Image forming apparatus

Abstract

To provide an image forming apparatus that can be reduced in size.SOLUTION: An image forming apparatus comprises: an image forming unit that includes a photoreceptor rotatable centered on a rotation axis extending in a first direction, and a transfer member transferring a toner image to a sheet; a fixing unit; an inversion conveying unit; a conveyance path that guides a sheet inverted by the inversion conveying unit toward the transfer member again; a conveying unit that conveys a sheet on the conveyance path; a driving source that drives the photoreceptor and the conveying unit; and a drive input unit that inputs driving force transmitted from the driving source to the conveying unit. The driving source is arranged between the transfer member and the fixing unit in a second direction parallel to a sheet conveyance direction in the conveying unit. The drive input unit is arranged so as to overlap the driving source in the first direction, to overlap the driving source in a third direction orthogonal to the first direction and the second direction, and not to overlap the driving source in the second direction.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Conventionally, a printer has been proposed that has a process cartridge having a photosensitive drum, and left and right side plates that detachably support the process cartridge (see Patent Document 1). A motor is disposed between the left and right side plates, and the driving force of the motor is transmitted to the main body coupling via a gear train. The process cartridge has a drum coupling that rotates together with the photosensitive drum, and the driving force is transmitted from the motor to the photosensitive drum when the drum coupling engages with the main body coupling. The printer also has a double-sided printing path for transporting a sheet with an image formed on its first side back toward the photosensitive drum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-45375 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for miniaturization of printers capable of printing on both sides of a sheet, such as that disclosed in Patent Document 1.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an image forming apparatus that can be made compact. [Means for solving the problem]

[0006] The present invention is an image forming apparatus comprising: an image forming unit rotatably supported around a rotation axis extending in a first direction, the image forming unit including a photosensitive member carrying a toner image and a transfer member that transfers the toner image to a sheet; a fixing unit that fixes the toner image transferred by the transfer member to the sheet; a reversing conveying unit that inverts and conveys the sheet conveyed by the fixing unit; a conveying path that guides the sheet inverted by the reversing conveying unit back toward the transfer member; a conveying unit that conveys the sheet in the conveying path; a drive source that drives the photosensitive member and the conveying unit; and a drive input unit that inputs a drive force transmitted from the drive source to the conveying unit, wherein the drive source is disposed between the transfer member and the fixing unit in a second direction parallel to the sheet conveying direction in the conveying unit, and the drive input unit is disposed so as to overlap the drive source in the first direction, overlap the drive source in a third direction perpendicular to the first direction and the second direction, and not overlap the drive source in the second direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide an image forming apparatus that can be made compact. [Brief description of the drawings]

[0008] [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. 3 is a cross-sectional view showing the peripheral configuration of the motor. [Figure 4] FIG. 4 is a cross-sectional view showing a cross section taken along line 4A-4A of FIG. 3 . [Diagram 5] FIG. 2 is a perspective view showing the peripheral configuration of a motor. [Figure 6] FIG. 6 is a cross-sectional view showing a cross section taken along line 6A-6A in FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 11 is a cross-sectional view showing an image forming apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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).

[0015] 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.

[0016] 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).

[0017] 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).

[0018] 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.

[0019] The sheet S includes paper such as paper and envelopes, plastic films such as overhead projector sheets (OHP), cloth, and the like.

[0020] 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.

[0021] A transfer roller 91 as a transfer member forms a transfer nip N1 together with the photosensitive drum 11. The 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.

[0022] The discharge / reversal unit 111 includes a guide member 115, a discharge conveyance path 182, a pair of intermediate conveyance rollers 112, a pair of discharge rollers 113, a full-load detection flag 117, a reverse conveyance path 181, a pair of reverse rollers 114, and an intermediate conveyance guide 116. The guide member 115 is supported rotatably around a pivot boss 115p and is configured to be rotatable between a discharge position shown by a solid line in FIG. 1 and a reverse position shown by a broken line in FIG. 1. When the guide member 115 is located at the discharge position, it guides the sheet S sent from the fixing unit 101 toward the discharge conveyance path 182. When the guide member 115 is located at the reverse position, it guides the sheet S sent from the fixing unit 101 toward the reverse conveyance path 181.

[0023] 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.

[0024] The double-sided conveying unit 184 has a double-sided conveying path 183 as a conveying path through which the sheet S conveyed from the reversing conveying path 181 passes, a double-sided conveying guide 160, a double-sided sensor 163, and conveying roller pairs 161 and 162. The double-sided conveying guide 160 forms at least a part of the double-sided conveying path 183 and guides the sheet S. The double-sided sensor 163 detects the position of the leading edge of the sheet S passing through the double-sided conveying path 183. The conveying roller pairs 161 and 162 convey the sheet S passing through the double-sided conveying path 183. The double-sided conveying path 183 has a U-shaped portion 185 curved in a U-shape at a downstream end in the sheet conveying direction, and the sheet S is conveyed to the registration roller pair 81 via the U-shaped portion 185.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The fixing unit 101 controls a heater built into 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 apparatus 1 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.

[0029] 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).

[0030] 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 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 pair of discharge rollers 113 discharges the sheet S outside the machine, and the sheet S is loaded onto a discharge tray 118 formed on the upper surface of the image forming apparatus 1.

[0031] 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.

[0032] 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. In this embodiment, the Z direction parallel to the vertical direction is perpendicular to the Y direction (first direction) and the X direction (second direction).

[0033] 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.

[0034] When toner images are formed on both sides of the sheet S, the guide member 115 is positioned in advance at the reversing position. 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 the reversing conveying path 181 by the guide member 115 positioned at the reversing position. The reversing conveying path 181 is provided with a pair of reversing rollers 114 having a reversing drive roller 114r formed of a rubber roller and a reversing driven roller 114k which rotates driven by the reversing drive 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 reversing position to the discharge position.

[0035] 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.

[0036] The conveying roller pair 161 as the conveying section and the first conveying section is in a stopped state, and the sheet S hits the nip of the conveying roller pair 161 in the stopped state, 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 section 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.

[0037] [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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] 5, 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.

[0042] 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.

[0043] 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, which is the second direction. This allows the image forming apparatus 1 to be more compact in the X direction.

[0044] 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.

[0045] Further, the conveying roller pair 161 is disposed at a position spaced apart from the reversing roller pair 114 by a distance of 210 mm or less along the double-sided conveying path 183. Similarly, the conveying roller pair 162 as the second conveying section 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. The A5 portrait size, which is the minimum size sheet that can be conveyed along 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] [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 with respect 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 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. 4) as the first direction. In addition, the double-sided conveying guide 160 is rotatable about a rotation center 160p, and can open the double-sided conveying path 183.

[0051] 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.

[0052] 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 1B from the apparatus main body 1A. This allows the user to access the jammed sheet S and clear the jam.

[0053] 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.

[0054] 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.

[0055] [Motor placement] Next, the arrangement of the motor 30 will be described with reference to Figs. 1 to 6. Fig. 3 is a cross-sectional view showing the peripheral configuration of the motor 30. Fig. 4 is a cross-sectional view showing the 4A-4A cross section of Fig. 3. Fig. 5 is a perspective view showing the peripheral configuration of the motor 30. Fig. 6 is a cross-sectional view showing the 6A-6A cross section of Fig. 3. Note that the fixing unit 101 has been removed in Fig. 5, and a motor cover unit 43, which will be described later, is not shown in Figs. 1 and 3 so that the arrangement of the motor 30 can be seen.

[0056] As shown in FIG. 1 and FIG. 3, the motor 30 as a driving source is disposed between the transfer roller 91 and the fixing unit 101 as viewed in the X direction. In other words, the motor 30 is disposed between the transfer nip N1 and the fixing nip N2 in the sheet conveying direction CD of the conveying roller pair 161 shown in FIG. 3. The sheet conveying direction CD is the moving direction of the sheet conveyed by the conveying roller pair 161, and is a direction parallel to the X direction. That is, the motor 30 is disposed between the transfer nip N1 and the fixing nip N2 in the X direction as the second direction. In addition, a central frame 42 is disposed above the double-sided conveying guide 160, and the central frame 42 connects a right side plate 40 (see FIG. 6) and a left side plate 41, which will be described later. The motor 30 is disposed so as to overlap the double-sided conveying guide 160 and the central frame 42 as viewed in the X direction, as shown in FIG. 3.

[0057] 3 and 5, an agitating member 23 that rotates to agitate the waste toner in the waste toner storage unit 14 is provided inside the waste toner storage unit 14. The agitating member 23 is driven by an agitation drive unit 24 that is driven by a driving force transmitted from a motor 30. The agitation drive unit 24 is disposed downstream of the waste toner storage unit 14 in the Y2 direction, and is composed of, for example, one gear or multiple gears.

[0058] As shown in FIG. 5, the motor 30 is covered by a motor cover portion 43 that is integrally provided on the central frame 42. More specifically, a rotor portion 30a of the motor 30, which will be described later, is covered by the right side plate 40 and the motor cover portion 43. The motor 30 is disposed close to the photosensitive drum 11 of the process cartridge 1B, but the motor 30 and the motor cover portion 43 are disposed so as not to interfere with the waste toner storage portion 14 and the agitation drive portion 24 in the X1 direction and the Z1 direction. In other words, the motor 30 is disposed so as not to overlap the waste toner storage portion 14 and the agitation drive portion 24 when viewed in the Y direction as shown in FIG. 3. That is, the motor 30 is disposed close to the photosensitive drum 11 while ensuring a space for arranging the waste toner storage portion 14 and the agitation drive portion 24.

[0059] 1, 3 and 4, a cassette 72 serving as a sheet storage section for storing sheets S is disposed below the motor 30 in the vertical direction (Z direction). The cassette 72 is provided with a pair of side regulating plates 76 serving as a sheet regulating section for regulating the position in the X direction of the sheets S supported by a middle plate 74. The device main body 1A is provided with a cassette case 75 for holding the cassette 72 so that it can be inserted and removed, and the motor 30 is disposed so as to ensure a space for arranging the cassette case 75.

[0060] Furthermore, the motor 30 and the motor cover part 43 are arranged so as to overlap part of the cassette 72 and the side regulating plate 76 when viewed in the Y direction. Also, as shown in FIG. 4, the motor 30 is arranged so as not to overlap the cassette 72 and the side regulating plate 76 when viewed in the X direction, but the motor cover part 43 partially overlaps the side regulating plate 76 in the Y direction. That is, the motor 30 is arranged close to the sheets S accommodated in the cassette 72 in the Y direction while ensuring a space for arranging the cassette 72 and the side regulating plate 76. Note that the cassette 72 refers only to a box-shaped cassette body that accommodates the sheets S, and does not include, for example, a decorative cover attached to the front of the cassette body.

[0061] 1 and 3, the apparatus body 1A is provided with a fan 35 that cools the motor 30 by blowing air to the motor 30. The fan 35 is disposed between a right side plate 40 and a left side plate 41 (described later) in the Y direction, and is supported on the inner surface of the right side plate 40. The fan 35 is disposed below the fixing unit 101 and the double-sided conveying path 183 in the vertical direction (Z direction).

[0062] [Arrangement of conveyor roller pairs] 3 and 6, the arrangement of the conveying roller pair 161 and its surrounding configuration that conveys the sheet S in the double-sided conveying path 183 will be described in detail. As shown in Fig. 3, the conveying roller pair 161 is disposed between the motor 30 and the fixing unit 101 when viewed in the X direction. In other words, the conveying roller pair 161 is disposed between the motor 30 and the fixing nip N2 in the sheet conveying direction CD.

[0063] The fixing unit 101 can be removed from the apparatus main body 1A in the X2 direction by opening the rear door 131. Since the conveying roller pair 161 is disposed upstream of the fixing unit 101 in the X2 direction, the conveying roller pair 161 does not interfere with the fixing unit 101 when the fixing unit 101 is attached to or detached from the apparatus main body 1A. This improves the ease of replacement and maintenance of the fixing unit 101.

[0064] The conveying roller pair 161 has a roller shaft 161b and a roller portion 161a fixed to the roller shaft 161b. A roller gear 513 is fixed to the downstream end of the roller shaft 161b in the Y2 direction as a drive input portion that inputs a drive force from the motor 30 to the roller shaft 161b. As shown in Fig. 6, the roller gear 513 is arranged so as to overlap the motor 30 in the Y direction but not to overlap the motor 30 in the X direction. This allows the roller gear 513 and the motor 30 to be arranged near the end in the Y direction of the sheet S passing through the double-sided conveying path 183, and the image forming apparatus 1 can be made smaller in size in the Y direction.

[0065] 8, which will be described later, the roller gear 513 overlaps the motor 30 in the vertical direction (Z direction). Furthermore, as shown in Fig. 3, the roller gear 513 and the pair of conveying rollers 161 overlap a part of the fixing unit 101 (e.g., the fixing frame 105) in the X direction and the Z direction. This allows the fixing unit 101, the motor 30, the pair of conveying rollers 161, and the roller gear 513 to be disposed close to the cassette 72 in the vertical direction (Z direction), and the image forming apparatus 1 can be made compact.

[0066] [Motor mounting configuration] Next, the mounting structure of the motor 30 will be described with reference to Figures 4, 6 and 7. Figure 7 is an exploded perspective view showing the mounting structure of the motor 30. As shown in Figure 6, the device body 1A has a right side plate 40 as a first side plate that supports the motor 30, and a left side plate 41 as a second side plate that is disposed on the opposite side to the right side plate 40 across the double-sided conveying path 183 in the Y direction.

[0067] As shown in Figures 4, 6 and 7, the motor 30 has a rotor unit 30a that generates a driving force, an output shaft 30b that rotates together with the rotor unit 30a, and a pinion gear 31 fixed to the output shaft 30b as a drive transmission member. The motor 30 has a stator (not shown) that does not rotate, and when the motor 30 is energized, the rotor unit 30a rotates together with the output shaft 30b and the pinion gear 31. The motor 30 is, 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.

[0068] The motor 30 is fixed to a motor mounting plate 32 by a motor screw 33. A through hole 32a is formed in the motor mounting plate 32, and the pinion gear 31 passes through the through hole 32a and is disposed on the opposite side of the motor mounting plate 32 from the rotor portion 30a. The motor mounting plate 32 is fixed to the right side plate 40 by a screw 34 from the downstream side in the Y2 direction.

[0069] As a result, the pinion gear 31 of the motor 30 protrudes downstream of the right side plate 40 in the Y2 direction, and the rotor unit 30a is disposed upstream of the right side plate 40 in the Y2 direction. In other words, the pinion gear 31 is disposed on the opposite side of the right side plate 40 from the left side plate 41 in the Y direction, and the rotor unit 30a is disposed on the same side of the right side plate 40 as the left side plate 41 in the Y direction. At this time, the rotor unit 30a passes through an opening 40a provided in the right side plate 40 and is disposed inside the image forming apparatus 1 relative to the right side plate 40, and is covered by the motor cover unit 43. This prevents the rotor unit 30a from contacting the cassette 72, the side regulating plate 76, the sheets S accommodated in the cassette 72, and the like.

[0070] Also, since the rotor portion 30a of the motor 30 is disposed inside the image forming apparatus 1 in the Y direction relative to the right side plate 40, the image forming apparatus 1 can be made smaller in size in the Y direction. Furthermore, the motor 30 is supported by the right side plate 40 by fixing the motor mounting plate 32 to the right side plate 40 from the downstream side in the Y2 direction using screws 34. Therefore, by removing the screws 34 from the downstream side of the right side plate 40 in the Y2 direction, i.e., from the outside of the image forming apparatus 1 in the Y direction, the motor 30 and the motor mounting plate 32 can be removed from the right side plate 40. This improves the maintainability of the motor 30.

[0071] [Drive transmission section] Next, the drive transmission unit 501 that transmits the driving force of the motor 30 will be described with reference to Fig. 8. Fig. 8 is a rear view showing the drive transmission unit 501. That is, Fig. 8 is a view of the drive transmission unit 501 supported on the right side plate 40, as viewed from the upstream side in the Y1 direction. Note that in Fig. 8, the gear train that transmits the drive force from the motor 30 to the sheet feeding unit 70 and the discharging / reversing unit 111 is omitted.

[0072] 8, the drive transmission unit 501 has a plurality of gears and transmits the drive force of the pinion gear 31 of the motor 30 to the photosensitive drum 11, the pressure roller 103, the pair of conveying rollers 161, etc. In the drive transmission unit 501, a drum drive gear 503 as an output gear and one idler gear 521 are provided on a path for transmitting the drive force from the pinion gear 31 to the photosensitive drum 11. The drum drive gear 503 as an output gear outputs a drive force to the photosensitive drum 11 via a gear coupling (not shown). The idler gear 521 meshes with the pinion gear 31 and the drum drive gear 503, and transmits the drive force of the motor 30 to the drum drive gear 503.

[0073] Here, the motor described in the above-mentioned Patent Document 1 (JP 2016-45375 A) is disposed away from the photosensitive drum, and the gear train for transmitting the driving force of the motor to the photosensitive drum includes a drum drive gear and a plurality of idler gears. When the photosensitive drum and the motor are disposed away from each other in this way, the number of gears for transmitting the driving force of the motor to the photosensitive drum increases. Then, the rotation speed of the photosensitive drum becomes unstable due to the influence of speed fluctuations caused by the meshing of each gear, and there is a risk of image defects such as image unevenness occurring.

[0074] On the other hand, the motor 30 of the present embodiment is disposed close to the photosensitive drum 11 in the X direction, and only one idler gear 521 is provided between the pinion gear 31 of the motor 30 and the drum drive gear 503 that outputs a drive force to the photosensitive drum 11. This makes it possible to suppress the effect of speed fluctuations caused by the meshing of each gear in the drive transmission path from the pinion gear 31 to the drum drive gear 503, and to rotate the photosensitive drum 11 at a stable speed. This makes it possible to suppress image defects such as image unevenness and form a high-quality image on the sheet.

[0075] In addition, in the drive transmission unit 501, a path for transmitting the drive from the pinion gear 31 to the pressure roller 103 includes a first gear train 523 including a gear 522 meshing with the pinion gear 31, and a pressure roller gear 504. The pressure roller gear 504 outputs a drive force to the pressure roller 103 of the fixing unit 101. The drive force of the pinion gear 31 of the motor 30 is transmitted to the pressure roller gear 504 via the first gear train 523. In addition, in the drive transmission unit 501, a path for transmitting the drive from the pinion gear 31 to the conveying roller pair 161 includes a second gear train 524 meshing with the gear 522, an electromagnetic clutch 511, a clutch output gear 512, and a roller gear 513. The roller gear 513 outputs a drive force to the conveying roller pair 161. The driving force of the pinion gear 31 is transmitted to the roller gear 513 via the gear 522 , the second gear train 524 , the electromagnetic clutch 511 and the clutch output gear 512 .

[0076] The electromagnetic clutch 511 can be in a conducting or non-conducting state to disconnect or connect the driving between the second gear train 524 and the clutch output gear 512. This allows the conveying roller pair 161 to rotate and stop while the motor 30 is driven.

[0077] The drive transmission unit 501 is disposed in the Y direction between the right side plate 40 and an exterior (not shown) of the image forming apparatus 1. The pinion gear 31 of the motor 30 is disposed on the outer side of the right side plate 40 in the Y direction, and the rotor unit 30a of the motor 30 is disposed on the inner side of the right side plate 40 in the Y direction, so that the image forming apparatus 1 can be made compact in the Y direction.

[0078] 6, a drive transmission mechanism 600 is provided on the opposite side of the double-sided conveying path 183 from the motor 30 and the drive transmission unit 501 in the Y direction. The drive transmission mechanism 600 is disposed between the left side plate 41 and the double-sided conveying path 183 in the Y direction, and transmits the drive force input from the motor 30 to the conveying roller pair 161 via the drive transmission unit 501 to the conveying roller pair 162.

[0079] The conveying roller pair 162 has a roller shaft 162b and a roller portion 162a fixed to the roller shaft 162b. The drive transmission mechanism 600 has a pulley 514, a pulley gear 516, a timing belt 515, and a roller drive gear 517. The pulley 514 is fixed to the end of the roller shaft 161b of the conveying roller pair 161 opposite to the roller gear 513, i.e., the downstream end in the Y1 direction. The roller drive gear 517 is fixed to the downstream end of the roller shaft 162b in the Y1 direction.

[0080] The timing belt 515 is wound around the pulley 514 and a pulley portion of the pulley gear 516, and transmits the rotation of the pulley 514 to the pulley gear 516. The gear portion of the pulley gear 516 is meshed with the roller drive gear 517. That is, the driving force transmitted from the motor 30 to the conveying roller pair 161 is transmitted to the conveying roller pair 162 via the pulley 514, the timing belt 515, the pulley gear 516, and the roller drive gear 517. Thus, the conveying roller pairs 161 and 162 are driven in conjunction with each other. Therefore, when the conveying roller pair 161 is stopped by the electromagnetic clutch 511 cutting off the drive, the conveying roller pair 162 is also stopped. Also, when the conveying roller pair 161 is rotating by the electromagnetic clutch 511 connecting the drive, the conveying roller pair 162 is also rotated.

[0081] By positioning the drive transmission mechanism 600 on the opposite side of the motor 30 across the double-sided conveying path 183 in the Y direction, the space between the double-sided conveying path 183 and the left side plate 41 can be effectively utilized, and the image forming device 1 can be made smaller in size in the Y direction.

[0082] As described above, in this embodiment, the motor 30 is disposed between the transfer roller 91 and the fixing unit 101 when viewed in the Y direction, and is disposed close to the photosensitive drum 11. At this time, the motor 30 is disposed so as not to interfere with the waste toner storage unit 14 and the agitation drive unit 24 in the X1 and Z1 directions. In addition, the motor 30 is disposed so as not to interfere with the cassette 72 and the side regulating plate 76 in the X1 and Z2 directions.

[0083] In this way, by disposing the motor 30 close to the photosensitive drum 11, the pinion gear 31 of the motor 30 and the drum drive gear 503 are drive-coupled by only one idler gear 521. This makes it possible to suppress the effects of speed fluctuations caused by the meshing of the gears in the drive transmission path from the pinion gear 31 to the drum drive gear 503, and to rotate the photosensitive drum 11 at a stable speed. This makes it possible to suppress image defects such as image unevenness and form a high-quality image on the sheet.

[0084] Furthermore, in this embodiment, a pair of conveying rollers 161 is disposed between the motor 30 and the fixing unit 101 as viewed in the Y direction. The rotor unit 30a of the motor 30 is disposed on the inside of the right side plate 40, so that the motor 30 is disposed close to the sheets S accommodated in the cassette 72 in the Y direction. The roller gear 513 is disposed so as to overlap the motor 30 in the Y direction. Furthermore, a drive transmission mechanism 600 that drives and connects the pair of conveying rollers 161, 162 is disposed by utilizing the space between the double-sided conveying path 183 and the left side plate 41 in the Y direction. This allows the image forming apparatus 1 to be made smaller in size in the Y direction.

[0085] In addition, in this embodiment, the conveying roller pairs 161, 162 are arranged to overlap in the Z direction, and the roller gear 513 is arranged to overlap the motor 30 in the Z direction. The roller gear 513 and the conveying roller pair 161 overlap a part of the fixing unit 101 (e.g., a fixing frame) in the Y direction. This allows the fixing unit 101, the motor 30, the conveying roller pair 161, 162, and the roller gear 513 to be arranged close to the cassette 72 in the vertical direction (Z direction), and the image forming apparatus 1 can be made smaller in size in the Z direction.

[0086] Further, a pair of conveying rollers 161, 162 are arranged so that sheets of A5 portrait size, A4 size, LTR size, etc. can be stably conveyed on the double-sided conveying path 183. This allows the image forming apparatus 1 to be configured to be compact while being capable of double-sided printing on sheets of various sizes.

[0087] <Second embodiment> Next, a second embodiment of the present invention will be described, which differs from the image forming apparatus 1 of the first embodiment in the shape of the transport path and the arrangement of each component. In the following, configurations having the same functions as those of the image forming apparatus 1 of the first embodiment will be described with the same reference numerals in the drawings or omitted from illustration.

[0088] FIG. 9 is a schematic overall view showing an image forming apparatus 201 as viewed in the Y direction. As shown in FIG. 9, the image forming apparatus 201 according to the second embodiment has an apparatus main body 1A and a process cartridge 1B detachably supported by the apparatus main body 1A. The sheet feeding section 70, the photosensitive drum 11, the fixing section 101, and the discharge / reversal unit 111 provided in the apparatus main body 1A are arranged in a vertical direction (Z direction). That is, in this embodiment, the Y direction as the first direction is the same as in the first embodiment, but the second direction parallel to the sheet conveying direction CD in the conveying roller pair 161 corresponds to the Z direction. In addition, the third direction perpendicular to the first and second directions corresponds to the X direction.

[0089] The motor 30 is disposed between the transfer roller 91 and the fixing unit 101 as viewed in the Y direction, and is disposed so as not to interfere with the process cartridge 1B. In other words, the motor 30 is disposed between the transfer roller 91 and the fixing unit 101 in the Z direction. A pair of conveying rollers 161 and 162 is disposed in the double-sided conveying path 183, and the pair of conveying rollers 161 is disposed between the fixing unit 101 and the motor 30 as viewed in the Y direction. The pair of conveying rollers 161 is disposed so as to at least partially overlap the fixing unit 101 and the motor 30 in the X direction.

[0090] 9, the apparatus body 1A of the image forming apparatus 201 has a right side plate 40 and a left side plate 41 (see FIG. 6), and the rotor portion 30a of the motor 30 is disposed on the inside of the apparatus of the right side plate 40 in the Y direction, similar to the first embodiment. Furthermore, the roller gear 513 that inputs a driving force to the conveying roller pair 161 is disposed so as to overlap the motor 30 in the Y direction, overlap the motor 30 in the X direction, and not overlap the motor 30 in the Z direction.

[0091] In addition, since the motor 30 is disposed close to the photosensitive drum 11, the same effect as in the first embodiment is achieved. That is, the effect of speed fluctuations caused by meshing of the gears in the drive transmission path from the pinion gear 31 to the drum drive gear 503 can be suppressed, and the photosensitive drum 11 can be rotated at a stable speed. Therefore, image defects such as image unevenness can be suppressed, and a high-quality image can be formed on the sheet.

[0092] Furthermore, the configuration for miniaturizing the image forming apparatus 201 in the Y and Z directions is also the same as in the first embodiment. Also, conveying roller pairs 161, 162 are arranged so that sheets of A5 portrait size, A4 size, LTR size, etc. can be stably conveyed on the double-sided conveying path 183. This allows the image forming apparatus 201 to be configured to be compact while being capable of double-sided printing on sheets of various sizes.

[0093] <Other embodiments> 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.

[0094] In addition, in any of the above-described embodiments, the driving force is transmitted from the drum driving gear 503 to the photosensitive drum 11 using a gear coupling, but this is not limiting. For example, instead of the gear coupling, another coupling such as an Oldham coupling may be used.

[0095] In addition, in all of the embodiments described above, the motor 30 is attached from the outside of the right side plate 40 using the motor mounting plate 32, but this is not limiting. For example, the motor 30 may be attached from the inside of the right side plate 40 without using the motor mounting plate 32.

[0096] In addition, in any of the above-described embodiments, the fan 35 blows air to the motor 30 to cool the motor 30, but the fan 35 may cool an object to be cooled other than the motor 30. For example, the object to be cooled may be the process cartridge 1B, the fixing unit 101, the sheet S conveyed through the discharge / reversal unit 111, or the like.

[0097] In addition, in any of the embodiments described above, the drive transmission mechanism 600 transmits the drive force using the pulley 514 and the timing belt 515, but is not limited to this. For example, the drive transmission mechanism 600 may transmit the drive force using a gear train.

[0098] In addition, in any of the above-described embodiments, the drive transmission unit 501 is configured to transmit the drive force using a plurality of gears, but is not limited to this. For example, a pinion pulley may be used instead of the pinion gear 31, and the drive transmission unit 501 may be configured to transmit the drive force by a timing belt wound around the pinion pulley.

[0099] 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. In other words, the present invention may be applied not only to image forming apparatuses such as monochrome printers, but also to full-color image forming apparatuses.

[0100] The disclosure of the present embodiment also includes the following configuration examples and method examples. (Configuration 1) an image forming section that is rotatably supported around a rotation axis extending in a first direction and includes a photoconductor that carries a toner image and a transfer member that transfers the toner image to a sheet; a fixing section for fixing the toner image transferred by the transfer member onto a sheet; a reversing conveying unit that reverses and conveys the sheet conveyed by the fixing unit; a conveying path that guides the sheet reversed by the reversing conveying unit toward the transfer member again; a conveying section that conveys a sheet in the conveying path; a drive source that drives the photoconductor and the transport unit; a drive input unit that inputs a drive force transmitted from the drive source to the transport unit, the driving source is disposed between the transfer member and the fixing unit in a second direction parallel to a sheet conveying direction in the conveying unit, the drive input portion is disposed so as to overlap the drive source in the first direction, to overlap the drive source in a third direction perpendicular to the first direction and the second direction, and not to overlap the drive source in the second direction. 1. An image forming apparatus comprising: (Configuration 2) the drive source includes a rotor unit that generates a drive force, an output shaft that rotates together with the rotor unit, and a drive transmission member that is fixed to the output shaft; A first side plate supporting the driving source; a second side plate disposed on an opposite side of the first side plate across the transport path in the first direction, The drive transmission member is disposed on an opposite side of the first side plate from the second side plate in the first direction. 2. The image forming apparatus according to claim 1, (Configuration 3) the drive transmission member is a pinion gear, an output gear for outputting a driving force to the photoconductor; and an idler gear that meshes with the pinion gear and the output gear and transmits the driving force of the driving source to the output gear. 3. The image forming apparatus according to claim 2, (Configuration 4) The rotor portion is disposed between the first side plate and the transport path in the first direction. 4. The image forming apparatus according to claim 2 or 3. (Configuration 5) The transport unit is a first transport unit, a second conveying section that conveys the sheet conveyed by the first conveying section toward the transfer member in the conveying path; a drive transmission mechanism that transmits a drive force input from the drive source to the first transport section via the drive input section to the second transport section, The drive transmission mechanism is disposed between the second side plate and the transport path in the first direction. 5. The image forming apparatus according to claim 2, wherein the first and second electrodes are arranged in a first direction. (Configuration 6) Further, a fan is provided to blow air to the driving source to cool the driving source, the fan is disposed between the first side plate and the second side plate in the first direction, and is disposed below the fixing unit and the transport path. 6. The image forming apparatus according to any one of configurations 2 to 5. (Configuration 7) the conveying unit is disposed between the driving source and the fixing unit as viewed in the first direction. 7. The image forming apparatus according to any one of configurations 1 to 6. (Configuration 8) a sheet storage section for storing a sheet; a sheet regulating portion provided in the sheet accommodating portion and regulating a position of the sheet supported in the sheet accommodating portion in the first direction, The driving source is disposed so as not to overlap the sheet regulating portion when viewed in the second direction. 8. 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 9) the image forming unit has a waste toner storage unit that stores toner remaining on the photoconductor after the toner image is transferred onto a sheet by the transfer member, The driving source is disposed so as not to overlap with the waste toner storage unit when viewed in the first direction. 9. The image forming apparatus according to any one of configurations 1 to 8. [Explanation of symbols]

[0101] 1,201: image forming apparatus / 1D: image forming section / 11: photosensitive body (photosensitive drum) / 11a: rotating shaft / 14: waste toner storage section / 30: driving source (motor) / 30a: rotor section / 30b: output shaft / 31: driving transmission member, pinion gear / 35: fan / 40: first side plate (right side plate) / 41: second side plate (left side plate) / 72: sheet storage section (cassette) / 76: sheet regulation section (side regulation plate) / 91: transfer member ( transfer roller) / 101: fixing section / 114: reverse conveying section (reverse roller pair) / 161: conveying section, first conveying section (conveying roller pair) / 162: second conveying section (conveying roller pair) / 183: conveying path (double-sided conveying path) / 503: output gear (drum driving gear) / 513: drive input section (roller gear) / 521: idler gear / 600: drive transmission mechanism / S: sheet / X: second direction / Y: first direction / Z: third direction (vertical direction)

Claims

1. An image forming unit that is rotatable around a rotation axis extending in a first direction and includes a photoreceptor that carries a toner image and a transfer member that transfers the toner image onto a sheet, A fixing unit that fixes the toner image transferred by the transfer member onto the sheet, A reversing conveying unit that reverses and conveys the sheet conveyed by the fixing unit, A conveying path that guides the sheet, which has been inverted by the inversion conveying unit, back toward the transfer member, A conveying unit for conveying a sheet along the aforementioned conveying path, comprising a roller shaft and a roller portion fixed to the roller shaft, A drive source that drives the photoreceptor and the transport unit, The system includes a drive input unit attached to the roller shaft, which inputs the driving force transmitted from the drive source to the conveying unit, The drive source is positioned between the transfer member and the fixing unit in a second direction parallel to the sheet transport direction in the transport unit. In the first direction, at least a portion of the drive input section and at least a portion of the drive source are in the same position, and in the third direction perpendicular to the first and second directions, at least a portion of the drive input section and at least a portion of the drive source are in the same position. In the second direction, the drive input unit and the drive source are arranged at positions far apart from each other. An image forming apparatus characterized by the following features.

2. An image forming unit comprising a photoreceptor that is rotatable about a rotation axis extending in a first direction and carries a toner image, and a transfer member that transfers a toner image to a sheet, A fixing unit that fixes the toner image transferred by the transfer member onto a sheet, A reversing conveying unit that reverses and conveys the sheet conveyed by the fixing unit, A conveying path that guides the sheet, which has been inverted by the inversion conveying unit, back toward the transfer member, A conveying unit for conveying a sheet along the aforementioned conveying path, the conveying unit having a roller shaft and a roller portion fixed to the roller shaft, A drive source that drives the photoreceptor and the transport unit, The system includes a drive input unit attached to the roller shaft, which inputs the driving force transmitted from the drive source to the conveying unit, The drive source is positioned between the transfer member and the fixing unit in a second direction parallel to the horizontal direction and perpendicular to the first direction. In the first direction, at least a portion of the drive input section and at least a portion of the drive source are in the same position, and in the third direction perpendicular to the first and second directions, at least a portion of the drive input section and at least a portion of the drive source are in the same position. In the second direction, the drive input unit and the drive source are arranged at positions far apart from each other. An image forming apparatus characterized by the following features.

3. The drive source comprises a rotor section that generates driving force, and an output shaft that rotates together with the rotor section and is equipped with a drive transmission section. The first side plate supporting the drive source, The first direction further comprises a second side plate positioned on the opposite side from the first side plate across the transport path, The drive transmission unit is positioned in the first direction on the side opposite to the second side plate relative to the first side plate. The image forming apparatus according to claim 1 or 2.

4. The aforementioned drive transmission unit is a pinion gear, An output gear that outputs driving force to the photoreceptor, The system further comprises an idler gear that meshes with the pinion gear and the output gear and transmits the driving force of the drive source to the output gear. The image forming apparatus according to feature 3.

5. The rotor portion is positioned between the first side plate and the transport path in the first direction. The image forming apparatus according to feature 3.

6. The transport unit is the first transport unit, A second conveying unit conveys the sheet conveyed by the first conveying unit toward the transfer member along the conveying path, The system further includes a drive transmission mechanism that transmits the driving force input from the drive source to the first transport unit via the drive input unit to the second transport unit, The drive transmission mechanism is arranged between the second side plate and the transport path in the first direction. The image forming apparatus according to feature 3.

7. The system further includes a fan that cools the drive source by blowing air onto it. The fan is positioned between the first side plate and the second side plate in the first direction, and below the fixing section and the transport path. The image forming apparatus according to feature 3.

8. In the first direction, at least a part of the drive input section and at least a part of the rotor section are in the same position, The image forming apparatus according to feature 3.

9. The transport unit is positioned between the drive source and the fixing unit when viewed in the first direction. The image forming apparatus according to claim 1 or 2.

10. A seat storage section for storing the seat, The sheet storage section is further provided with a sheet regulating section that restricts the position of the sheet supported by the sheet storage section in the first direction, The drive source is positioned such that, when viewed in the second direction, it does not overlap the seat restricting portion. The image forming apparatus according to claim 1 or 2.

11. The image forming unit has a waste toner storage unit that stores toner remaining on the photoreceptor after the toner image has been transferred to the sheet by the transfer member. The drive source is positioned such that, when viewed in the first direction, it does not overlap the waste toner storage section. The image forming apparatus according to claim 1 or 2.

12. The drive source comprises a rotor section that generates driving force, and an output shaft that rotates together with the rotor section and is equipped with a drive transmission section, In the first direction, at least a portion of the drive input section and at least a portion of the rotor section are in the same position. The image forming apparatus according to claim 1 or 2.

13. The drive transmission unit is a pinion gear, An output gear that outputs driving force to the photoreceptor, The system further comprises an idler gear that meshes with the pinion gear and the output gear and transmits the driving force of the drive source to the output gear. The image forming apparatus according to feature 12.

14. The transport unit is positioned between the drive source and the fixing unit when viewed in the first direction. The image forming apparatus according to feature 12.

15. A sheet storage section for storing a sheet, The sheet storage section is further provided with a sheet regulating section that restricts the position of the sheet supported by the sheet storage section in the first direction, The drive source is positioned such that, when viewed in the second direction, it does not overlap the seat restricting portion. The image forming apparatus according to feature 12.

16. The image forming unit has a waste toner storage unit that stores toner remaining on the photoreceptor after the toner image has been transferred to the sheet by the transfer member, The drive source is positioned such that, when viewed in the first direction, it does not overlap the waste toner storage section. The image forming apparatus according to feature 12.

Images