Image forming apparatus

Abstract

An image forming apparatus includes: an apparatus body provided with an opening portion; an opening / closing member; a fixing unit; and a moving unit provided in the apparatus body and provided to move the fixing unit from the first position toward a second position above the first position. The movement of the fixing unit 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 permitted in a state in which the opening / closing member is located at the open position. The moving unit includes a support portion provided to support the fixing unit at the second position such that the fixing unit is attachable and detachable. The support portion extends in a longitudinal direction of the fixing unit and supports the fixing unit from below.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus for forming a toner image on a sheet. Background Art

[0002] Japanese Patent Application Laid-Open No. 2010-244018 proposes an imaging apparatus including an openable and closable door and a tray for pulling a cartridge out to the outside with the door open. The cartridge is configured to be attachable to and detachable from the tray with the tray pulled out.

[0003] Japanese Patent Application Laid-Open No. 2012-047806 discloses an image forming apparatus including a pair of arm members pivotable relative to an apparatus body, and a fixing unit held at distal ends of the arm members. The fixing unit is configured to be movable between an internal attachment position and a temporary holding position closer to an opening of the apparatus body than the internal attachment position by pivoting the pair of arm members.

[0004] In recent years, there has been a demand for an image forming apparatus in which a fixing unit can be easily attached to and detached from an apparatus body in order to replace or maintain the fixing unit. Summary of the Invention

[0005] According to one aspect of the present invention, an image forming apparatus is configured to form a toner image on a sheet, the image forming apparatus including: an apparatus body having an opening; an opening / closing member supported to be openable and closable relative to the apparatus body between an open position and a closed position, the opening / closing member covering the opening in the closed position and opening the opening in the open position; a fixing unit supported to be attachable to and detachable from the apparatus body through the opening and configured to apply heat and pressure to the sheet to fix the toner image to the sheet; and a moving unit disposed in the apparatus body and configured to move the fixing unit from a first position to a second position above the first position. When the opening / closing member is in the closed position, movement of the fixing unit from the first position to the second position is restricted, and when the opening / closing member is in the open position, movement of the fixing unit from the first position to the second position is permitted. The moving unit includes a supporting portion configured to support the fixing unit in the second position so that the fixing unit is attachable and detachable. The supporting portion extends in a longitudinal direction of the fixing unit and supports the fixing unit from below.

[0006] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a perspective view of the imaging apparatus according to the first embodiment.

[0008] Figure 2 is a cross-sectional view showing the imaging apparatus.

[0009] Figure 3 is a perspective view of the mobile unit.

[0010] Figure 4 is a perspective view of the lower surface of the fixing unit.

[0011] Figure 5 is a perspective view of the imaging apparatus in a state where the door is open.

[0012] Figure 6 It is a perspective view of the fixed lock and the locking part.

[0013] Figure 7 is a sectional view of the imaging apparatus in a state where the door is open.

[0014] Figure 8 is a perspective view showing the fixing unit located at the second position.

[0015] Figure 9 It is a perspective view showing a state in which the fixing unit has been removed from the supporting portion.

[0016] Figure 10 is a perspective view of a moving unit according to a second embodiment.

[0017] Figure 11 It is a perspective view of the supporting portion in a state where the fixing unit is attached.

[0018] Figure 12 is another perspective view of the supporting portion in a state in which the fixing unit is attached. DETAILED DESCRIPTION

[0019] First embodiment

[0020] Overall structure

[0021] First, a first embodiment of the present disclosure will be described. An image forming apparatus 1 according to the first embodiment is a full-color laser beam printer of an electrophotographic system. Figure 1 is a perspective view of the imaging apparatus 1 . Figure 2 is a cross-sectional view of the imaging apparatus 1 .

[0022] It should be noted that examples of imaging devices include printers, copiers, fax machines, and multifunction devices. These devices form images on sheets serving as recording media based on image information input from an external personal computer (PC), image information read from a manuscript, and so on. Furthermore, there are cases where peripheral devices (such as optional feeders, image reading devices, or sheet handling devices) are connected to a main body having imaging functions, and the entire system of these peripheral devices and the main body also functions as an imaging device. Examples of sheets include paper (such as paper sheets and envelopes), plastic film (such as sheets used for overhead projectors), and cloth.

[0023] like Figure 1 and 2 As shown, the imaging apparatus 1 includes an apparatus body 1A having an opening portion 9 and a door 20 serving as an opening / closing member. The door 20 is supported relative to the apparatus body 1A so as to be openable and closable between a closed position in which the door 20 covers the opening portion 9 and an open position in which the door 20 opens the opening portion 9. The door 20 is arranged to be pivotable about a pivot shaft 20b. It should be noted that the frame and exterior of the apparatus body 1A and the door 20 may also be collectively referred to as the main frame 10.

[0024] The apparatus body 1A houses an imaging unit 70 (which forms an image on a sheet S), a feeding unit 30, a fixing unit 80, a discharge unit 130, and a moving unit 140 (described later). The imaging unit 70 includes a transfer unit 40, a tray unit 50 disposed above the transfer unit 40, and a scanner 2 disposed above the tray unit 50.

[0025] The tray unit 50 includes a tray 51 that can be pulled out from the apparatus 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), respectively. The four process cartridges PY, PM, PC, and PK are arranged on the tray 51.

[0026] It should be noted that the four process cartridges PY, PM, PC, and PK have the same configuration except for the color of the image formed therefrom. 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.

[0027] The process cartridge PY includes a photosensitive drum 61, a charging roller 62, and a developing roller 71. The photosensitive drum 61 is formed by applying an organic photoconductive layer to the outer peripheral surface of an aluminum cylinder, and is rotated by a drive motor (not shown). The directions of the rotation axes of the photosensitive drum 61, the developing roller 71, and the charging roller 62 are parallel to each other.

[0028] The transfer unit 40 includes a drive roller 46, a tension roller 47, and an intermediate transfer belt 41 looped around the drive roller 46 and tension roller 47. Primary transfer rollers 42Y, 42M, 42C, and 42K are disposed on the inner circumference of the intermediate transfer belt 41. Furthermore, a secondary transfer roller 45 is disposed opposite the drive roller 46, with the intermediate transfer belt 41 positioned between the secondary transfer roller 45 and the drive roller 46. The intermediate transfer belt 41 and the secondary transfer roller 45 form a transfer nip where an image is transferred to a sheet S conveyed thereto. It should be noted that an optical sensor 44 for detecting the toner image transferred to the intermediate transfer belt 41 is disposed within the imaging unit 70. The rotational 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.

[0029] The feeding unit 30 is provided in the lower portion of the image forming apparatus 1 and includes a cassette 31 that supports the sheet S and a pickup roller 32 that feeds the sheet S supported by the cassette 31 serving as a supporting portion. The cassette 31 is provided so as to be attachable to and detachable from the apparatus body 1A on the same side as the opening portion 9. The discharge unit 130 includes a discharge roller pair 131 and a discharge tray 1f that supports the sheet S discharged by the discharge roller pair 131.

[0030] The fixing unit 80 includes a fixing portion 81, a guide member 5, and a pair of reverse conveying rollers 132. The fixing portion 81 fixes the toner image to the sheet by applying heat and pressure to the sheet. The fixing portion 81 includes a heating roller 83 (the heating roller 83 includes a heater (not shown)) and a pressure roller 84, and the heating roller 83 and the pressure roller 84 form a fixing nip that clamps the sheet S. The guide member 5 is provided so as to be pivotable. Figure 2 The solid line in the figure indicates the discharge position and the Figure 2 The guide member 5 guides the sheet S toward the discharge path 1 d at the discharge position, and guides the sheet S toward the reverse conveyance path 1 e at the reverse conveyance position.

[0031] The image forming operation of the image forming apparatus 1 configured in this manner will be described below. The image forming apparatus 1 includes a controller 3 connected to an external host device 110. The controller 3 controls the scanner 2 based on an image signal received from the external host device 110 or a reading unit so as to irradiate the photosensitive drum 61 of the process cartridge PY with laser light corresponding to the image signal. Examples of the external host device 110 include a personal computer, an image reader, and a facsimile machine.

[0032] 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 thereon by irradiating the surface 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.

[0033] It should be noted that the developing roller 71 is provided so as to be able to contact and release the photosensitive drum 61. When the image forming apparatus 1 does not perform an image forming operation, the life of the photosensitive drum 61 and the developing roller 71 can be extended by separating the developing roller 71 from the photosensitive drum 61.

[0034] Similarly, laser light from scanner 2 illuminates the corresponding photosensitive drums of process cartridges PM, PC, and PK, forming magenta (M), cyan (C), and black (K) toner images on the corresponding photosensitive drums. The corresponding color toner images formed on the corresponding photosensitive drums are transferred to intermediate transfer belt 41 by primary transfer rollers 42Y, 42M, 42C, and 42K, and conveyed to the transfer nip by intermediate transfer belt 41, which is rotated by drive roller 46. It should be noted that the image formation process for each color is performed at such a timing that the toner images formed by process cartridges located further downstream are superimposed on the toner images formed by process cartridges located further upstream and transferred to intermediate transfer belt 41 by primary transfer. Furthermore, any residual toner remaining on the photosensitive drums 61 is removed by a cleaning blade.

[0035] In parallel with this image forming process, the sheet S accommodated in the cassette 31 of the feeding unit 30 is fed to the conveying path 1c by the pickup roller 32. Then, the skew of the sheet S is corrected by the registration roller pair 4 provided in the conveying path 1c, and the sheet S is conveyed at a predetermined conveying timing that matches the transfer timing of the image at the transfer nip.

[0036] The full-color toner image on the intermediate transfer belt 41 is then transferred to the sheet S at the transfer nip by a secondary transfer bias applied to the secondary transfer roller 45. Residual toner remaining on the intermediate transfer belt 41 is removed by a cleaning blade 43A provided in the cleaning section 43. The sheet S, onto which the toner image has been transferred, is subjected to predetermined heat and pressure applied by the heating roller 83 and pressure roller 84 of the fixing unit 80, causing the toner to melt and adhere (fix) to the sheet. The sheet S, having passed through the fixing unit 80, is guided by the guide member 5 to the discharge path 1d or the reverse transport path 1e.

[0037] When a single-sided print job for printing an image on only one surface is input, the guide member 5 is located 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 to the outside of the apparatus by the discharge roller pair 131 and is supported by the discharge tray 1f.

[0038] When a duplex print job is input, in which an image is formed on each surface of a sheet S, the sheet S (on whose first surface an image has been formed at the transfer nip) is guided to the reverse conveyance path 1e by the guide member 5 located at the reverse conveyance position. After the trailing end of the sheet S passes the guide member 5, the reverse conveyance roller pair 132 provided in the reverse conveyance path 1e rotates in the reverse direction, thereby switching the sheet S back. Simultaneously, the guide member 5 moves to the ejection position, and the reversed sheet S is guided by the guide member 5 to the duplex conveyance path 20a.

[0039] The sheet S guided to the duplex transport path 20a is transported to the transport path 1c by a plurality of transport roller pairs, whereby an image is formed on the second surface of the sheet S at the transfer nip. The toner image is then fixed to the sheet S by the fixing unit 80 as described above, and the sheet S is then discharged onto the discharge tray 1f by the discharge roller pair 131.

[0040] Furthermore, as the door 20 opens from the closed position to the open position, the opening portion 9 is opened, thereby exposing the conveying path 1c and the duplex conveying path 20a. Therefore, sheets S stuck in the conveying path 1c or the duplex conveying path 20a can be removed. Furthermore, the door 20 pivotally supports the secondary transfer frame, which supports the secondary transfer roller 45. With the door 20 in the open position, the duplex conveying path 20a can be opened more widely by pivoting the secondary transfer frame.

[0041] Mobile Unit

[0042] The following will refer to Figures 2 to 6 The mobile unit 140 is described. Figure 3 is a perspective view of the mobile unit 140 . Figure 4 80 is a perspective view of the lower surface 80 a of the fixing unit 80 . Figure 5 is a perspective view of the image forming apparatus 1 in a state where the door 20 is opened. Figure 6 is a perspective view of the fixing lock 85 and the locking portion 86.

[0043] The moving unit 140 is disposed between the right side plate and the left side plate which are not shown and constitute a part of the main frame 10, and the moving unit 140 includes a supporting portion 90 and a lifting / lowering portion 100, as shown in FIG. Figure 3As shown. The lifting / lowering portion 100 includes arms 101aL and 101bL arranged on one side of the fixing unit 80 in the longitudinal direction LD; and urging members 102aL and 102bL that urge the arms 101aL and 101bL. It should be noted that the longitudinal direction LD is a direction orthogonal to the vertical direction VD and parallel to the horizontal direction.

[0044] In addition, the lifting / lowering portion 100 includes: arms 101aR and 101bR, which are arranged on the other side of the fixing unit 80 in the longitudinal direction LD; and pushing members 102aR and 102bR, which push the arms 101aR and 101bR. One end of the arms 101aL, 101bL, 101aR, and 101bR is pivotally supported relative to the device body 1A. The arms 101aL and 101bL and the arms 101aR and 101bR each constitute a link mechanism. It should be noted that although the pushing members 102aL, 102bL, 102aR, and 102bR are all composed of coil springs in this embodiment, the structure is not limited to this. For example, the urging members 102aL, 102bL, 102aR, and 102bR may each be composed of a different spring (eg, a leaf spring), and the urging members 102aL, 102bL, 102aR, and 102bR may be composed of a plurality of springs.

[0045] The support portion 90 includes a pair of shaft members 91 and 92 extending in the longitudinal direction LD, and a pair of coupling members 93 and 94 coupling the respective ends of the shaft members 91 and 92 in the longitudinal direction LD. Since the shaft members 91 and 92 are integrally connected by the coupling members 93 and 94, the rigidity of the support portion 90 is improved. The support portion 90 is coupled to the lifting / lowering portion 100 and moves up and down together with the lifting / lowering portion 100. It should be noted that the support portion 90 may be coupled to at least one pair of the arms 101aL and 101aR and the arms 101bL and 101bR of the lifting / lowering portion 100.

[0046] A pair of concave portions 88 and 89 corresponding to the pair of shaft members 91 and 92 are provided on the lower surface 80a of the fixing unit 80, as shown in FIG. Figure 4As shown. With the fixing unit 80 supported by the support portion 90, the recessed portions 88 and 89 engage with the shaft members 91 and 92, respectively. When the recessed portions 88 and 89 of the fixing unit 80 engage with the shaft members 91 and 92, the fixing unit 80 is positioned along an intersecting direction ID that intersects both the vertical direction VD and the longitudinal direction LD. This is because the recessed portion 88 engages with a portion of the outer peripheral surface of the shaft member 91 on the shaft member 92 side in the intersecting direction ID, and the recessed portion 89 engages with a portion of the outer peripheral surface of the shaft member 92 on the shaft member 91 side in the intersecting direction ID.

[0047] A space SP1 through which the sheet S can pass is provided between the concave portions 88 and 89. Figure 3 As shown, the support portion 90 has an opening SP2 between the shaft members 91 and 92 , and in a state where the fixing unit 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 .

[0048] When the door 20 is in the closed position, the fixing unit 80 is Figure 2 The fixing unit 80 is shown as being housed in the image forming apparatus 1 and is located at a first position where a toner image can be fixed to a sheet S in an image forming operation. The moving unit 140 can move the fixing unit 80 to the position in a state where the fixing unit 80 is supported by the supporting portion 90. Figure 8 It should be noted that in the first position, the fixing unit 80 is slightly away from the supporting portion 90 of the moving unit 140 , and there is a slight gap between the fixing unit 80 and the pair of shaft members 91 and 92 of the supporting portion 90 .

[0049] like Figure 5 As shown, when the door 20 is moved to the open position, the fixing unit 80 is exposed to the outside of the image forming apparatus 1 through the opening portion 9. In particular, as shown in FIG. Figure 1 and 5As shown, the door 20 includes a side surface 20c, which constitutes one side surface of the imaging apparatus 1, and a top surface 20d, which constitutes a portion of the top surface of the imaging apparatus 1. The door 20 is formed generally in an approximately L-shape. Specifically, when the door 20 is moved to the open position, the space above the fusing unit 80, which was covered by the top surface 20d of the door 20 in the closed position, is opened. Therefore, the fusing unit 80 can 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 fusing unit 80 from the first position to the second position is restricted, while when the door 20 is in the open position, movement of the fusing unit 80 from the first position to the second position is permitted. It should be noted that in this embodiment, when viewed in the longitudinal direction LD, the fusing unit 80 in the first position does not overlap with the door 20 in the closed position, and when viewed in the longitudinal direction LD, the fusing unit 80 in the second position at least partially overlaps with the door 20 in the open position.

[0050] Then, when the door 20 opens 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 moved upward by the urging force of the urging members 102aL, 102bL, 102aR, and 102bR serving as the urging portion. The supporting portion 90 also moves upward in conjunction with the upward movement of the lifting / lowering portion 100. Then, the supporting portion 90 abuts against the fixing unit 80 located at the first position, and then moves the fixing unit 80 upward toward the second position.

[0051] The fixing unit 80 is provided with a fixing lock 85. Figure 6 As shown, when the fixing unit 80 starts to move upward, the fixed lock 85 engages with the locking portion 86 provided in the device body 1A, which serves as a restricting portion. The fixed lock 85 is supported by the frame member of the fixing unit 80 so as to be movable between the restricting position and the allowing position, and is urged to the restricting position by an urging member (not shown). The fixed lock 85 is capable of restricting the movement of the fixing unit 80 from the first position to the second position (upward movement operation) by engaging with the locking portion 86 at the restricting position. In addition, at the allowing position, the engagement between the fixed lock 85 and the locking portion 86 is released, thereby allowing the fixing unit 80 to move from the first position to the second position (upward movement operation).

[0052] In a state where the fixing lock 85 located at the restricting position and the locking portion 86 are engaged with each other, lifting of the fixing unit 80 from the supporting portion 90 is restricted. Therefore, the fixing unit 80 cannot be detached from the supporting portion 90.

[0053] It should be noted that in the present embodiment, the fixing lock 85 and the locking portion 86 are provided only on one side of the imaging apparatus 1 in the longitudinal direction LD, but may be provided on each side of the imaging apparatus 1 in the longitudinal direction LD.

[0054] Attaching / detaching operation of the fixing unit

[0055] The following will refer to Figures 7 to 9 The attaching / detaching operation of the fixing unit 80 is described. Figure 7 is a cross-sectional view of the image forming apparatus 1 in a state where the door 20 is opened. Figure 8 is a perspective view of the fixing unit 80 located at the second position. Figure 9 1 is a perspective view showing a state in which the fixing unit 80 is detached from the supporting portion 90 .

[0056] First, a process of removing the fixing unit 80 from the supporting portion 90 of the moving unit 140 will be described. Figure 7 As shown, the user first moves the door 20 from the closed position to the open position. Then, the fixing unit 80 starts the upward movement operation through the moving unit 140, but as shown in FIG. Figure 6 As shown, the fixing lock 85 is engaged with the locking portion 86, so the upward movement operation of the fixing unit 80 is restricted. For example, in the case of performing jam removal in the conveying path 1c or the duplex conveying path 20a, the user can Figure 7 Perform jam removal in the state of

[0057] To remove the support portion 90 from the fixing unit 80, the user presses Figure 6 As a result, the upward movement operation of the fixing unit 80 by the moving unit 140 is restarted, and the fixing unit 80 is lifted to the second position, as shown in FIG. Figure 8 In this state, the user can remove the fixing unit 80 from the supporting portion 90 by lifting the fixing unit 80. The fixing unit 80 is arranged only on the pair of shaft members 91 and 92 of the supporting portion 90, so the fixing unit 80 can be easily removed from the supporting portion 90 simply by lifting the fixing unit 80.

[0058] In addition, after the mobile unit 140 has moved upward Figure 8In a state in which the fixing unit 80 is in the second position, the transfer unit 40, which serves as an image forming section for forming a toner image on a sheet, and the tray unit 50 can be attached to and detached from the apparatus body 1A through the opening portion 9. If the moving unit 140 has been moved upward, the transfer unit 40 and the tray unit 50 can be attached to and detached from the apparatus body 1A even in a state in which the fixing unit 80 is attached to the supporting portion 90. That is, in a state in which the fixing unit 80 is in the second position, the transfer unit 40 and the tray unit 50 are arranged so as to be attachable to and detachable from the apparatus body 1A through the opening portion 9.

[0059] As described above, the fixing unit 80, the transfer unit 40, and the tray unit 50 are each configured to be attachable to and detachable from the image forming apparatus 1 on the door 20 side. Therefore, when attaching or detaching the fixing unit 80, the transfer unit 40, and the tray unit 50, the image forming apparatus 1 can be accessed from one side, which improves usability and reduces the installation space required for installing the image forming apparatus 1. Furthermore, since the cartridge 31 is also configured to be attachable to and detachable from the apparatus body 1A on the same side as the opening portion 9, usability can be improved and space can be reduced.

[0060] At the same time, the fixing unit 80 in the first position overlaps the movement trajectory of the transfer unit 40 and the tray unit 50 for attaching and detaching the transfer unit 40 and the tray unit 50 to and from the apparatus body 1A. Therefore, the imaging apparatus 1 can be miniaturized. It should be noted that in this embodiment, the transfer unit 40 and the tray unit 50 are arranged to be attachable to and detachable from the apparatus body 1A independently of each other, but they may also be arranged to be attachable to and detachable from the apparatus body 1A as a whole.

[0061] In a state where the supporting portion 90 is detached from the fixing unit 80, the supporting portion 90 can be visually recognized as follows. Figure 9 As shown. In addition, the shaft members 91 and 92 of the support portion 90 extend along the entire length of the fixing unit 80 in the longitudinal direction LD, and the user can intuitively recognize the position where the fixing unit 80 is to be placed. Moreover, in a state where the fixing unit 80 is detached from the support portion 90, since the moving unit 140 is kept in the raised state, the support portion 90 is located near the opening portion 9, and thus the visibility of the support portion 90 can be improved.

[0062] For example, when consumable parts of the fixing unit 80 expire, the fixing unit 80 is replaced. When a brand new fixing unit 80 is attached to the support portion 90, the fixing unit 80 is arranged on the support portion 90 so that the shaft members 91 and 92 engage with the recessed portions 88 and 89 provided in the lower surface 80a of the fixing unit 80. After the fixing unit 80 is attached to the support portion 90, the user pushes the fixing unit 80 or the moving unit 140 downward, thereby moving the fixing unit 80 downward until the movement of the fixing unit 80 is restricted by the locking portion 86. The user closes the door 20 in a state in which the fixing lock 85 provided on the fixing unit 80 is engaged with the locking portion 86.

[0063] When the door 20 is closed, the movable unit 140 is pushed downward by a push portion (not shown) provided on the door 20. As a result, the fixing unit 80 is held in the first position, separated from the support portion 90 of the movable unit 140. It should be noted that in the first position, the fixing unit 80 is held by at least one of the apparatus body 1A and the door 20. It should be noted that the fixing unit 80 can be moved to the second position not only for replacement but also for, for example, removing a sheet S that has become jammed while being gripped by the fixing nip of the fixing unit 80.

[0064] As described above, the fixing unit 80 is provided so as to be attachable to and detachable from the supporting portion 90 of the moving unit 140 at the second position close to the opening portion 9. In addition, since the supporting portion 90 extends in the longitudinal direction LD and supports the fixing unit 80 from below, the fixing unit 80 can be detached from the supporting portion 90 simply by lifting the fixing unit 80, and thus the attachability and detachability of the fixing unit 80 can be improved.

[0065] Moreover, in a state where the fixing unit 80 is detached from the supporting portion 90, the supporting portion 90 is located near the opening portion 9 and can be visually recognized. In addition, since the supporting portion 90 includes the shaft members 91 and 92 arranged parallel to each other, the user can intuitively recognize the position to attach the fixing unit 80, thereby improving the attachability and detachability of the fixing unit 80.

[0066] In addition, when the fixing unit 80 is pushed downward from the second position to the first position, the fixing lock 85 engages with the locking portion 86, thereby locking the fixing unit 80. Therefore, the user can intuitively determine to which position the fixing unit 80 should be pushed downward. In addition, since the supporting portion 90 is formed into a rectangular shape by a pair of shaft members 91 and 92 and a pair of coupling members 93 and 94, its rigidity can be improved. Therefore, when the fixing unit 80 is pushed downward from the second position toward the first position, the fixing unit 80 is stably supported so as to maintain its posture and there is no interference between the fixing unit 80 and the inner wall of the device body 1A, thereby improving the attachability and detachability of the fixing unit 80.

[0067] Furthermore, even when the door 20 is opened from the closed position to the open position, the fixing lock 85 is engaged with the locking portion 86, thereby maintaining the fixing unit 80 in a position close to the first position. In other words, even when the door 20 is opened, the fixing unit 80 is not automatically moved upward to the second position by the moving unit 140. Therefore, for example, when clearing a jam in the transport path 1c or the duplex transport path 20a, the fixing unit 80 is not raised or lowered unless the fixing lock 85 is pressed, thereby improving jam removal performance and usability.

[0068] Second embodiment

[0069] Next, a second embodiment of the present invention will be described. The second embodiment has a configuration in which the shape of the support portion 90 of the first embodiment is changed. Therefore, illustration of elements substantially identical to those in the first embodiment will be omitted, or these elements will be denoted by the same reference numerals for ease of description.

[0070] Figure 10 is a perspective view of a moving unit 240 according to the second embodiment. Figure 11 is a perspective view of a supporting portion 190 to which the fixing unit 80 is attached. Figure 12 is another perspective view of the supporting portion 190 to which the fixing unit 80 is attached.

[0071] Mobile Unit

[0072] The moving unit 240 according to this embodiment includes a supporting portion 190 and a lifting / lowering portion 100, as shown in FIG. Figure 10 The lifting / lowering portion 100 has substantially the same configuration as that of the first embodiment, and the supporting portion 190 is coupled to the lifting / lowering portion 100 so as to move in conjunction with the lifting / lowering operation of the lifting / lowering portion 100 .

[0073] The support portion 190 includes a placement surface 95 extending in the longitudinal direction LD and supporting the fixing unit 80 from below, and a pair of side surfaces 96 and 97 extending upward from respective ends of the placement surface 95 in the longitudinal direction LD. Furthermore, the support portion 190 includes a coupling surface 98 extending upward from the placement surface 95 and coupling the pair of side surfaces 96 and 97. The pair of side surfaces 96 and 97 and the coupling surface 98 are arranged so as to surround the fixing unit 80 when the fixing unit 80 is arranged on the placement surface 95. An opening SP3 is provided in the placement surface 95, and a sheet S is conveyed through the opening SP3 to the fixing nip of the fixing unit 80 arranged on the placement surface 95.

[0074] Attaching / detaching operation of the fixing unit

[0075] Next, the attaching / detaching operation of attaching and detaching the fixing unit 80 to and from the supporting portion 190 will be described. Regarding the attaching / detaching operation of the fixing unit 80, the operation until the fixing unit 80 is detached is basically the same as in the first embodiment. In a state where the fixing unit 80 is detached from the supporting portion 190, the supporting portion 190 can be visually recognized, as shown in FIG. Figure 10 In addition, the placement surface 95 of the support portion 190 extends over the entire length of the fixing unit 80 in the longitudinal direction LD, and the user can intuitively recognize the position where the fixing unit 80 is to be placed. Moreover, the side surfaces 96 and 97 and the coupling surface 98 are arranged along the outer periphery of the fixing unit 80, so the user can easily visually recognize the position where the fixing unit 80 is to be attached.

[0076] When attaching the fixing unit 80 to the supporting portion 190, the user aligns the side surfaces 96 and 97 with the outside of the fixing unit 80 and aligns the rear side of the fixing unit 80 with the coupling surface 98. In this state, the fixing unit 80 is placed on the placement surface 95 as shown in FIG. Figure 11 and 12 shown.

[0077] like Figure 11 As shown, when the fixing unit 80 is placed on the placement surface 95, a gap 99 for air flow is ensured between the fixing unit 80 and the coupling surface 98. When the image forming apparatus 1 performs an image forming operation, air blown by a fan (not shown) provided in the apparatus body 1A flows toward the gap 99, thereby reducing heat transfer from the fixing unit 80 to the support portion 190. As a result, when the user attaches and detaches the fixing unit 80 to and from the support portion 190, the support portion 190 can be prevented from reaching a high temperature, and the attachability and detachability of the fixing unit 80 can be improved.

[0078] Other embodiments

[0079] It should be noted that while the support portion 90 includes a pair of shaft members 91 and 92 in the first embodiment that engage with the recessed portions 88 and 89 of the fixing unit 80, the configuration is not limited to this. The shape of the support portion 90 is not limited, as long as it supports the fixing unit 80 from below. For example, the shaft members 91 and 92 of the support portion 90 are not limited to having a circular cross-section and can have different shapes, such as a polygonal or elliptical cross-section. Furthermore, the number of shaft members is not limited to two and can be three or more. The recessed portions arranged in the fixing unit 80 can be provided in the same number as the shaft members. Alternatively, the support portion 90 can be provided with one or more protruding or recessed portions, and the fixing unit 80 can be provided with one or more recessed or protruding portions. In this case, the protruding and recessed portions can engage with each other. Alternatively, the fixing unit 80 can have a recessed portion that engages with the coupling members 93 and 94 of the support portion 90.

[0080] In addition, although the support portion 190 includes the placement surface 95, the side surfaces 96 and 97, and the coupling surface 98 in the second embodiment, the structure is not limited to this. For example, the support portion 190 may omit any one of the coupling surface 98 and the side surfaces 96 and 97. In addition, the support portion 190 may include another coupling surface that is arranged on the opposite side of the coupling surface 98 across the fixing unit 80 and couples the side surfaces 96 and 97.

[0081] In addition, although the second position of the fixing unit 80 is above the first position in any of the above embodiments, the structure is not limited thereto. For example, the fixing unit 80 may be moved horizontally from the first position toward the second position, or may be moved obliquely downward.

[0082] Furthermore, although the lifting / lowering section 100 includes a linkage mechanism composed of a plurality of arms in any of the above-described embodiments, the structure is not limited thereto. For example, the lifting / lowering section 100 may include a rack portion, and the support section 90 or 190 may be configured to be lifted and lowered by engagement between the rack portion and a pinion provided on the support section 90 or 190. Alternatively, the support section 90 or 190 may be provided with a pinion, and the lifting / lowering section 100 may be provided with a rack portion. As described above, the configuration of the lifting / lowering section 100 is not limited.

[0083] Furthermore, although the fixing unit 80 includes the heating roller 83 and the pressure roller 84 in any of the above-described embodiments, the structure is not limited thereto. For example, a heating unit including a heater (e.g., a ceramic heater) and a fixing film heated by the heater may be used in place of the heating roller 83. Alternatively, a fixing belt including a heat-generating layer that generates heat through induction heating may be used in place of the heating roller 83.

[0084] In addition, although the photosensitive drum 61, charging roller 62, and developing roller 71 are provided in each process cartridge (PY to PK) in any of the above embodiments, the structure is not limited to this. That is, the photosensitive drum 61, charging roller 62, and developing roller 71 may be provided in the process cartridge or the tray 51.

[0085] In addition, although the door 20 is provided so as to be pivotable about the pivot shaft 20 b in any of the above embodiments, the configuration is not limited thereto. For example, a cover that can slide or be detached relative to the apparatus body 1A may be provided instead of the door 20 .

[0086] In addition, although the opening SP2 is provided between the shaft members 91 and 92 in the first embodiment and the opening SP3 is provided in the placement surface 95 in the second embodiment, the shapes of these openings are not limited. For example, these openings may be through holes or cutouts as long as the sheet S can pass therethrough.

[0087] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus configured to form a toner image on a sheet, the image forming apparatus comprising: A device body, wherein the device body is provided with an opening portion; an opening / closing member supported so as to be openable and closable relative to the apparatus body between an open position and a closed position, the opening / closing member covering the opening portion at the closed position and opening the opening portion at the open position; a fixing unit supported so as to be attachable to and detachable from the apparatus body through the opening portion and configured to apply heat and pressure to the sheet so as to fix the toner image to the sheet; as well as a moving unit disposed in the apparatus body and configured to move the fixing unit from a first position toward a second position above the first position; wherein movement of the fixing unit from the first position to the second position is restricted in a state where the opening / closing member is located in the closed position, and is permitted in a state where the opening / closing member is located in the open position, wherein the moving unit includes a supporting portion configured to support the fixing unit located at the second position so that the fixing unit can be attached and detached; and The supporting portion extends in a longitudinal direction of the fixing unit and supports the fixing unit from below.

2. The imaging device according to claim 1, wherein: When viewed in the longitudinal direction, the fixing unit located at the first position does not overlap with the opening / closing member located at the closed position, and Here, when viewed in the longitudinal direction, at least a portion of the second position of the fixing unit overlaps with the opening / closing member located at the closed position.

3. The imaging device according to claim 1, wherein: The support portion includes a pair of shaft members extending in the longitudinal direction, and The lower surface of the fixing unit is provided with a pair of concave portions, and the pair of concave portions are configured to engage with the pair of shaft members.

4. The imaging device according to claim 3, wherein: The supporting portion includes a pair of coupling members provided so that respective ends of the pair of shaft members in the longitudinal direction are coupled to each other.

5. The imaging device according to claim 1, wherein: The supporting portion includes: a placement surface extending in a longitudinal direction, on which the fixing unit is arranged; a pair of side surfaces standing upward from respective ends of the placement surface in the longitudinal direction; and a connecting surface standing upward from the placement surface so as to connect the pair of side surfaces.

6. The imaging device according to claim 5, wherein: In a state where the fixing unit is arranged on the placement surface, the fixing unit is provided with a gap between the fixing unit and the coupling surface, and air flows through the gap.

7. The imaging device according to claim 1, wherein: The supporting portion is provided with an opening through which a sheet conveyed toward the fixing unit located at the first position can pass.

8. The imaging device according to claim 1, wherein: The moving unit includes an urging portion configured to urge the fixing unit from a first position toward a second position.

9. The imaging device according to claim 1, further comprising: A restriction portion is configured to restrict movement of the fixing unit from the first position to the second position.

10. The imaging device according to claim 9, wherein: The fixing unit includes an engaging portion, which is configured to move to a restricting position and a allowing position, wherein the restricting position engages with the restricting portion so as to restrict the movement of the fixing unit from the first position to the second position, and the allowing position wherein the engagement between the restricting portion and the engaging portion is released so as to allow the movement of the fixing unit from the first position to the second position.

11. The imaging device according to claim 10, wherein: The fixing unit is moved to the second position by the moving unit when the opening / closing member is moved from the closing position to the opening position and the restricting portion is moved from the restricting position to the allowing position.

12. The imaging device according to any one of claims 1 to 11, wherein: When the opening / closing member is located at the closed position, the supporting portion of the moving unit is separated from the fixing unit located at the first position.

13. The imaging device according to any one of claims 1 to 11, further comprising: an image forming portion configured to form a toner image on a sheet, The image forming section is configured to be attachable to and detachable from the apparatus body through the opening portion in a state where the fixing unit has been moved to the second position by the moving unit.

14. The imaging device according to claim 13, wherein: The fixing unit located at the first position overlaps with a movement trajectory of the image forming section to and from the apparatus body.

15. The imaging device according to any one of claims 1 to 11, further comprising: a supporting portion configured to support a sheet fed toward the fixing unit, The support portion is configured to be attachable to and detachable from the device body on the same side as the opening portion.

Images