Image forming apparatus

Abstract

To provide an image forming apparatus that can improve the operability of a guide member.SOLUTION: An image forming apparatus comprises an apparatus body, and an opening and closing member movable between a closed position where it is closed relative to the apparatus body and an open position where it is open relative to the apparatus body. The apparatus body includes an image forming unit, a sheet conveyance path including a first conveyance path and a second conveyance path through which a sheet passes, a guide member movable to a first guide position, a second guide position, and a first retreat position, a driving source, and a guide moving member capable of moving the guide member from the first guide position to the second guide position. A pressing part of the guide moving member located at a first position is arranged at a position not overlapping a movement locus of a part to be pressed when the guide member moves between the first guide position, second guide position, and first retreat position.SELECTED DRAWING: Figure 14

Description

[Technical field]

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

[0002] Conventionally, an image forming apparatus has been proposed that includes a main transport path for transporting an image-formed sheet toward a discharge tray, a reverse transport path branched off from the main transport path, and a switching member (see Patent Document 1). The switching member is configured to be capable of switching between a main transport position for guiding the sheet to the main transport path, a switching position for guiding the sheet to the reverse transport path, and a separated position for separating from the main transport path.

[0003] A reciprocating piece of a solenoid is connected to the switching member, and when the solenoid is energized, the switching member switches from the main transport position to the switching position. When a right cover member provided in the image forming apparatus is opened, the switching member can transition to the separated position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-153521 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the reciprocating piece of the solenoid is always connected to the switching member described in Patent Document 1. For example, when the switching member is shifted to the separated position by a user's operation, the reciprocating piece of the solenoid connected to the switching member also moves. This increases the force required to operate the switching member, and reduces the operability of the switching member.

[0006] SUMMARY OF THE DISCLOSURE An object of the present invention is to provide an image forming apparatus capable of improving the operability of a guide member. [Means for solving the problem]

[0007] The present invention relates to an image forming apparatus comprising: an apparatus main body; and an opening / closing member movable between a closed position where the opening / closing member is closed relative to the apparatus main body and an open position where the opening / closing member is open relative to the apparatus main body, the apparatus main body including an image forming unit that forms an image on a sheet; a sheet transport path including a first transport path and a second transport path through which a sheet passes; a guide member that is movable to a first guide position where the opening / closing member is located at the closed position and that guides the sheet toward the first transport path and a second guide position where the sheet is guided toward the second transport path; a drive source; and a guide moving member having a pressing portion, the pressing portion pressing a pressed portion of the guide member. and a guide moving member that is movable from a first position to a second position upon receiving a driving force from the driving source so as to move the guide member from the first guide position to the second guide position, wherein when the opening / closing member is located at the open position and the guide moving member is at the first position, the guide member is movable to a first retracted position that opens the sheet transport path, and the pressing portion of the guide moving member that is located at the first position is arranged at a position that does not overlap with a moving trajectory of the pressed portion when the guide member moves between the first guide position, the second guide position, and the first retracted position. Effect of the Invention

[0008] According to the present invention, the operability of the guide member can be improved. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the image forming apparatus with the front door, the rear door, and the double-sided conveying guide open. [Diagram 3] FIG. [Figure 4] FIG. 4A is a perspective view showing the switching mechanism, and FIG. 4B is another perspective view showing the switching mechanism. [Diagram 5] 4A is a cross-sectional view showing the A1-A1 section in FIG. 3, FIG. 4B is a cross-sectional view showing the B1-B1 section in FIG. 3, and FIG. 4C is a side view showing the discharge and reversing unit. [Figure 6] 4A is a cross-sectional view showing the A1-A1 section in FIG. 3, FIG. 4B is a cross-sectional view showing the B1-B1 section in FIG. 3, and FIG. 4C is a side view showing the discharge and reversing unit. [Figure 7] 4A is a cross-sectional view showing the A1-A1 section in FIG. 3, FIG. 4B is a cross-sectional view showing the B1-B1 section in FIG. 3, and FIG. 4C is a side view showing the discharge and reversing unit. [Figure 8] 4A is a cross-sectional view showing the A1-A1 section in FIG. 3, FIG. 4B is a cross-sectional view showing the B1-B1 section in FIG. 3, and FIG. 4C is a side view showing the discharge and reversing unit. [Figure 9] 4A is a cross-sectional view showing the A1-A1 section in FIG. 3, FIG. 4B is a cross-sectional view showing the B1-B1 section in FIG. 3, and FIG. 4C is a side view showing the discharge and reversing unit. [Figure 10] 1A is a cross-sectional view showing the discharging and reversing unit when the rear door is in a closed position, and FIG. 1B is a cross-sectional view showing the discharging and reversing unit when the rear door is in an open position. [Figure 11] (a) is a side view showing the position control spring when the guide member is located at the discharge position, (b) is a side view showing the position control spring when the guide member is located at the first jam processing position, and (c) is a side view showing the position control spring when the guide member is located at the second jam processing position. [Figure 12] 1A is a side view illustrating the force acting on the pivot control boss when the guide member is located at the first jam clearing position, and FIG. 1B is a side view illustrating the force acting on the pivot control boss when the guide member is located at the second jam clearing position. [Figure 13] FIG. 11 is a cross-sectional view showing the guide member positioned at the second jam clearance position. [Figure 14] 4A is a cross-sectional view showing the positional relationship between a pressed portion of a guide member and a pressing portion of a switching gear, and FIG. 4B is a cross-sectional view showing the movement trajectory of the pressed portion and the positional relationship between the pressing portion of the switching gear. [Figure 15]1A is a cross-sectional view showing the state where the cam of the rear door and the cam of the guide member located at the first jam clearance position abut against each other, and FIG. 1B is a cross-sectional view showing the state where the cam of the rear door and the cam of the guide member located at the second jam clearance position abut against each other. [Figure 16] (a) is a cross-sectional view showing the rear door in the open position and the fixing unit in the attached position, (b) is a cross-sectional view showing the fixing unit being pulled out from the device body, and (c) is a cross-sectional view showing the fixing unit being further pulled out from the device body. [Figure 17] 10A is a side view showing a switching mechanism according to a second embodiment, FIG. 10B is a side view showing the switching mechanism, and FIG. 10C is a side view showing the switching mechanism. [Figure 18] 10A is a side view showing a switching mechanism according to a second embodiment, and FIG. 10B is a side view showing the switching mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <First embodiment> [Overall structure] In the following, an embodiment in which the image forming apparatus according to the present invention is applied to an electrophotographic laser printer will be specifically described as an example of the configuration of the image forming apparatus according to the present invention.

[0011] 1 is a cross-sectional view showing the configuration of an image forming apparatus according to a first embodiment. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to those alone.

[0012] The image forming apparatus includes printers, copiers, facsimiles, and multifunction machines, and refers to an apparatus that forms an image on a sheet used as a recording medium based on image information input from an external PC or image information read from an original. In addition, an image forming apparatus may be connected to an optional feeder, an image reader, a sheet processing device, and other auxiliary devices in addition to a main body having an image forming function, and the entire system to which such auxiliary devices are connected is also a type of image forming apparatus.

[0013] 1, the image forming apparatus 1 is made up of an apparatus main body 1A, a process cartridge 1B, and a toner cartridge 1C. The process cartridge 1B and the toner cartridge 1C are detachably attached to the apparatus main body 1A.

[0014] The process cartridge 1B includes a cleaning unit 8 having a photosensitive drum 11 as a photosensitive member, and a developing unit 9 having a developing roller 16 that carries a developer including toner. The cleaning unit 8 includes the photosensitive drum 11, a cleaning blade 10, a charging roller 12, and a waste toner storage section 14. The photosensitive drum 11 is supported rotatably about a rotation shaft 11a extending in the Y direction, and carries a toner image. The charging roller 12 is disposed so as to come into contact with the outer circumferential surface of the photosensitive drum 11, and charges the photosensitive drum 11 by applying a voltage thereto from the apparatus main body 1A. The charging roller 12 is rotated in a driven manner relative to the photosensitive drum 11.

[0015] The cleaning blade 10 is an elastic member disposed so as to contact the outer peripheral surface of the photosensitive drum 11. The cleaning blade 10 removes toner remaining on the photosensitive drum 11 after a toner image is transferred to a sheet S, which will be described later, by bringing its tip into elastic contact with the photosensitive drum 11. The removed toner, i.e., waste toner, passes through the waste toner storage unit 14 and is transported to the toner cartridge 1C via a waste toner transport path (not shown), and is stored in a waste toner recovery unit (not shown).

[0016] The developing unit 9 has a developing roller 16, a supply roller 15, a developing blade 17, a developing chamber 18, a toner storage chamber 19, and an agitating member 20. The developing roller 16 supplies toner to a developing area of ​​the photosensitive drum 11. The developing roller 16 uses the toner to develop the electrostatic latent image formed on the photosensitive drum 11 into a toner image. The supply roller 15 supplies toner to the developing roller 16. The developing blade 17 contacts the circumferential surface of the developing roller 16 to regulate the amount of toner that adheres to the circumferential surface of the developing roller 16. The developing blade 17 also imparts a triboelectric charge to the toner.

[0017] The toner stored in the toner storage chamber 19 is sent to the developing chamber 18 by the rotation of the stirring member 20, and is supplied to the developing roller 16. The amount of toner remaining in the toner storage chamber 19 is detected by a remaining amount detection unit (not shown). When the amount of toner in the toner storage chamber 19 falls below a certain amount, toner is supplied from the toner cartridge 1C to the process cartridge 1B by a supply unit (not shown).

[0018] The toner cartridge 1C has a toner storage section 21 and an agitation transport unit 22. When toner is supplied from the toner cartridge 1C to the toner storage chamber 19 of the process cartridge 1B, the agitation transport unit 22 transports the toner contained in the toner storage section 21 toward a supply section (not shown).

[0019] The apparatus main body 1A has a sheet feeding section 70, a transfer roller 91, a laser scanner 61, a fixing section 101, a discharge / reversal unit 111, a duplex conveying unit 184, and the like. The laser scanner 61, the transfer roller 91, and the process cartridge 1B constitute an image forming section 1D that forms an image on a sheet S. The sheet feeding section 70 has a cassette 72 detachably supported by the apparatus main body 1A, a pickup roller 71a, and a separation roller pair 71b. In this embodiment, the cassette 72 can be pulled out from the apparatus main body 1A to the front side of the image forming apparatus 1, i.e., in the X1 direction, and can be attached in the X2 direction.

[0020] The sheet S includes paper such as paper and envelopes, plastic films such as overhead projector sheets (OHP), cloth, and the like.

[0021] The cassette 72 has a middle plate 74 that supports the sheet S and is provided so as to be liftable and lowerable about a rotation shaft 74p, and a lift arm 77 that is provided so as to be rotatable about a rotation shaft 78p. The lift arm 77 rotates about the rotation shaft 78p as the lift gear 78 rotates. When the lift arm 77 rotates upward about the rotation shaft 78p, the lift arm 77 lifts the middle plate 74 upward about the rotation shaft 74p.

[0022] A transfer roller 91 as a transfer unit forms a transfer nip N1 together with the photosensitive drum 11. A fixing unit 101 has a heating roller 102 incorporating a heater, and a pressure roller 103 that is in pressure contact with the heating roller 102 and forms a fixing nip N2 together with the heating roller 102.

[0023] The image forming apparatus 1 is provided with a sheet conveying path 186 along which the sheet S is conveyed. In this embodiment, the sheet conveying path 186 is disposed downstream of the fixing unit 101 in the conveying direction of the sheet S. The sheet conveying path 186 includes a discharge conveying path 182 and a reverse conveying path 181. The discharge reversing unit 111 includes a guide member 115, an intermediate conveying roller pair 112, a discharge roller pair 113, a full-load detection flag 117, a reverse roller pair 114, an intermediate conveying guide 116, and the like. The discharge reversing unit 111 includes the discharge conveying path 182 and the reverse conveying path 181. The guide member 115 is supported rotatably around a pivot center boss 115p, and is configured to be rotatable between a discharge position as a first guide position shown by a solid line in FIG. 1 and a reverse position as a second guide position shown by a dashed line in FIG. 1. When the guide member 115 is located at the discharge position, the guide member 115 guides the sheet S sent from the fixing unit 101 toward the discharge conveying path 182. When the guide member 115 is located at the reversing position, the guide member 115 guides the sheet S sent from the fixing unit 101 toward the reversing conveying path 181.

[0024] The intermediate conveying roller pair 112 is disposed between the fixing unit 101 and the discharge roller pair 113, and conveys the sheet S passing through the discharge conveying path 182 toward the discharge roller pair 113. The reversing roller pair 114 as a reversing conveying unit is disposed above a guide member 115, and conveys the sheet S conveyed to the reversing conveying path 181 upward once, and then conveys it downward. That is, the reversing roller pair 114 switches back the sheet S and conveys it toward the double-sided conveying unit 184.

[0025] The image forming apparatus 1 is provided with a duplex conveying path 183 as a third conveying path through which the sheet S conveyed from the reversing conveying path 181 passes. The duplex conveying path 183 can also be considered as a part of the sheet conveying path 186. The duplex conveying unit 184 has a duplex conveying guide 160, a duplex sensor 163, and conveying roller pairs 161 and 162. The duplex conveying guide 160 forms at least a part of the duplex conveying path 183 and guides the sheet S. The duplex sensor 163 detects the position of the leading edge of the sheet S passing through the duplex conveying path 183. The conveying roller pairs 161 and 162 convey the sheet S passing through the duplex conveying path 183. The downstream end of the duplex conveying path 183 in the sheet conveying direction has a U-shaped portion 185 curved in a U-shape, and the sheet S is conveyed to the registration roller pair 81 via the U-shaped portion 185.

[0026] When an image formation command is output to the image forming apparatus 1, an image forming process is started by the image forming unit 1D based on image information input from an external computer or the like connected to the image forming apparatus 1. The laser scanner 61 irradiates the photosensitive drum 11 with laser light based on the input image information. At this time, the photosensitive drum 11 is pre-charged by the charging roller 12, and an electrostatic latent image is formed on the photosensitive drum 11 by irradiating it with the laser light. Thereafter, the electrostatic latent image is developed by the developing roller 16, and a monochrome toner image is formed on the photosensitive drum 11.

[0027] In parallel with the image forming process described above, a sheet S is fed from the sheet feeding section 70. When the sheet S is fed from the sheet feeding section 70, the lifting arm 77 is driven to rotate the middle plate 74 upward about the rotation shaft 74p. As a result, the sheet S placed on the middle plate 74 comes into contact with the pickup roller 71a. In this state, the pickup roller 71a and the separation roller pair 71b are driven, and the sheet S is fed by the pickup roller 71a. In addition, the sheets S fed by the pickup roller 71a are separated one by one by the separation roller pair 71b and transported.

[0028] The sheets S separated one by one by the separation roller pair 71b are transported by the transport roller pair 73 through the feeding transport path 180 to the registration roller pair 81, and skew is corrected by the registration roller pair 81. A paper width sensor 82 and a registration sensor 83 are disposed downstream in the sheet transport direction of the registration roller pair 81. The paper width sensor 82 detects the size in the width direction of the sheet transported by the registration roller pair 81 at a predetermined transport timing, and the registration sensor 83 detects the position of the leading edge of the sheet S. The width direction is a direction perpendicular to the sheet transport direction and the thickness direction of the sheet S.

[0029] The fixing unit 101 controls a heater built in the heating roller 102 in accordance with the size in the width direction of the sheet S detected by the paper width sensor 82. The image forming unit 1D determines the timing of forming a toner image based on the position of the leading edge of the sheet S detected by the registration sensor 83.

[0030] Then, an electrostatic load bias is applied to the transfer roller 91, whereby the toner image on the photosensitive drum 11 is transferred to the sheet S at the transfer nip N1. Residual toner remaining on the photosensitive drum 11 is collected into a waste toner storage unit 14 by the cleaning blade 10. A predetermined amount of heat and pressure is applied to the sheet S, onto which the toner image has been transferred, at the fixing nip N2 by the heating roller 102 and pressure roller 103 of the fixing unit 101, so that the toner is melted and fixed (fixed).

[0031] When a toner image is formed on only one side of the sheet S, the sheet S that has passed through the fixing unit 101 is guided to a discharge conveying path 182 serving as a first conveying path by a guide member 115 located at the discharge position. Then, the sheet S passes through the discharge conveying path 182 and is conveyed to a discharge roller pair 113 by a pair of intermediate conveying rollers 112. The discharge roller pair 113 serving as a discharge unit discharges the sheet S outside the machine, and the sheet S is stacked on a discharge tray 118 formed on the upper surface of the image forming apparatus 1.

[0032] When the pair of discharge rollers 113 discharges the sheet S outside the apparatus, the full-load detection flag 117 is pressed by the sheet S and is raised from the standby position indicated by the solid line in Fig. 1 to the position indicated by the dashed line. When the height of the sheets S stacked on the discharge tray 118 reaches a predetermined height, the full-load detection flag 117 located at the standby position comes into contact with the sheets S stacked on the discharge tray 118. When more sheets S are discharged onto the discharge tray 118 and the full-load detection flag 117 rotates from the standby position by a predetermined angle or more, it is determined that the discharge tray 118 is in a full-load state, and the conveyance of the sheets S by the image forming apparatus 1 is stopped.

[0033] In this embodiment, the discharge tray 118 is inclined downward in the vertical direction (Z direction) toward the upstream in the discharge direction of the sheet S along the X1 direction. As a result, the sheet S discharged to the discharge tray 118 slides down along the discharge tray 118 and hits the regulating surface 118a. As a result, the sheet S is aligned in the discharge direction.

[0034] In addition, in the present embodiment, the bottommost portion 118b of the discharge tray 118 in the vertical direction, which is continuous with the regulating surface 118a, is located below the intermediate conveying roller pair 112. In this manner, the discharge tray 118 is formed relatively deep so that a large amount of sheets S can be stacked. If the discharge tray 118 is formed deep, the discharge conveying path 182 between the fixing unit 101 and the discharge roller pair 113 becomes long. However, in the present embodiment, since the intermediate conveying roller pair 112 is disposed between the fixing unit 101 and the discharge roller pair 113, even a sheet of the minimum size that the image forming apparatus 1 can convey can be reliably conveyed along the discharge conveying path 182.

[0035] When toner images are formed on both sides of the sheet S, the guide member 115 is positioned at the inversion position in advance. Then, the sheet S, on which an image is formed on the first side and which has passed through the fixing unit 101, is guided to a reversing conveying path 181 as a second conveying path by the guide member 115 positioned at the inversion position. The reversing conveying path 181 is provided with a pair of reversing rollers 114 having a reversing driving roller 114r formed of a rubber roller and a reversing driven roller 114k which rotates driven by the reversing driving roller 114r. When the rear end of the sheet S reaches a predetermined position, the rotation direction of the pair of reversing rollers 114 is switched by a rotation direction switching unit (not shown). The guide member 115 moves from the inversion position to the discharge position.

[0036] As a result, the sheet S is switched back in the reversing conveying path 181, and is guided to a double-sided conveying path 183 of a double-sided conveying unit 184 by a guide member 115 located at the discharge position. The position of the leading edge of the sheet S conveyed to the double-sided conveying path 183 is detected by a double-sided sensor 163. Based on the detection result of the double-sided sensor 163, the image forming apparatus 1 determines the timing at which the sheet S enters the conveying roller pair 161.

[0037] The conveying roller pair 161 is in a stopped state, and the sheet S hits the nip of the stopped conveying roller pair 161, so that the skew is corrected. Then, a predetermined time after the double-sided sensor 163 detects the position of the leading edge of the sheet S, the conveying roller pair 161 is driven. The sheet S is conveyed to the registration roller pair 81 via the U-shaped portion 185 by the conveying roller pairs 161 and 162. A toner image is transferred to the second surface of the sheet S at the transfer nip N1, and the toner image is fixed to the sheet S by the fixing unit 101. Then, the sheet S passes through the discharge conveying path 182 and is discharged to the discharge tray 118 by the discharge roller pair 113.

[0038] [Layout of each part of the device] Next, the characteristic arrangement of each part of the device main body 1A will be described with reference to Fig. 1. As shown in Fig. 1 and Fig. 5, the directions (X1, X2, Y1, Y2, Z1, Z2) are defined as follows.

[0039] The up-down direction is indicated by the Z axis. Arrow Z1 indicates the upward direction, and arrow Z2 indicates the downward direction. The surface at the end of image forming apparatus 1 in the Z1 direction is called the top surface (upper surface), and the surface at the end in the Z2 direction is called the bottom surface (bottom, lower part, lower end). The top surface of image forming apparatus 1 faces upward (Z1 direction), and the bottom surface faces downward (Z2 direction). The Z1 direction and Z2 direction may be collectively referred to as the up-down direction, height direction, vertical direction, gravity direction, or Z direction or Z-axis direction.

[0040] The front-to-rear direction is indicated by the X-axis. The direction toward the upstream side in the mounting direction when cassette 72 is mounted into device body 1A of image forming device 1 is referred to as the X1 direction, and the direction toward the downstream side in the mounting direction is referred to as the X2 direction. For convenience, the X1 direction is referred to as the front, and the X2 direction is referred to as the rear. In other words, the surface provided at the end of image forming device 1 in the X1 direction is referred to as the front surface (front part, front end) of image forming device 1, and the surface provided at the end in the X2 direction is referred to as the rear surface (rear part, rear end, rear part).

[0041] The front surface of the image forming apparatus 1 faces forward (X1 direction), and the rear surface faces backward (X2 direction). The X1 direction and X2 direction may be collectively called the front-rear direction, the X direction, or the X-axis direction.

[0042] 3, the left-right direction of the image forming apparatus 1 is indicated by the Y axis. For convenience, the left direction when viewed along the mounting direction (i.e., the X2 direction) when the cassette 72 is mounted in the apparatus main body 1A is indicated by the arrow Y1, and the right direction is indicated by the arrow Y2. The surface provided at the end of the image forming apparatus 1 in the Y1 direction is called the left side (left surface, left end, left part), and the surface provided at the end in the Y2 direction is called the right side (right surface, right part, right end). The Y1 direction and the Y2 direction may be collectively referred to as the left-right direction, horizontal direction, width direction, Y direction, Y-axis direction, etc.

[0043] The X-axis, Y-axis, and Z-axis are perpendicular to each other. For example, the X-axis is perpendicular to both the Y-axis and the Z-axis. A plane perpendicular to the X-axis is sometimes called the YZ plane, a plane perpendicular to the Y-axis is sometimes called the ZX plane, and a plane perpendicular to the Z-axis is sometimes called the XY plane. For example, the XY plane is a horizontal plane. The X and Y directions are directions along the horizontal XY plane, that is, the horizontal direction.

[0044] 1, the reversing roller pair 114 is disposed lower in the Z direction than the intermediate conveying roller pair 112. This is because disposing the reversing roller pair 114 lower shortens the double-sided conveying path 183 and improves the productivity of double-sided printing. In addition, the reversing roller pair 114 and the intermediate conveying roller pair 112 are disposed so as to at least partially overlap each other in the X direction. This allows the image forming apparatus 1 to be more compact in the X direction.

[0045] The conveying roller pair 161, 162 is disposed at a position where a relatively long sheet such as A4 size or LTR size can be stably conveyed through the U-shaped portion 185, which has a small curvature and a large conveying resistance. The length of the A4 size in the longitudinal direction is 297 mm, and the length of the LTR size in the longitudinal direction is 279.4 mm.

[0046] Further, the conveying roller pair 161 is disposed at a position that is 210 mm or less away from the reversing roller pair 114 along the double-sided conveying path 183. Similarly, the conveying roller pair 162 is disposed at a position that is 210 mm or less away from the conveying roller pair 161 along the double-sided conveying path 183. The A5 portrait size, which is the minimum size sheet that can be conveyed on the double-sided conveying path 183, has a longitudinal length of 210 mm. Since the conveying roller pairs 161 and 162 are disposed as described above, the conveying roller pairs 161 and 162 can stably convey the minimum size sheet conveyed to the double-sided conveying path 183 by the reversing roller pair 114.

[0047] The conveying roller pair 161 is disposed as close as possible to the fixing unit 101, improving the degree of freedom in arranging the reversing roller pair 114 in the Z1 direction. For example, in a product in which the volume of sheets that can be stacked on the discharge tray 118 is small, the discharge roller pair 113 and the reversing roller pair 114 may be integrated into one roller pair. In this case, a configuration can be realized in which it is not necessary to provide an additional intermediate conveying roller pair between the reversing roller pair 114 (one roller pair) and the conveying roller pair 161 of the reversing conveying path 181.

[0048] Further, the pair of conveying rollers 161, 162 are disposed so as to at least partially overlap in the Z direction with the transfer roller 91. This allows the image forming apparatus 1 to be made compact in the Z direction.

[0049] Also, at least a part of the lift gear 78 is disposed downstream of the conveying roller pair 162 in the X1 direction. This is for the following reasons. First, the conveying roller pair 162 is disposed so as to avoid the transfer roller 91, the paper width sensor 82, and the registration sensor 83. Furthermore, the conveying roller pair 162 is disposed at a position spaced apart from the conveying roller pair 161 by a distance of 210 mm or less along the double-sided conveying path 183. This allows the conveying roller pair 162 to stably convey a minimum-sized sheet conveyed to the double-sided conveying path 183.

[0050] Next, the lift gear 78 is disposed so that the rotation axis 78p of the lift gear 78 is as close as possible to the rotation axis 74p of the middle plate 74 in the X direction. This is to ensure that the relationship between the amount of lift of the middle plate 74 and the amount of rotation of the lift gear 78 does not change as much as possible depending on the amount of sheets S stored in the cassette 72. This allows the sheet feeding section 70 to stably feed the sheets S. For the above reasons, the lift gear 78 and the conveying roller pair 162 are disposed in the above-mentioned positional relationship.

[0051] As viewed in the X direction, a motor 30 serving as a drive source is disposed between the transfer roller 91 and the fixing unit 101. The motor 30 drives the photosensitive drum 11. The motor 30 may be, for example, a DC motor such as a brushed DC motor, but is not limited thereto. The motor 30 may be, for example, a servo motor or a stepping motor. The apparatus main body 1A also includes a fan 35 that cools the motor 30 by blowing air to the motor 30. The fan 35 is disposed below the fixing unit 101 and the double-sided conveying path 183 in the vertical direction (Z direction).

[0052] [Configuration for Jam Handling] Next, a configuration for clearing a jammed sheet S in the device body 1A of the image forming apparatus 1 will be described with reference to Figs. 1 and 2. As shown in Figs. 1 and 2, the image forming apparatus 1 has a front door 170 and a rear door 131 that are provided so as to be openable and closable relative to the device body 1A. The front door 170 is provided on the front surface of the image forming apparatus 1 and is rotatable about a rotation center 170p. The rear door 131 as an opening / closing member is provided on the rear surface of the image forming apparatus 1 and is rotatable about a rotation shaft 131p that extends in the Y direction (see Fig. 3). In addition, the double-sided conveying guide 160 is rotatable about a rotation center 160p, and can open the double-sided conveying path 183.

[0053] If a jam occurs with the leading edge of the sheet S in the feeding conveying path 180, the user pulls out the cassette 72 from the apparatus main body 1A in the X1 direction. This allows the user to access the feeding conveying path 180 and clear the jam.

[0054] When a jam occurs with the leading edge of the sheet S between the feeding conveying path 180 and the fixing unit 101, the user opens the front door 170. Then, the user removes the toner cartridge 1C and the process cartridge B from the apparatus main body 1A. This allows the user to access the jammed sheet S and clear the jam.

[0055] If a jam occurs with the leading edge of the sheet S between the fixing unit 101 and the pair of discharge rollers 113, or if a jam occurs with the leading edge of the sheet S that has switched back between the fixing unit 101 and the pair of conveying rollers 161, the user opens the rear door 131. This allows the user to access the jammed sheet S and clear the jam.

[0056] When a jam occurs with the leading edge of the sheet S between the conveying roller pair 161 and the registration roller pair 81, the user pulls out the cassette 72 from the apparatus main body 1A in the X1 direction. Furthermore, the user opens the duplex conveying guide 160 downward about the rotation center 160p to open the duplex conveying path 183. This allows the user to access the jammed sheet S in the duplex conveying path 183 and clear the jam. When the duplex conveying path 183 is opened downward, the nip of the conveying roller pair 162 is separated, but the nip of the conveying roller pair 161 is not separated. Because of this configuration, a user who accesses the duplex conveying path 183 from the downstream side in the X1 direction can easily find the jammed sheet S in the duplex conveying path 183, improving jam clearing performance.

[0057] [Switching mechanism configuration] Next, the configuration of a switching mechanism 800 for switching the position of the guide member 115 between the discharge position and the reverse position will be described with reference to Figures 3 to 4(b). Figure 3 is a front view showing the discharge / reverse unit 111.

[0058] 3, the discharge / reversal unit 111 has a discharge frame (discharge unit) 720 fixed to an apparatus frame (not shown) of the apparatus main body 1A, and the discharge frame 720 rotatably supports the guide member 115. The discharge frame 720 also holds the reversal drive roller 114r of the reversal roller pair 114. The discharge frame 720 has a function of guiding the sheet S conveyed through the discharge conveying path 182 and the reversing conveying path 181.

[0059] The discharge frame 720 has two rotation center holes 720p (see FIG. 3) and two rotation center bosses 720g. A rotation center boss 115w is provided at both ends of the guide member 115 in the Y direction. The rotation center boss 115w of the guide member 115 is inserted into the rotation center hole 720p. This allows the guide member 115 to be supported rotatably relative to the discharge frame 720 around the rotation center boss 115p and the rotation center hole 720p.

[0060] The rotation center boss 720g is inserted into the rotation center hole 116p of the intermediate conveying guide 116. As a result, the intermediate conveying guide 116 is supported rotatably with respect to the discharge frame 720 around the rotation center boss 720g and the rotation center hole 116p. The switching mechanism 800 is provided on the upstream side of the discharge frame 720 in the Y1 direction. The discharge frame 720 has a relay guide 119 between the intermediate conveying guide 116 and the guide member 115.

[0061] Fig. 4(a) is a perspective view showing the switching mechanism 800, and Fig. 4(b) is another perspective view showing the switching mechanism 800. Both Figs. 4(a) and 4(b) are views seen from the upstream side in the Y1 direction.

[0062] 4(a) and (b), the switching mechanism 800 has an electromagnetic clutch 702, an idler gear 705, a switching gear 701, and a switching gear spring 712. In this embodiment, the electromagnetic clutch 702, the idler gear 705, the switching gear 701, and the switching gear spring 712 are supported by the discharge frame 720, but may be supported by other members.

[0063] An electromagnetic clutch 702 serving as a clutch is provided in a drive transmission path between the motor 30 (see FIG. 1) and a switching gear 701. When the electromagnetic clutch 702 is energized, it transitions to a transmission state in which the drive force of the motor 30 is transmitted to a gear portion 702g of the electromagnetic clutch 702. When the electromagnetic clutch 702 is deenergized, it transitions to a non-transmission state in which the drive force of the motor 30 is not transmitted to the gear portion 702g.

[0064] In this embodiment, the driving force of the motor 30 is transmitted or not transmitted to the switching gear 701 using the electromagnetic clutch 702, but the present invention is not limited to this. For example, instead of the electromagnetic clutch 702, other clutches such as a mechanical clutch, a hydraulic clutch, or a pneumatic clutch may be used.

[0065] The idler gear 705 meshes with a gear portion 702g of the electromagnetic clutch 702 and a gear portion 701g of the switching gear 701, and transmits the rotation of the gear portion 702g to the gear portion 701g. The switching gear 701 as a guide moving member has a gear portion 701g and a pressing portion 701a, and is rotatable around a rotation center 701p. That is, the switching gear 701 is configured to be rotatable around a rotation axis extending in the Y direction, and the gear portion 701g receives a driving force from the motor 30. In addition, the switching gear 701 has a switching gear spring 712 as a first biasing member composed of a torsion coil spring built in.

[0066] The ejection frame 720 is provided with the restricting portions 714 and 720a, an opening 720t through which the pressed portion 115s of the guide member 115 penetrates, and a boss portion 720b. A fixed arm 712a of a switching gear spring 712 built into the switching gear 701 is fixed to the restricting portion 720a, and an operating arm 712b of the switching gear spring 712 is engaged with the switching gear spring 712. The switching gear 701 is biased by the switching gear spring 712 in the R1 direction (clockwise direction) in FIG. 4(a)(b) about the rotation center 701p, and is positioned at the first position by hitting a stopper (not shown). In other words, the switching gear spring 712 biases the switching gear 701 toward the first position. In FIG. 4(a)(b) and FIG. 5(a)-(c), the switching gear 701 is located at the first position.

[0067] Furthermore, when the electromagnetic clutch 702 is energized, a driving force is transmitted from the motor 30 to the switching gear 701, and the switching gear 701 rotates in the R2 direction, which is opposite to the R1 direction which is the biasing direction of the switching gear spring 712. That is, the switching gear 701 rotates in the R2 direction against the biasing force of the switching gear spring 712. The biasing force of the switching gear spring 712 is set to be larger than the gear idling torque of the electromagnetic clutch 702.

[0068] The boss portion 720b of the discharge frame 720 is provided coaxially with the rotation center hole 720p, and a coil portion 711c of the spring 711 is attached thereto. A fixed arm 711a of the spring 711 serving as a second biasing member is fixed to the regulating portion 720a, and an operating arm 711b of the spring 711 is engaged with an end portion of the pressed portion 115s of the guide member 115. The pressed portion 115s is disposed outside the conveying area of ​​the sheet S in the Y direction. The pressed portion 115s is biased by the spring 711, so that the guide member 115 is biased in the T1 direction (counterclockwise direction in FIGS. 4(a) and (b)) around the rotation center boss 115w.

[0069] The guide member 115, which is biased in the T1 direction by the spring 711, is positioned at the ejection position by abutting against the rotation restriction portion 131e of the rear door 131 when the rear door 131 is in the closed position as shown in FIG. 10(a).

[0070] [Operation of switching mechanism and guide member] Next, the operation of the switching mechanism 800 and the guide member 115 will be described with reference to FIGS.

[0071] 5(a) to 9(c) show five patterns of positional relationships between the guide member 115 and the switching gear 701. FIG. 5(a) is a cross-sectional view showing the A1-A1 cross section of FIG. 3 in a state where the guide member 115 is located at the discharge position and the switching gear 701 is located at the first position. FIG. 5(b) is a cross-sectional view showing the B1-B1 cross section of FIG. 3 in a state where the guide member 115 is located at the discharge position and the switching gear 701 is located at the first position. FIG. 5(c) is a side view of the discharging and reversing unit 111 as viewed from the upstream side in the Y1 direction in a state where the guide member 115 is located at the discharge position and the switching gear 701 is located at the first position.

[0072] 5(a) to (c), the rear door 131 is closed and the electromagnetic clutch 702 is in a non-energized state. At this time, the driving force of the motor 30 is not transmitted to the switching gear 701. Therefore, the switching gear 701 is located at a first position shown in FIGS. 5(a) to (c) by the biasing force of the switching gear spring 712. Also, the guide member 115 is biased in the T1 direction by the spring 711 and abuts against the rotation restriction portion 131e of the rear door 131 (see FIG. 10(a)), thereby being positioned at the ejection position.

[0073] Fig. 6(a) is a cross-sectional view showing the A1-A1 section in Fig. 3 just before the guide member 115 moves from the discharge position to the reverse position and in the middle of the switching gear 701 rotating from the first position to the second position. Fig. 6(b) is a cross-sectional view showing the B1-B1 section in Fig. 3 just before the guide member 115 moves from the discharge position to the reverse position and in the middle of the switching gear 701 rotating from the first position to the second position. Fig. 6(c) is a side view of the discharging and reversing unit 111 seen from the upstream side in the Y1 direction just before the guide member 115 moves from the discharge position to the reverse position and in the middle of the switching gear 701 rotating from the first position to the second position.

[0074] 6(a) to 6(c), when the electromagnetic clutch 702 is energized, the driving force of the motor 30 is transmitted to the switching gear 701. As a result, the switching gear 701 rotates in the R2 direction against the biasing force of the switching gear spring 712. When the switching gear 701 rotates in the R2 direction, the pressing portion 701a of the switching gear 701 comes into contact with the pressed portion 115s of the guide member 115 located at the ejection position. When the switching gear 701 further rotates in the R2 direction, the pressing portion 701a presses the pressed portion 115s, and the guide member 115 rotates in the T2 direction from the ejection position to the reverse position.

[0075] Fig. 7(a) is a cross-sectional view showing the A1-A1 section of Fig. 3 in a state where the guide member 115 is in the reverse position and the switching gear 701 is in the second position. Fig. 7(b) is a cross-sectional view showing the B1-B1 section of Fig. 3 in a state where the guide member 115 is in the reverse position and the switching gear 701 is in the second position. Fig. 7(c) is a side view of the discharging and reversing unit 111 as seen from the upstream side in the Y1 direction in a state where the guide member 115 is in the reverse position and the switching gear 701 is in the second position.

[0076] As shown in FIG. 7(a) to (c), when the pressing portion 701a presses the pressed portion 115s and the guide member 115 reaches the reversing position, the guide member 115 hits a restricting portion (not shown) and stops. At this time, the drive of the motor 30 is transmitted to the electromagnetic clutch 702 via a torque limiter (not shown) provided in a drive transmission path between the motor 30 and the electromagnetic clutch 702. The torque limit value at which the drive connection of the torque limiter is cut off is greater than the biasing force of the spring 711 when the guide member 115 is located at the reversing position. Therefore, the guide member 115 maintains the reversing position as long as the motor 30 is driven and the electromagnetic clutch 702 is in an energized state. Note that when the electromagnetic clutch 702 is in an energized state, if the rear door 131 is opened, the electromagnetic clutch 702 is de-energized. When the electromagnetic clutch 702 is de-energized, the switching gear 701 is located at the first position.

[0077] Fig. 8(a) is a cross-sectional view showing the A1-A1 section in Fig. 3 in a state where the guide member 115 is located at the first jam clearing position and the switching gear 701 is located at the first position. Fig. 8(b) is a cross-sectional view showing the B1-B1 section in Fig. 3 in a state where the guide member 115 is located at the first jam clearing position and the switching gear 701 is located at the first position. Fig. 8(c) is a side view of the discharge and reversing unit 111 as seen from the upstream side in the Y1 direction in a state where the guide member 115 is located at the first jam clearing position and the switching gear 701 is located at the first position.

[0078] Fig. 9(a) is a cross-sectional view showing the A1-A1 section in Fig. 3 in a state where the guide member 115 is located at the second jam clearing position and the switching gear 701 is located at the first position. Fig. 9(b) is a cross-sectional view showing the B1-B1 section in Fig. 3 in a state where the guide member 115 is located at the second jam clearing position and the switching gear 701 is located at the first position. Fig. 9(c) is a side view of the discharge and reversing unit 111 as seen from the upstream side in the Y1 direction in a state where the guide member 115 is located at the second jam clearing position and the switching gear 701 is located at the first position.

[0079] FIG. 10(a) is a cross-sectional view showing the discharging and reversing unit 111 when the rear door 131 is in the closed position, and FIG. 10(b) is a cross-sectional view showing the discharging and reversing unit 111 when the rear door 131 is in the open position.

[0080] Fig. 11(a) is a side view of the position regulating spring 716 seen from the upstream side in the Y2 direction when the guide member 115 is located at the discharge position. Fig. 11(b) is a side view of the position regulating spring 716 seen from the upstream side in the Y2 direction when the guide member 115 is located at the first jam clearing position. Fig. 11(c) is a side view of the position regulating spring 716 seen from the upstream side in the Y2 direction when the guide member 115 is located at the second jam clearing position.

[0081] Fig. 12(a) is a side view for explaining the force acting on the rotation restriction boss 115z when the guide member 115 is located at the first jam clearing position. Fig. 12(b) is a side view for explaining the force acting on the rotation restriction boss 115z when the guide member 115 is located at the second jam clearing position. Figs. 12(a) and 12(b) are both views seen from the upstream side in the Y2 direction. Fig. 13 is a cross-sectional view showing the guide member 115 located at the second jam clearing position.

[0082] As shown in FIG. 10(b), when the rear door 131 is opened, the rear door 131 moves away from the guide member 115. Therefore, the guide member 115, which is biased in the T1 direction by the spring 711, rotates around the pivot boss 115p toward the first jam clearing position, which is the first retracted position shown in FIG. 8(a) and FIG. 10(b). In other words, the spring 711 biases the guide member 115 toward the first jam clearing position. When the guide member 115 is in the first jam clearing position and a second jam clearing position described later, the sheet conveying path 186 is opened and exposed toward the outside of the device main body 1A. At this time, the discharge conveying path 182, which was covered by the guide member 115, is also opened and exposed toward the outside of the device main body 1A. That is, the guide member 115 opens the sheet conveying path 186 including the discharge conveying path 182 at the first jam clearing position and the second jam clearing position. Moreover, when the rear door 131 is in the open position, the reverse conveying path 181 is opened. The first jam clearing position and the second jam clearing position are different from the positions (discharge position, reverse position) for the guide member 115 to convey the sheet S. In this embodiment, when the rear door 131 is closed, the guide member 115 is restricted from moving to the first jam clearing position and the second jam clearing position. Also, when the rear door 131 is open, the operation of conveying the sheet S is restricted. Therefore, the guide member 115 does not guide the sheet S at the first jam clearing position and the second jam clearing position.

[0083] 11(a) to 11(c), ejection frame 720 is provided with support portion 720q and restriction portions 720e and 720f, and support portion 720q supports position restriction spring 716 as an elastic member formed of a torsion coil spring. Fixed arm 716a of position restriction spring 716 abuts against restriction portion 720e, and operating arm 716b of position restriction spring 716 abuts against restriction portion 720f.

[0084] In the Y2 direction, a rotation restriction boss 115z is provided at the upstream end of the guide member 115, and the rotation restriction boss 115z is configured to be able to abut against the operating arm 716b of the position restriction spring 716. When the guide member 115 is located at the discharge position and at the reverse position shown in FIG. 11(a), the rotation restriction boss 115z is separated from the operating arm 716b of the position restriction spring 716.

[0085] As shown in Figures 8(a) to 8(c) and 11(b), when the rear door 131 is opened and the guide member 115 rotates in the T1 direction around the rotation center boss 115p by the biasing force of the spring 711, the rotation restriction boss 115z abuts against the operating arm 716b. At this time, as shown in Figure 12(a), the force with which the operating arm 716b abutting against the restricting portion 720f presses the rotation restriction boss 115z is set to be larger than the force F115 with which the rotation restriction boss 115z presses the operating arm 716b by the biasing force of the spring 711. Therefore, the guide member 115 is positioned at the first jam disposal position shown in Figures 8(a), 11(b), and 12(b) by the rotation restriction boss 115z abutting against the operating arm 716b.

[0086] When the rear door 131 is opened from the closed position to the open position, the intermediate conveying guide 116 rotates by its own weight about the rotation center hole 116p from the guide position shown in Fig. 10(a) to the jam clearing position shown in Fig. 10(b). In this state, the user can clear the jam in the discharge conveying path 182 from between the relay guide 119 and the intermediate conveying guide 116.

[0087] 13, when, for example, removing the fixing unit 101 from the apparatus main body 1A and clearing a jam in the discharge conveyance path 182, the user can manually lift the guide member 115 to rotate the guide member 115 to the second jam clearing position shown in Fig. 13. This further opens the sheet conveyance path 186. In addition, the working space L between the guide member 115 and the rear door 131 is expanded, improving maintainability.

[0088] As shown in Figs. 9(a) to (c) and 13, when the user rotates the guide member 115 to the second jam clearing position as the second retracted position, the rotation restriction boss 115z of the guide member 115 is in the position shown in Fig. 11(c). The second jam clearing position is a position opposite to the discharge position and the inversion position with respect to the first jam clearing position. At this time, as shown in Fig. 12(b), the force F115' with which the rotation restriction boss 115z presses the operating arm 716b by the user's operation of rotating the guide member 115 to the second jam clearing position becomes larger than the force with which the operating arm 716b presses the rotation restriction boss 115z. That is, the rotation restriction boss 115z presses the operating arm 716b of the position restriction spring 716 downward to elastically deform it, and the operating arm 716b moves away from the restriction portion 720f.

[0089] 13, when the guide member 115 is located at the second jam clearing position, the rotation restricted portion 115e of the guide member 115 abuts against the rotation shaft 114s of the reverse drive roller 114r. Therefore, the guide member 115 does not open above the second jam clearing position.

[0090] In the present embodiment, the position restriction spring 716 is made of a torsion coil spring, but is not limited to this. For example, the position restriction spring 716 may be made of an elastic member such as a leaf spring, a torsion bar, a sponge, or rubber.

[0091] [Positional relationship between the pressed part and the pressing part] Next, the positional relationship between the pressed portion 115s of the guide member 115 and the pressing portion 701a of the switching gear 701 will be described with reference to Figs. 14(a) and (b). Fig. 14(a) is a cross-sectional view showing the positional relationship between the pressed portion 115s of the guide member 115 and the pressing portion 701a of the switching gear 701, and Fig. 14(b) is a cross-sectional view showing the positional relationship between the movement trajectory 115k of the pressed portion 115s and the pressing portion 701a of the switching gear 701.

[0092] In Fig. 14(a)(b), the guide member 115 shown by the solid line is located at the inverted position, and the guide member 115 shown by the dashed line is located at the second jam processing position. In Fig. 14(a)(b), the switch gear 701 is located at the first position. In Fig. 14(b), the arc-shaped area shown by the diagonal lines indicates the movement trajectory 115k of the pressed part 115s when the guide member 115 moves between the inverted position and the second jam processing position. In other words, the movement trajectory 115k is the space through which the pressed part 115s passes when the guide member 115 moves between the inverted position and the second jam processing position. In other words, the movement trajectory 115k is the movement trajectory of the pressed part 115s when the guide member 115 moves between the discharge position, the inverted position, the first jam processing position, and the second jam processing position. The movement trajectory 115k includes the movement trajectory of the pressed portion 115s when the guide member 115 moves between the discharge position, the reversing position, and the first jam processing position.

[0093] 14(b), in this embodiment, the pressing portion 701a of the switching gear 701 located at the first position is disposed at a position that does not overlap with the moving trajectory of the pressed portion 115s when the guide member 115 moves between the discharge position, the reverse position, and the first jam clearing position. Therefore, when the guide member 115 moves to the first jam clearing position, the pressed portion 115s does not come into contact with the pressing portion 701a of the switching gear 701.

[0094] In this embodiment, as shown in FIG. 14(b), the pressing portion 701a of the switching gear 701 located at the first position is disposed at a position that does not overlap with the movement locus 115k. Therefore, when the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the pressed portion 115s does not come into contact with the pressing portion 701a of the switching gear 701. When the guide member 115 is located at the first jam clearing position or the second jam clearing position, the rear door 131 is located at the open position, and the electromagnetic clutch 702 is in a non-energized state. At this time, the switching gear 701 is located at the first position. Therefore, even if the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the user does not receive a load required to rotate the switching gear 701 or the gear portion 702g of the electromagnetic clutch 702. Therefore, the force required to operate the guide member 115 can be reduced, and the operability of the guide member 115 can be improved.

[0095] When the switching gear 701 moves from the first position to the second position, that is, when the rear door 131 is in the closed position and the electromagnetic clutch 702 switches from a non-energized state to an energized state, the guide member 115 is in the ejection position. When the switching gear 701 is in the first position, the pressing portion 701a is separated from the pressed portion 115s, as shown in Figs. 5(a) to (c). When the switching gear 701 moves from the first position to the second position, the pressing portion 701a comes into contact with the pressed portion 115s, as shown in Figs. 6(a) to (c).

[0096] That is, when the switching gear 701 moves from the first position to the second position, the pressed portion 115s is located downstream in the moving direction of the pressing portion 701a. Therefore, the pressing portion 701a and the pressed portion 115s are configured such that the pressed portion 115s does not enter upstream in the moving direction of the pressing portion 701a. Therefore, the guide member 115 can be rotated stably.

[0097] [Operation of guide member when closing rear door] Next, the operation of the guide member 115 when the rear door 131 is closed from the open position to the closed position will be described with reference to Figures 15(a) and (b). Figure 15(a) is a cross-sectional view showing a state in which the cam 115f of the rear door 131 abuts against the cam 115f of the guide member 115 located at the first jam clearing position. Figure 15(b) is a cross-sectional view showing a state in which the cam 115f of the rear door 131 abuts against the cam 115f of the guide member 115 located at the second jam clearing position.

[0098] 15(a), once the rear door 131 is opened, the guide member 115 is held at the first jam clearing position by the action of the above-mentioned spring 711 and the position restriction spring 716. Then, when the user closes the rear door 131 from the open position to the closed position, the cam 115f of the rear door 131 abuts against the cam 115f of the guide member 115 located at the first jam clearing position.

[0099] At this time, the direction of force F131 that cam 115f receives from cam 131f always passes below in the vertical direction (Z direction) relative to rotation center boss 115w of guide member 115. That is, the force F131 causes guide member 115 to rotate in the T2 direction around rotation center boss 115w toward the ejection position.

[0100] 10(a), when the rear door 131 is in the closed position, the guide member 115 abuts against the rear door 131 in the closed position and is held in the discharge position. When the rear door 131 is closed from the open position to the closed position, the intermediate conveyance guide 116 is pressed by the rear door 131 and rotates from the jam processing position shown in FIG. 10(b) to the guide position shown in FIG. 10(a).

[0101] 15(b), consider the case where the rear door 131 is closed when the guide member 115 is located at the second jam clearing position. At this time, the direction of the force F131' that the cam 115f receives from the cam 131f passes above the rotation center boss 115w of the guide member 115 in the vertical direction (Z direction). In other words, the force F131' causes the guide member 115 to try to rotate further upward from the second jam clearing position.

[0102] 11(a) to 11(c), however, a position restriction spring 716 is provided for holding the guide member 115 at the first jam clearing position when the rear door 131 is opened. Therefore, when the rear door 131 is closed, the guide member 115 is located at the first jam clearing position. In other words, when the user releases the guide member 115, the urging force of the position restriction spring 716 causes the guide member 115 to be automatically held at the first jam clearing position.

[0103] In this way, the guide member 115 and the intermediate conveying guide 116 rotate to the ejection position and the guide position, respectively, in conjunction with the operation of closing the rear door 131, thereby improving usability.

[0104] [Mounting and unmounting of the fixing unit] Fig. 16(a) is a cross-sectional view showing a state in which the rear door 131 is in the open position and the fixing unit 101 is in the attached position. Fig. 16(b) is a cross-sectional view showing the fixing unit 101 being pulled out from the device main body 1A. Fig. 16(c) is a cross-sectional view showing the fixing unit 101 being further pulled out from the device main body 1A.

[0105] 16(a), when removing the fixing unit 101 from a frame (not shown) of the apparatus main body 1A, the user first moves the rear door 131 to the open position. At this time, as described above, the guide member 115 moves to the first jam clearing position by the biasing force of the spring 711. The lower end 115t of the guide member 115 located at the first jam clearing position is located higher in the vertical direction (Z direction) than the fixing unit 101 located at the mounting position. Also, the upper end 131t of the rear door 131 located at the open position is located lower in the vertical direction (Z direction) than the fixing unit 101 located at the mounting position.

[0106] Therefore, by opening the rear door 131 to the open position, the fixing unit 101 can move in the X2 direction through between the lower end 115t of the guide member 115 and the upper end 131t of the rear door 131. The user can remove the fixing unit 101 in the X2 direction along the horizontal direction from the frame (not shown) of the apparatus main body 1A, as shown in FIG. 16(b). Then, the user can remove the fixing unit 101 from the frame (not shown) of the apparatus main body 1A by further moving the fixing unit 101 in a direction between the X2 direction and the Z1 direction, as shown in FIG. 16(c).

[0107] The device body 1A may have a guide rail that guides the fixing unit 101 from the mounting position shown in Fig. 16(a) to the position shown in Fig. 16(b), for example. The user may remove the fixing unit 101 from the device body 1A with the guide member 115 lifted from the first jam clearing position to the second jam clearing position.

[0108] When mounting the fixing unit 101 in the device main body 1A, the operations for removing the fixing unit 101 from the device main body 1A are performed in reverse. In this way, by opening the rear door 131 to the open position, the fixing unit 101 can be mounted and removed from the device main body 1A, improving the ease of maintenance and jam handling.

[0109] As described above, in this embodiment, as described in Figure 10 (b), the pressing portion 701a of the switching gear 701 located in the first position is positioned so as not to overlap with the movement trajectory 115k of the pressed portion 115s of the guide member 115.

[0110] Therefore, when the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the pressed portion 115s does not come into contact with the pressing portion 701a of the switching gear 701. Therefore, even if the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the user does not receive the load required to rotate the switching gear 701 or the gear portion 702g of the electromagnetic clutch 702. Therefore, the force required to operate the guide member 115 can be reduced, and the operability of the guide member 115 can be improved.

[0111] Furthermore, the guide member 115 is not subjected to the load when the rear door 131 is opened and the guide member 115 is rotated to the first jam clearing position by the biasing force of the spring 711. This makes it possible to reduce not only the force required by the user to operate the guide member 115 but also the biasing force required for the spring 711, and allows the selection of an inexpensive or small spring 711. This allows the image forming apparatus 1 to be made smaller and at a lower cost.

[0112] <Second embodiment> Next, a second embodiment of the present invention will be described. The second embodiment is a modification of the first embodiment in terms of the configuration of the switching mechanism 800. Therefore, configurations similar to those in the first embodiment will be described with the same reference numerals or will be omitted from the drawings.

[0113] A switching mechanism 730 according to the second embodiment will be described with reference to Fig. 17(a). Fig. 17(a) is a side view of the switching mechanism 730 as viewed from the upstream side in the Y1 direction in a state in which the guide member 115 is located at the discharge position and the switching slider 734 is located at the first position.

[0114] As shown in FIG. 17( a ), a switching mechanism 730 according to the second embodiment includes a solenoid 731 , a link 732 , a rail 733 , a switching slider 734 , and a separating spring 735 .

[0115] The solenoid 731 as a driving source has a main body 731a and a plunger 731b that can reciprocate relative to the main body 731a. The main body 731a has an electromagnetic coil (not shown) wound around the plunger 731b. When a current flows through the coil, the plunger 731b is attracted toward the main body 731a.

[0116] The link 732 is rotatable about a rotation center 732p, and has an engagement portion 732a that engages with the plunger 731b and an engagement portion 732b that engages with the switching slider 734. The switching slider 734 is supported on the rail 733 so as to be slidable in the X direction. The plunger 731b is connected to the switching slider 734 via the link 732, and therefore moves in conjunction with the switching slider 734. The switching slider 734 serving as a guide moving member has a pressing portion 734a that can press the pressed portion 115s of the guide member 115.

[0117] One end of the separating spring 735, which is a tension spring, is engaged with the rail 733, and the other end of the separating spring 735 is engaged with the switching slider 734. When no current flows through the electromagnetic coil of the solenoid 731, the switching slider 734 moves downstream in the X1 direction by the biasing force of the separating spring 735 and hits the rail 733, thereby being positioned at the first position. In other words, the separating spring 735 as the first biasing member biases the switching slider 734 toward the first position. Also, the plunger 731b engaged with the switching slider 734 moves downstream in the X2 direction, that is, in the direction protruding from the main body 731a.

[0118] [Operation of switching mechanism and guide member] Next, the operation of the switching mechanism 730 and the guide member 115 will be described with reference to Fig. 17(a) to Fig. 18(b). Fig. 17(b) is a side view of the switching mechanism 730 seen from the upstream side in the Y1 direction just before the guide member 115 moves from the discharge position to the reverse position and while the switching slider 734 is in the middle of moving from the first position to the second position. Fig. 17(c) is a side view of the switching mechanism 730 seen from the upstream side in the Y1 direction in a state in which the guide member 115 is located at the reverse position and the switching slider 734 is located at the second position.

[0119] 17(a) to (c), the rear door 131 is closed, and in Fig. 18(a) and (b), the rear door 131 is open. As shown in Fig. 17(a), when the rear door 131 is closed and the solenoid 731 is in a non-energized state, the pressing portion 734a of the switching slider 734 is separated from the pressed portion 115s of the guide member 115. Therefore, the guide member 115 is positioned at the ejection position by the biasing force of the spring 711 (see Figs. 4(a) and (b)).

[0120] As shown in FIG. 17(b), when a current flows through the electromagnetic coil of the solenoid 731 and the solenoid is in an energized state, the plunger 731b moves downstream in the X1 direction against the biasing force of the separating spring 735. As a result, the link 732 engaged with the plunger 731b rotates clockwise around the rotation center 732p. In conjunction with the rotation of the link 732, the switching slider 734 moves downstream in the X2 direction from the first position shown in FIG. 17(a) to the second position shown in FIG. 17(c). When the pressing portion 734a of the switching slider 734 presses the pressed portion 115s of the guide member 115 downstream in the X2 direction, the guide member 115 rotates in the T2 direction from the discharge position to the inverted position around the rotation center boss 115w.

[0121] 17(c), when the switching slider 734 is located at the second position and the guide member 115 reaches the reverse position, the guide member 115 hits a restricting portion (not shown) and stops. Note that as long as the solenoid 731 is kept energized, the guide member 115 is held at the reverse position.

[0122] 17(c), when the solenoid 731 is de-energized, the switching slider 734 moves downstream in the X1 direction due to the biasing force of the separating spring 735. That is, the switching slider 734 moves from the second position to the first position. As a result, the guide member 115 separates from the switching slider 734 and returns to the ejection position due to the biasing force of the spring 711.

[0123] Fig. 18(a) is a side view of the switching mechanism 730 seen from the upstream side in the Y1 direction in a state in which the guide member 115 is located at the first jam clearing position and the switching slider 734 is located at the first position. Fig. 18(b) is a side view of the switching mechanism 730 seen from the upstream side in the Y1 direction in a state in which the guide member 115 is located at the second jam clearing position and the switching slider 734 is located at the first position.

[0124] As shown in Fig. 18(a), when the rear door 131 is opened to the open position, the solenoid 731 is in a non-energized state. Therefore, the switching slider 734 is located at the first position, as in Fig. 17(a). Furthermore, when the rear door 131 is opened, the rear door 131 moves away from the guide member 115 (see Fig. 10(b)). Therefore, the guide member 115, which is biased in the T1 direction by the spring 711, rotates toward the first jam clearing position shown in Fig. 10(b).

[0125] The configuration for holding the guide member 115 at the first jam clearing position is the same as in the first embodiment, and therefore the description will be omitted. As shown in Fig. 18(b) and Fig. 13, the user can rotate the guide member 115 to the second jam clearing position by manually lifting the guide member 115, as in the first embodiment. This increases the working space L between the guide member 115 and the rear door 131, improving maintainability.

[0126] As shown in Figures 17(a) to 18(b), the pressing portion 734a of the switching slider 734 located in the first position is positioned so as not to overlap with the movement trajectory 115k (see Figure 14(b)) of the pressed portion 115s when the guide member 115 moves between the reversal position and the second jam processing position.

[0127] Therefore, when the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the pressed portion 115s does not come into contact with the pressing portion 734a of the switching slider 734. Therefore, even if the user operates the guide member 115 from the first jam clearing position to the second jam clearing position, the user does not receive the load required to move the switching slider 734, the link 732, and the plunger 731b. Therefore, the force required to operate the guide member 115 can be reduced, and the operability of the guide member 115 can be improved.

[0128] <Third embodiment> Next, a third embodiment of the present invention will be described, which is a modification of the first embodiment by omitting the position restriction spring 716. Therefore, a description of the same configuration as the first embodiment will be omitted.

[0129] In the third embodiment, the guide member 115 is configured to be movable to the discharge position, the reversing position, and the first jam clearing position, but does not move to the second jam clearing position. That is, when the rear door 131 is opened, the guide member 115 rotates in the T1 direction by the urging force of the spring 711 (see FIG. 10(b)). Then, the guide member 115 abuts against an abutting member (not shown) at the first jam clearing position, and is thereby positioned at the first jam clearing position. For example, the rotating shaft 114s of the reversing drive roller 114r (see FIG. 13) may be used as the abutting member, and the configuration of the abutting member is not limited.

[0130] This makes it possible to omit the position restriction spring 716, thereby reducing costs. Also, by opening the rear door 131 to the open position, the guide member 115 automatically rotates to the first jam clearing position. In this state, the fixing unit 101 can be attached and detached from the apparatus main body 1A, improving ease of maintenance and jam clearing. Also, in conjunction with the operation of closing the rear door 131, the guide member 115 and the intermediate conveyance guide 116 rotate to the discharge position and the guide position, respectively, thereby improving usability.

[0131] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described, which is different from the first embodiment in that position restriction spring 716 is omitted and the spring pressure of spring 711 is changed. Therefore, a description of the same configuration as the first embodiment will be omitted.

[0132] The spring pressure of the spring 711 according to the fourth embodiment is set so that the position of the guide member 115 when the weight of the guide member 115 and the spring pressure of the spring 711 are balanced is an intermediate position between the discharge position and the first jam clearing position. In other words, when the rear door 131 is opened, the guide member 115 is held in an intermediate position between the discharge position and the first jam clearing position.

[0133] The intermediate position includes the first jam clearing position. That is, when the guide member 115 is located at the first jam clearing position, the weight of the guide member 115 and the biasing force of the spring 711 may be balanced.

[0134] Furthermore, the guide member 115 of the present embodiment is configured to be rotatable from the intermediate position to the second jam clearing position (see FIG. 13) by the user lifting the guide member 115. This can improve the ease of maintenance and jam clearing.

[0135] Furthermore, when the rear door 131 is closed, the guide member 115 located at the intermediate position is pressed by the cam 131f (see FIG. 15(a)) of the rear door 131. As described in the first embodiment, the guide member 115 and the intermediate conveying guide 116 rotate to the ejection position and the guide position, respectively, in conjunction with the operation of closing the rear door 131, thereby improving usability.

[0136] <Other embodiments> The third and fourth embodiments may be combined with the second embodiment. That is, the position restriction spring 716 of the second embodiment may be omitted. Also, the spring pressure of the spring 711 may be changed as described in the fourth embodiment.

[0137] In addition, in any of the above-mentioned embodiments, the process cartridge 1B and the toner cartridge 1C are configured to be detachable from the main body 1A of the apparatus, but this is not limiting. The number of cartridges detachable from the main body 1A of the apparatus can be set arbitrarily, and for example, the process cartridge 1B may be configured to be non-detachable from the main body 1A of the apparatus.

[0138] In addition, in any of the above-described embodiments, the image forming apparatus is configured to directly transfer the toner image from the photosensitive drum 11 to the sheet S, but the present invention is not limited to this. For example, the toner image on the photosensitive drum 11 may be transferred to the sheet S via an intermediate transfer belt. That is, the present invention may be applied not only to image forming apparatuses such as monochrome printers, but also to full-color image forming apparatuses. In addition, the present invention may be applied not only to electrophotographic image forming apparatuses, but also to inkjet image forming apparatuses that form an image on a sheet by ejecting ink liquid from nozzles.

[0139] In addition, in any of the above-described embodiments, the guide member 115 is configured to be restricted by the rear door 131 in the closed state and to move to the first jam processing position in conjunction with the opening of the rear door 131, but this is not limiting. For example, a restricting portion equivalent to the rotation restricting portion 131e of the rear door 131 may be provided separately from the rear door 131, and after the rear door 131 is opened, the restricting portion may be moved to move the guide member 115 to the first jam processing position.

[0140] In the first embodiment, the switching gear spring 712 is used to move the switching gear 701 to the first position, but the present invention is not limited to this. For example, the switching gear spring 712 may be omitted, and the switching gear 701 may be biased toward the first position by a moment generated by the weight of the switching gear 701.

[0141] In addition, in any of the above-described embodiments, the guide member 115 is biased toward the first jam clearing position by the spring 711, but this is not limiting. For example, the guide member 115 may be biased toward the first jam clearing position by its own weight. Furthermore, even if the user opens the rear door 131, the guide member 115 may be held at the discharge position or at a position between the discharge position and the first jam clearing position by its own weight. In this case, the user can operate the guide member 115 to move the guide member 115 to the first jam clearing position or the second jam clearing position.

[0142] The disclosure of the present embodiment also includes the following configuration examples and method examples. (Configuration 1) A device body, an opening / closing member movable between a closed position in which the opening / closing member is closed relative to the device body and an open position in which the opening / closing member is opened relative to the device body; The device body includes: an image forming unit that forms an image on a sheet; a sheet conveying path including a first conveying path and a second conveying path through which a sheet passes; a guide member that is movable between a first guide position for guiding the sheet toward a first conveying path and a second guide position for guiding the sheet toward a second conveying path when the opening / closing member is located at the closed position; A driving source; a guide moving member having a pressing portion, the guide moving member being movable from a first position to a second position upon receiving a driving force from the driving source such that the pressing portion presses a pressed portion of the guide member to move the guide member from the first guide position to the second guide position; When the opening / closing member is located at the open position and the guide moving member is located at the first position, the guide member is movable to a first retracted position to open the sheet transport path, The pressing portion of the guide moving member located at the first position is disposed at a position that does not overlap with a moving trajectory of the pressed portion when the guide member moves between the first guide position, the second guide position, and the first retracted position. 1. An image forming apparatus comprising: (Configuration 2) The guide movement member is configured to be located at the first position when the opening / closing member is located at the open position. 2. The image forming apparatus according to claim 1, (Configuration 3) The device body has a first biasing member that biases the guide moving member toward the first position. 3. The image forming apparatus according to claim 1, wherein the first and second components are arranged in a same plane. (Configuration 4) The guide member moves toward the first retracted position in conjunction with the opening / closing member moving from the closed position to the open position. 4. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction. (Configuration 5) The guide member moves toward the first guide position in association with the movement of the opening / closing member from the open position to the closed position. 5. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction and a second direction. (Configuration 6) The guide moving member is configured to be rotatable. 6. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction and a second direction. (Configuration 7) the drive source is a motor, The guide moving member has a gear portion that receives a driving force from the motor. 7. The image forming apparatus according to configuration 6, (Configuration 8) The device body has a clutch that is provided in a drive transmission path between the motor and the guide moving member and is capable of transitioning between a transmission state in which the drive force of the motor is transmitted to the guide moving member and a non-transmission state in which the drive force of the motor is not transmitted to the moving member. 8. The image forming apparatus according to claim 7, (Configuration 9) When the opening / closing member is in the closed position and the clutch is in the non-transmitting state, the guide moving member is in the first position and the guide member is in the first guide position, When the opening / closing member is located at the closed position, the clutch transitions from the non-transmitting state to the transmitting state, causing the guide moving member to move from the first position to the second position and the guide member to move from the first guide position to the second guide position, In conjunction with the movement of the opening / closing member from the closed position to the open position, the guide member moves toward the first retracted position. 9. The image forming apparatus according to configuration 8, (Configuration 10) The guide moving member is configured to be slidably movable. 6. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction and a second direction. (Configuration 11) The driving source is a solenoid having a plunger that is interlocked with the guide moving member. 11. The image forming apparatus according to claim 10, (Configuration 12) When the opening / closing member is in the closed position and the solenoid is in a de-energized state, the guide moving member is in the first position and the guide member is in the first guide position, When the opening / closing member is located at the closed position, the solenoid transitions from the non-energized state to the energized state, causing the guide movement member to move from the first position to the second position and the guide member to move from the first guide position to the second guide position, In conjunction with the movement of the opening / closing member from the closed position to the open position, the guide member moves toward the first retracted position. 12. The image forming apparatus according to claim 11, (Configuration 13) the apparatus body has a second biasing member that biases the guide member toward the first retracted position, When the opening / closing member is located at the closed position, the guide member is positioned at the first guide position by abutting against the opening / closing member, and when the opening / closing member moves from the closed position to the open position, the guide member moves toward the first retracted position by the biasing force of the second biasing member. 13. The image forming apparatus according to any one of configurations 1 to 12. (Configuration 14) the guide member is movable to a second retracted position on an opposite side to the first guide position and the second guide position with respect to the first retracted position when the opening / closing member is located at the open position, The pressing portion of the guide moving member located at the first position is disposed at a position that does not overlap with a moving trajectory of the pressed portion when the guide member moves among the first guide position, the second guide position, the first retracted position, and the second retracted position. 14. The image forming apparatus according to claim 13, (Configuration 15) the device body has an elastic member that is spaced apart from the guide member that is positioned at the first guide position and the second guide position and that abuts against the guide member that is positioned at the first retracted position, When the guide member is located at the first retracted position, the force that the guide member receives from the elastic member is greater than the force that the guide member receives from the second biasing member, and the guide member elastically deforms the elastic member when the guide member moves from the first retracted position to the second retracted position. 15. The image forming apparatus according to claim 14, (Configuration 16) When the guide member is located at the first retracted position, the weight of the guide member and the biasing force of the second biasing member are balanced. 14. The image forming apparatus according to claim 13, (Configuration 17) The apparatus body has an abutting member that abuts against the guide member located at the first retracted position to position the guide member at the first retracted position. 14. The image forming apparatus according to claim 13, (Configuration 18) The guide member is configured to be rotatable. 18. The image forming apparatus according to any one of configurations 1 to 17. (Configuration 19) The device body includes: a fixing unit that fixes the image formed on the sheet by the image forming unit, onto the sheet; a discharge section that discharges the sheet on which the image has been fixed by the fixing section to the outside of the apparatus; a reversing conveying unit that reverses and conveys the sheet conveyed by the fixing unit; the first conveying path that guides the sheet that has passed through the fixing unit to the discharge unit; the second conveying path in which the reverse conveying section is provided; and a third conveying path that guides the sheet reversed by the reversing conveying unit toward the image forming unit again. 19. The image forming apparatus according to any one of configurations 1 to 18. (Configuration 20) the fixing unit is detachable from the frame of the apparatus body when the opening / closing member is located at the open position and the guide member is located at the first retracted position. 20. The image forming apparatus according to claim 19, (Configuration 21) the image forming unit includes a photoconductor that carries a toner image and a transfer unit that transfers the toner image to a sheet; The driving source drives the photoconductor. 21. The image forming apparatus according to any one of configurations 1 to 20, [Explanation of symbols]

[0143] 1: Image forming apparatus / 1A: Apparatus main body / 1D: Image forming section / 11: Photosensitive body (photosensitive drum) / 30,731: Drive source (motor, solenoid) / 91: Transfer section (transfer roller) / 101: Fixing section / 113: Discharge section (pair of discharge rollers) / 114: Reverse transport section (pair of reversal rollers) / 114s: Abutment member (rotating shaft) / 115: Guide member (guide member) / 115k: Movement trajectory / 115s: Pressed section / 131: Opening / closing member (rear door) / 181: Second transport path (reverse conveying path) / 182: first conveying path (discharge conveying path) / 186: sheet conveying path / 183: third conveying path (double-sided conveying path) / 701, 734: guide moving member (switching gear, switching slider) / 701a: pressing portion / 701g: gear portion / 702: clutch (electromagnetic clutch) / 711: second biasing member (spring) / 712, 735: first biasing member (switching gear spring, separation spring) / 716: elastic member (position regulating spring) / 731a: plunger / S: sheet

Claims

1. The main body of the device, The device comprises an opening / closing member that is movable between a closed position, which is closed relative to the device body, and an open position, which is open relative to the device body. The main body of the aforementioned device is An image forming unit that forms an image on a sheet, A sheet transport path including a first transport path and a second transport path through which the sheet passes, With the opening / closing member in the closed position, a guide member is movable to a first guide position that guides the sheet toward the first transport path and a second guide position that guides the sheet toward the second transport path. Power source and A guide moving member having a pressing portion and configured to be in a first position when the opening / closing member is in the open position, wherein when it moves from the first position to the second position in response to a driving force from the drive source, the pressing portion presses the pressed portion of the guide member, thereby moving the guide member from the first guide position to the second guide position, With the opening / closing member in the open position and the guide moving member in the first position, the guide member is movable to a first retracted position that opens the sheet transport path. The pressing portion of the guide moving member located at the first position is positioned so as not to overlap with the movement trajectory of the pressed portion when the guide member moves between the first guide position, the second guide position, and the first retracted position. An image forming apparatus characterized by the following features.

2. The device body has a first biasing member that biases the guide moving member toward the first position. The image forming apparatus according to feature 1.

3. The guide member moves toward the first retracted position in conjunction with the opening / closing member moving from the closed position to the open position. The image forming apparatus according to feature 1.

4. The guide member moves toward the first guide position in conjunction with the opening / closing member moving from the open position to the closed position. The image forming apparatus according to feature 1.

5. The guide moving member is configured to be rotatable. The image forming apparatus according to feature 1.

6. The aforementioned drive source is a motor, The guide moving member has a gear section that receives driving force from the motor. The image forming apparatus according to feature 5.

7. The main body of the device is provided in the drive transmission path between the motor and the guide moving member and has a clutch that can transition between a transmission state in which the driving force of the motor is transmitted to the guide moving member and a non-transmission state in which the driving force of the motor is not transmitted to the guide moving member. The image forming apparatus according to feature 6.

8. When the opening / closing member is in the closed position and the clutch is in the non-transmission state, the guide moving member is in the first position and the guide member is in the first guide position. With the opening / closing member in the closed position, the clutch transitions from the non-transmission state to the transmission state, causing the guide moving member to move from the first position to the second position and the guide member to move from the first guide position to the second guide position. As the opening / closing member moves from the closed position to the open position, the guide member moves toward the first retracted position. The image forming apparatus according to feature 7.

9. The guide moving member is configured to be slidable, The image forming apparatus according to feature 1.

10. The drive source is a solenoid having a plunger that is interlocked with the guide moving member. The image forming apparatus according to feature 9.

11. When the opening / closing member is in the closed position and the solenoid is de-energized, the guide moving member is in the first position and the guide member is in the first guide position. With the opening / closing member in the closed position, the solenoid transitions from the de-energized state to the energized state, causing the guide moving member to move from the first position to the second position and the guide member to move from the first guide position to the second guide position. As the opening / closing member moves from the closed position to the open position, the guide member moves toward the first retracted position. The image forming apparatus according to feature 10.

12. The device body has a second biasing member that biases the guide member toward the first retracted position, The guide member is positioned at the first guide position by abutting against the opening / closing member when the opening / closing member is in the closed position, and moves toward the first retracted position by the biasing force of the second biasing member when the opening / closing member moves from the closed position to the open position. The image forming apparatus according to feature 1.

13. The guide member is movable to a second retracted position opposite to the first guide position and the second guide position when the opening / closing member is in the open position, The pressing portion of the guide moving member located at the first position is positioned so as not to overlap with the movement trajectory of the pressed portion when the guide member moves between the first guide position, the second guide position, the first retracted position, and the second retracted position. The image forming apparatus according to feature 12.

14. The device body has an elastic member that is spaced apart from the guide members located at the first guide position and the second guide position, and that contacts the guide member located at the first retracted position. When the guide member is in the first retracted position, the force it receives from the elastic member is greater than the force it receives from the second biasing member, causing the elastic member to elastically deform when it moves from the first retracted position to the second retracted position. The image forming apparatus according to feature 13.

15. When the guide member is in the first retracted position, the weight of the guide member and the biasing force of the second biasing member are balanced. The image forming apparatus according to feature 12.

16. The main body of the device has a stopper member that abuts against the guide member located in the first retracted position, thereby positioning the guide member in the first retracted position. The image forming apparatus according to feature 12.

17. The guide member is configured to be rotatable. The image forming apparatus according to feature 1.

18. The main body of the aforementioned device is A fixing unit that fixes the image formed on the sheet by the image forming unit onto the sheet, A discharge unit for discharging the sheet on which the image has been fixed by the fixing unit to the outside of the machine, A reversing conveying unit that reverses and conveys the sheet conveyed by the fixing unit, The first transport path guides the sheet that has passed through the fixing section to the discharge section, The second transport path, on which the reversing transport section is provided, A third transport path guides the sheet, which has been inverted by the inverting transport unit, back toward the image forming unit. The image forming apparatus according to feature 1.

19. The fixing portion is detachable from the frame of the device body when the opening / closing member is in the open position and the guide member is in the first retracted position. The image forming apparatus according to feature 18.

20. The image forming unit includes a photoreceptor that carries a toner image and a transfer unit that transfers the toner image to a sheet. The drive source drives the photoreceptor, The image forming apparatus according to any one of claims 1 to 19.

Images