Image forming device

Abstract

To provide an image formation apparatus which can make a region occupied by a supply path and a discharge path in the horizontal direction narrower in comparison to a case where the supply path through which a recording medium conveyed to an image formation unit passes through and the discharge path through which the recording medium discharged from the image formation unit to the outside of the apparatus body are apart from each other in the horizontal direction.SOLUTION: A first conveyance unit conveys a recording medium along a supply path extending from one side to the other side in the horizontal direction to an image formation unit. A second conveyance unit conveys the recording medium along a discharge path which extends from the other side to the one side in the horizontal direction from the image formation unit to the outside of the apparatus body and at least a portion of which overlaps at least a portion of the supply path in the vertical direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent document 1 describes a transfer paper transport device that moves a recording head having an array of light-emitting elements and an imaging system at a constant speed in the approximate direction of the generatrix of a photosensitive drum that rotates at a constant speed, scans the photosensitive drum spirally to form a latent image, and develops this toner image to transfer it to transfer paper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 59-7966 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional image forming apparatus, an image forming unit that forms a toner image on a recording medium and a supply path through which the recording medium passes as it is transported toward the image forming unit are sometimes arranged horizontally side by side. Also, the image forming unit and a discharge path through which the recording medium passes as it is discharged from the image forming unit to the outside of the apparatus body after the toner image is formed are sometimes arranged horizontally side by side. In such an image forming apparatus, the supply path and the discharge path are spaced apart horizontally, resulting in a large area occupied by the supply path and the discharge path.

[0005] The object of the present invention is to narrow the area occupied by the supply path and the discharge path in the horizontal direction compared to when the supply path through which the recording medium transported to the image forming unit passes and the discharge path through which the recording medium passes from the image forming unit to the outside of the device main body are separated in the horizontal direction. [Means for solving the problem]

[0006] An image forming apparatus according to a first aspect of the present invention is characterized by comprising: an image forming unit that forms a toner image on a recording medium; a first conveying unit that conveys the recording medium along a supply path that extends from one side to the other side in a horizontal direction to the image forming unit; and a second conveying unit that conveys the recording medium along a discharge path that extends from the image forming unit to the outside of the apparatus main body in a horizontal direction from the other side to one side, at least a portion of which overlaps with at least a portion of the supply path in a vertical direction.

[0007] An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, characterized in that the discharge path is disposed above the supply path in the vertical direction.

[0008] An image forming apparatus according to a third aspect of the present invention is characterized in that, in the image forming apparatus according to the second aspect, it is provided with a storage section that is arranged below the discharge path in the vertical direction and that stores the recording medium to be sent to the supply path.

[0009] An image forming apparatus according to a fourth aspect of the present invention is an image forming apparatus according to any one of the first to third aspects, characterized in that it comprises a third conveying unit that conveys a recording medium along an inversion path that branches off from a midpoint of the discharge path, extends from the other side to one side in the horizontal direction, and also extends from one side to the other side in the horizontal direction to join a midpoint of the supply path, and in the vertical direction, the inversion path is arranged between the supply path and the discharge path.

[0010] An image forming apparatus according to a fifth aspect of the present invention is an image forming apparatus according to any one of the first to third aspects, characterized in that it comprises a third conveying unit that conveys a recording medium along an inversion path that branches off from a portion midway through the discharge path and joins a portion midway through the supply path, and in which the front and back of the recording medium sent out to the supply path are inverted, and in the vertical direction, the inversion path is arranged between the supply path and the discharge path.

[0011] An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to the fourth or fifth aspect, characterized in that the third conveying unit conveys the recording medium from the other side to one side in the horizontal direction, stops the conveying, and then conveys the recording medium from one side to the other side in the horizontal direction, and is provided with a measuring unit that measures the size of the recording medium in a state where the conveying has been stopped by the third conveying unit.

[0012] An image forming apparatus according to a seventh aspect of the present invention is an image forming apparatus according to any one of the fourth to sixth aspects, characterized in that the portion of the supply path extending to one side of the image forming unit, the portion of the discharge path extending to one side of the image forming unit, and the third conveying unit are positioned horizontally offset from the image forming unit and overlap each other vertically. An image forming apparatus according to an eighth aspect of the present invention is the image forming apparatus according to the seventh aspect, characterized in that the image forming apparatus has multiple housings, and the supply path, the discharge path, and the reversal path are arranged in the same housing.

[0013] An image forming apparatus according to a ninth aspect of the present invention is characterized in that, in the image forming apparatus according to any one of the fourth to eighth aspects, the reversing path is provided with a turning path in which the conveying direction of the recording medium is reversed, and the turning path is positioned at a position lower than the vertical top of the image forming unit.

[0014] An image forming apparatus according to a 10th aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, characterized in that the first conveying section overlaps the image forming section in the vertical direction, and the second conveying section is arranged so as not to overlap the image forming section in the vertical direction. [Effects of the Invention]

[0015] In the image forming device according to the first aspect of the present invention, the area occupied by the supply path and the discharge path in the horizontal direction can be narrowed compared to when the supply path through which the recording medium transported to the image forming unit passes and the discharge path through which the recording medium passes from the image forming unit to the outside of the device body are separated in the horizontal direction.

[0016] In the image forming apparatus according to the second aspect of the present invention, the position of the discharge section from which the recording medium is discharged outside the apparatus body can be higher than when the discharge path is arranged below the supply path.

[0017] In the image forming apparatus according to the third aspect of the present invention, the area occupied by the storage unit and the discharge path in the horizontal direction can be narrowed compared to when the storage unit and the discharge path are separated in the horizontal direction.

[0018] In the image forming apparatus according to the fourth aspect of the present invention, the area between the supply path and the discharge path can be used more effectively than when the area between the supply path and the discharge path and the reversal path are separated horizontally.

[0019] In the image forming apparatus according to the fifth aspect of the present invention, the area between the supply path and the discharge path can be used more effectively than when the area between the supply path and the discharge path and the reversal path are separated horizontally.

[0020] In the image forming apparatus according to the sixth aspect of the present invention, it is possible to obtain a configuration in which it is not necessary to stop the conveyance of the recording medium just for the measurement.

[0021] In the image forming apparatus according to the seventh aspect of the present invention, the height of the image forming apparatus body does not increase compared to when the portion of the supply path extending to one side of the image forming unit, the portion of the discharge path extending to one side of the image forming unit, and the third conveying section overlap vertically with the image forming unit. In the image forming apparatus according to the eighth aspect of the present invention, adjustment of the reversing path when installing the image forming apparatus can be simplified compared to when the reversing path is located in a housing different from the supply path or discharge path.

[0022] In the image forming apparatus according to the ninth aspect of the present invention, the height of the image forming apparatus body does not increase compared to when the turning path is positioned higher than the vertical top of the image forming unit.

[0023] In the image forming apparatus according to the tenth aspect of the present invention, the height of the image forming apparatus body does not increase compared to when the first conveying section and the second conveying section overlap the image forming section in the vertical direction. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a side view showing a paper feed mechanism, a paper discharge mechanism, and the like of an image forming apparatus according to an embodiment of the present invention; [Figure 2] 1 is a side view showing an image forming unit of an image forming apparatus according to an embodiment of the present invention; [Figure 3] 2 is a side view showing a fixing device in an image forming unit of the image forming apparatus according to the exemplary embodiment of the present invention. FIG. [Figure 4] 2 is a side view showing a supply path in a paper feed mechanism and a discharge path in a paper discharge mechanism of the image forming apparatus according to the exemplary embodiment of the present invention; [Figure 5] FIG. 2 is a plan view showing a measurement unit of the image forming apparatus according to the exemplary embodiment of the present invention. [Figure 6] FIG. 2 is a plan view showing a blowing unit of a fixing device in an image forming section of an image forming apparatus according to an exemplary embodiment of the present invention. [Figure 7] 2 is a perspective view showing a main heating section of a fixing device in an image forming section of an image forming apparatus according to an exemplary embodiment of the present invention; [Figure 8] 2 is a cross-sectional view showing a main heating section of a fixing device in an image forming section of an image forming apparatus according to an exemplary embodiment of the present invention. [Figure 9] FIG. 2 is a perspective view showing a secondary transfer roll of the image forming apparatus according to the exemplary embodiment of the present invention. [Figure 10] 3 is a perspective view showing a chain gripper of a fixing device in an image forming unit of an image forming apparatus according to an exemplary embodiment of the present invention; FIG. [Figure 11] FIG. 2 is a side view showing a cooling unit of the image forming apparatus according to the exemplary embodiment of the present invention. [Figure 12] 1 is a configuration diagram illustrating a toner image forming unit of an image forming apparatus according to an embodiment of the present invention; [Figure 13]1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. [Figure 14] FIG. 10 is a side view showing a fixing device of an image forming apparatus according to a comparative example to the embodiment of the present invention. [Figure 15] FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to a comparative example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] An example of an image forming apparatus according to an embodiment of the present invention will be described with reference to Figures 1 to 16. In the figures, arrow H indicates the up-down direction (vertical direction) of the apparatus, arrow W indicates the width direction (horizontal direction) of the apparatus, and arrow D indicates the depth direction (horizontal direction) of the apparatus.

[0026] <Image forming apparatus 10> The image forming apparatus 10 according to this embodiment is an electrophotographic image forming apparatus that forms a toner image on a sheet material P serving as a recording medium. As shown in FIG. 14 , the image forming apparatus 10 includes a storage section 50, a paper feed mechanism 48, an image forming section 12, a paper discharge mechanism 56, a discharge section 52, an inverting mechanism 58, and a control section 18 that controls each section. The image forming apparatus 10 also includes an apparatus main body 14 that houses each section. The apparatus main body 14 is composed of three substantially rectangular housings that are adjacently arranged in the width direction of the apparatus. The three housings are designated housing 14a, housing 14b, and housing 14c, respectively, from one side in the width direction of the apparatus (left side in the figure). Furthermore, housing 14a is shorter than housing 14b in the vertical direction of the apparatus. As a result, housing 14a exposes the upper side surface of housing 14b on one side in the width direction of the apparatus (left side in the figure).

[0027] (Storage section 50) The storage section 50 has a function of storing the sheet material P. The image forming apparatus 10 is provided with four storage sections 50. The sheet material P is selectively sent out from the four storage sections 50.

[0028] In this embodiment, three storage sections 50 are arranged side by side in the width direction of the device, and one storage section 50 is arranged above the storage section 50 that is arranged furthest to one side in the width direction of the device (left side in the drawing) of the three storage sections 50. In other words, two storage sections 50 are arranged side by side in the vertical direction of the device, and two more storage sections 50 are arranged side by side in the width direction of the device on the other side in the width direction of the device (right side in the drawing) of the storage section 50 that is arranged lower among the two storage sections 50.

[0029] In the following description, for convenience, of the three storage units 50 lined up in the device width direction, the storage unit 50 located furthest to one side in the device width direction (left side in the drawing) will be referred to as storage unit 50A, and the storage unit 50 located above storage unit 50A will be referred to as storage unit 50B. Furthermore, the storage unit 50 located next to storage unit 50A will be referred to as storage unit 50C, and the storage unit 50 located next to storage unit 50C will be referred to as storage unit 50D. Note that when there is no need to particularly distinguish between the storage units 50, the final alphabet will be omitted. The housing units 50A and 50B are disposed in the housing 14a, and the housing units 50C and 50D are disposed in the housing 14b.

[0030] The storage section 50 includes a stacking section 78 on which the sheet members P are stacked, and a delivery roll 80 that delivers the uppermost sheet member P stacked on the stacking section 78 to the supply path 40.

[0031] In addition, an output path 98 is formed through which the sheet material P sent out from the stacking section 78 by the output roll 80 passes, and the end of the output path 98 merges with the supply path 40 through which the sheet material P passes as it is transported toward the image forming section 12.

[0032] (Paper feed mechanism 48) The paper feeding mechanism 48 has a function of transporting the sheet material P stored in the storage unit 50 to a chain gripper 66 provided in the fixing device 100 of the image forming unit 12.

[0033] 14, the paper feed mechanism 48 includes a plurality of transport rolls 64 that transport the sheet material P along the supply path 40 along which the sheet material P is transported. The paper feed mechanism 48 will be described in detail later.

[0034] (Image forming unit 12) The image forming unit 12 has a function of forming an image on the sheet material P by electrophotography. As shown in FIG. 14, the image forming unit 12 is disposed on the other side of the storage unit 50 in the device width direction (the right side in the figure). The image forming unit 12 is also disposed within a housing 14c. The image forming unit 12 includes a toner image forming unit 20 that forms a toner image, a transfer device 30 that transfers the toner image formed in the toner image forming unit 20 to the sheet material P, and a fixing device 100 that fixes the toner image to the sheet material P.

[0035] A plurality of toner image forming units 20 are provided to form toner images for each color. The image forming unit 12 is provided with toner image forming units 20 for a total of four colors: yellow (Y), magenta (M), cyan (C), and black (K). (Y), (M), (C), and (K) shown in FIG. 14 indicate components corresponding to the above colors. When there is no particular distinction between the colors (Y, M, C, K), the last letters are omitted.

[0036] [Toner image forming unit 20] The toner image forming units 20Y, 20M, 20Y, and 20K are basically configured in the same manner except for the toners used.

[0037] As shown in FIG. 2, the toner image forming units 20Y, 20M, 20C, and 20K are arranged along the inclined portion of a transfer belt 31 provided in a transfer device 30.

[0038] 13, the toner image forming unit 20 includes a photosensitive drum 21 (=photosensitive element) that rotates in the direction of arrow A02 in the figure, and a charger 22 that charges the photosensitive drum 21. The toner image forming unit 20 also includes an exposure device 23 that exposes the photosensitive drum 21 charged by the charger 22 to light to form an electrostatic latent image, and a development device 24 that develops the electrostatic latent image with toner to form a toner image.

[0039] [Transfer device 30] The transfer device 30 has a function of primarily transferring the toner images of the photosensitive drums 21 of each color onto an intermediate transfer body in a superimposed manner, and then secondarily transferring the superimposed toner images onto a sheet member P. Specifically, as shown in FIG. 2, the transfer device 30 includes a transfer belt 31 as an intermediate transfer body, a plurality of rolls 32, a primary transfer roll 33, a secondary transfer roll 36, and a removal unit (not shown).

[0040] Transfer belt 31 is endless and is wound around multiple rolls 32 so as to assume an inverted triangular shape. Toner image forming units 20Y, M, C, and K are lined up along the inclined portion of transfer belt 31 on the other side in the device width direction (the right side in the figure). Transfer belt 31 rotates in the direction of arrow B when at least one of the multiple rolls 32 is driven to rotate.

[0041] In the following explanation, among the multiple rolls 32, the roll 32 arranged so as to push out the inclined portion of the transfer belt 31 on one side in the device width direction (left side in the figure) will be referred to as roll 32a, and the roll 32 around which the portion of the transfer belt 31 on one side in the device width direction is wrapped will be referred to as roll 32b.

[0042] The primary transfer roll 33 is disposed on the opposite side of the photosensitive drum 21 of each color across the transfer belt 31. The primary transfer roll 33 has a function of transferring the toner image formed on the photosensitive drum 21 to the transfer belt 31 at a primary transfer position T (see FIG. 13) between the photosensitive drum 21 and the primary transfer roll 33.

[0043] The secondary transfer roll 36 is disposed on the opposite side of the roll 32a across the transfer belt 31. The secondary transfer roll 36 has a function of transferring the toner image transferred onto the transfer belt 31 onto the sheet member P at a secondary transfer position NT between the transfer belt 31 and the secondary transfer roll 36.

[0044] The removing unit (not shown) is disposed on the opposite side of the transfer belt 31 from the roll 32b, and has the function of removing any adhering matter from the transfer belt 31.

[0045] [Fixing device 100] The fixing device 100 has a function of fixing the toner image transferred onto the sheet member P by the transfer device 30 onto the sheet member P.

[0046] As shown in FIG. 3, the fixing device 100 includes a chain gripper 66, a preheating section 102 that heats the toner image transferred to the sheet material P without contact, a main heating section 120 that heats the toner image by contacting the sheet material P, and a spraying unit 170.

[0047] -Chain Gripper 66- The chain gripper 66 includes a pair of chains 72, a leading end holding portion 68 that holds the leading end of the sheet material P, and sprockets 71, 73, and 96.

[0048] As shown in Fig. 10, the pair of chains 72 are spaced apart in the device depth direction, and the chains 72 are endless. As shown in Fig. 3, the pair of chains 72 are wound around a pair of sprockets 73 (see Fig. 9) that are arranged at both axial ends of the secondary transfer roll 36 and whose axial direction is the device depth direction. The pair of chains 72 are also wound around a pair of sprockets 71 (see Fig. 7) that are arranged at one and the other axial ends of the pressure roll 140 (described later) and whose axial direction is the device depth direction. The pair of chains 72 are also wound around a pair of sprockets 96 that are spaced apart in the device depth direction.

[0049] Furthermore, sprockets 71 (see FIG. 7) arranged on both ends of the pressure roll 140 and sprockets 73 (see FIG. 9) arranged on both ends of the secondary transfer roll 36 are adjacent to each other. When viewed from the depth direction of the device, sprocket 71 is arranged on one side (the left side in the drawing) of sprocket 73 in the depth direction of the device and above sprocket 73.

[0050] Furthermore, when viewed from the depth direction of the device, the pair of sprockets 96 are arranged below the sprockets 73 and 71, on one side in the device width direction of the sprocket 73, and on the other side in the device width direction of the sprocket 71. Furthermore, a transport roll (not shown) is arranged between the pair of sprockets 96 and is coaxial with the pair of sprockets 96.

[0051] In this manner, the pair of sprockets 96 are disposed lower than the other sprockets 71, 73.

[0052] As shown in Figure 10, the tip holding portion 68 has an attachment member 75 extending in the depth direction of the device and a gripper 76 attached to the attachment member 75, and both sides of the tip holding portion 68 in the depth direction of the device are respectively attached to a pair of chains 72.

[0053] A plurality of tip holders 68 are provided and are arranged at predetermined intervals along the circumferential direction (circumferential direction) of the chain 72 (see FIG. 3).

[0054] A plurality of grippers 76 are provided and attached to the attachment member 75 at predetermined intervals along the depth direction of the device. The grippers 76 have the function of holding the leading edge of the sheet material P. Specifically, the grippers 76 have claws 76a. The attachment member 75 is also formed with contact portions 75a (see FIG. 8) with which the claws 76a come into contact.

[0055] The gripper 76 is configured to hold the sheet material P by pinching the leading end of the sheet material P between the claw 76a and the contact portion 75a. Note that the gripper 76 has the claw 76a pressed against the contact portion 75a by a spring or the like, and the claw 76a is moved toward and away from the contact portion 75a by the action of a cam or the like, for example.

[0056] In this configuration, when a rotational force is transmitted to one of the multiple sprockets 71, 73, and 96 shown in Figure 3, the pair of chains 72 rotates in the direction of arrow C in the figure, moving from the sprocket 73 side to the sprocket 71 side.

[0057] Furthermore, when the leading edge holding portions 68 attached to the pair of chains 72 reach the receiving position RE at the lower end of the sprocket 96, the grippers 76 of the leading edge holding portions 68 pinch the leading edge of the sheet material P conveyed along the supply path 40 by the conveyance rolls 64, thereby holding and receiving the sheet material P. Then, the chains 72, which rotate in the direction of arrow C, convey the sheet material P held by the leading edge holding portions 68 toward the secondary transfer position NT. The rotating chains 72 further convey the sheet material P to face the preheating portion 102, and then convey it toward the main heating portion 120. Furthermore, at the sending position SE where the leading edge of the sheet material P has passed the main heating portion 120, the leading edge holding portions 68 release their hold on the leading edge of the sheet material P, and the chain grippers 66 send the sheet material P to the discharge path 42, which will be described later.

[0058] -Preheating section 102- As shown in FIG. 3, the preheating unit 102 is disposed downstream of the secondary transfer position NT in the conveying direction of the sheet material P (hereinafter referred to as the "sheet conveying direction") so as to face the upper surface of the conveyed sheet material P. The preheating unit 102 includes a reflecting member 104, a plurality of infrared heaters 106 (hereinafter referred to as the "heaters 106"), and a wire mesh 112.

[0059] The reflecting member 104 is made of aluminum plate and has a shallow box shape with an open side facing the sheet material P to be conveyed. In other words, when viewed from the width direction of the device, it has a U-shape with an open side facing the sheet material P to be conveyed. The heater 106 is an infrared heater with a cylindrical outer shape that extends in the depth direction of the device. Furthermore, multiple heaters 106 are provided and aligned in the sheet conveying direction. The wire mesh 112 is fixed to the edge of the reflecting member 104 by a fixing member (not shown) and separates the inside of the reflecting member 104 from the outside of the reflecting member 104.

[0060] In this configuration, the preheating unit 102 heats the sheet material P, which is conveyed by the rotating chain 72, in a non-contact manner from the thickness direction of the sheet material P. By heating the sheet material P, the toner constituting the toner image transferred to the sheet material P is softened.

[0061] -Spraying Unit 170- 3, the blowing unit 170 is disposed so as to face the preheating section 102 in the thickness direction of the sheet material P being transported, and the sheet material P being transported passes between the blowing unit 170 and the preheating section 102. In addition, as shown in FIG. 6, the blowing unit 170 includes a plurality of fans 172 arranged in the width direction of the sheet material P being transported and in the sheet transport direction.

[0062] In this configuration, the plurality of fans 172 blow air toward the sheet material P being transported, thereby stabilizing the transport posture of the sheet material P being transported.

[0063] -Main heating section 120- As shown in FIG. 3, the main heating section 120 is disposed downstream of the preheating section 102 in the sheet conveying direction.

[0064] As shown in FIG. 7, the heating section 120 includes a heating roll 130 that contacts the sheet material P being transported and heats the sheet material P, a pressure roll 140 that pressurizes the sheet material P toward the heating roll 130, and a driven roll 150 that rotates in accordance with the heating roll 130.

[0065] The heating roll 130 is arranged to contact the upward surface of the sheet material P being conveyed and to extend in the device depth direction with its axial direction being the device depth direction. Furthermore, shaft portions 139a extending in the device depth direction are formed on both ends of the heating roll 130 in the device depth direction, and support members 139b are provided to support the shaft portions 139a, respectively.

[0066] The driven roll 150 is disposed on the opposite side of the sheet member P being conveyed across the heating roll 130, and extends in the device depth direction with its axial direction being the device depth direction. The driven roll 150 also has a heater (not shown). In this configuration, the driven roll 150 rotates driven by the heating roll 130. The driven roll 150 heats the heating roll 130.

[0067] The pressure roll 140 is disposed on the opposite side of the heating roll 130 with the sheet material P being conveyed therebetween, in contact with the downward-facing surface of the sheet material P being conveyed, and extends in the device depth direction with its axial direction being the device depth direction. As shown in Fig. 8, a recess 140a extending in the device depth direction is formed on the outer peripheral surface of the pressure roll 140. When the sheet material P passes between the pressure roll 140 and the heating roll 130, the leading edge holding portion 68 that grips the leading edge of the sheet material P is accommodated in this recess 140a.

[0068] As shown in FIG. 7, a pair of shafts 148 are formed at both ends in the depth direction of the device, have a smaller diameter than the pressure roll 140, and extend in the axial direction.

[0069] Furthermore, the main heating section 120 includes a support member 156 that supports the pressure roll 140, and a biasing member 158 that biases the pressure roll 140 toward the heating roll 130 via the support member 156. A pair of support members 156 are provided. The pair of support members 156 are each arranged to rotatably support the pair of shafts 148 of the pressure roll 140 from below.

[0070] In this configuration, the pair of urging members 158 urge the pressure roll 140 toward the heating roll 130, causing the pressure roll 140 to press the sheet member P toward the heating roll 130. Furthermore, a rotational force is transmitted to the pressure roll 140 from a driving member (not shown), causing it to rotate. The heating roll 130 rotates in response to the rotating pressure roll 140, and the driven roll 150 rotates in response to the rotating heating roll 130. Furthermore, the heating roll 130 and the pressure roll 140 sandwich and transport the sheet member P to which the toner image has been transferred, causing the toner image to be heated and fixed to the sheet member P.

[0071] [Paper ejection mechanism 56, ejection section 52] The paper discharge mechanism 56 has a function of discharging the sheet material P sent out from the sending position SE of the image forming unit 12 from a discharge port provided on the side surface of the housing 14b facing the housing 14a. In this embodiment, the paper discharge mechanism 56 transports the sheet material P sent out from the sending position SE of the image forming unit 12 to a discharge unit 52 provided outside the housing 14a.

[0072] 1, the sheet discharge mechanism 56 includes a plurality of transport rolls 54 that transport the sheet material P along the discharge path 42 along which the sheet material P is transported, and a cooling unit 90 that cools the sheet material P while transporting the sheet material P along the discharge path 42. The sheet discharge mechanism 56 will be described in detail later.

[0073] The discharge section 52 is a section where the sheet material P conveyed by the paper discharge mechanism 56 is discharged. As shown in FIG. 1, the discharge section 52 is disposed outside the housing 14a above the two storage sections 50 arranged in the vertical direction of the device.

[0074] [Reversing mechanism 58] The reversing mechanism 58 has a function of reversing the front and back of the sheet material P. Specifically, as shown in FIG. 1, the reversing mechanism 58 includes a plurality of diverting rolls 82 that transport the sheet material P along the reversing path 44 along which the sheet material P is transported, and a transport roll 86. The reversing mechanism 58 will be described in detail later.

[0075] (Action of image forming device) In the image forming apparatus 10 shown in Fig. 14, a toner image is formed on a sheet member P as follows. First, the charger 22 for each color shown in Fig. 13 uniformly negatively charges the surface of the photosensitive drum 21 for each color to a predetermined potential. Next, based on image data input from the outside, the exposure device 23 irradiates the charged surface of the photosensitive drum 21 for each color with exposure light to form an electrostatic latent image.

[0076] As a result, electrostatic latent images corresponding to the image data are formed on the surfaces of the respective photosensitive drums 21. The developing devices 24 for each color then develop these electrostatic latent images into visible toner images. Furthermore, the primary transfer rolls 33 of the transfer device 30 shown in FIG. 2 transfer the toner images formed on the surfaces of the photosensitive drums 21 for each color onto the transfer belt 31 at the primary transfer position T.

[0077] Therefore, the sheet material P sent out from the storage section 50 (see FIG. 14) to the supply path 40 by the delivery roll 80 is conveyed by the conveying roll 64 and handed over to the tip holding portion 68 of the chain gripper 66 at the receiving position RE shown in FIG. 3 for further conveyance. The sheet material P conveyed by the chain gripper 66 is sent out toward the secondary transfer position NT along a conveyance path that is folded back at the secondary transfer position NT, including the supply path 40, the conveyance path conveyed by the chain gripper 66 to the secondary transfer position NT, and a conveyance path downstream of the secondary transfer position NT. At the secondary transfer position NT, the sheet material P is sandwiched between the transfer belt 31 and the secondary transfer roll 36 and conveyed, so that the toner image on the surface of the transfer belt 31 is transferred to the surface of the sheet material P.

[0078] Furthermore, the fixing device 100 fixes the toner image transferred onto the surface of the sheet material P onto the sheet material P, and the sheet material P transported by the chain gripper 66 is sent out to the discharge path 42 at the sending-out position SE. The sheet material P sent out to the discharge path 42 shown in FIG. 1 is cooled by being transported by the cooling unit 90, and is transported by the transport rolls 54. Then, the sheet material P is discharged to the discharge unit 52 outside the housing 14a.

[0079] On the other hand, when a toner image is formed on the back surface of the sheet material P, the sheet material P that has passed through the cooling section 90 is sent from a partway along the discharge path 42 to the reversing path 44, and is conveyed along the reversing path 44, thereby turning the sheet material P upside down. The turned-up sheet material P is then sent to a partway along the supply path 40. Then, in order to form a toner image on the back surface of the sheet material P, the above-described process is carried out again.

[0080] (Main part configuration) Next, the paper feed mechanism 48, the paper discharge mechanism 56, the reversing mechanism 58, etc. will be described.

[0081] [Paper feed mechanism 48] The sheet feeding mechanism 48 has a function of transporting the sheet material P stored in the storage unit 50 to the receiving position RE of the image forming unit 12. As shown in FIGS. 1 and 14, the sheet feeding mechanism 48 is disposed on one side in the device width direction (the left side in the drawings) of the receiving position RE of the image forming unit 12.

[0082] The sheet feeding mechanism 48 also includes a plurality of transport rollers 64 that transport the sheet material P along the supply path 40 through which the sheet material P travels as it is transported from the storage unit 50 toward the receiving position RE. The transport rollers 64 are an example of a first transport unit. The transport rollers 64 are arranged in the housings 14a, 14b, and 14c.

[0083] -Supply route 40- 1 and 14, the supply path 40 is passed by the sheet material P transported from the storage unit 50 toward the receiving position RE, and extends from one side to the other in the device width direction (horizontal direction) while changing its position in the up-down direction. In other words, the supply path 40 extends in the device width direction so that the sheet material P is transported from one side to the other in the device width direction by the transport rolls 64. In other words, the supply path 40 extends from one side to the other in the device width direction of the image forming device 10 until the sheet material P is delivered from one side in the device width direction to the image forming unit 12 at the receiving position RE. Specifically, there are two supply paths 40: one extending from the storage units 50A and 50B of the housing 14a, and the other extending from the storage units 50C and 50D of the housing 14b. These two supply paths 40 converge within the housing 14b and extend to the receiving position RE of the image forming unit 12 in the housing 14c. That is, the supply paths 40 are arranged in the housings 14a, 14b, and 14c. In other words, the supply paths 40 extending from the storage units 50C and 50D are arranged across the housings 14b and 14c. Furthermore, the supply paths 40 extending from the storage units 50A and 50B in the housing 14a are arranged across the housings 14a, 14b, and 14c. In yet other words, a portion of the supply path 40 is arranged in the housing 14a. A portion of the supply path 40 is arranged in the housing 14b. A portion of the supply path 40 is arranged in the housing 14c.

[0084] In this embodiment, the supply path 40 extends from one side to the other in the width direction of the apparatus without being directly upward or downward in the conveyance direction at any part of the supply path 40. The upstream side of the supply path 40 in the conveyance direction of the sheet material P has a portion that does not overlap in the vertical direction with the image forming unit 12, particularly the fixing device 100. That is, this upstream portion of the supply path 40 in the conveyance direction is an example of a portion of the supply path that extends to one side of the image forming unit. Furthermore, the other side of the conveyance path extending from one side to the other in the width direction of the apparatus of the supply path 40, i.e., the portion closer to the image forming unit 12, is arranged so as to overlap in the vertical direction with the image forming unit 12, particularly the fixing device 100.

[0085] Here, the "supply path" refers to a transport path through which the sheet material P travels as it is transported from the storage section 50 toward the receiving position RE, and is the transport path through which the sheet material P travels until it is handed over to one of the members of the image forming section 12.

[0086] In this configuration, the delivery roll 80 of the storage unit 50 delivers the uppermost sheet material P stacked in the stacking unit 78 to the supply path 40 through the delivery path 98. Furthermore, the plurality of transport rolls 64 transport the sheet material P delivered to the supply path 40 to the receiving position RE.

[0087] [Paper ejection mechanism 56] The paper discharge mechanism 56 has a function of transporting the sheet material P sent out from the sending position SE of the image forming unit 12 to the discharge unit 52 provided outside the housing 14a. As shown in Fig. 1, the paper discharge mechanism 56 is disposed on one side in the device width direction (the left side in the drawing) of the sending position SE of the image forming unit 12. Specifically, the paper discharge mechanism 56 is disposed in the housing 14b.

[0088] The sheet discharge mechanism 56 also includes a plurality of transport rolls 54 that transport the sheet material P along the discharge path 42 through which the sheet material P passes as it is transported from the delivery position SE toward the discharge section 52, and a cooling section 90 that cools the sheet material P while transporting it. The cooling section 90 and the plurality of transport rolls 54 are arranged in this order from upstream to downstream in the sheet transport direction.

[0089] -Exhaust channel 42- The discharge path 42 passes through the sheet material P conveyed from the discharge position SE of the image forming unit 12 toward the discharge unit 52 provided outside the housing 14a, and extends from the other side to one side in the device width direction (horizontal direction). In other words, the discharge path 42 extends in the device width direction so as to convey the sheet material P from the other side to one side in the device width direction. In other words, the discharge path 42 receives the sheet material P at the discharge position SE and then extends from the other side to one side in the device width direction. Specifically, the discharge path 42 extends in the device width direction from the discharge position SE of the housing 14c toward the housing 14b. That is, the discharge path 42 is disposed in both the housing 14b and the housing 14c. In other words, a portion of the discharge path 42 is disposed in the housing 14a. Furthermore, a portion of the discharge path 42 is disposed in the housing 14b.

[0090] In this embodiment, the conveying direction does not become directly upward or directly downward at any part of the way, and the discharge path 42 extends from the other side to one side in the device width direction.

[0091] Furthermore, in the up-down direction (vertical direction), the discharge path 42 is disposed above the supply path 40, and at least a portion of the discharge path 42 overlaps with at least a portion of the supply path 40 in the up-down direction. Furthermore, in the up-down direction, the discharge path 42 is disposed above the storage units 50C, 50D that store the sheet material P. In other words, the storage units 50C, 50D are disposed below the discharge path 42 in the up-down direction. Furthermore, the discharge path 42 is provided at a position that does not overlap with the fixing device 100 in the vertical direction. In other words, the discharge path 42 is disposed at a position that is shifted horizontally from the image forming unit 12 so as not to overlap with the image forming unit 12 in the vertical direction. In other words, the discharge path 42 has a portion that extends to one side of the image forming unit 12 in the device width direction.

[0092] Here, the "discharge path" refers to a conveying path through which the sheet material P on which the toner image is formed and discharged to the outside of the housing 14a passes, and is the conveying path through which the sheet material P sent out from any member of the image forming unit 12 is discharged to the discharge unit 52.

[0093] -Cooling section 90, conveying roll 54- As shown in FIG. 1, the cooling section 90 is disposed along the discharge path 42 so as to receive the sheet member P on which the toner image has been fixed by the fixing device 100.

[0094] 11, the cooling section 90 includes two rolls 90a arranged side by side in the width direction of the apparatus, and an endless belt 90b that is wound around the two rolls 90a and has an upper surface along the discharge path 42. The cooling section 90 also includes a cooling fan 90c that blows air onto the lower surface of the belt 90b to cool the belt 90b, and rolls 90d that are respectively arranged on the opposite sides of the two rolls 90a with the discharge path 42 and the belt 90b in between. The cooling section 90 is an example of a second conveying section.

[0095] 1, a plurality of transport rolls 54 are provided along the discharge path 42 downstream of the cooling section 90 in the sheet transport direction. The transport rolls 54 are an example of a second transport section.

[0096] In this configuration, one of the two rolls 90a is rotated by a rotational force transmitted from a driving member (not shown). As a result, the belt 90b, cooled by the cooling fan 90c, rotates in the direction of the arrow in the figure (counterclockwise), causing the roll 90d to rotate in conjunction with the rotating belt 90b. Furthermore, the rotating belt 90b and the roll 90d, which rotates in conjunction with the rotating belt 90b, sandwich and transport the sheet material P. This cools the sheet material P. The cooling unit 90 then delivers the sheet material P to the transport rolls 54, which transport the received sheet material P along the discharge path 42 and discharge it to the discharge unit 52.

[0097] [Reversing mechanism 58] The reversing mechanism 58 has a function of receiving the sheet material P being transported along the discharge path 42 from a midpoint of the discharge path 42, reversing the sheet material P upside down, and sending it out to a midpoint of the supply path 40. As shown in FIG. 1, the reversing mechanism 58 is disposed on one side of the image forming unit 12 in the device width direction (the left side in the drawing), and between the paper feed mechanism 48 and the paper discharge mechanism 56 in the up-down direction. The reversing mechanism 58 is disposed in the housing 14b.

[0098] The reversing mechanism 58 also includes a diverting roll 82 and a conveying roll 86 that convey the sheet material P along a reversing path 44 that branches off from a portion midway through the discharge path 42 and joins a portion midway through the supply path 40, a switching member 174, and a guide member 176. The diverting roll 82 and the conveying roll 86 are an example of a third conveying section.

[0099] -Reverse Road 44- As shown in Fig. 4, the reversing path 44 has a branch path 44a that branches off from the discharge path 42 at a portion downstream of the cooling unit 90 in the sheet conveying direction (see G01 in Fig. 4) and extends from the other side to one side in the device width direction. The reversing path 44 further has a change path 44b that extends from the end of the branch path 44a from the other side to one side in the device width direction, and in which the conveying direction of the sheet material P is reversed. The reversing path 44 also has a merging path 44c that extends from the end of the change path 44b from one side to the other in the device width direction separately from the branch path 44a and merges with a midpoint of the supply path 40 (see G02 in Fig. 4). The reversing path 44 is disposed in the housing 14b.

[0100] In this embodiment, the reversing path 44 extends in the width direction of the apparatus, without the conveying direction being either upward or downward at any intermediate portion. The vertical height position of the turning path 44b of the reversing path 44 is provided at a position lower than the image forming unit 12. That is, the turning path 44b is located at a position lower than the vertical top of the image forming unit 12. Furthermore, the supply path 40, the discharge path 42, and the reversing path 44 are located so as to overlap each other in the vertical direction but not so as to overlap with the image forming unit 12 in the vertical direction. That is, the portion of the supply path extending to one side of the image forming unit, the portion of the discharge path extending to one side of the image forming unit, and the third conveying unit are located so as to overlap each other in the vertical direction but are offset horizontally from the image forming unit.

[0101] Here, the "reversal path 44" is a conveying path in which the front and back of the sheet material P sent to the supply path 40 are reversed, and is a conveying path that branches off from a part way through the discharge path 42 and merges with a part way through the supply path 40.

[0102] -Conversion roll 82, conveying roll 86- 4, two diverting rolls 82 are provided, and are arranged at both end portions of the diverting path 44b, respectively. The two diverting rolls 82 receive the sheet material P sent from the branching path 44a to the diverting path 44b, and reverse the conveying direction of the sheet material P. Specifically, the diverting rolls 82 receive the sheet material P sent from the branching path 44a to the diverting path 44b while rotating in one direction, and then rotate in the other direction to send the sheet material P from the branching path 44a to the merging path 44c.

[0103] The transport rolls 86 are disposed in the junction flow path 44c. The transport rolls 86 reverse the transport direction to receive the sheet material P sent from the changeover path 44b to the junction flow path 44c, and send the sheet material P to a midway portion of the supply path 40.

[0104] -Switching member 174, guide member 176- 4, the switching member 174 is disposed at a portion where the branch path 44a branches off from a midpoint (see G01 in the figure) of the discharge path 42. The switching member 174 switches between conveying the sheet material P cooled by the cooling unit 90 along the discharge path 42 as is or sending it to the branch path 44a.

[0105] The guide member 176 is disposed at a portion where the diverting path 44b and the merging path 44c are connected (see G03 in the drawing). The guide member 176 guides the sheet material P, which is conveyed in the reverse direction in the diverting path 44b, to the merging path 44c and sends it out.

[0106] In this configuration, when a toner image is formed on the back side of a sheet material P having a toner image formed on its front side, the switching member 174 sends the sheet material P, which has a toner image formed on its front side and is being transported along the discharge path 42, from a midpoint of the discharge path 42 to the branch path 44a. The diverting roll 82 receives the sheet material P that has been sent from the branch path 44a to the diverting path 44b while rotating in one direction, and then rotates in the other direction while receiving the sheet material P, thereby reversing the transport direction of the sheet material P. Specifically, when the diverting roll 82, which rotates in one direction, rotates in the other direction, the rotation of the diverting roll 82, which rotates in one direction, is temporarily stopped, and then the diverting roll 82 rotates in the other direction. In other words, after the transport of the sheet material P is stopped in the diverting path 44b, the transport direction of the sheet material P is reversed.

[0107] The guide member 176 guides the sheet material P, which is conveyed in the reverse direction at the diverting path 44b, to the merging path 44c and sends it out. Furthermore, the conveying roll 86 receives the sheet material P sent from the diverting path 44b to the merging path 44c, and sends the sheet material P to a midway portion of the supply path 40.

[0108] 〔others〕 The image forming apparatus 10 includes a measuring unit 180 that measures the size of the sheet material P when the conveyance is stopped at the diverging path 44b. In this embodiment, the conveyance of the sheet material P is stopped when the rear end of the sheet material P passes through the diverging path 44a.

[0109] 5, the measurement unit 180 includes a pair of detectors 180a that detect the position of a leading edge P01 of the sheet material P whose conveyance has been stopped, and a pair of detectors 180b that detect the position of a base edge P02 of the sheet material P whose conveyance has been stopped. Furthermore, the measurement unit 180 includes a detector 180c that detects the position of one side edge P03 of the sheet material P whose conveyance has been stopped, and a detector 180d that detects the position of the other side edge P04 of the sheet material P whose conveyance has been stopped.

[0110] The detectors 180a, 180b, 180c, and 180d are known optical sensors. The pair of detectors 180a are arranged in the width direction of the device, and the pair of detectors 180b are arranged in the width direction of the device.

[0111] In this configuration, measurement unit 180 measures the size of sheet material P based on the detection results of each of detection units 180a, 180b, 180c, and 180d. Then, control unit 18 adjusts the position at which the toner image is transferred onto sheet material P so that the distance between the edge of the toner image and the edge of sheet material P is the same for all edges.

[0112] (Function of main components) Next, the operation of the main configuration will be described while comparing it with an image forming apparatus 510 according to a comparative embodiment. First, the configuration of the image forming apparatus 510 according to the comparative embodiment will be described, focusing on the parts that are different from the image forming apparatus 10.

[0113] [Image forming apparatus 510] As shown in FIG. 16, the image forming apparatus 510 includes a storage section 550, a paper feeding mechanism 548, an image forming section 512, a paper discharge mechanism 56, a discharge section 52, and a reversing mechanism 558.

[0114] - Storage unit 550- 16, the storage section 550 is arranged on the other side in the device width direction relative to the image forming section 512. The image forming apparatus 510 is provided with four storage sections 550. Three storage sections 550 are arranged side by side in the device width direction, and one storage section 550 is arranged above the storage section 550 that is arranged furthest to the other side in the device width direction (the right side in the figure) of the three storage sections 550.

[0115] -Paper feed mechanism 548- As shown in FIG. 16, the paper feed mechanism 548 is disposed on the other side in the device width direction (the right side in the drawing) of the receiving position RE of the image forming unit 512.

[0116] The sheet feed mechanism 548 also includes a plurality of transport rollers 564 that transport the sheet material P along a supply path 540 through which the sheet material P travels as it is transported toward the receiving position RE. The supply path 540 extends from one side to the other side in the device width direction. In other words, the supply path 540 extends from the other side to one side in the horizontal direction.

[0117] -Image forming unit 512- Image forming section 512 includes toner image forming section 20, transfer device 30, and fixing device 600. As shown in FIG. 15, fixing device 600 includes chain gripper 566, preheating section 102, main heating section 120, and spray unit 170. Chain gripper 566 includes a pair of chains 72, a leading edge holding section 68 that holds the leading edge of sheet material P, and sprockets 71, 73, and 596. Sprocket 596 is located below sprocket 73 and on the other side in the device width direction.

[0118] In this configuration, when the tip holding portion 68 attached to the pair of chains 72 reaches the receiving position RE in the upper part of the sprocket 596, the gripper 76 of the tip holding portion 68 holds and receives the sheet material P by clamping the tip of the sheet material P transported along the supply path 540 by the transport roll 564.

[0119] -Reversal mechanism 558- As shown in FIG. 16, the reversing mechanism 558 includes a diverting roll 82 and a transport roll 586 that transport the sheet material P along the reversing path 544, a switching member 174, and a guide member 176.

[0120] The reversing path 544 has a branching path 44a, a changeover path 44b, and a merging path 544c. The merging path 544c extends from an end of the changeover path 44b to the other side in the device width direction separately from the branching path 44a, and merges with a portion of the supply path 540.

[0121] [Operation of Image Forming Apparatus 10, 510] 16, transport rolls 564 of a paper feed mechanism 548 arranged on the other side of the receiving position RE of the image forming unit 512 in the device width direction transport the sheet material P along the supply path 540. Specifically, the multiple transport rolls 564 transport the sheet material P from a storage unit 550 arranged on the other side of the image forming unit 512 in the device width direction toward the receiving position RE.

[0122] 14, in contrast, transport rolls 46 of a paper feed mechanism 48 arranged on one side of the receiving position RE of the image forming unit 12 in the device width direction transport the sheet material P along the supply path 40. Specifically, the multiple transport rolls 46 transport the sheet material P from a storage unit 50 arranged on one side of the image forming unit 12 in the device width direction toward the receiving position RE of the image forming unit 12.

[0123] Furthermore, the image forming unit 12, 512 forms a toner image on the surface of the sheet material P received at the receiving position RE, and sends it out from the sending position SE to the discharge path 42.

[0124] The cooling section 90 and the plurality of transport rolls 54 of the sheet discharge mechanism 56 arranged on one side of the delivery position SE in the device width direction transport the sheet material P along the discharge path 42 and discharge it to the discharge section 52.

[0125] On the other hand, when a toner image is to be formed on the back side of the sheet material P having a toner image formed on the front side, the switching member 174 sends the sheet material P, which is being transported along the discharge path 42, from a midpoint of the discharge path 42 to the branch path 44a. The diverting roll 82 receives the sheet material P that is sent from the branch path 44a to the diverting path 44b while rotating in one direction, and reverses the transport direction of the sheet material P by rotating in the other direction. Specifically, when the diverting roll 82, which rotates in one direction, rotates in the other direction, the rotation of the diverting roll 82, which rotates in one direction, is temporarily stopped, and then the diverting roll 82 rotates in the other direction. In other words, after the transport of the sheet material P is stopped at the diverting path 44b, the transport direction of the sheet material P is reversed.

[0126] Furthermore, the guide member 176 guides the sheet material P, which has been conveyed in the opposite direction at the switching path 44b, to the merging paths 44c and 544c and sends it out. Furthermore, the conveying rolls 86 and 586 receive the sheet material P sent from the switching path 44b to the merging paths 44c and 544c, convey the sheet material P along the merging paths 44c and 544c, and send the sheet material P to a midpoint of the supply paths 40 and 540. Then, by repeating the above-described process, a toner image is formed on the rear surface of the sheet material P. Furthermore, the cooling unit 90 and the multiple conveying rolls 54 of the paper discharge mechanism 56 convey the sheet material P along the discharge path 42 and discharge it to the discharge unit 52.

[0127] 5 measures the size of the sheet material P in a state where the conveyance is stopped at the turning path 44b of the reversing path 44. Then, the control unit 18 receives the measurement result of the measurement unit 180 and controls the image forming units 12, 512 to adjust the position where the toner image is transferred to the sheet material P. Specifically, the control unit 18 adjusts the position where the toner image is transferred to the sheet material P so that the distance between the edge of the toner image and the edge of the sheet material P is the same for all edges.

[0128] (summary) As described above, in the image forming apparatus 510, the paper feed mechanism 548 is disposed on the other side in the device width direction relative to the receiving position RE of the image forming unit 512. The supply path 540 through which the sheet material P passes as it is transported toward the receiving position RE of the image forming unit 512 extends from the other side to one side in the device width direction. On the other hand, in the image forming apparatus 10, the paper feed mechanism 48 is disposed on one side in the device width direction relative to the receiving position RE of the image forming unit 12. The supply path 40 through which the sheet material P passes as it is transported toward the receiving position RE of the image forming unit 12 extends from one side to the other side in the device width direction.

[0129] Furthermore, in the image forming apparatuses 10 and 510, the sheet discharge mechanism 56 is disposed on one side of the image forming unit 12 in the device width direction relative to the delivery position SE. The discharge path 42, through which the sheet material P conveyed toward the discharge unit 52 passes, extends from the other side to one side in the device width direction. Furthermore, in the image forming apparatus 510, the supply path 540 and the discharge path 42 are spaced apart in the device width direction (see FIG. 16). In other words, the supply path 540 and the discharge path 42 do not overlap in the up-down direction (vertical direction). In contrast, in the image forming apparatus 10, at least a portion of the discharge path 42 overlaps with at least a portion of the supply path 40 in the up-down direction (vertical direction).

[0130] As a result, in the image forming apparatus 10, the area occupied by the supply path 40 and the discharge path 42 in the device width direction (horizontal direction) is narrower than in the image forming apparatus 510.

[0131] Furthermore, in the image forming apparatus 10, the discharge path 42 is disposed above the supply path 40 in the vertical direction. As a result, the position of the discharge section 52 is higher than when the discharge path 42 is disposed below the supply path 40. In other words, the user takes out the sheet material P from the discharge section 52 in a standing position.

[0132] Furthermore, in the image forming apparatus 10, the storage units 50C, 50D are disposed below the discharge path 42 in the vertical direction. Therefore, the area occupied by the storage units 50C, 50D and the discharge path 42 in the horizontal direction is narrower than when the storage units 50C, 50D and the discharge path 42 are spaced apart in the device width direction.

[0133] Furthermore, in the image forming apparatus 10, the reversing path 44 is disposed between the supply path 40 and the discharge path 42 in the vertical direction. Therefore, the area between the supply path 40 and the discharge path 42 is used more effectively than when the area between the supply path 40 and the discharge path 42 and the reversing path 44 are separated in the device width direction.

[0134] Furthermore, in the image forming apparatus 10, the measurement unit 180 measures the size of the sheet material P in a state where the conveyance is stopped at the turning path 44b. Therefore, a configuration is obtained in which the conveyance of the sheet material P does not need to be stopped just for the measurement.

[0135] Furthermore, in image forming apparatus 10, supply path 40, discharge path 42, and reversing path 44 are arranged so as to overlap each other in the vertical direction, but not at positions where they overlap image forming unit 12 in the vertical direction. Therefore, the height of the main body of image forming apparatus 10 does not increase compared to when image forming apparatus 10 is arranged so that supply path 40, discharge path 42, reversing path 44, and image forming unit 12 overlap in the vertical direction.

[0136] Furthermore, in the image forming apparatus 10, the supply path 40, the discharge path 42, and the reversing path 44 are arranged in the same housing 14b. Specifically, the reversing path 44 merges with the supply path 40 and the discharge path 42 inside the housing 14b where a portion of the supply path 40 and a portion of the discharge path 42 are arranged. Therefore, in the image forming apparatus 10, adjustment of the reversing path 44b when installing the image forming apparatus 10 can be simplified compared to when the reversing path 44b is arranged in a housing different from that of the supply path 40 or the discharge path 42.

[0137] Furthermore, in the image forming apparatus 10, the turning path 44b is disposed at a position lower than the vertical top of the image forming unit 12. Therefore, the height of the image forming apparatus 10 body does not increase compared to when the turning path is disposed at a position higher than the vertical top of the image forming unit.

[0138] Furthermore, the image forming apparatus 10 is disposed at a position offset horizontally from the image forming unit 12 so that the discharge path 42 does not overlap the image forming unit 12 in the vertical direction. Therefore, the height of the image forming apparatus 10 body does not increase compared to when the supply path 40 and the discharge path 42 overlap the image forming unit 12 in the vertical direction.

[0139] As described above, the present invention has been described in detail with respect to a specific embodiment, but the present invention is not limited to such an embodiment, and it will be apparent to those skilled in the art that various other embodiments are possible within the scope of the present invention. For example, in the above embodiment, the cooling unit 90 is disposed in the discharge path 42, but the cooling unit 90 may not be disposed.

[0140] In the above embodiment, the discharge path 42 is disposed above the supply path 40 in the vertical direction, but the discharge path may be disposed below the supply path 40. However, in this case, the effect achieved by disposing the discharge path 42 above the supply path 40 is not achieved.

[0141] Furthermore, in the above embodiment, the storage units 50C, 50D are arranged below the discharge path 42 in the vertical direction, but the storage units 50C, 50D may be spaced apart from the discharge path 42 in the device width direction. In this case, the effect achieved by arranging the storage units 50C, 50D below the discharge path 42 in the vertical direction will not be achieved.

[0142] In addition, in the above embodiment, the reversing path 44 is disposed between the supply path 40 and the discharge path 42 in the up-down direction, but the reversing path does not have to be disposed between the supply path and the discharge path. In this case, however, the effect achieved by disposing the reversing path 44 between the supply path 40 and the discharge path 42 is not achieved.

[0143] Although not specifically described in the above embodiment, any two of the plurality of transport rolls 64 may have a function as a registration roll for correcting the transport posture of the sheet member P.

[0144] Furthermore, in the above embodiment, the sheet member P conveyed by the secondary transfer roll 36 is folded back, but for example, the sheet member P conveyed by the main heating section 120 of the fixing device 100 may be folded back.

[0145] Furthermore, in the above embodiment, the reversing mechanism 58 is provided, but the reversing mechanism 58 may not be provided. In this case, however, the effect achieved by providing the reversing mechanism 58 will not be achieved.

[0146] Furthermore, in the above embodiment, the reversing path 44 is arranged between the supply path 40 and the discharge path 42 in the vertical direction, and is arranged in the housing 14b in which a portion of the supply path 40 and a portion of the discharge path 42 are also arranged. However, in the image forming apparatus according to the present invention, as long as the reversing path 44 is arranged between the supply path 40 and the discharge path 42 in the vertical direction, the reversing path 44 may be arranged in a housing separate from the housing in which a portion of the supply path 40 or a portion of the discharge path 42 is arranged. In this case, the effect achieved by arranging a portion of the supply path 40, a portion of the discharge path 42, and the reversing path 44 in the same housing is not achieved.

[0147] In the above embodiment, the device main body 14 is configured with three housings 14a, 14b, and 14c. However, the device main body according to the present invention may be configured with two housings, or may be configured with four or more housings. Furthermore, the device main body according to the present invention may have a configuration in which each unit of the image forming device is housed in a single housing. [Explanation of symbols]

[0148] 10 Image forming device 14 Device body 14a Case 14b Case 14c case 12 Image forming unit 40 Supply route 42 Exhaust channel 44 Reverse Path 44b Diversion 50C storage section 50D storage section 54 Conveying roll (an example of the second conveying section) 64 Conveyor roll (an example of the first conveyor section) 82 Diversion roll (an example of the third conveying section) 86 Transport roll (an example of the third transport section) 90 Cooling section (an example of the second conveying section) 180 Measuring section P sheet member (an example of a recording medium)

Claims

1. an image forming unit that forms a toner image on a recording medium; a first conveying unit that conveys the recording medium along a supply path that extends from one side to the other side in a horizontal direction to the image forming unit and includes a portion that extends to one side of the image forming unit; a second conveying unit that conveys the recording medium along a discharge path that extends from the image forming unit to the outside of the apparatus body from the other side to the one side in the horizontal direction and at least a portion of which overlaps with at least a portion of the supply path in the vertical direction, and that includes a portion that extends to the one side of the image forming unit; a third conveying unit that conveys the recording medium along a reversing path that branches off from a midpoint of the discharge path, extends from one side to the other side in a horizontal direction, and also extends from one side to the other side in the horizontal direction to join a midpoint of the supply path; Equipped with In the vertical direction, the reversing path is disposed between the supply path and the discharge path, the third transport unit transports the recording medium from the other side to the one side in the horizontal direction, stops the transport, and then transports the recording medium from the one side to the other side in the horizontal direction; a measuring unit for measuring the size of the recording medium when the conveyance is stopped by the third conveyance unit; Image forming device.

2. An image forming unit that forms a toner image on a recording medium; a first conveying unit that conveys the recording medium along a supply path that extends from one side to the other side in a horizontal direction to the image forming unit and includes a portion that extends to one side of the image forming unit; a second conveying unit that conveys the recording medium along a discharge path that extends from the image forming unit to the outside of the apparatus body from the other side to the one side in the horizontal direction and at least a portion of which overlaps with at least a portion of the supply path in the vertical direction, and that includes a portion that extends to the one side of the image forming unit; a third conveying unit that conveys the recording medium along a reversing path that branches off from a middle portion of the discharge path and joins a middle portion of the supply path, and inverts the front and back of the recording medium sent out to the supply path; Equipped with In the vertical direction, the reversing path is disposed between the supply path and the discharge path, the third transport unit transports the recording medium from the other side to the one side in the horizontal direction, stops the transport, and then transports the recording medium from the one side to the other side in the horizontal direction; a measuring unit for measuring the size of the recording medium when the conveyance is stopped by the third conveyance unit; Image forming device.

3. An image forming apparatus as described in claim 1 or 2, wherein the discharge path is arranged above the supply path in the vertical direction.

4. An image forming apparatus as described in claim 3, which is provided with a storage section that is arranged below the discharge path in the vertical direction and that stores the recording medium that is sent to the supply path.

5. An image forming device described in any one of claims 1 to 4, characterized in that the portion of the supply path extending to one side of the image forming unit, the portion of the discharge path extending to one side of the image forming unit, and the third conveying unit are positioned horizontally offset from the image forming unit and overlap each other vertically.

6. The device body includes a plurality of housings, The image forming apparatus according to claim 5 , wherein the supply path, the discharge path, and the reversing path are arranged in the same housing.

7. An image forming apparatus described in any one of claims 1 to 6, characterized in that the reversing path has a turning path in which the transport direction of the recording medium is reversed, and the turning path is positioned at a position lower than the vertical top of the image forming unit.

8. An image forming apparatus described in any one of claims 1 to 7, characterized in that the first conveying section overlaps the image forming section in the vertical direction, and the second conveying section is arranged so as not to overlap the image forming section in the vertical direction.

Images