Image forming apparatus

Abstract

To provide an image forming apparatus that has a new configuration to arrange a link that is connected to a shutter and is in contact with a cartridge.SOLUTION: An image forming apparatus 1 has: an apparatus body 2; a fuser 6 that has a heating unit 61 and fixes a toner image to a sheet; a shutter 64 that is movable to a closed position where it covers the upstream in the sheet conveyance direction of the heating unit 61 and to an open position where it opens the upstream in the sheet conveyance direction of the heating unit 61; a link 8 that is connected to the shutter 64, and that is in contact with a process cartridge 50 removably mounted in the apparatus body 2 to move the shutter 64 to the closed position and the open position; a power supply substrate 72 on which an electronic component 721 is mounted; and a fan 71 that exhausts air inside the apparatus body 2 to the outside of the apparatus body 2. The power supply substrate 72 and the fan 71 are separated from each other to form a first air flow passage FP1, and the direct-acting link 82 of the link 8 is located between the power supply substrate 72 and the fan 71.SELECTED DRAWING: Figure 29

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art In a conventional image forming apparatus having a removable cartridge, a shutter is provided in front of the fixing unit having a heating portion to prevent a user's hand from touching the fixing unit.

[0003] For example, the image forming device disclosed in Patent Document 1 is equipped with a link that is connected to the shutter and can abut against the cartridge. When the cartridge is installed, the link abuts against the cartridge and moves, and the shutter opens in accordance with the movement of the link. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6961471 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in an image forming apparatus configured to open and close the shutter by a link that can abut against the cartridge, the link needs to be disposed outside the sheet passage range so as not to impede the passage of the sheet. However, since multiple parts are disposed outside the sheet passage range in the image forming apparatus, some ingenuity was required to dispose the link in the image forming apparatus.

[0006] Therefore, the present invention provides an image forming apparatus having a novel structure for arranging a link that is connected to the shutter and comes into contact with the cartridge. [Means for solving the problem]

[0007] The image forming apparatus that solves the above problem has the following features.

[0008] That is, the image forming apparatus has a device main body, a fixing unit having a heating section and fixing a toner image to a sheet, a shutter that is movable between a closed position that covers the upstream side of the heating section in the sheet transport direction and an open position that opens the upstream side of the heating section in the sheet transport direction, a link connected to the shutter and abuts against a cartridge that is attached to or detached from the device main body to move the shutter between the closed position and the open position, a board on which electronic components are mounted, and a fan that moves air inside the device main body, the board and the fan are spaced apart so that an air flow path is formed, and the link is located between the board and the fan.

[0009] This allows the links to be arranged efficiently by utilizing the air flow path between the board and the fan.

[0010] Further, the board has a board surface on which the electronic components are mounted, the board surface extending in a first direction and a second direction perpendicular to the first direction, the fan is located away from the board in the first direction and overlaps with the board in the second direction, and the link is located between the board and the fan in the first direction.

[0011] This allows the links to be arranged efficiently by utilizing the air flow path between the board and the fan in the first direction.

[0012] Moreover, the link is a linear link that is movable in the second direction.

[0013] This allows the link to be moved without interfering with the board and fan.

[0014] The device further includes a biasing member for biasing the link, the biasing member having a biasing spring and a contact portion that is pressed by the biasing spring and contacts the link, the biasing spring and the contact portion being positioned between the substrate and the fan in the first direction.

[0015] This allows the biasing spring and the abutment portion to be efficiently disposed by utilizing the air flow path between the board and the fan.

[0016] In addition, the link has a protrusion that protrudes toward the biasing member and has an inclined surface that is inclined with respect to the second direction, and the abutment portion that is pressed by the biasing spring abuts against the inclined surface of the protrusion.

[0017] With this, the abutting portion abuts against the inclined surface of the protrusion, thereby biasing the link in the forward and backward directions.

[0018] The device also includes a substrate cover located between the link and the substrate and covering the substrate, the substrate cover having a first portion having an air vent formed therein and a second portion having no air vent formed therein, the link being located between the first portion and the second portion and the fan, and the biasing spring being located between the second portion and the fan.

[0019] As a result, heat generated by electronic components mounted on the board is transferred through the vent in the first portion of the board cover to the fan side rather than the board cover. However, since the biasing spring is located between the fan and the second portion where no vent is formed, it is less susceptible to the effects of heat, and fluctuations in the biasing force of the biasing spring can be suppressed.

[0020] The sensor further includes a cable extending from the substrate, the cable being positioned alongside the link in a third direction perpendicular to the first direction and the second direction.

[0021] This allows the cables, in addition to the links, to be efficiently positioned utilizing the air flow path between the board and the fan.

[0022] The link cover is located between the link and the cable in the third direction and restricts movement of the link in the third direction.

[0023] This can prevent the link and the cable from interfering with each other due to the link cover.

[0024] The device further includes a board cover that is positioned between the link and the board and covers the board.

[0025] This makes it possible for the board cover to prevent interference between the link and the board.

[0026] The board cover is located between the link and the board and has a first portion extending in a direction perpendicular to a board surface of the board, and an air vent is formed in the first portion.

[0027] This allows heat generated by the electronic components mounted on the board to be released toward the fan through the vent in the first portion.

[0028] Additionally, the link is shorter than the first portion in a direction perpendicular to the substrate surface.

[0029] This can prevent the vent from being blocked by the link.

[0030] The actuator further includes a first frame and a second frame that face each other with the cartridge therebetween, and a board cover that covers the board, and the first frame supports the link, the board cover, and the fan.

[0031] This allows the link to be efficiently positioned together with the board cover and the fan.

[0032] The cartridge also has a photosensitive drum that rotates around a drum shaft, and the link abuts against the drum shaft.

[0033] As a result, the movement of the drum shaft is transmitted to the shutter via the link, so that even if the distance between the mounting position of the cartridge in the device body and the shutter is large, the driving force can be transmitted efficiently to the shutter.

[0034] The printer further includes an air duct disposed across the first frame and the second frame, the air duct and the fan being positioned to overlap when viewed from the opposing direction of the first frame and the second frame, and the air duct being located between the cartridge and the fixing unit in a direction perpendicular to the opposing direction.

[0035] This allows the link to be positioned without interfering with the fan, even if the fan is located midway along the link that extends from the drum axis of the cartridge to the portion where the fixation unit is located, in a direction perpendicular to the opposing direction of the first frame and the second frame. Effect of the Invention

[0036] According to the present invention, the links can be arranged efficiently by utilizing the air flow path between the board and the fan. [Brief description of the drawings]

[0037] [Figure 1] 1 is a schematic central cross-sectional view showing an image forming apparatus. [Diagram 2] FIG. 2 is a perspective view showing the image forming apparatus with the front cover in an open position. [Diagram 3] FIG. [Figure 4] FIG. 2 is a perspective view showing a heating unit and a pressure roller of the fixing unit. [Diagram 5] FIG. 2A is a perspective view showing the fixing unit when the shutter is in a closed position, and FIG. 2B is a perspective view showing the fixing unit when the shutter is in an open position. [Figure 6]FIG. 2A is a side view showing the fixing unit when the shutter is in a closed position, and FIG. 2B is a side view showing the fixing unit when the shutter is in an open position. [Figure 7] FIG. 2A is a side cross-sectional view showing the fixing unit when the shutter is in a closed position, and FIG. 2B is a side cross-sectional view showing the fixing unit when the shutter is in an open position. [Figure 8] FIG. 2A is a front view showing the right end portion of the fixing unit when the shutter is in a closed position, and FIG. 2B is a front view showing the right end portion of the fixing unit when the shutter is in an open position. [Figure 9] FIG. 2 is a perspective view showing a process cartridge. [Figure 10] FIG. 2 is a side view showing the process cartridge. [Figure 11] FIG. 4 is a side view showing the left side surface of the first main body frame. [Figure 12] FIG. 4 is a side view showing the right side surface of the first main body frame. [Figure 13] 13 is a side view showing the link in a state in which the first boss of the abutment piece is located in the middle of the abutment piece rail and the second boss is located in the front of the abutment piece rail. FIG. [Figure 14] A side view showing the first main body frame in a state where the process cartridge is located at the installation start position, the first boss of the abutment piece is located at the middle of the abutment piece rail, and the second boss is located at the front of the abutment piece rail. [Figure 15] FIG. [Figure 16] 13 is an enlarged side view showing a state in which the drum shaft that has entered the center of the cartridge rail abuts against a first boss of the abutment piece. FIG. [Figure 17] 13 is a side view showing the link in a state in which the drum shaft is in contact with the contact piece, a rear portion of the first boss of the contact piece is located at the rear of the contact piece rail, and the second boss is located at the center of the contact piece rail. [Figure 18] This is a side view showing the first main body frame in a state in which the drum shaft is in contact with the abutment piece, a rear portion of the first boss of the abutment piece is located at the rear of the abutment piece rail, and the second boss is located at the center of the abutment piece rail. [Figure 19]1 is an enlarged side view showing a state in which the drum shaft is in contact with the contact piece, a rear portion of the first boss of the contact piece is located at the rear of the contact piece rail, and the second boss is located at the center of the contact piece rail. [Figure 20] 13 is a side view showing the link in a state in which the drum shaft is in contact with the contact piece, the first boss of the contact piece is located at the rear part of the contact piece rail, and the second boss is located at the center part of the contact piece rail. FIG. [Figure 21] 1 is a side view showing the first main body frame in a state in which the drum shaft is in contact with the abutment piece, the first boss of the abutment piece is located at the rear of the abutment piece rail, and the second boss is located at the middle of the abutment piece rail. [Figure 22] 13 is an enlarged side view showing a state in which the drum shaft has moved from the center to the rear of the cartridge rail and the abutment piece and the drum shaft are separated from each other. FIG. [Diagram 23] 20 is a side view showing a state in which the linear motion link has moved rearward from the position shown in FIG. 19 due to a pressing force from the pressing arm. FIG. [Figure 24] 22 is an enlarged side view showing a state in which a first boss of the abutment piece has moved rearward from the position shown in FIG. 21. FIG. [Diagram 25] 13 is a side view showing the first main body frame in a state where the process cartridge has reached the mounting position after the drum shaft has been separated from the contact piece. FIG. [Figure 26] FIG. 4 is a right rear perspective view showing the first body frame, the second body frame, and the air duct. [Figure 27] FIG. 2 is a left-front perspective view showing a first main body frame, a second main body frame, and an air duct. [Figure 28] FIG. 2 is a plan view showing the first main body frame, the second main body frame, and the air duct. [Figure 29] 4 is a side view showing a first main body frame supporting a fan and a board cover. FIG. [Diagram 30] This is a cross-sectional view taken along the line AA in Figure 29. [Diagram 31] 29 is a cross-sectional view of FIG. [Diagram 32] FIG. [Diagram 33]FIG. 2 is a central cross-sectional view showing the image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0039] [Image forming equipment] An image forming apparatus 1 shown in FIG. 1 is one embodiment of an image forming apparatus equipped with a sheet conveying device according to the present invention, and is a laser printer that forms an image on a sheet S by electrophotography.

[0040] In the following description, the right side in Fig. 1 is defined as the front side of the image forming apparatus 1, the left side in Fig. 1 is defined as the rear side of the image forming apparatus 1, the front side of the paper in Fig. 1 is defined as the left side of the image forming apparatus 1, and the back side of the paper in Fig. 1 is defined as the right side of the image forming apparatus 1. In addition, the upper and lower sides in Fig. 1 are defined as the upper and lower sides of the image forming apparatus 1, respectively.

[0041] The image forming apparatus 1 includes an apparatus main body 2, a paper feed section 3, an image forming section 5, a fixing unit 6, and a paper discharge section 29.

[0042] The device body 2 houses the paper feed section 3, the image forming section 5, the fixing unit 6, and the paper discharge section 29. An opening 2A is open at the front of the device body 2, and the device body 2 has a front cover 21 that can open and close the opening 2A. The front cover 21 is configured to be rotatable about a rotation shaft 21a at the bottom end, and by rotating about the rotation shaft 21a, it is possible to move between a closed position where the opening 2A is closed and an open position where the opening 2A is opened.

[0043] The paper feed unit 3 includes a paper feed tray 10 that supports the sheet S, a sheet transport unit 30, a transport roller pair 34, and a registration roller 35a. The paper feed unit 3 is disposed at the bottom of the device body 2, and transports the sheet S supported by the paper feed tray 10 to the image forming unit 5. The image forming device 1 has a transport path P for the sheet S that runs from the paper feed unit 3 to the paper discharge unit 29 via the image forming unit 5.

[0044] The paper feed tray 10 has a pressure plate 12 and a pressing plate 13. The pressure plate 12 is a plate-shaped member that supports the sheets S from below. The pressure plate 12 is rotatable about a rotation fulcrum 12a at the rear end, and can be raised and lowered between a lowered position and an upper position by rotating about the rotation fulcrum 12a. The pressing plate 13 is located below the pressure plate 12, and can raise and lower the pressure plate 12 between the lowered position and the upper position.

[0045] The sheet conveying section 30 is a conveying mechanism that separates and takes out the sheets S supported by the paper feed tray 10 one by one, and conveys the sheets S toward the image forming section 5, and includes a paper feed roller 31, a separation roller 32, and a separation pad 33.

[0046] The paper feed roller 31 is a roller for sending the sheet S supported by the paper feed tray 10 toward the separation roller 32. The separation roller 32 is disposed downstream of the paper feed roller 31 in the sheet conveying direction, and the separation pad 33 is disposed opposite to the separation roller 32 and is biased toward the separation roller 32.

[0047] The sheets S sent by the paper feed roller 31 toward the separation roller 32 are separated one by one between the separation roller 32 and the separation pad 33. The separated sheets S are sent to a conveying path P.

[0048] The sheet S sent to the conveying path P is conveyed toward the image forming unit 5 by the conveying roller pair 34, the registration roller 35a, and the pinch roller 35b arranged opposite the registration roller 35a. The registration roller 35a regulates the movement of the leading edge of the conveyed sheet S, temporarily stops the sheet S, and then conveys the sheet S toward the image forming unit 5 at a predetermined timing.

[0049] The image forming section 5 is disposed downstream of the paper feed section 3 in the sheet transport direction, and forms an image on the sheet S transported from the paper feed section 3. The image forming section 5 includes a process cartridge 50 that transfers an image onto the surface of the sheet S transported from the paper feed section 3, a transfer roller 55 that is disposed opposite a photosensitive drum 54 of the process cartridge 50, and an exposure unit 56 that exposes the surface of the photosensitive drum 54. The process cartridge 50 is an example of a cartridge that is detachably attached to the apparatus main body.

[0050] The process cartridge 50 is disposed above the paper feed unit 3 in the apparatus main body 2, and includes a developer storage chamber 51, a supply roller 52, a developing roller 53, and a photosensitive drum 54. The process cartridge 50 supports a pinch roller 35b.

[0051] The process cartridge 50 includes a drum cartridge having a photosensitive drum 54, and a developer cartridge that is attached to the drum cartridge and has a developing roller 53, and is detachably attached to the device main body 2. In this case, the process cartridge 50 is attached to the device main body 2 by inserting the drum cartridge and the developer cartridge attached to the drum cartridge together into the device main body 2, and is detached from the device main body 2 by removing the drum cartridge and the developer cartridge attached to the drum cartridge together from the device main body 2.

[0052] The process cartridge 50 is an example of a cartridge and can include at least one of a photosensitive drum, a developing roller, and a toner container. The process cartridge 50 can be attached to and detached from the apparatus main body 2 when the front cover 21 is in the open position.

[0053] When the process cartridge 50 is attached to the apparatus main body 2, the photosensitive drum 54 is disposed in a position in which the axis X is aligned along the left-right direction. The photosensitive drum 54 has a metallic drum shaft 54a extending along the axis X. The photosensitive drum 54 rotates around the drum shaft 54a.

[0054] In this embodiment, the process cartridge 50 comprises a drum cartridge having a photosensitive drum 54, and a developing cartridge attached to the drum cartridge and having a developing roller 53, but it can also be configured to comprise a cartridge having the photosensitive drum 54 and the developing roller 53, and a toner box attached to the cartridge for containing toner.

[0055] Furthermore, the image forming apparatus can be configured so that a drum cartridge having a photosensitive drum 54 and a developer cartridge having a developer roller 53 are separately mounted in the apparatus main body 2. That is, the process cartridge 50 includes at least one of a photosensitive drum, a developer roller, and a toner container, and can be configured so as to be detachably mounted in the apparatus main body.

[0056] The exposure unit 56 is equipped with a laser diode, a polygon mirror, a lens, a reflecting mirror, etc., and exposes the surface of the photosensitive drum 54 by irradiating the photosensitive drum 54 with laser light based on image data input to the image forming apparatus 1.

[0057] Toner that becomes the developer is accommodated in the developer accommodating chamber 51. The toner accommodated in the developer accommodating chamber 51 is sent to the supply roller 52 while being stirred by a stirring member (not shown). The supply roller 52 further supplies the toner sent from the developer accommodating chamber 51 to the developing roller 53.

[0058] The developing roller 53 is disposed in close contact with the supply roller 52, and carries the toner supplied from the supply roller 52 and positively charged by a sliding contact member (not shown). A developing bias is applied to the developing roller 53 by a bias application means (not shown).

[0059] The photosensitive drum 54 is disposed adjacent to the developing roller 53. The surface of the photosensitive drum 54 is uniformly charged by a charger (not shown) and then exposed by the exposure unit 56. The exposed portion of the photosensitive drum 54 has a lower potential than other portions, and an electrostatic latent image based on the image data is formed on the photosensitive drum 54. Then, positively charged toner is supplied from the developing roller 53 to the surface of the photosensitive drum 54 on which the electrostatic latent image has been formed, thereby visualizing the electrostatic latent image into a toner image.

[0060] The transfer roller 55 is disposed opposite the photosensitive drum 54, and a transfer bias is applied to it by a bias application means (not shown). With the transfer bias applied to the surface of the transfer roller 55, the sheet S is conveyed while being sandwiched between the photosensitive drum 54 on which the toner image is formed and the transfer roller 55, whereby the toner image formed on the surface of the photosensitive drum 54 is transferred to the surface of the sheet S. The sheet S on which the toner image has been transferred is conveyed to the fixing unit 6.

[0061] The fixing device 6 includes a heating unit 61 and a pressure roller 62, and fixes the image transferred onto the sheet S by the process cartridge 50. The heating unit 61 is heated by supplying power from a power source (not shown). The heating unit 61 is an example of a heating section, and the pressure roller 62 is an example of a pressure section. The pressure roller 62 is disposed opposite the heating unit 61. One of the heating unit 61 and the pressure roller 62 is biased toward the other by a biasing mechanism (not shown), and the heating unit 61 and the pressure roller 62 are in close contact with each other.

[0062] When the sheet S onto which the toner image has been transferred is conveyed to the fixing device 6, the sheet S is conveyed while being sandwiched between a heating unit 61 and a pressure roller 62, whereby the sheet S is heated and the toner image transferred onto the conveyed sheet S is fixed. In this manner, the fixing device 6 fixes the toner image onto the sheet S.

[0063] The paper discharge section 29 is located downstream of the image forming section 5 in the sheet transport direction, and discharges the sheet S on which an image has been formed by the image forming section 5 to the outside of the image forming apparatus 1. The paper discharge section 29 includes a pair of paper discharge rollers 291 and a paper discharge tray 292. The pair of paper discharge rollers 291 is configured to be able to discharge the sheet S, which has been transported from the fixing unit 6 along the transport path P, to the outside of the device body 2. The paper discharge tray 292 is formed on the upper surface of the device body 2, and supports the sheet S discharged to the outside of the device body 2 by the pair of paper discharge rollers 291.

[0064] As shown in Fig. 2, the device body 2 includes a first body frame 24 and a second body frame 25 that are spaced apart from each other in the left-right direction. The first body frame 24 is located at the right end of the device body 2, and the second body frame 25 is located at the left end of the device body 2. The first body frame 24 extends in the front-rear and up-down directions and is disposed with its plate surface facing the left-right directions. The second body frame 25 extends in the front-rear and up-down directions and is disposed with its plate surface facing the left-right directions.

[0065] The first main body frame 24 is an example of a first frame, and the second main body frame 25 is an example of a second frame. The up-down direction is an example of a first direction, the front-rear direction is an example of a second direction perpendicular to the first direction, and the left-right direction is an example of a third direction perpendicular to the first and second directions.

[0066] The process cartridge 50 and the fixing unit 6 are disposed between the first body frame 24 and the second body frame 25. The first body frame 24 is disposed to the right of the process cartridge 50 and the fixing unit 6, and the second body frame 25 is disposed to the left of the process cartridge 50 and the fixing unit 6. The first body frame 24 and the second body frame 25 face each other with the process cartridge 50 in between. The process cartridge 50 is detachably supported by the first body frame 24 and the second body frame 25.

[0067] [Fuser] 3 and 4, the heating unit 61 of the fixing device 6 includes a heater 611, a holder 612, a stay 613, and a belt 614. The heater 611 is a flat plate-shaped heater extending in the left-right direction. The heater 611 has a first surface 611A and a second surface 611B opposite to the first surface 611A, and the first surface 611A is supported by the holder 612.

[0068] The holder 612 is made of, for example, a resin member, and has a guide surface 612a and a support wall 612b. The guide surface 612a contacts an inner circumferential surface 614a of the belt 614 to guide the belt 614. The support wall 612b has a support surface 612A that supports the heater 611. The support surface 612A of the support wall 612b abuts against a first surface 611A of the heater 611. The stay 613 is a member that supports the holder 612, and is formed by bending a plate material having greater rigidity than the holder 612, such as a steel plate, into a generally U-shaped cross section.

[0069] The belt 614 is an endless belt having heat resistance and flexibility, and includes a metal tube made of a metal such as stainless steel and a fluororesin layer covering the metal tube. The heater 611, the holder 612, and the stay 613 are disposed inside the belt 614. The belt 614 is configured to rotate around the heater 611, the holder 612, and the stay 613. An inner peripheral surface 614a of the belt 614 contacts the heater 611.

[0070] The pressure roller 62 has a metal shaft 62A and an elastic layer 62B that covers the shaft 62A. The pressure roller 62 is pressed against the heater 611 via a belt 614. The pressure roller 62 sandwiches the belt 614 between itself and the heater 611 to form a nip NP for heating and pressurizing the sheet S. In other words, the pressure roller 62 forms a nip NP with the pressure roller 62, and in the nip NP, the sheet S is heated and pressurized together with the heater 611.

[0071] The pressure roller 62 is configured to be rotationally driven by a driving force transmitted from a motor included in the image forming apparatus 1. The pressure roller 62 is rotationally driven to rotate the belt 614 by frictional force with the belt 614 or the sheet S sandwiched in the nip NP. As a result, the sheet S onto which the toner image has been transferred is transported between the pressure roller 62 and the heated belt 614, whereby the toner image is thermally fixed.

[0072] As shown in FIG. 1 and FIG. 5 to FIG. 7, the fixing unit 6 has a fixing frame 63 that covers the heating member 61 and the pressure roller 62, and a shutter 64 supported by the fixing frame 63. The fixing frame 63 holds the heating member 61 and the pressure roller 62. The fixing frame 63 covers the periphery of the heating member 61 and the pressure roller 62, and has a first opening 63a formed on the upstream side of the heating member 61 and the pressure roller 62 in the sheet conveying direction, and a second opening 63b formed on the downstream side of the heating member 61 and the pressure roller 62 in the sheet conveying direction. The fixing frame 63 covers the heating unit 61 from above.

[0073] The shutter 64 is located upstream of the first opening 63a in the fixing frame 63 in the sheet conveying direction, and has a rotation shaft 641 extending along the left-right direction, and a connecting shaft 642 protruding in a direction parallel to the rotation shaft 641. The rotation shaft 641 is rotatably supported by the fixing frame 63. The rotation shaft 641 is provided at both left and right ends of the shutter 64, and the connecting shaft 642 protrudes rightward from the right end of the shutter 64.

[0074] The shutter 64 is configured to be rotatable about a rotation shaft 641, and by rotating about the rotation shaft 641, the shutter 64 can move between a closed position (position shown in Figs. 5(a), 6(a), and 7(a)) where the first opening 63a is closed and an open position (position shown in Figs. 5(b), 6(b), and 7(b)) where the first opening 63a is opened. When the shutter 64 is in the closed position, the nip NP between the heating member 61 and the pressure roller 62 is covered by the shutter 64, and when the shutter 64 is in the open position, the nip NP between the heating member 61 and the pressure roller 62 is exposed to the outside of the fixing frame 63 through the first opening 63a.

[0075] Furthermore, the shutter 64 covers the upstream side of the heating member 61 in the sheet transport direction when in the closed position, and opens the upstream side of the heating member 61 in the sheet transport direction when in the open position. That is, the shutter 64 is movable between a closed position that covers the upstream side of the heating member 61 in the sheet transport direction and an open position that opens the upstream side of the heating member 61 in the sheet transport direction.

[0076] As shown in FIGS. 5, 7, and 8, the shutter 64 has a contact end 64a located at the upper end when the shutter 64 is in the closed position. The fixing frame 63 has a contact surface 631 against which the shutter 64 in the open position contacts. The contact surface 631 faces the upstream side in the sheet conveying direction, and the contact end 64a of the shutter 64 contacts the contact surface 631 when the shutter 64 is in the open position. When the contact end 64a of the shutter 64 contacts the contact surface 631, the shutter 64 is restricted from moving further in the opening direction. In other words, the contact surface 631 is a restricting surface on the open position side that contacts the shutter 64 in the open position to restrict the position of the shutter 64.

[0077] 5, 6 and 8, the shutter 64 has a contact portion 64b that contacts the fixing frame 63 when the shutter 64 is in the closed position. The contact portion 64b is located at the right end portion of the shutter 64. The fixing frame 63 has a contact surface 632 that contacts the shutter 64 in the closed position.

[0078] The abutment surface 632 faces the upstream side in the sheet conveying direction, and is abutted by the abutment portion 64b of the shutter 64 when the shutter 64 is in the closed position. The abutment portion 64b of the shutter 64 abuts against the abutment surface 632, thereby restricting the shutter 64 from moving further in the closing direction. In other words, the abutment surface 632 is a restricting surface on the closed position side that abuts against the shutter 64 in the closed position and restricts the position of the shutter 64.

[0079] In this embodiment, the fixing device 6 includes a heating unit 61 having a heater 611 and a belt 614, and a pressure roller 62, but the fixing device 6 can also include a heating roller with a built-in heater and a pressure roller pressed against the heating roller. The fixing device 6 can also include a heating roller with a built-in heater and a pressure belt pressed against the heating roller by an elastic member.

[0080] [Drum shaft] 9 and 10, the drum shaft 54a of the photosensitive drum 54 protrudes rightward along the axis X from the right end of the process cartridge 50. In other words, the drum shaft 54a protrudes toward the first main body frame 24 along the axis X.

[0081] [First body frame] 11 and 12, the first main body frame 24 has a front frame 24A located in the front and a rear frame 24B located behind the front frame 24A. The front frame 24A and the rear frame 24B are integrally formed continuously in the front-rear direction. The front frame 24A of the first main body frame 24 is an example of a frame.

[0082] The front frame 24A of the first main body frame 24 has a cartridge rail 241 and a contact piece rail 242. The cartridge rail 241 is formed in a groove shape that is open on the left side. The cartridge rail 241 extends in the front-rear direction and is inclined downward as it goes from the front to the rear.

[0083] The drum shaft 54a of the photosensitive drum 54 can enter the cartridge rail 241, and the cartridge rail 241 guides the drum shaft 54a when the process cartridge 50 is mounted in the apparatus main body 2 and when the process cartridge 50 is removed from the apparatus main body 2. The drum shaft 54a, guided by the cartridge rail 241, enters the cartridge rail 241 from the left side. The process cartridge 50 is mounted in the apparatus main body 2 from the front to the rear, and is removed from the apparatus main body 2 from the rear to the front.

[0084] In this way, the cartridge rail 241 of the front frame 24A guides the drum shaft 54a when the process cartridge 50 is attached to and detached from the apparatus main body 2. The cartridge rail 241 is an example of a first guide groove that guides the drum shaft.

[0085] The contact piece rail 242 is formed in a groove shape that is open on the right side. The contact piece rail 242 extends in the front-rear direction and is inclined downward as it goes from the front to the rear. The contact piece rail 242 is located to the right of the cartridge rail 241 in the left-right direction. In other words, the contact piece rail 242 is located outside the cartridge rail 241 in the left-right direction.

[0086] The cartridge rail 241 has a front portion 241a located in the front, a rear portion 241c located in the rear, and a middle portion 241b located between the front portion 241a and the rear portion 241c. The contact piece rail 242 has a front portion 242a located in the front, a rear portion 242c located in the rear, and a middle portion 242b located between the front portion 242a and the rear portion 242c.

[0087] The middle portion 241b of the cartridge rail 241 and the middle portion 242b of the abutment piece rail 242 overlap and communicate with each other. The middle portions 241b and 242b form a through hole 24C that passes through the front frame 24A in the left-right direction.

[0088] That is, a middle portion 241b that is a part of the cartridge rail 241 and a middle portion 242b that is a part of the abutment piece rail 242 overlap with each other, and the overlapping portion between the cartridge rail 241 and the abutment piece rail 242 is the through hole 24C. Since the cartridge rail 241 and the abutment piece rail 242 partially overlap in this manner, it is possible to use the same material for forming the cartridge rail 241 and the abutment piece rail 242.

[0089] The drum shaft 54a of the cartridge rail 241 enters the through hole 24C when the process cartridge 50 is mounted to the apparatus main body 2 and when the process cartridge 50 is removed from the apparatus main body 2.

[0090] A front portion 242 a of the contact piece rail 242 is positioned higher than a front portion 241 a of the cartridge rail 241 , and a rear portion 242 c of the contact piece rail 242 is positioned higher than a rear portion 241 c of the cartridge rail 241 .

[0091] [link] As shown in Figures 6, 13 and 14, the apparatus main body 2 is provided with a link 8 which is capable of coming into contact with the process cartridge 50 and which comes into contact with the process cartridge 50 to move the shutter 64 between an open position and a closed position. The link 8 is connected to the shutter 64. When the process cartridge 50 is attached to the apparatus main body 2, the link 8 comes into contact with the process cartridge 50 to move the shutter 64 from the closed position to the open position, and when the process cartridge 50 is detached from the apparatus main body 2, the link 8 comes into contact with the process cartridge 50 to move the shutter 64 from the open position to the closed position. In this way, the link 8 moves the shutter 64 to the closed position and the open position in response to the operation of the process cartridge 50.

[0092] In other words, the link 8 is configured so that the shutter 64 opens and closes in response to the attachment and detachment of the process cartridge 50 to and from the apparatus main body 2. Specifically, when the process cartridge 50 is attached to the image forming apparatus 1, the shutter 64 moves to an open position, and when the process cartridge 50 is detached from the image forming apparatus 1, the shutter 64 moves to a closed position. The link 8 is located on the opposite side of the process cartridge 50 attached to the apparatus main body 2 with respect to the front frame 24A of the first main body frame 24 in the left-right direction.

[0093] The link 8 is movable to a first position before the process cartridge 50 is attached to the apparatus main body 2. When the link 8 is in the first position, the shutter 64 is moved to a closed position. The link 8 is movable to a second position after the process cartridge 50 is attached to the apparatus main body 2. When the link 8 is in the second position, the shutter 64 is moved to an open position.

[0094] That is, the link 8 is displaceable between a first position for moving the shutter 64 to the closed position and a second position for moving the shutter 64 to the open position. The link 8 displaces from the first position toward the second position when the shutter 64 is moved from the closed position to the open position. Also, the link 8 displaces from the second position toward the first position when the shutter 64 is moved from the open position to the closed position.

[0095] The link 8 has a contact piece 80 , a first rotating link 81 , a linear link 82 , a second rotating link 83 , a third rotating link 84 , a shutter link 85 , and a coil spring 86 .

[0096] The abutment piece 80 moves in contact with the drum shaft 54a of the photosensitive drum 54. That is, the link 8 abuts against the drum shaft 54a. The abutment piece 80 is slidably fitted into the abutment piece rail 242, and the abutment piece rail 242 guides the abutment piece 80 that moves in contact with the drum shaft 54a.

[0097] 15, the abutment piece 80 has a main body 801, a connecting portion 802, a first boss 803, and a second boss 804. The main body 801 is formed of a plate-like member whose plate surface faces in the left-right direction. The connecting portion 802 is a protrusion that protrudes rightward from the right surface of the main body 801.

[0098] The first boss 803 and the second boss 804 are protrusions that protrude leftward from the left surface of the main body portion 801. The first boss 803 and the second boss 804 enter the contact piece rail 242 of the first main body frame 24 from the right side, and are guided by the contact piece rail 242.

[0099] In a state where the first boss 803 and the second boss 804 have entered the contact piece rail 242, the second boss 804 is located upstream of the first boss 803 in the mounting direction of the process cartridge 50 into the apparatus body 2. Note that the mounting direction refers to the direction in which the process cartridge 50 inserted into the apparatus body 2 moves toward the mounting position when the process cartridge 50 is mounted into the apparatus body 2.

[0100] The contact piece 80 is located on the opposite side of the process cartridge 50 mounted in the apparatus main body 2 with respect to the front frame 24A of the first main body frame 24. The first boss 803 and the second boss 804 are located at positions not protruding toward the process cartridge 50 side beyond the front frame 24A of the first main body frame 24 when inserted into the contact piece rail 242.

[0101] The first boss 803 abuts against the drum shaft 54a when the process cartridge 50 is attached to the apparatus body 2, and the second boss 804 abuts against the drum shaft 54a when the process cartridge 50 is removed from the apparatus body 2. In other words, the first boss 803 abuts against the drum shaft 54a of the process cartridge 50 attached to the apparatus body 2, and the second boss 804 abuts against the drum shaft 54a of the process cartridge 50 removed from the apparatus body 2.

[0102] In this case, when the first boss 803 is located at the middle portion 242b (through hole 24C) of the contact piece rail 242, it abuts against the drum shaft 54a of the process cartridge 50 mounted in the apparatus main body 2 through the through hole 24C. Also, when the second boss 804 is located at the middle portion 242b (through hole 24C) of the contact piece rail 242, it abuts against the drum shaft 54a of the process cartridge 50 detached from the apparatus main body 2 through the through hole 24C.

[0103] The drum shaft 54a, which abuts against the first boss 803 and the second boss 804 through the through hole 24C, may abut against the first boss 803 and the second boss 804 inside the through hole 24C, or may abut against the first boss 803 and the second boss 804 at a position extending to the right of the through hole 24C in the left-right direction.

[0104] In this embodiment, the abutment piece 80 is configured to move in contact with the drum shaft 54a, but it is also possible to form a cartridge protrusion on the process cartridge 50 that protrudes toward the first main body frame 24 side separately from the drum shaft 54a, and to configure the abutment piece 80 to move in contact with this cartridge protrusion.

[0105] The first rotating link 81 is a substantially linear member that is rotatably connected to the abutment piece 80. The first rotating link 81 is located to the right of the front frame 24A of the first main body frame 24 in the left-right direction. The first rotating link 81 has a fitting portion 811 that is located at the front end and into which the connecting portion 802 of the abutment piece 80 is rotatably fitted, and a boss 812 that is located at the rear end and protrudes to the left. The first rotating link 81 is disposed in an inclined position in which the fitting portion 811 is located above and forward of the boss 812. The first rotating link 81 is connected to the abutment piece 80 by fitting the connecting portion 802 into the fitting portion 811, and rotates along with the movement of the abutment piece 80.

[0106] The linear link 82 is a substantially linear member that is rotatably connected to the first rotating link 81 and extends in the front-rear direction. The linear link 82 is supported by the first main body frame 24 so as to be movable in the front-rear direction. The linear link 82 is located to the right of the front frame 24A of the first main body frame 24 in the left-right direction. The linear link 82 is located at the front end and has a fitting portion 821 into which the boss 812 of the first rotating link 81 is rotatably fitted, and a connecting hole 822 located at the rear end. The linear link 82 is connected to the first rotating link 81 by fitting the boss 812 into the fitting portion 821, and moves linearly in the front-rear direction along with the rotation of the first rotating link 81. The linear link 82 is a linear link that can move in the second direction.

[0107] The linear link 82 moves from front to rear when the link 8 moves the shutter 64 from the closed position to the open position, and moves from rear to front when the link 8 moves the shutter 64 from the open position to the closed position. The position of the linear link 82 that moves the shutter 64 to the closed position is the first position, and the position of the linear link 82 that moves the shutter 64 to the open position is the second position.

[0108] The second rotating link 83 is connected to the linear link 82 and supported by the first main body frame 24. The second rotating link 83 has a support part 831 that is rotatably supported by the first main body frame 24, a first arm 832 that extends substantially downward from the support part 831, and a second arm 833 that extends substantially upward from the support part 831. An engagement pin 832a that protrudes leftward is formed at the tip of the first arm 832, and a connecting hole 833a is formed at the tip of the second arm 833.

[0109] The engagement pin 832a of the first arm 832 enters the connecting hole 822 of the linear link 82 from the right, and engages with the connecting hole 822 as the linear link 82 moves in the front-rear direction. The second rotating link 83 is connected to the linear link 82 by the engagement of the engagement pin 832a with the connecting hole 822, and rotates about the support part 831 as the linear link 82 moves.

[0110] The third rotating link 84 is connected to the second rotating link 83, and is rotatably supported by the support shaft 65 of the fixing unit 6. The third rotating link 84 has a support portion 841 rotatably supported by the support shaft 65, an engagement pin 842 protruding rightward from the support portion 841, an operation cam 843 formed in a different phase from the engagement pin 842 in the circumferential direction of the support portion 841, and a connecting hole 844 formed in the operation cam 843. The connecting hole 844 penetrates the operation cam 843 in the left-right direction.

[0111] The engagement pin 842 of the third rotating link 84 enters the connecting hole 833a of the second rotating link 83 from the left, and engages with the connecting hole 833a as the second rotating link 83 rotates. The third rotating link 84 is connected to the second rotating link 83 by the engagement of the engagement pin 842 with the connecting hole 833a, and rotates about the support shaft 65 as the second rotating link 83 rotates.

[0112] 5 and 6, the shutter link 85 is connected to the third rotating link 84 and is rotatably supported on the support shaft 65 of the fixing unit 6. The shutter link 85 moves along with the movement of the third rotating link 84 to move the shutter 64 of the fixing unit 6 between a closed position and an open position. The shutter link 85 is located at the right end of the fixing unit 6 and has a support portion 851, an arm portion 852, an engagement portion 853, and an engagement pin 854.

[0113] The support portion 851 is rotatably supported by a support shaft 65 that protrudes rightward from the right end of the fixing frame 63. The arm portion 852 is an arm member that extends forward from the support portion 851. The engagement portion 853 is located at the front end of the arm portion 852, and has an oval engagement hole 853a that is long in the front-rear direction. A connecting shaft 642 that protrudes rightward from the right end of the shutter 64 engages with the engagement hole 853a. The engagement hole 853a engages with the connecting shaft 642, connecting the shutter link 85 to the shutter 64.

[0114] The shutter link 85 can rotate around the support portion 851 in a direction in which the engaging portion 853 moves up and down, and when the shutter link 85 rotates and the engaging portion 853 moves downward, the shutter 64 moves to the closed position (see Figs. 5(a) and 6(a)), and when the shutter link 85 rotates and the engaging portion 853 moves upward, the shutter 64 moves to the open position (see Figs. 5(b) and 6(b)). In other words, the shutter link 85 moves the shutter 64 to the closed position by rotating downward, and moves the shutter 64 to the open position by rotating upward.

[0115] The engagement pin 854 protrudes rightward from the end of the arm portion 852 on the support portion 851 side. The engagement pin 854 of the shutter link 85 enters the connection hole 844 of the third rotating link 84 from the left.

[0116] The coil spring 86 is supported by a support portion 841 of the third rotating link 84. The coil spring 86 moves along with the movement of the third rotating link 84. The coil spring 86 has an arm portion 861. The arm portion 861 extends from the inner diameter side of the connecting hole 844 toward the outer diameter side, and enters the connecting hole 844.

[0117] The arm 861 is located above the engagement pin 854 in the connecting hole 844. The coil spring 86 is rotatable along with the rotation of the third rotating link 84. The edge of the lower end of the connecting hole 844 in the operation cam 843 of the third rotating link 84 forms an engagement surface 844a. The engagement surface 844a is located below the engagement pin 854. The connecting hole 844 has an inner circumferential surface 844b on the edge opposite to the edge on the side where the engagement surface 844a is formed in the circumferential direction. The inner circumferential surface 844b is located above the arm 861, and a gap exists between the inner circumferential surface 844b and the arm 861.

[0118] The engagement surface 844a of the connecting hole 844 engages with the engagement pin 854 as the third rotating link 84 rotates in the side in which the operation cam 843 moves upward. The arm portion 861 of the coil spring 86 engages with the engagement pin 854 as the third rotating link 84 rotates in the side in which the operation cam 843 moves downward.

[0119] The shutter link 85 is connected to the third rotating link 84 by the engagement pin 854 engaging with the arm portion 861 or the engagement surface 843a, and moves in accordance with the rotation of the third rotating link 84, moving the shutter 64 between the closed position and the open position.

[0120] Specifically, along with the rotation of the third rotating link 84 toward the side where the operation cam 843 moves downward, the shutter link 85 is pressed by the coil spring 86 to rotate downward, and the shutter 64 moves to the closed position. The position of the third rotating link 84 when the shutter 64 moves to the closed position due to the rotation of the third rotating link 84 is the first position.

[0121] In addition, along with the rotation of the third rotating link 84 toward the side where the operation cam 843 moves upward, the shutter link 85 is pressed by the engagement surface 844a of the connecting hole 844 and rotates upward, and the shutter 64 moves to the open position. The position of the third rotating link 84 when the shutter 64 moves to the open position by the rotation of the third rotating link 84 is the second position.

[0122] In the image forming apparatus 1, when the process cartridge 50 is attached to or detached from the device main body 2, the abutment piece 80 of the link 8 abuts against the drum shaft 54a and moves along the abutment piece rail 242, whereby a driving force is transmitted to the shutter 64 via the link 8, and the shutter 64 moves between the closed position and the open position.

[0123] In this embodiment, the link 8 has a configuration including the abutment piece 80, the first rotating link 81, the linear link 82, the second rotating link 83, the third rotating link 84, the shutter link 85, and the coil spring 86, but is not limited to this and may be configured as one link that is connected to the shutter 64 and abuts against the process cartridge 50 to open and close the shutter 64. Furthermore, the movement of the link 8 is not limited to rotation or sliding, and it may be any movement that opens and closes the shutter 64 in an appropriate manner in response to the insertion and removal of the process cartridge 50.

[0124] [Using member] 13, the device body 2 includes a biasing member 9. In the process in which the link 8 moves the shutter 64 from the closed position to the open position, before the shutter 64 moves to the open position, the biasing member 9 presses the link 8 in a direction in which the shutter 64 moves to the open position. When the shutter 64 is in the open position, the biasing member 9 biases the link 8 in a first direction in which the link 8 moves from the first position to the second position.

[0125] Furthermore, in the process in which the link 8 moves the shutter 64 from the open position to the closed position, before the shutter 64 moves to the closed position, the biasing member 9 presses the link 8 in a direction in which the shutter 64 moves to the closed position. When the shutter 64 is in the closed position, the biasing member 9 biases the link 8 in a second direction in which the link 8 moves from the second position to the first position.

[0126] Furthermore, the biasing member 9 restricts the movement of the link 8 that has moved the shutter 64 to the open position or the closed position by pressing the link 8. That is, when the shutter 64 is in the closed position, the biasing member 9 biases the shutter 64 so as to be held in the closed position, and when the shutter 64 is in the open position, the biasing member 9 biases the shutter 64 so as to be held in the open position.

[0127] In this way, when the shutter 64 is in the closed position, the biasing member 9 biases the shutter 64 to be held in the closed position, and when the shutter 64 is in the open position, the biasing member 9 biases the shutter 64 to be held in the open position, so that the single biasing member 9 can stably hold the shutter 64 in the open position in an open state, and can stably hold the shutter 64 in the closed position in a closed state.

[0128] The biasing member 9 has a pressing spring 92 and a pressing arm 91 that is pressed by the pressing spring 92 and abuts against the upper surface 82A of the linear link 82. The pressing spring 92 is an example of a pressing spring, and the pressing arm 91 is an example of a contact portion that is pressed by the pressing spring and abuts against the link. The pressing spring 92 presses the tip of the pressing arm 91 toward the upper surface 82A of the linear link 82. The upper surface 82A of the linear link 82 is an example of a pressed surface that is pressed by the pressing arm. The biasing member 9 can stably press the linear link 82 by the pressing arm 91 connected to the pressing spring 92.

[0129] The pressing arm 91 has a support portion 911 located at the base end of the pressing arm 91 and rotatably supported on the first main body frame 24, a contact portion 912 located at the tip of the pressing arm 91 and contacting the upper surface 82A of the linear link 82, and a fitting portion 913 into which the pressing spring 92 fits. The pressing arm 91 extends in the front-rear direction, with the support portion 911 located at the front end and the contact portion 912 located at the rear end. The fitting portion 913 is located above the contact portion 912. The contact portion 912 is rotatable in the up-down direction around the support portion 911.

[0130] The support portion 911 is a rotation center of the pressing arm 91. The base end of the pressing arm 91 is an example of one end of a pressing portion of a biasing member, and the tip of the pressing arm 91 is an example of the other end of a pressing portion of a biasing member. The pressing arm 91 has an abutment portion 912 at its tip, which enables the pressing arm 91 to smoothly press the linear link 82.

[0131] The pressing spring 92 is supported by the first main body frame 24, and its lower end is fitted into a fitting portion 913 of the pressing arm 91. The pressing spring 92 biases the abutting portion 912 of the pressing arm 91 downward toward the upper surface 82A of the linear motion link 82, and the abutting portion 912 is pressed against the upper surface 82A from above.

[0132] The upper surface 82A of the linear link 82 has a link protrusion 823 between the fitting portion 821 and the connecting hole 822, protruding upward toward the biasing member 9 side. The link protrusion 823 is an example of a protrusion protruding toward the biasing member side. The link protrusion 823 is formed in a mountain shape having a first pressed surface 823a, a second pressed surface 823b, and a third pressed surface 823c.

[0133] The second pressed surface 823b and the third pressed surface 823c are inclined surfaces that are inclined with respect to the front-rear direction which is the movement direction of the linear link 82. The inclination direction of the third pressed surface 823c with respect to the movement direction of the linear link 82 is different from the inclination direction of the second pressed surface 823b with respect to the movement direction of the linear link 82.

[0134] The first pressed surface 823a is located at the apex of the mountain shape and extends horizontally. The second pressed surface 823b is located in front of the first pressed surface 823a and is formed as an inclined surface that rises toward the rear. In other words, the second pressed surface 823b is inclined from the bottom to the top along the rear direction. In this way, the second pressed surface 823b, which is the second inclined surface, has an inclined shape that rises along the moving direction of the linear link 82 from the first position to the second position. The rear end of the second pressed surface 823b is connected to the front end of the first pressed surface 823a.

[0135] The third pressed surface 823c is located behind the first pressed surface 823a, and is formed as an inclined surface that descends toward the rear. That is, the third pressed surface 823c is inclined from top to bottom along the rear direction. In this way, the third pressed surface 823c, which is the first inclined surface, has an inclined shape that ascends along the moving direction of the linear link 82 from the second position to the first position. The front end of the third pressed surface 823c is connected to the rear end of the first pressed surface 823a. The third pressed surface 823c is located on the opposite side to the second pressed surface 823b across the first pressed surface 823a in the front-rear direction.

[0136] By moving in the front-rear direction, the linear link 82 can be located at a position where the abutting portion 912 of the pressing arm 91 presses the first pressed surface 823a, a position where the abutting portion 912 of the pressing arm 91 presses the second pressed surface 823b, and a position where the abutting portion 912 of the pressing arm 91 presses the third pressed surface 823c. The pressing arm 91 pressed by the pressing spring 92 abuts against the second pressed surface 823b and the third pressed surface 823c. Specifically, the third pressed surface 823c abuts against the pressing arm 91 when the linear link 82 is in the first position, and the second pressed surface 823b abuts against the pressing arm 91 when the linear link 82 is in the second position.

[0137] Since the first pressed surface 823a is a surface extending horizontally, when the pressing arm 91 presses the first pressed surface 823a from above, the pressing force of the pressing arm 91 does not act in either the backward direction in which the linear link 82 moves toward the second position, or the forward direction in which the linear link 82 moves toward the first position.

[0138] Since the second pressed surface 823b is a surface that inclines from the bottom to the top along the rearward direction, when the pressing arm 91 presses the second pressed surface 823b from above, the pressing force of the pressing arm 91 acts in the rearward direction, which is the direction in which the linear motion link 82 moves toward the second position. In a state in which the pressing arm 91 abuts against the second pressed surface 823b, the biasing direction of the pressing spring 92, which is downward, is converted by the second pressed surface 823b into the direction in which the linear motion link 82 moves from the first position to the second position. In addition, in a state in which the pressing arm 91 presses the second pressed surface 823b from above, the abutting portion 912 of the pressing arm 91 and the second pressed surface 823b are engaged with each other, and the forward movement of the linear motion link 82 is restricted.

[0139] Since the third pressed surface 823c is a surface that inclines from above to below along the rearward direction, when the pressing arm 91 presses the third pressed surface 823c from above, the pressing force of the pressing arm 91 acts in a forward direction in which the linear motion link 82 moves toward the first position. When the pressing arm 91 is in contact with the third pressed surface 823c, the downward biasing direction of the pressing spring 92 is converted by the third pressed surface 823c to a direction in which the linear motion link 82 moves from the second position to the first position. Also, when the pressing arm 91 is pressing the third pressed surface 823c from above, the abutting portion 912 of the pressing arm 91 and the third pressed surface 823c are engaged with each other, and the rearward movement of the linear motion link 82 is restricted.

[0140] In this way, since the linear link 82 has the link protrusion 823 having the second pressed surface 823b and the third pressed surface 823c, the pressing arm 91 pressed by the pressing spring 92 abuts against the second pressed surface 823b or the third pressed surface 823c, thereby biasing the linear link 82 in the front-rear direction. This makes it possible to stably hold the shutter 64 in the closed position in a closed state by the biasing force of the pressing spring 92, and to stably hold the shutter 64 in the open position in an open state.

[0141] Link Behavior Next, the operation of the link 8 will be described.

[0142] (Operation when installing a process cartridge) First, the operation of the link 8 when the process cartridge 50 is mounted in the apparatus main body 2 will be described.

[0143] As shown in Figures 13 and 14, when the process cartridge 50 is in a state after being removed from the apparatus main body 2 and before being attached to the apparatus main body 2, and when the leading end 50A of the process cartridge 50 in the insertion direction is in the attachment start position inserted into the apparatus main body 2 (the position shown in Figure 14), the drum shaft 54a is spaced forward from the abutment piece 80, and the abutment piece 80 is located across the front part 242a and the middle part 241b of the abutment piece rail 242.

[0144] Specifically, the abutment piece 80 is fitted to the abutment piece rail 242 with the first boss 803 located in the middle portion 242b (through hole 24C) of the abutment piece rail 242 and the second boss 804 located in the front portion 242a of the abutment piece rail 242. The insertion direction of the process cartridge 50 is the same as the mounting direction.

[0145] 14, the shutter 64 is moved to the closed position by the link 8 as shown in Fig. 6(a). As a result, when the process cartridge 50 is in a state where it is detached from the apparatus main body 2, even if the user inserts his / her hand into the apparatus main body 2 through the opening 2A, the shutter 64 can prevent the user's hand from touching the heating unit 61 of the fixing device 6.

[0146] 14, as shown in Fig. 13, the abutment portion 912 of the pressing arm 91 abuts against the third pressed surface 823c of the linear link 82, restricting the backward movement of the linear link 82. As a result, the linear link 82 is fixed by the biasing member 9 in a state in which the shutter 64 is moved to the closed position by the link 8, and the shutter 64 does not move inadvertently from the closed position to the open position, so that the closed position of the shutter 64 can be stably maintained.

[0147] Furthermore, the abutment piece rail 242 of the front frame 24A that guides the abutment piece 80 is located outside the cartridge rail 241 in the left-right direction, and the first boss 803 and the second boss 804 of the abutment piece 80 are located so as not to protrude further toward the process cartridge 50 than the front frame 24A. Therefore, when the process cartridge 50 is detached from the apparatus main body 2, it is possible to prevent the user from coming into contact with the abutment piece 80, and it is possible to prevent the link 8 from moving and the shutter 64 from opening inadvertently.

[0148] When the process cartridge 50, which is in the installation start position, is further inserted toward the installation position, the drum shaft 54a enters the front portion 241a of the cartridge rail 241 and moves inside the cartridge rail 241. As shown in FIG. 16, when the drum shaft 54a moving inside the cartridge rail 241 enters the middle portion 241b (through hole 24C), the drum shaft 54a comes into contact with the first boss 803 of the abutment piece 80.

[0149] As shown in FIGS. 17 to 19, the contact piece 80 that comes into contact with the drum shaft 54a moving within the middle portion 241b (through hole 24C) of the cartridge rail 241 is pressed by the drum shaft 54a and moves downstream in the mounting direction of the process cartridge 50.

[0150] The first boss 803 of the contact piece 80, which moves in contact with the drum shaft 54a moving in the middle portion 241b (through hole 24C), has a rear part located at the rear portion 242c of the contact piece rail 242, and the other part located at the middle portion 242b (through hole 24C) of the contact piece rail 242. In addition, the second boss 804 is located at the middle portion 242b (through hole 24C) of the contact piece rail 242.

[0151] When the abutment piece 80 moves, the first rotating link 81 connected to the abutment piece 80 moves rearward while rotating in a direction in which the inclination angle with respect to the horizontal direction becomes smaller. When the first rotating link 81 rotates and moves, the linear link 82 connected to the first rotating link 81 moves rearward linearly.

[0152] When the linear link 82 moves rearward, the connecting hole 822 of the linear link 82 engages with the engaging pin 832a of the second rotating link 83, and the second rotating link 83 rotates in a direction in which the engaging pin 832a moves rearward. When the second rotating link 83 rotates, the connecting hole 833a of the second rotating link 83 engages with the engaging pin 842 of the third rotating link 84, and the third rotating link 84 rotates in a direction in which the engaging pin 842 moves forward.

[0153] In this case, as the linear link 82 moves backward, the abutment portion 912 of the pressing arm 91 of the urging member 9 moves up the third pressed surface 823c of the linear link 82 against the pressing force of the pressing spring 92, and then rides from the third pressed surface 823c onto the first pressed surface 823a. That is, when the process cartridge 50 is mounted in the apparatus main body 2, the pressing arm 91 abuts against the third pressed surface 823c and then the first pressed surface 823a. In a state in which the pressing arm 91 abuts against the first pressed surface 823a, which is a surface extending in the horizontal direction, the restriction by the pressing member 9 of the shutter 64 moving from the closed position to the open position is released.

[0154] In this way, when the process cartridge 50 is attached to the apparatus main body 2, the linear link 82 moves backward in the first direction against the pressing force from the pressing arm 91, thereby making it possible to switch the shutter 64 from a state in which it is held in the closed position to a state in which it can be moved to the open position.

[0155] 20 and 21, when the process cartridge 50 is further inserted from the position shown in Fig. 18 toward the mounting position, the abutment piece 80 is moved further downstream in the mounting direction by the drum shaft 54a moving within the middle portion 241b (through hole 24C) of the cartridge rail 241. In Fig. 21, the first boss 803 of the abutment piece 80 is located at the rear portion 242c of the abutment piece rail 242, and the second boss 804 is located at the middle portion 242b (through hole 24C) of the abutment piece rail 242.

[0156] As shown in FIG. 22, the drum shaft 54a moves the abutment piece 80 until the first boss 803 is positioned at the rear 242c of the abutment piece rail 242, and then moves from the middle 241b to the rear 241c of the cartridge rail 241, and the abutment piece 80 and the drum shaft 54a become separated.

[0157] When the abutment piece 80 moves, the first rotating link 81 moves rearward while rotating in a direction in which the inclination angle with respect to the horizontal direction becomes smaller. When the first rotating link 81 rotates and moves, the linear motion link 82 moves further rearward in a straight line. When the linear motion link 82 moves, the second rotating link 83 rotates further in the direction in which the engagement pin 832a moves rearward. When the second rotating link 83 rotates, the third rotating link 84 rotates further in the direction in which the engagement pin 842 moves forward.

[0158] When the third rotating link 84 rotates, an engagement surface 844a of the connecting hole 844 in the operation cam 843 engages with an engagement pin 854 of the shutter link 85 from below. When the engagement surface 844a of the connecting hole 844 engages with the engagement pin 854, the shutter link 85 rotates in a direction in which the engagement portion 853 moves upward, and the shutter 64 moves from the closed position to the open position.

[0159] In this case, the movement of the drum shaft 54a abutting against the abutment piece 80 is transmitted to the shutter 64 via the link 8, so that even if the distance between the mounting position of the process cartridge 50 in the device main body 2 and the shutter 64 is large, it is possible to efficiently transmit the driving force to the shutter 64.

[0160] When the drum shaft 54a moves the abutment piece 80 until the first boss 803 is positioned at the rear 242c of the abutment piece rail 242, the linear link 82 moves rearward, and the abutment portion 912 of the pressing arm 91 in the biasing member 9 transfers from the first pressed surface 823a to the second pressed surface 823b of the linear link 82 due to the pressing force of the pressing spring 92.

[0161] When the abutment piece 80 is moved by the drum shaft 54a until the first boss 803 is positioned at the rear 242c of the abutment piece rail 242, the abutment position of the abutment portion 912 of the pressing arm 91 against the second pressed surface 823b varies depending on the dimensional tolerances of each component that constitutes the link 8 and the tolerances of the connecting positions of each component, etc.

[0162] In this case, the positional relationship between the pressing arm 91 and the link 8 is set so that when the drum shaft 54a moves the abutting piece 80 until the first boss 803 is positioned at the rear part 242c of the abutting piece rail 242, the abutting portion 912 of the pressing arm 91 always abuts against the second pressed surface 823b. Furthermore, even if the abutting portion 912 of the pressing arm 91 abuts against the lowermost side of the second pressed surface 823b within the tolerance range of each member constituting the link 8, the abutting portion 912 is set not to come into contact with the upper surface 82A located forward of the second pressed surface 823b.

[0163] After the abutment piece 80 moves until the first boss 803 is positioned at the rear part 242c of the abutment piece rail 242 and the abutment portion 912 abuts against the second pressed surface 823b, the first boss 803 and the drum shaft 54a are separated from each other, so the drum shaft 54a does not move the abutment piece 80. However, as shown in Fig. 23, because the abutment portion 912 of the pressing arm 91 abuts against the second pressed surface 823b, a pressing force is applied from the pressing arm 91 to the linear link 82 in a direction toward the second position, and the linear link 82 moves backward.

[0164] As shown in FIG. 6(b), when the linear link 82 moves rearward due to the pressing force from the pressing arm 91, the shutter link 85 rotates in a direction in which the engaging portion 853 moves upward, and the shutter 64 moves to the open position.

[0165] In this case, even if the linear link 82 moves backward by the pressing force from the pressing arm 91 until the shutter 64 moves to the open position, the abutting portion 912 of the pressing arm 91 is set not to come into contact with the upper surface 82A located forward of the second pressed surface 823b (see FIG. 23). This makes it possible to hold the shutter 64 in the open position by the pressing force from the pressing arm 91.

[0166] Furthermore, as shown in FIG. 24, when the linear link 82 moves rearward due to the pressing force from the pressing arm 91, the abutment piece 80 is pulled rearward by the first pivot link 81, and the first boss 803 of the abutment piece 80 moves rearward from the position shown in FIG. 22 along the rear portion 241c of the abutment piece rail 242.

[0167] When the shutter 64 moves to the open position, the contact end 64a comes into contact with the contact surface 631 of the fixing frame 63, restricting further movement and also stopping the movement of the link 8. Since the shutter 64 is restricted from moving further by coming into contact with the contact surface 631, it is possible to hold the shutter 64 in the open position. Furthermore, since the movement of the link 8 is also stopped, the movement range of the link 8 can be kept small.

[0168] Furthermore, in a state where the pressing arm 91 is in contact with the second pressed surface 823b, the contact portion 912 of the pressing arm 91 and the second pressed surface 823b are engaged to restrict the forward movement of the linear motion link 82. As a result, when the shutter 64 is moved to the open position, the position of the linear motion link 82 is fixed by the biasing member 9, and it is possible to prevent the shutter 64 from moving inadvertently from the open position to the closed position.

[0169] In this manner, in the image forming apparatus 1, when the drum shaft 54a of the process cartridge 50 mounted in the apparatus main body 2 abuts against the abutment piece 80 of the link 8 and the drum shaft 54a moves the abutment piece 80, the shutter 64 moves from the closed position toward the open position, and before the shutter 64 moves to the open position, the abutment piece 80 and the drum shaft 54a separate, and the abutment piece 80, now separated from the drum shaft 54a, moves further in the direction in which the shutter 64 moves to the open position.

[0170] In this configuration, when the shutter 64 moves to the open position, the link 8 having the abutment piece 80 and the process cartridge 50 having the drum shaft 54a are separated from each other, so that the user's operation on the process cartridge 50 does not affect the open / closed state of the shutter 64. In addition, after the shutter 64 moves to the open position, there is no need to further move the link 8, and the movement range of the link 8 can be kept small.

[0171] In addition, when the process cartridge 50 is attached to the main body 2 of the apparatus, when the process cartridge 50 and the link 8 come into contact with each other and then the link 8 and the process cartridge 50 separate from each other, the pressing arm 91 of the urging member 9 presses the linear link 82 toward the second position.

[0172] As a result, even after the link 8 and the process cartridge 50 are separated, the link 8 is pressed toward the second position by the biasing member 9, so that the pressed link 8 can move the shutter 64 to the open position.

[0173] In particular, by pressing the second pressed surface 823b of the linear motion link 82 with the pressing arm 91, the link 8 can be moved toward the second position, and the shutter 64 can be moved to the open position.

[0174] In addition, when the process cartridge 50 mounted in the apparatus main body 2 comes into contact with the abutment piece 80 of the link 8, the pressing arm 91 comes into contact with the first pressed surface 823a of the link 8, and the link 8 is configured to move toward the second position so that the second pressed surface 823b of the link 8 comes into contact with the pressing arm 91 before the link 8 and the process cartridge 50 separate.

[0175] As a result, when the link 8 and the process cartridge 50 are separated, the pressing arm 91 abuts against the second pressed surface 823b, so that even after the link 8 and the process cartridge 50 are separated, the shutter 64 can be moved to the open position by the link 8.

[0176] 21 toward the mounting position, the drum shaft 54a moves from the middle part 241b to the rear part 241c of the cartridge rail 241, and then moves in the rear part 241c in the mounting direction. Thereafter, the process cartridge 50 reaches the mounting position as shown in FIG. 25, and is mounted in the apparatus main body 2.

[0177] (Operation when removing the process cartridge) Next, there will be described the operation of the link 8 when the process cartridge 50 in the mounting position is removed from the apparatus main body 2. When removing the process cartridge 50, the link 8 operates in the opposite manner to the operation when the process cartridge 50 is mounted.

[0178] When the process cartridge 50 in the mounting position shown in Fig. 25 is removed forward from the apparatus main body 2, the drum shaft 54a moves downstream in the removal direction within the rear portion 241c of the cartridge rail 241. The removal direction is the direction in which the process cartridge 50, which is extracted from the mounting main body 2, moves toward the outside of the mounting main body 2 when the process cartridge 50 is removed from the apparatus main body 2. As shown in Fig. 21, when the drum shaft 54a moving within the cartridge rail 241 reaches the middle portion 241b (through hole 24C), the drum shaft 54a abuts against the second boss 804 of the abutment piece 80.

[0179] 18, the contact piece 80 in contact with the drum shaft 54a is pressed by the drum shaft 54a and moves downstream in the removal direction of the process cartridge 50. That is, the contact piece 80 moves from a position where the first boss 803 is at the rear part 242c of the contact piece rail 242 to a position where the first boss 803 is at the middle part 242b (through hole 24C).

[0180] When the abutment piece 80 moves, the first rotating link 81 moves forward while rotating in a direction in which the inclination angle with respect to the horizontal direction increases, and the linear link 82 moves forward linearly. When the linear link 82 moves forward, the connecting hole 822 of the linear link 82 engages with the engaging pin 832a of the second rotating link 83, and the second rotating link 83 rotates in a direction in which the engaging pin 832a moves forward. When the second rotating link 83 rotates, the connecting hole 833a of the second rotating link 83 engages with the engaging pin 842 of the third rotating link 84, and the third rotating link 84 rotates in a direction in which the engaging pin 842 moves backward.

[0181] When the process cartridge 50 is further removed from the apparatus main body 2, the contact piece 80 is moved further downstream in the removal direction by the drum shaft 54a moving within the middle portion 241b (through hole 24C) of the cartridge rail 241.

[0182] This movement of the abutment piece 80 causes the third rotating link 84 to further rotate in the direction in which the engagement pin 842 moves rearward. When the third rotating link 84 rotates, the coil spring 86 rotates along with the rotation of the third rotating link 84, and the arm portion 861 of the coil spring 86 engages with the engagement pin 854 of the shutter link 85 from above. As the arm portion 861 engages with the engagement pin 854, the shutter link 85 rotates in the direction in which the engagement portion 853 moves downward. This causes the shutter 64 to move from the open position toward the closed position.

[0183] In this way, when the process cartridge 50 mounted in the apparatus main body 2 is removed from the apparatus main body 2, the abutment piece 80 of the link 8 comes into contact with the drum shaft 54a of the process cartridge 50, and the link 8 moves in a direction in which the shutter 64, which is in the open position, moves to the closed position. Therefore, accompanying the operation of removing the process cartridge 50 from the apparatus main body 2, it is possible to move the shutter 64 to the closed position.

[0184] As described above, in the image forming apparatus 1, when the process cartridge 50 is attached to the apparatus main body 2, the drum shaft 54a abuts against the first boss 803 of the abutment piece 80, causing the link 8 to move in the direction in which the shutter 64 moves from the closed position to the open position, and when the process cartridge 50 is removed from the apparatus main body 2, the drum shaft 54a abuts against the second boss 804 of the abutment piece 80, causing the link 8 to move in the direction in which the shutter 64 moves from the open position to the closed position. With this simple configuration, it is possible to operate the link 8 both when the process cartridge 50 is attached and when it is removed.

[0185] [Relative positions of the fan, power supply board, board cover, and links] 26 to 28, the image forming apparatus 1 has a fan 71, a power supply board 72, a board cover 73, a control board 74, and an air duct 26. The fan 71 is supported by the first main body frame 24, and exhausts air inside the apparatus body 2 to the outside of the apparatus body 2.

[0186] Electronic components 721 are mounted on the power supply board 72. The board cover 73 is supported by the first main body frame 24 and covers the power supply board 72. The power supply board 72 is supported by the board cover 73. In other words, the power supply board 72 is supported by the first main body frame 24 via the board cover 73. The power supply board 72 is an example of a board on which electronic components are mounted.

[0187] The control board 74 is supported by the second main body frame 25. A cable 75 extends from the power supply board 72, and the power supply board 72 and the control board 74 are connected by the cable 75.

[0188] The air duct 26 extends in the left-right direction and is disposed across the first main body frame 24 and the second main body frame 25. Air can flow through the air duct 26. The air duct 26 guides the air inside the apparatus main body 2 toward the fan 71.

[0189] As shown in Figures 26, 29, and 30, the power supply board 72 is located at the bottom of the first main body frame 24. The power supply board 72 extends in the vertical and front-rear directions and has a first surface 72A facing left, and a second surface 72B extending in the vertical and front-rear directions and facing right opposite the first surface 72A. Electronic components 721 are mounted on the first surface 72A and the second surface 72B. The first surface 72A and the second surface 72B are each an example of a board surface on which electronic components are mounted.

[0190] The board cover 73 has an upper plate 731 covering the upper side of the power supply board 72, a lower plate 732 covering the lower side of the power supply board 72, a left plate 733 covering the left side of the power supply board 72, a right plate 734 covering the right side of the power supply board 72, a front plate 735 covering the front of the power supply board 72, and a rear plate 736 covering the rear of the power supply board 72.

[0191] An air vent 737 that communicates between the inside and outside of the board cover 73 is formed in approximately the center in the front-to-rear direction of the upper plate 731 and the left plate 733. Some of the electronic components 721 mounted on the power supply board 72 generate heat during operation, and the heat generated from the electronic components 721 is released from the inside of the board cover 73 to the outside through the air vent 737.

[0192] In the front-rear direction, a region of upper plate 731 where ventilation hole 737 is formed is first portion 731A, and a region of upper plate 731 where ventilation hole 737 is not formed is second portion 731B. First portion 731A is located approximately in the center of upper plate 731 in the front-rear direction, and second portion 731B is located in front of and behind first portion 731A.

[0193] In the front-rear direction, the area of ​​left plate 733 where ventilation hole 737 is formed is first portion 733A, and the area of ​​left plate 733 where ventilation hole 737 is not formed is second portion 733B. First portion 733A is located approximately in the center of left plate 733 in the front-rear direction, and second portion 733B is located in front of and behind first portion 733A.

[0194] The fan 71 is located above the power supply board 72. The fan 71 is located above and spaced apart from the power supply board 72. A first air flow path FP1 is formed between the fan 71 and the power supply board 72 in the vertical direction, through which air discharged from the inside of the board cover 73 to the outside can flow. In other words, the fan 71 and the power supply board 72 are spaced apart in the vertical direction so that the first air flow path FP1 is formed. The first air flow path FP1 is an example of an air flow path.

[0195] The power supply board 72 is disposed from a position rearward of the fan 71 to a position forward of the fan 71 in the front-rear direction, and the fan 71 is positioned so as to overlap with the power supply board 72 in the front-rear direction.

[0196] The upper plate 731 of the board cover 73 is a plate-like member extending in the front-rear and left-right directions, and is located between the power supply board 72 and the fan 71 in the up-down direction. Ventilation holes 737 formed in the upper plate 731 and the left plate 733 are disposed at positions overlapping with the fan 71 in the front-rear direction, and the fan 71 is located above the ventilation holes 737. That is, first portions 731A, 733A of the upper plate 731 and the left plate 733 are located at positions overlapping with the fan 71 in the front-rear direction. That is, the first portions 731A, 733A are located at positions overlapping with the fan 71 when viewed in the up-down direction.

[0197] 29, the second air flow path FP2 formed by the first main body frame 24 is located to the left of the first air flow path FP1, and the third air flow path FP3 formed by the air duct 26 is located above the second air flow path FP2. The first air flow path FP1 and the second air flow path FP2 are in communication, and the second air flow path FP2 and the third air flow path FP3 are in communication. In addition, the third air flow path FP3 and the fan 71 are in communication.

[0198] Therefore, the air discharged from the inside of the board cover 73 to the outside can flow through the first air flow path FP1, the second air flow path FP2, and the third air flow path FP3, and then can be exhausted to the outside of the device body 2 by the fan 71. Heat generated from the electronic components 721 can be released from the inside of the board cover 73 to the outside by this air flow, and can also be discharged to the outside of the device body 2.

[0199] A linear link 82 of the link 8 is located between the power supply board 72 and the fan 71 in the vertical direction. That is, the linear link 82 is disposed in a first air flow path FP1 formed between the power supply board 72 and the fan 71. By positioning the linear link 82 between the power supply board 72 and the fan 71 in this way, it is possible to efficiently dispose the linear link 82 by utilizing the first air flow path FP1 between the power supply board 72 and the fan 71 in the vertical direction.

[0200] In this case, since the linear link 82 is movable in the front-rear direction, the linear link 82 can be moved without interfering with the power supply board 72 and the fan 71 .

[0201] In addition, the first main body frame 24 supports the linear motion link 82, the board cover 73 that covers the power supply board 72, and the fan 71. This allows the linear motion link 82, the board cover 73, and the fan 71 to be efficiently arranged.

[0202] The linear link 82 is located above the upper plate 731 of the board cover 73 in the up-down direction. That is, the upper plate 731 is located between the linear link 82 and the power supply board 72. The linear link 82 is movable in the front-rear direction, but since the upper plate 731 is located between the linear link 82 and the power supply board 72, the upper plate 731 can suppress interference between the linear link 82 moving in the front-rear direction and the power supply board 72.

[0203] Moreover, the first portion 731A of the upper plate 731 is located between the linear link 82 and the power supply board 72 in the vertical direction. Therefore, heat generated from the electronic components 721 mounted on the power supply board 72 can be released from inside the board cover 73 toward the fan 71 through the ventilation hole 737 of the first portion 731A.

[0204] 30, the first portion 731A of the upper plate 731 has a left-right length W1, and the portion of the linear link 82 located at the first portion 731A has a left-right length W2. The left-right length W2 of the linear link 82 is shorter than the left-right length W1 of the first portion 731A. This makes it possible to reduce the range in which the linear link 82 is located above the ventilation hole 737 formed in the upper plate 731, and to prevent the ventilation hole 737 from being blocked by the linear link 82.

[0205] [Relative position of links, cables and link covers] 29 and 30, in the first air flow path FP1 at the location where the first portion 731A is formed in the front-rear direction, the cable 75 is located to the left of the linear link 82. The cable 75 extends in the front-rear direction to the left of the linear link 82. In other words, the cable 75 is located alongside the linear link 82 in the left-right direction. This makes it possible to efficiently arrange the cable 75 in addition to the linear link 82 by utilizing the first air flow path FP1 between the power supply board 72 and the fan 71.

[0206] 29 and 31, the image forming apparatus 1 has a link cover 76 that covers the link 8 from the right side. The link cover 76 is located forward of the first portions 731A, 733A of the board cover 73 in the front-rear direction. In other words, the link cover 76 is located above the second portions 731B, 733B of the board cover 73. The link cover 76 is fixed to the first main body frame 24, and covers the front portions of the abutment piece 80, the first rotating link 81, and the linear link 82 of the link 8.

[0207] 32, the link cover 76 has a first surface 76A that faces left and can come into contact with the link 8, and a second surface 76B that faces right and is opposite the first surface 76A. The link cover 76 has a plurality of fixing holes 761 into which screws are inserted for fixing the link cover 76 to the first main frame 24. The link 8 comes into contact with the first surface 76A of the link cover 76, thereby restricting movement of the link 8 to the right. In other words, the link cover 76 restricts movement of the link 8 in the left-right direction.

[0208] At a location where second portions 731B, 733B are formed forward of first portions 731A, 733A of board cover 73, cable 75 is located to the right of link cover 76. Cable 75 is located alongside linear link 82 in the left-right direction, and link cover 76 is located between linear link 82 and cable 75. In this manner, by positioning link cover 76 between linear link 82 and cable 75, interference between linear link 82 and cable 75 can be suppressed by link cover 76.

[0209] [Positional relationship of the fan, power supply board, board cover, and biasing member] The linear link 82 is disposed in the front-rear direction from the second portion 731B in front of the first portion 731A of the upper plate 731, through the first portion 731A, to the second portion 731B behind the first portion 731A of the upper plate 731. In other words, the linear link 82 is disposed between the first portion 731A and the second portion 731B of the upper plate 731 and the fan 71 in the up-down direction.

[0210] 29, the biasing member 9 is located at a location where the second portions 731B, 733B are formed rearward of the first portions 731A, 733A of the board cover 73 in the front-rear direction. The pressing spring 92 and pressing arm 91 of the biasing member 9 are located between the power supply board 72 and the fan 71 in the up-down direction.

[0211] By positioning the pressure spring 92 and the pressure arm 91 between the power supply board 72 and the fan 71, the pressure spring 92 and the pressure arm 91 can be efficiently positioned by utilizing the first air flow path FP1 between the power supply board 72 and the fan 71.

[0212] Moreover, the pressure spring 92 and the pressure arm 91 of the biasing member 9 are positioned between the second portions 731B, 733B of the board cover 73 and the fan 71 in the vertical direction.

[0213] In the image forming apparatus 1, heat generated from the electronic components 721 mounted on the power supply board 72 is transferred to the fan 71 side rather than the board cover 73 through the ventilation holes 737 formed in the first portions 731A, 733A of the board cover 73. However, since the pressure spring 92 is located between the fan 71 and the second portions 731B, 733B where the ventilation holes 737 are not formed, it is less susceptible to the effects of heat, and it is possible to suppress fluctuations in the biasing force of the pressure spring 92. This allows the pressure arm 91 of the biasing member 9 to stably press the linear link 82.

[0214] [Relative positions of air duct, fan, fuser unit, and process cartridge] As shown in FIGS. 26 to 28 and 33, the air duct 26 is connected to the upper part in the up-down direction and approximately the center in the front-rear direction of the first main body frame 24 and the second main body frame 25.

[0215] The air duct 26 and the fan 71 are disposed in a position where they overlap when viewed from the left-right direction, which is the opposing direction of the first main body frame 24 and the second main body frame 25. In other words, the air duct 26 and the fan 71 are disposed in a position where they overlap in the front-rear direction and the up-down direction. The right end of the air duct 26 communicates with the fan 71. This allows the air inside the device main body 2 to be efficiently guided to the fan 71 by the air duct 26, and then discharged to the outside of the device main body 2 by the fan 71.

[0216] Furthermore, the air duct 26 is located between the process cartridge 50 and the fixing unit 6 in the front-rear direction, which is a direction perpendicular to the opposing direction of the first main body frame 24 and the second main body frame 25. This makes it possible to arrange the link 8 without interfering with the fan 71, even if the fan 71 is located in the middle of the link 8 that extends from the drum shaft 54a of the process cartridge 50 to the portion where the fixing unit 6 is located in the front-rear direction.

[0217] In this embodiment, the link 8 has the abutment piece 80, the first rotating link 81, the linear link 82, the second rotating link 83, the third rotating link 84, the shutter link 85, and the coil spring 86, but is not limited to this, and for example, a configuration in which one link connected to the shutter 64 abuts against the process cartridge 50 is also possible. Furthermore, the movement of each link of the link 8 is not limited to the movement in this embodiment, and may be a movement other than rotation or linear movement.

[0218] In this embodiment, the shutter 64 is opened and closed by the drum shaft 54a of the process cartridge 50 abutting against the abutment piece 80 of the link 8, but this is not limited to this and another part of the process cartridge 50 may abut against the link 8.

[0219] In this embodiment, the fan 71 is an exhaust fan that exhausts the air inside the device body 2 to the outside of the device body 2, but it may be an intake fan that draws in air outside the device body 2 and sends the outside air into the device body 2. In other words, the fan 71 may be any fan that moves the air inside the device body 2.

[0220] In this embodiment, the link 8 is disposed between the power supply board 72 and the fan 71, but it may be any board other than the power supply board 72 as long as it is a board on which electronic components are mounted. For example, it may be a main board, a high-voltage board, or the like. [Explanation of symbols]

[0221] 1. Image forming device 2. Device body 6 Fixing unit 8 Links 9. Pressing member 24 First body frame 25 Second body frame 26 Air Duct 50 Process Cartridge 54 Photosensitive drum 54a Drum shaft 61 Heating unit 62 Pressure roller 64 Shutter 71 Fans 72 Power supply board 72A 1st page 72B 2nd side 73 Circuit Board Cover 75 Cable 76 Link cover 80 Contact piece 81 First rotating link 82 Linear Link 91 Pressing arm 92 Compression spring 721 Electronic Components 731 Upper Board 731A Part 1 731B 2nd part 737 Vent 823 Link protrusion 823b 2nd pressed surface 823c 3rd pressed surface FP1 First air flow path W1 (length of the first part of the top plate of the board cover in the left-right direction) W2 (lateral length of linear link)

Claims

1. A device body, a fixing device having a heating section and fixing the toner image onto a sheet; a shutter that is movable between a closed position that covers the upstream of the heating unit in the sheet conveying direction and an open position that opens the upstream of the heating unit in the sheet conveying direction; a link connected to the shutter, the link abutting against a cartridge that is attached to or detached from the main body of the apparatus to move the shutter between the closed position and the open position; A substrate on which electronic components are mounted; A fan for moving air inside the device body, The substrate and the fan are spaced apart to form an air flow path, and the link is located between the substrate and the fan.

2. the substrate has a substrate surface on which the electronic components are mounted, the substrate surface extending in a first direction and a second direction perpendicular to the first direction; the fan is located at a position spaced apart from the substrate in the first direction and overlaps with the substrate in the second direction; The image forming apparatus according to claim 1 , wherein the link is located between the board and the fan in the first direction.

3. The image forming apparatus according to claim 2 , wherein the link is a linear link that is movable in the second direction.

4. a biasing member for biasing the link, the biasing member having a biasing spring and a contact portion that is pressed by the biasing spring and comes into contact with the link; The image forming apparatus according to claim 3 , wherein the biasing spring and the contact portion are located between the board and the fan in the first direction.

5. the link has a protrusion that protrudes toward the biasing member and has an inclined surface that is inclined with respect to the second direction, The image forming apparatus according to claim 4 , wherein the contact portion pressed by the biasing spring contacts the inclined surface of the projection.

6. a substrate cover positioned between the link and the substrate and covering the substrate; the substrate cover has a first portion in which a vent hole is formed and a second portion in which the vent hole is not formed; the link is located between the first and second parts and the fan; 6. The image forming apparatus according to claim 4, wherein the biasing spring is located between the second portion and the fan.

7. a cable extending from the substrate; The image forming apparatus according to claim 2 , wherein the cable is positioned alongside the link in a third direction perpendicular to the first direction and the second direction.

8. 8. The image forming apparatus according to claim 7, further comprising a link cover positioned between the link and the cable in the third direction and restricting movement of the link in the third direction.

9. 2. The image forming apparatus according to claim 1, further comprising a board cover positioned between the link and the board and covering the board.

10. the board cover is located between the link and the board and has a first portion extending in a direction perpendicular to a board surface of the board; 10. The image forming apparatus according to claim 9, wherein the first portion is formed with a vent hole.

11. The image forming apparatus according to claim 10 , wherein the link is shorter than the first portion in a direction perpendicular to the substrate surface.

12. a first frame and a second frame opposed to each other with the cartridge therebetween; and a substrate cover for covering the substrate.

2. The image forming apparatus according to claim 1, wherein the first frame supports the link, the board cover, and the fan.

13. The cartridge has a photosensitive drum that rotates around a drum axis, 13. The image forming apparatus according to claim 12, wherein the link abuts against the drum shaft.

14. an air duct disposed across the first frame and the second frame; the air duct and the fan are positioned to overlap when viewed from a direction in which the first frame and the second frame face each other, 14. The image forming apparatus according to claim 13, wherein the air duct is located between the cartridge and the fixing unit in a direction perpendicular to the opposing direction.

Images