaft member.

15. The image forming apparatus according to claim 14.

19. further comprising an image forming unit for forming a toner image on the sheet; the image forming unit is configured to be detachable from the apparatus main body through the opening when the fixing device is moved to the second position by the moving unit.

19. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images