Image forming apparatus

Abstract

To provide an image forming apparatus in which the attachability and detachability of a fixing device are improved.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 at which the opening portion is covered and an open position at which the opening portion is opened 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 the movement 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. The support portion extends in a longitudinal direction of the fixing device and supports the fixing device from below.SELECTED DRAWING: Figure 9

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 an openable / closable door and a tray for pulling out a cartridge to the outside when the door is open (see Patent Document 1). The cartridge is configured to be detachable from the tray when the tray is pulled out.

[0003] Also, 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 2). 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]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-244018 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-047806 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for an image forming apparatus in which the fixing device can be easily attached to and detached from the main body of the apparatus for replacement or maintenance of the fixing device.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which the ease of attachment and detachment of a fixing device is improved. [Means for solving the problem]

[0007] 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 removably 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 from the first position to the second position is permitted, and the moving unit has a support portion that removably supports the fixing device when positioned at the second position, and the support portion extends in the longitudinal direction of the fixing device and supports the fixing device from below. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an embodiment of an image forming apparatus in which the attachability and detachability of the fixing device is improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an image forming apparatus according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing an image forming apparatus. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view showing the bottom surface of the fixing device. [Figure 5] FIG. 2 is a perspective view showing the image forming apparatus with the door open. [Figure 6] FIG. 4 is a perspective view showing a fixing lock and a locked portion. [Figure 7] FIG. 2 is a cross-sectional view showing the image forming apparatus with the door open. [Figure 8] FIG. 4 is a perspective view showing the fixing device positioned at a second position. [Figure 9] FIG. 4 is a perspective view showing a state in which the fixing device is removed from the support portion. [Figure 10] FIG. 10 is a perspective view showing a moving unit according to a second embodiment. [Figure 11] FIG. 4 is a perspective view showing the support portion with the fixing device attached thereto. [Figure 12] FIG. 10 is another perspective view showing the support portion with the fixing device attached thereto. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment [Overall structure] First, a first embodiment of the present invention will be described. An image forming apparatus 1 according to the first embodiment is an electrophotographic full-color laser beam printer. Fig. 1 is a perspective view showing the image forming apparatus 1. Fig. 2 is a cross-sectional view showing the image forming apparatus 1.

[0011] 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.

[0012] 1 and 2, 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.

[0013] 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.

[0014] The tray unit 50 has a tray 51 that can be pulled out from 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 mounted on the tray 51.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] The feeding unit 30 is provided at the bottom of the image forming apparatus 1 and has a cassette 31 for stacking sheets S, and a pickup roller 32 for feeding the sheets S supported by the cassette 31 as a stacking section. 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 stacked.

[0019] The fixing device 80 has a fixing section 81 that fixes a toner image to a 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 with a built-in heater (not shown) and a pressure roller 84, and a fixing nip that holds the sheet S between them is formed by the heating roller 83 and the pressure roller 84. The guide member 5 is configured to be rotatable between a discharge position shown by a solid line in FIG. 2 where the guide member 5 guides the sheet S toward the discharge path 1d, and a reversing position shown by a dashed line in FIG. 2 where the guide member 5 guides the sheet S toward the reversing path 1e.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 that supports the secondary transfer roller 45. By rotating the secondary transfer frame when the door 20 is in the open position, the duplex conveying path 20a can be opened widely.

[0030] [Mobile Unit] Next, the moving unit 140 will be described with reference to Figures 2 to 6. Figure 3 is a perspective view showing the moving unit 140. Figure 4 is a perspective view showing the underside 80a of the fixing device 80. Figure 5 is a perspective view showing the image forming apparatus 1 with the door 20 open. Figure 6 is a perspective view showing the fixing lock 85 and the locked portion 86.

[0031] 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. 3, has a support section 90 and an elevator section 100. The elevator section 100 has arms 101aL and 101bL that are disposed on one side in the longitudinal direction LD of the fixing device 80, and biasing members 102aL and 102bL that bias the arms 101aL and 101bL. The longitudinal direction LD is perpendicular to the vertical direction VD and extends horizontally.

[0032] The lifting unit 100 also includes arms 101aR and 101bR disposed on the other side of the fixing device 80 in the longitudinal direction LD, and biasing members 102aR and 102bR that bias the arms 101aR and 101bR. One end of each of the arms 101aL, 101bL, 101aR, and 101bR is rotatably supported relative to the device main body 1A. The arms 101aL and 101bL and the arms 101aR and 101bR each constitute a link mechanism. In this embodiment, the biasing members 102aL, 102bL, 102aR, and 102bR are formed of coil springs, but are not limited thereto. For example, the biasing members 102aL, 102bL, 102aR, and 102bR may be formed of other springs such as leaf springs, and the biasing members 102aL, 102bL, 102aR, and 102bR may be formed of a plurality of types of springs.

[0033] The support unit 90 has a pair of shaft members 91, 92 extending in the longitudinal direction LD, and a pair of connecting members 93, 94 connecting both ends of the shaft members 91, 92 in the longitudinal direction LD. The shaft members 91, 92 are integrated by the connecting members 93, 94, which improves the rigidity of the support unit 90. The support unit 90 is connected to the lifting unit 100 and moves up and down together with the lifting unit 100. It is sufficient that the support unit 90 is connected to at least one of the arms 101aL, 101aR and the arms 101bL, 101bR of the lifting unit 100.

[0034] 4, a pair of recesses 88 and 89 corresponding to the pair of shaft members 91 and 92 are provided on the underside 80a of the fixing device 80. When the fixing device 80 is supported by the support part 90, the recesses 88 and 89 engage with the shaft members 91 and 92, respectively. When the recesses 88 and 89 of the fixing device 80 engage with the shaft members 91 and 92, the fixing device 80 is positioned in the cross direction ID that intersects both the vertical direction VD and the longitudinal direction LD. This is because the recess 88 engages with the outer peripheral surface of the shaft member 91 on the side of the shaft member 92 in the cross direction ID, and the recess 89 engages with the outer peripheral surface of the shaft member 92 on the side of the shaft member 91 in the cross direction ID.

[0035] A space SP1 through which the sheet S can pass is defined between the recesses 88 and 89. As shown in Fig. 3, the support portion 90 has an opening SP2 between the shaft members 91 and 92, and when the fixing device 80 is supported by the support portion 90, the sheet S is conveyed to the fixing nip through the opening SP2 and the space SP1.

[0036] 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. 2, 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. 8, with the fixing device 80 supported by the support portion 90. Note that, at the first position, the fixing device 80 is slightly spaced from the support portion 90 of the moving unit 140, and there is a slight gap between the fixing device 80 and a pair of shaft members 91, 92 of the support portion 90.

[0037] As shown in FIG. 5, 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 and 5, the door 20 has a side surface 20c that constitutes one side of the image forming apparatus 1 and a top surface 20d that constitutes 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.

[0038] When the door 20 is opened from the closed position to the open position, the engagement between the door 20 and the moving unit 140 is released. Then, the arms 101aL, 101bL, 101aR, and 101bR of the moving unit 140 are raised by the biasing forces of the biasing members 102aL, 102bL, 102aR, and 102bR serving as biasing units. In conjunction with this rise of the lifting unit 100, the support unit 90 also rises. Then, the support unit 90 comes into contact with the fixing device 80 located at the first position, and then raises the fixing device 80 toward the second position.

[0039] As shown in FIG. 6 , the fixing device 80 is provided with a fixing lock 85. When the fixing device 80 starts to rise, the fixing lock 85 engages with a locked portion 86, which serves as a restricting portion and is provided on the device main body 1A. The fixing lock 85, which serves as an engaging portion, is movably supported on a frame member of the fixing device 80 between a restricting position and an allowable position, and is biased to the restricting position by a biasing member (not shown). At the restricting position, the fixing lock 85 engages with the locked portion 86, thereby restricting movement of the fixing device 80 from the first position to the second position (rising operation). At the allowable position, the fixing lock 85 disengages from the locked portion 86, thereby allowing movement of the fixing device 80 from the first position to the second position (rising operation).

[0040] When the fixing lock 85 located in the restricting position is engaged with the locked portion 86, the fixing device 80 is restricted from being lifted upward from the support portion 90. Therefore, the fixing device 80 cannot be removed from the support portion 90.

[0041] In this embodiment, the fixing lock 85 and the locked portion 86 are provided only on one side of the image forming apparatus 1 in the longitudinal direction LD, but they may be provided on both sides of the image forming apparatus 1 in the longitudinal direction LD.

[0042] [Attaching and detaching the fixing unit] Next, the attachment and detachment operation of the fixing device 80 will be described with reference to Figures 7 to 9. Figure 7 is a cross-sectional view showing the image forming apparatus 1 with the door 20 open. Figure 8 is a perspective view showing the fixing device 80 in the second position. Figure 9 is a perspective view showing the fixing device 80 removed from the support part 90.

[0043] 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. 7, the user first moves the door 20 from the closed position to the open position. Then, the fixing device 80 starts to rise due to the movement of the moving unit 140, but as described in FIG. 6, the fixing lock 85 engages with the locked portion 86, restricting the rising movement of the fixing device 80. 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. 7.

[0044] To remove the fixing device 80 from the support section 90, the user presses the pressing section 87 of the fixing lock 85 shown in FIG. 6 to move the fixing lock 85 from the restricting position to the allowing position. This causes the moving unit 140 to resume the movement of the fixing device 80, and the fixing device 80 is lifted to the second position as shown in FIG. 8. In this state, the user can remove the fixing device 80 from the support section 90 by lifting it up. Because the fixing device 80 is simply placed on the pair of shaft members 91, 92 of the support section 90, the fixing device 80 can be easily removed from the support section 90 by simply lifting it up.

[0045] 8, the transfer unit 40 and the tray unit 50, which serve as image forming units for forming a toner image on a sheet, are detachable from the apparatus main body 1A through the opening 9. As long as the moving unit 140 is in the elevated state, the transfer unit 40 and the tray unit 50 can be detachable from the apparatus main body 1A even when the fixing device 80 is attached to the support portion 90. In other words, when the fixing device 80 is in the second position, the transfer unit 40 and the tray unit 50 are detachable from the apparatus main body 1A through the opening 9.

[0046] 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.

[0047] 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.

[0048] 9, when the fixing device 80 is removed from the support part 90, the support part 90 is visible. Furthermore, the shaft members 91 and 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 remains in the raised state, so the support part 90 is located near the opening 9, improving the visibility of the support part 90.

[0049] 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 fixing device 80 is placed on the support part 90 so that the shaft members 91, 92 engage with the recesses 89, 89 on the underside 80a of the fixing device 80. After attaching the fixing device 80 to the support part 90, the user pushes the fixing device 80 or the moving unit 140 downward to move the fixing device 80 downward until its movement is restricted by the locked part 86. With the fixing lock 85 provided on the fixing device 80 engaged with the locked part 86, the user closes the door 20.

[0050] When the door 20 is closed, the moving unit 140 is pushed downward by a pushing portion (not shown) provided on the door 20. As a result, the fixing device 80 is held at the first position in a state where it is separated from the support portion 90 of the moving unit 140. The fixing device 80 is held at the first position by at least one of the apparatus main body 1A and the door 20. The fixing device 80 is not only moved to the second position for replacement, but may also be moved to the second position to process a sheet S that has jammed while being sandwiched in the fixing nip of the fixing device 80, for example.

[0051] As described above, fixing device 80 is configured to be detachable from support part 90 of moving unit 140 at the second position close to opening 9. Furthermore, since support part 90 extends in longitudinal direction LD and supports fixing device 80 from below, fixing device 80 can be removed from support part 90 simply by lifting fixing device 80, improving the detachability of fixing device 80.

[0052] Furthermore, when the fixing device 80 is removed from the support part 90, the support part 90 is located near the opening 9 and is visible. Also, since the support part 90 has shaft members 91 and 92 arranged in parallel, the user can intuitively recognize the position where the fixing device 80 should be attached, thereby improving the ease of attaching and detaching the fixing device 80.

[0053] Furthermore, when the fixing device 80 is pushed down from the second position to the first position, the fixing lock 85 engages with the locked portion 86, locking the fixing device 80. This allows the user to intuitively determine to which position the fixing device 80 should be pushed down. Furthermore, the support portion 90 is formed in a rectangular shape by a pair of shaft members 91, 92 and a pair of connecting members 93, 94, thereby improving rigidity. Therefore, when the fixing device 80 is pushed down from the second position to the first position, the fixing device 80 is stably supported while maintaining its posture, and the fixing device 80 does not interfere with the inner wall of the device main body 1A, improving the ease of attachment and detachment of the fixing device 80.

[0054] Furthermore, even when the door 20 is opened from the closed position to the open position, the fixing device 80 is held in a position close to the first position by the engagement between the fixing lock 85 and the locked portion 86. In other words, even when the door 20 is opened, the fixing device 80 is not automatically raised to the second position by the moving unit 140. Therefore, when clearing a jam in the conveying path 1c or the duplex conveying path 20a, for example, the fixing lock 85 must be pressed to avoid the need to raise or lower the fixing device 80, thereby improving jam clearing performance and usability.

[0055] <Second embodiment> Next, a second embodiment of the present invention will be described, in which the shape of the support portion 90 in the first embodiment is modified. Therefore, the same configurations as those in the first embodiment will be omitted from the illustrations or will be described with the same reference numerals in the drawings.

[0056] Fig. 10 is a perspective view showing a moving unit 240 according to the second embodiment. Fig. 11 is a perspective view showing a support part 190 with a fixing device 80 attached. Fig. 12 is another perspective view showing the support part 190 with a fixing device 80 attached.

[0057] [Mobile Unit] 10, a moving unit 240 according to this embodiment has a support section 190 and an elevating section 100. The elevating section 100 has the same configuration as in the first embodiment, and the support section 190 is linked to the elevating section 100 so as to move in conjunction with the elevating operation of the elevating section 100.

[0058] The support portion 190 has a mounting surface 95 that extends in the longitudinal direction LD and supports the fixing device 80 from below, and a pair of side surfaces 96 and 97 that rise upward from both ends of the mounting surface 95 in the longitudinal direction LD. The support portion 190 also has a connecting surface 98 that rises upward from the mounting surface 95 and connects the pair of side surfaces 96 and 97. The pair of side surfaces 96 and 97 and the connecting surface 98 are provided so as to surround the periphery of the fixing device 80 when the fixing device 80 is placed on the mounting surface 95. An opening SP3 is provided in the mounting surface 95, and the sheet S is transported through the opening SP to the fixing nip of the fixing device 80 placed on the mounting surface 95.

[0059] [Attaching and detaching the fixing unit] Next, the operation of attaching and detaching the fixing device 80 to and from the support part 190 will be described. The operation of attaching and detaching the fixing device 80 up to the removal of the fixing device 80 is the same as in the first embodiment. When the fixing device 80 is removed from the support part 190, the support part 190 is visible, as shown in FIG. 10 . Furthermore, the mounting surface 95 of the support part 190 extends 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 should be mounted. Furthermore, the side surfaces 96 and 97 and the connecting surface 98 are arranged along the outer periphery of the fixing device 80, making it easy for the user to visually recognize the position where the fixing device 80 should be mounted.

[0060] When attaching the fixing device 80 to the support part 190, the user aligns the positions of the side surfaces 96 and 97 with the exterior of the fixing device 80, while simultaneously aligning the rear side of the fixing device 80 with the connecting surface 98. In this state, the fixing device 80 is placed on the placement surface 95, as shown in FIGS.

[0061] 11 , when the fixing device 80 is placed on the placement surface 95, a gap 99 through which air can flow is secured between the fixing device 80 and the connecting surface 98. When the image forming apparatus 1 performs an image forming operation, air sent by a fan (not shown) provided in the apparatus main body 1A flows through the gap 99, thereby reducing the transfer of heat from the fixing device 80 to the support part 190. This prevents the support part 190 from becoming too hot when a user attaches or detaches the fixing device 80 to or from the support part 190, improving the ease of attachment and detachment of the fixing device 80.

[0062] <Other embodiments> In the first embodiment, the support portion 90 includes a pair of shaft members 91 and 92 that engage with the recesses 88 and 89 of the fixing device 80. However, this is not limiting. The shape of the support portion 90 is not limited as long as it supports the fixing device 80 from below. For example, the cross-sectional shape of the shaft members 91 and 92 of the support portion 90 is not limited to a circular shape, and may be other shapes such as a polygonal or elliptical shape. The number of shaft members is not limited to two, but may be three or more. The number of recesses provided in the fixing device 80 may also be the same as the number of shaft members. Alternatively, the support portion 90 may include one or more protrusions or recesses, and the fixing device 80 may include one or more recesses or protrusions. In this case, the protrusions and recesses are engageable with each other. The fixing device 80 may also include recesses that engage with the connecting members 93 and 94 of the support portion 90.

[0063] Furthermore, in the second embodiment, the support portion 190 has the placement surface 95, the side surfaces 96 and 97, and the connecting surface 98, but this is not limiting. For example, the support portion 190 may omit either the side surfaces 96 and 97 or the connecting surface 98. Furthermore, the support portion 190 may have another connecting surface that is disposed on the opposite side of the fixing device 80 from the connecting surface 98 and connects the side surfaces 96 and 97.

[0064] In addition, in all of the above-described embodiments, the second position of the fixing device 80 is a position 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.

[0065] Furthermore, in all of the above-described embodiments, the lifting unit 100 has a link mechanism made up of multiple arms, but this is not limited to this. For example, the lifting unit 100 may be configured to have a rack unit, and to raise and lower the support units 90, 190 by meshing the rack unit with a pinion gear provided on the support units 90, 190. Alternatively, a pinion gear may be provided on the support units 90, 190, and a rack member may be provided on the lifting unit 100. In this manner, the configuration of the lifting unit 100 is not limited.

[0066] In addition, in all of the above-described embodiments, the fixing device 80 has 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 applied instead of the heating roller 83. Also, a fixing belt having a heat-generating layer that generates heat by induction heating may be applied instead of the heating roller 83.

[0067] In addition, in all of the above-described embodiments, 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.

[0068] In addition, in all of the above-described embodiments, the door 20 is provided to be rotatable about the rotation axis 20b, but this is not limiting. For example, instead of the door 20, a cover that is slidable or removable relative to the device main body 1A may be provided.

[0069] In the first embodiment, the opening SP2 is provided between the shaft members 91 and 92, and in the second embodiment, the opening SP3 is provided in the placement surface 95, but the shapes of these openings are not limited to these. For example, these openings may be through holes or notches as long as the sheet S can pass through them.

[0070] 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 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, the support portion extends in the longitudinal direction of the fixing device and supports the fixing device from below; An image forming apparatus characterized by: (Configuration 2) 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, the fixing device positioned at the second position at least partially overlaps the opening / closing member positioned at the closed position as viewed in the longitudinal direction; 2. The image forming apparatus according to claim 1, (Configuration 3) The second position is a position higher than the first position. 3. The image forming apparatus according to claim 1, wherein: (Configuration 4) The support portion has a pair of shaft members extending in the longitudinal direction, a lower surface of the fixing device having a pair of recesses with which the pair of shaft members can be engaged; 4. The image forming apparatus according to any one of configurations 1 to 3. (Configuration 5) The support portion has a pair of connecting members that connect both ends of the pair of shaft members in the longitudinal direction. 5. The image forming apparatus according to configuration 4. (Configuration 6) The support portion has a mounting surface extending in the longitudinal direction and on which the fixing device is placed, a pair of side surfaces rising upward from both ends of the mounting surface in the longitudinal direction, and a connecting surface rising upward from the mounting surface and connecting the pair of side surfaces. 4. The image forming apparatus according to any one of configurations 1 to 3. (Configuration 7) the fixing device has a gap between the fixing device and the connecting surface, allowing air to flow when the fixing device is placed on the mounting surface; 7. The image forming apparatus according to configuration 6, (Configuration 8) the support portion has an opening through which a sheet conveyed toward the fixing device located at the first position can pass. 8. The image forming apparatus according to any one of configurations 1 to 7. (Configuration 9) the moving unit has a biasing portion that biases the fixing device from the first position toward the second position; 9. The image forming apparatus according to any one of configurations 1 to 8. (Configuration 10) a restricting portion that restricts movement of the fixing device from the first position to the second position; 10. The image forming apparatus according to any one of configurations 1 to 9. (Configuration 11) the fixing device has an engaging portion that is movable between a restricting position where the fixing device is engaged with the restricting portion to restrict movement of the fixing device from the first position to the second position, and an allowing position where the fixing device is allowed to move from the first position to the second position by being disengaged from the restricting portion. 11. The image forming apparatus according to claim 10, (Configuration 12) the fixing device is moved to the second position by the moving unit when the opening / closing member is moved from the closed position to the open position and the regulating portion is moved from the regulating position to the allowing position. 12. The image forming apparatus according to claim 11, (Configuration 13) the support portion of the moving unit is spaced apart from the fixing device, which is positioned at the first position, when the opening / closing member is positioned at the closed position. 13. The image forming apparatus according to any one of configurations 1 to 12. (Configuration 14) 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. 14. The image forming apparatus according to any one of configurations 1 to 13. (Configuration 15) the fixing device positioned at the first position overlaps with a movement locus when the image forming unit is attached to or detached from the apparatus main body; 15. The image forming apparatus according to configuration 14. (Configuration 16) a stacking section on which sheets to be fed toward the fixing device are stacked, the loading section is configured to be detachable from the device body from the same side as the opening section; 16. The image forming apparatus according to any one of configurations 1 to 15. [Explanation of symbols]

[0071] 1: Image forming apparatus / 1A: Apparatus body / 9: Opening / 20: Opening / closing member (door) / 31: Loading section (cassette) / 40, 50: Image forming section (transfer unit, tray unit) / 80: Fixing device / 80a: Underside / 85: Engagement section (fixing lock) / 86: Regulating section (locked section) / 88, 89: Recess / 90, 190: Support section / 91, 92: Shaft member / 93, 94: Connecting member / 95: Placement surface / 96, 97: Side / 98: Connecting surface / 99: Gap / 102aL, 102bL, 102aR, 102bR: Pressing section (pressing member) / 140, 240: Moving unit / LD: Longitudinal direction / S: Sheet / SP2, SP3: Opening

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 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, the support portion extends in the longitudinal direction of the fixing device and supports the fixing device from below; An image forming apparatus characterized by:

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

3. 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.

4. The support portion has a pair of shaft members extending in the longitudinal direction, a lower surface of the fixing device having a pair of recesses with which the pair of shaft members can be engaged; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. The support portion has a pair of connecting members that connect both ends of the pair of shaft members in the longitudinal direction.

5. The image forming apparatus according to claim 4.

6. the support portion has a mounting surface extending in the longitudinal direction and on which the fixing device is placed, a pair of side surfaces rising upward from both ends of the mounting surface in the longitudinal direction, and a connecting surface rising upward from the mounting surface and connecting the pair of side surfaces.

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

7. the fixing device has a gap between the fixing device and the connecting surface, allowing air to flow when the fixing device is placed on the mounting surface; 7. The image forming apparatus according to claim 6, wherein the image forming apparatus is a recording medium.

8. the support portion has an opening through which a sheet conveyed toward the fixing device located at the first position can pass.

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

9. the moving unit has a biasing portion that biases the fixing device from the first position toward the second position; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. a restricting portion that restricts movement of the fixing device from the first position to the second position; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. the fixing device has an engaging portion that is movable between a restricting position where the fixing device is engaged with the restricting portion to restrict movement of the fixing device from the first position to the second position, and an allowing position where the fixing device is allowed to move from the first position to the second position by being disengaged from the restricting portion.

11. The image forming apparatus according to claim 10.

12. the fixing device is moved to the second position by the moving unit when the opening / closing member is moved from the closed position to the open position and the regulating portion is moved from the regulating position to the allowing position.

12. The image forming apparatus according to claim 11.

13. the support portion of the moving unit is spaced apart from the fixing device, which is located at the first position, when the opening / closing member is located at the closed position; 13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

14. 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.

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

15. the fixing device positioned at the first position overlaps with a movement locus when the image forming unit is attached to or detached from the apparatus main body; 15. The image forming apparatus according to claim 14.

16. a stacking section on which sheets to be fed toward the fixing device are stacked, the loading section is configured to be detachable from the device body from the same side as the opening section; 13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images