Image forming apparatus, discharge device and image forming system

Abstract

To provide an image forming apparatus and an image forming system equipped with a discharge device that easily processes sheets when a sheet jam occurs.SOLUTION: An image forming apparatus 10 includes a discharge device 100 that is detachably mounted on the upper portion. The image forming apparatus 10 has a first discharge roller pair R1, and a main body transport path P1 and a main body discharge path P2 that transport the sheet S from an image forming unit 30 to the first discharge roller pair R1 inside the image forming apparatus 10. The discharge device 100 has a second discharge roller pair R2, an optional discharge path P5 that is connectable to the main body transport path P1 when mounted in the image forming apparatus 10 and transports the sheet S from the main body transport path P1 to the second discharge roller pair R2, and a discharge switching unit 101 that switches between a first position where the sheet S from the image forming unit 30 is guided toward the first discharge roller pair R1 via the main body discharge path P2 and a second position where the sheet S is guided toward the second discharge roller pair R2 via the optional discharge path P5.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that employs an electrophotographic method, an electrostatic recording method, an inkjet method, etc., such as a copying machine and a printer, a discharging device that is attached to the image forming apparatus to discharge a sheet, and an image forming system formed by attaching the discharging device to the image forming apparatus.

Background Art

[0002] Conventionally, in an image forming system such as a copying machine or a printer, there is known one having an image forming apparatus having an image forming unit and a discharging device that is detachably attached to the image forming apparatus and discharges a sheet conveyed from the image forming apparatus (see Patent Document 1). In this image forming system, a sheet on which an image is formed in the image forming unit is discharged to a first discharge tray provided in the image forming apparatus or to a second discharge tray provided in the discharging device. The image forming apparatus is provided with a first conveyance path for conveying a sheet from the image forming unit to the first discharge tray, and the discharging device is provided with a second conveyance path that branches from the first conveyance path and conveys the sheet to the second discharge tray. Further, the image forming apparatus is provided with a switching unit that switches, by rotation, whether to convey a sheet conveyed from the image forming unit to the first conveyance path or to the second conveyance path.

[0003] Also, in this image forming system, there may be a case where the discharging device is removed and the image forming apparatus is used alone. In this case, a cover is attached to the mounting portion where the discharging device is mounted. That is, the discharging device and the cover can be selectively attached to and detached from the image forming apparatus.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the image forming system described in Patent Document 1 above, since a switching unit is provided in the apparatus main body of the image forming apparatus, the number of parts of the apparatus main body of the image forming apparatus increases. For this reason, when a sheet jam occurs in the apparatus main body, it may be difficult to process the sheet.

[0006] An object of the present invention is to provide an image forming apparatus, a discharging apparatus, and an image forming system that can easily execute sheet processing when a sheet jam occurs.

Means for Solving the Problems

[0007] One aspect of the present invention includes an image forming apparatus having an image forming unit that forms an image on a sheet, and a discharging apparatus that is detachably mounted above the image forming apparatus. The image forming apparatus includes a first discharging unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharging unit inside the image forming apparatus. The discharging apparatus includes a second discharging unit that discharges the sheet, a second conveyance path that is connectable to the first conveyance path in a state of being mounted on the image forming apparatus and conveys the sheet from the first conveyance path to the second discharging unit, a first position that guides the sheet from the image forming unit toward the first discharging unit via the first conveyance path, and a second position that guides the sheet from the image forming unit toward the second discharging unit via the second conveyance path. The image forming system is characterized by having a first switching unit that switches between the two positions.

[0008] Another aspect of the present invention relates to a discharging device that is detachably attached to the upper part of an image forming apparatus having an image forming unit that forms an image on a sheet, a first discharging unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharging unit inside the image forming apparatus. The discharging device includes a second discharging unit that discharges the sheet, a second conveyance path that can be connected to the first conveyance path in a state where the discharging device is attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharging unit, a first position that guides the sheet from the image forming unit toward the first discharging unit via the first conveyance path, and a switching unit that switches to a second position that guides the sheet from the image forming unit toward the second discharging unit via the second conveyance path. The discharging device is characterized by including the switching unit.

[0009] Another aspect of the present invention relates to an image forming apparatus including: an image forming unit that forms an image on a sheet; a first discharging unit that discharges the sheet; a first conveyance path that conveys the sheet from the image forming unit to the first discharging unit inside the image forming apparatus; a second discharging unit that discharges the sheet; a second conveyance path that can be connected to the first conveyance path in a state where the discharging device is attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharging unit; a first position that guides the sheet from the image forming unit toward the first discharging unit via the first conveyance path; a second position that guides the sheet from the image forming unit toward the second discharging unit via the second conveyance path; a switching unit that switches between the first position and the second position; a mountable part to which the discharging device can be mounted; and a cover that is detachably attached to the mountable part with the discharging device removed.

[0010] Another aspect of the present invention includes an image forming apparatus having an image forming unit that forms an image on a sheet, and a discharging device that is detachably attached to the upper part of the image forming apparatus. The image forming apparatus has a first discharging unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharging unit inside the image forming apparatus. The discharging device has a second discharging unit that discharges the sheet, a second conveyance path that is connected to the first conveyance path in a state of being attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharging unit, and a guiding unit that guides the sheet conveyed in the first conveyance path to the second conveyance path. The image forming system is characterized by having these components.

Advantages of the Invention

[0011] According to the present invention, when a sheet jam occurs, the processing of the sheet can be easily executed.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0013] <First Embodiment> Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. In this embodiment, the image forming system 1 includes an image forming apparatus 10 and a discharging apparatus 100. As an example of the image forming apparatus 10, a case where a tandem type full-color printer is applied will be described. However, the present invention is not limited to the tandem type image forming apparatus 10, and other types of image forming apparatuses may be used. Also, it is not limited to full-color, and it may be monochrome or single-color. Further, it may be applied to an inkjet recording type image forming apparatus.

[0014] [Image Forming Apparatus] The overall configuration of the image forming apparatus 10 will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the image forming system 1 with the discharging apparatus 100 attached to the image forming apparatus 10 in the first embodiment, and FIG. 2 is a cross-sectional view thereof. In this embodiment, in the figure, the front side of the image forming system 1 is denoted as the front direction F, the back side as the back direction B, the right side as viewed from the front side as the right direction R, the left side as the left direction L, the upper side as the upper direction U, and the lower side as the lower direction D.

[0015] The image forming apparatus 10 includes a feeding unit 20, an image forming unit 30 which is an example of an image forming section, a discharging unit 40, and a re-conveying unit 50. The feeding unit 20 includes a sheet cassette 21 for accommodating the sheet S, a feeding section 22 composed of a pair of rollers for feeding the sheet S, and a registration roller pair 23 (registration roller pair) for conveying the fed sheet S to the image forming unit 30 while aligning the registration.

[0016] The image forming unit 30 forms an image on the sheet S fed and conveyed by the feeding unit 20. The image forming unit 30 includes four process cartridges PY, PM, PC, and PK that form toner images of four colors: yellow (Y), magenta (M), cyan (C), and black (K), an exposure unit 31, and an intermediate transfer belt 32. The four process cartridges PY, PM, PC, and PK have the same configuration except for the colors of the images they form. For this reason, only the configuration of the process cartridge PY and the image forming process will be described, and the descriptions of the process cartridges PM, PC, and PK will be omitted. Further, the image forming unit 30 includes a secondary transfer unit 33 and a fixing unit 34.

[0017] The process cartridge PY includes a photosensitive drum 35 that is a drum-type electrophotographic photosensitive member, a charging roller (not shown), and a developing roller 36. The photosensitive drum 35 is rotatably supported by the image forming apparatus 10 and is rotationally driven by a driving means (not shown). The charging roller charges the photosensitive drum 35. The developing roller 36 attaches toners of mutually different colors (yellow, magenta, cyan, black) to the surface of the photosensitive drum 35 for each of the process cartridges PY, PM, PC, and PK. The developing roller 36 attaches toner to the electrostatic latent image on the surface of the photosensitive drum 35 to develop the electrostatic latent image and forms a toner image on the surface of the photosensitive drum 35. The exposure unit 31 irradiates the surface of the charged photosensitive drum 35 with laser light based on image information to form an electrostatic latent image.

[0018] The intermediate transfer belt 32 is wound around a driving roller 32a and a tension roller 32b and is rotatably stretched. Inside the intermediate transfer belt 32, a primary transfer roller 37 is provided which abuts against the intermediate transfer belt 32 at a position facing the photosensitive drum 35. At a position facing the driving roller 32a of the secondary transfer unit 33, a secondary transfer roller 38 is provided which transfers the image formed on the intermediate transfer belt 32 to the sheet S. The fixing unit 34 is arranged above the secondary transfer roller 38 in the upward direction U and has a pressure roller and a heating roller. The sheet S on which the toner image is formed receives heat and pressure at the roller nip portion formed by the pressure roller and the heating roller, and the toners of each color are melted and mixed, and are fixed as a color image on the sheet S.

[0019] The discharge unit 40 is arranged above the fixing unit 34 in the upward direction U and has a main body conveyance path P1, a main body discharge path P2, a first discharge roller pair R1 which is an example of a first discharge portion for discharging the sheet S, a main body discharge tray 41, and a double-sided switching portion 42 which is a branching means. In the present embodiment, the first discharge portion for discharging the sheet S provided in the image forming apparatus 10 has only the first discharge roller pair R1. However, it is not limited to this, and the image forming apparatus 10 may have a plurality of discharge roller pairs and switch among them to discharge the sheet S.

[0020] The main body conveyance path P1 is provided upward from the fixing unit 34 and is connected to the main body discharge path P2 at the first connection position X1. The main body discharge path P2 conveys the sheet S from the first connection position X1 to the first discharge roller pair R1. The sheet S is discharged from the first discharge roller pair R1 to the main body discharge tray 41 and stacked. That is, the main body conveyance path P1 and the main body discharge path P2 are an example of a first conveyance path, and convey the sheet S from the image forming unit 30 to the first discharge roller pair R1 inside the image forming apparatus 10.

[0021] The re-conveying unit 50 has a first reversing path P3 that branches off from the main body conveying path P1, a pair of reversing rollers 51 provided on the first reversing path P3, and a re-conveying path P4 that branches off below the pair of reversing rollers 51 on the first reversing path P3. The first reversing path P3 is an example of a third conveying path and branches off from the main body conveying path P1 upstream in the sheet conveying direction from the first connection position X1. The pair of reversing rollers 51 reverses the conveying direction of the sheet S conveyed in the first direction D1 by the first reversing path P3 to the second direction D2 opposite to the first direction D1 and conveys it. The re-conveying path P4 is an example of a fourth conveying path and is connected to the first reversing path P3 at a second connection position X2 that is upstream of the pair of reversing rollers 51 in the first direction D1. Further, the re-conveying path P4 re-conveys the sheet S that has been conveyed in the first reversing path P3 and whose conveying direction has been reversed to the second direction D2 by the pair of reversing rollers 51 to the image forming unit 30.

[0022] On the other hand, FIG. 3 is a cross-sectional view of the image forming apparatus 10 in the first embodiment with the discharging apparatus 100 removed. As shown in FIG. 3, the image forming apparatus 10 has a mounted portion 11 that can be mounted on a mounting portion 103 (to be described later) of the discharging apparatus 100. The mounted portion 11 has a mounted surface 12 that supports a mounting surface 104 (to be described later) in a state where the mounting portion 103 is mounted, and a recess 13 that is recessed in a concave shape downward from the mounted surface 12 and into which a convex portion 105 (to be described later) is fitted. Further, the image forming apparatus 10 is provided with a guide member 14 that forms a main body discharge path P2. The guide member 14 is disposed in the downward direction D of the recess 13 and has an opening 14a above the main body discharge path P2. The opening 14a is exposed in the recess 13, and the main body discharge path P2 is exposed. Further, the first connection position X1 is set to a position facing the opening 14a. Also, the upper end of the first reversing path P3 communicates with a communication port 15 that is exposed on the mounted surface 12.

[0023] [Discharging Apparatus] Next, the configuration of the discharge device 100 will be described with reference to FIGS. 1 to 3. The discharge device 100 is detachably mounted on the upper part of the image forming apparatus 10. As shown in FIG. 2, the discharge device 100 includes a second discharge roller pair R2 that discharges the sheet S, an optional discharge path P5 that conveys the sheet S from the first connection position X1 to the second discharge roller pair R2, a discharge switching unit 101, and an optional discharge tray 102. The second discharge roller pair R2 is an example of a second discharge unit 110 that discharges the sheet S from the discharge device 100. In the present embodiment, the second discharge unit 110 has only the second discharge roller pair R2. However, the present invention is not limited to this, and the second discharge unit 110 may have a plurality of discharge roller pairs and switch among them to discharge the sheet S (see the fourth embodiment).

[0024] The optional discharge path P5 is an example of a second conveyance path, and can be connected to the main body conveyance path P1 when the discharge device 100 is mounted on the image forming apparatus 10, and conveys the sheet S from the first connection position X1 of the main body conveyance path P1 to the second discharge roller pair R2. The discharge switching unit 101 is an example of a first switching unit, and switches between a first position (shown by a solid line in FIG. 2) and a second position (shown by a broken line in FIG. 2) by rotation. When the discharge switching unit 101 is in the first position, it guides the sheet S from the image forming unit 30 toward the first discharge roller pair R1 via the main body conveyance path P1 and the main body discharge path P2. When the discharge switching unit 101 is in the second position, it guides the sheet S from the image forming unit 30 toward the second discharge roller pair R2 via the optional discharge path P5. The sheet S is discharged from the second discharge roller pair R2 to the optional discharge tray 102 and stacked.

[0025] Further, the discharge device 100 has a second reverse path P6, which is an example of a fifth conveyance path connected to the first reverse path P3 when the discharge device 100 is mounted on the image forming apparatus 10. Thereby, in a state where the discharge device 100 is mounted on the image forming apparatus 10, a retraction path is formed by the first reverse path P3 and the second reverse path P6 to retract the rear end of the sheet S conveyed in the first direction D1 downstream of the second connection position X2.

[0026] On the one hand, as shown in FIG. 3, the discharging device 100 has a mounting portion 103. The mounting portion 103 has a mounting surface 104 and a convex portion 105 that protrudes convexly downward from the mounting surface 104. When the mounting portion 103 is mounted on the mounted portion 11, the discharging device 100 is mounted on the image forming apparatus 10.

[0027] The discharge switching portion 101 is provided at the lower end portion of the convex portion 105. In a state where the discharging device 100 is mounted on the image forming apparatus 10, the discharge switching portion 101 located at the first position closes the opening 14a, and the guide member 14 of the image forming apparatus 10 forms the main body discharge path P2 together with the discharge switching portion 101. Further, the discharging device 100 has a guide member 106 which is an example of a second guide member that forms an option discharge path P5 together with the discharge switching portion 101 located at the second position. The lower end of the option discharge path P5 communicates with a communication port 107 exposed on the convex portion 105.

[0028] [Sheet conveyance path during sheet discharge] Next, the configuration of the sheet conveyance path in a state where the discharging device 100 is mounted on the image forming apparatus 10 will be described with reference to FIG. 2. As shown in FIG. 2, the image forming system 1 has a main body conveyance path P1 through which the sheet S conveyed from the fixing portion 34 is conveyed. The image forming system 1 has a main body discharge path P2 that branches from the main body conveyance path P1 and through which the sheet S is conveyed to the main body discharge tray 41, and an option discharge path P5 that branches from the main body conveyance path P1 and through which the sheet S is conveyed to the discharging device 100.

[0029] Further, the image forming system 1 has a re-conveyance path P4 that branches from the main body conveyance path P1 and through which the sheet S is switched back and conveyed to the image forming unit 30 again. The image forming system 1 includes a communication port 15 and a communication port 107 formed so that the sheet S can pass through the rear portion of the upper surface of the image forming apparatus 10, and a duplex switching portion 42 and a discharge switching portion 101 for switching the conveyance path of the sheet S.

[0030] The main body conveyance path P1 extends obliquely upward in front from the fixing unit 34. A pair of conveyance rollers 43 for conveying the sheet S is provided in the main body conveyance path P1. The main body discharge path P2 extends obliquely upward in front from the first connection position X1 which is the upper end of the main body conveyance path P1. Thus, the sheet conveyance path formed by the main body conveyance path P1 and the main body discharge path P2 curves toward the main body discharge tray 41 after extending away from the fixing unit 34. A first discharge roller pair R1 is arranged in the main body discharge path P2. The first discharge roller pair R1 is a pair of rollers arranged at the outlet of the main body discharge path P2, and discharges the sheet S to the main body discharge tray 41.

[0031] The optional discharge path P5 extends upward from the first connection position X1 between the pair of conveyance rollers 43 and the first discharge roller pair R1 in the main body conveyance path P1. The upper part of the main body conveyance path P1 communicates with the communication port 107. The communication port 107 communicates the optional discharge path P5 of the discharge device 100 mounted on the image forming apparatus 10 and the main body conveyance path P1.

[0032] The re-conveyance unit 50 has a first inversion path P3 and a re-conveyance path P4. Also, the discharge device 100 has a second inversion path P6. The first inversion path P3 extends rearward and upward from the main body conveyance path P1 and is a path leading to the discharge device 100 through the communication port 15. The second inversion path P6 is formed in the discharge device 100 and is a path extending upward from one end connected to the communication port 15. The re-conveyance path P4 is a path branching from the first inversion path P3 and extending toward the image forming unit 30.

[0033] In the vicinity below the communication port 15 of the first inversion path P3, an inversion roller pair 51 is disposed. The inversion roller pair 51 is a roller pair that conveys the sheet S sent from the main body conveyance path P1 to the first inversion path P3. The inversion roller pair 51 is a switchback roller configured to be rotatable in both forward and reverse directions. By rotating forward, the inversion roller pair 51 temporarily conveys the sheet S conveyed through the first inversion path P3 from the communication port 15 upward above the discharge device 100 outside the image forming apparatus 10 through the second inversion path P6 in the first direction D1. By rotating in the reverse direction, the inversion roller pair 51 conveys the sheet S in the second direction D2 that draws the sheet S into the image forming apparatus 10. The re-conveyance path P4 extends downward from the first inversion path P3, then bends forward, extends upward below the registration roller pair 23, and merges into the feeding path below the pair of registration roller pairs 23.

[0034] The duplex switching unit 42 is a member that switches the conveyance direction of the sheet S at the branch portion of the main body conveyance path P1 and the first inversion path P3, and is rotatably provided on the image forming apparatus 10. The duplex switching unit 42 is provided to be switchable between a discharge position (shown by a solid line in FIG. 2) and a duplex conveyance position (shown by a broken line in FIG. 2). When the duplex switching unit 42 is in the discharge position, it closes the first inversion path P3 so as to guide the sheet S conveyed from the fixing unit 34 to the main body discharge path P2. When the duplex switching unit 42 is in the duplex conveyance position, it swings forward from the discharge position to open the re-conveyance path P4 and closes the main body discharge path P2 so as to guide the sheet S conveyed from the fixing unit 34 to the re-conveyance path P4.

[0035] The discharge switching unit 101 is a member that switches the conveyance direction of the sheet S at the first connection position X1, which is a branch portion between the main body discharge path P2 and the option discharge path P5, and is rotatably provided in the discharge device 100. When the discharge switching unit 101 guides the sheet S conveyed from the conveyance roller pair 43 toward the first discharge roller pair R1 along the main body discharge path P2, it is located at the first position (shown by a solid line in FIG. 2) that closes the option discharge path P5. When the discharge switching unit 101 guides the sheet S conveyed from the conveyance roller pair 43 to the option discharge path P5, it swings forward from the first position to open the option discharge path P5 and is located at the second position (shown by a broken line in FIG. 2) that closes the main body discharge path P2.

[0036] As described above, according to the image forming system 1 of the present embodiment, the discharge switching unit 101 that switches the discharge destination of the sheet S is not provided in the image forming apparatus 10 but is provided in the discharge device 100. Therefore, when a sheet jam occurs in the vicinity of the discharge switching unit 101, particularly in the main body discharge path P2 or the main body conveyance path P1, the sheet can be easily processed by removing the discharge device 100.

[0037] Here, if the discharge switching unit 101 is provided in the image forming apparatus 10, the image forming apparatus 10 may have a complicated configuration, and there is a risk that the stability may decrease, such as the occurrence of sheet jams becoming more likely. On the other hand, in the image forming system 1 of the present embodiment, the discharge switching unit 101 is not provided in the image forming apparatus 10 but is provided in the discharge device 100. Therefore, the number of parts of the image forming apparatus 10 can be reduced, the occurrence rate of sheet jams can be decreased, the stability can be improved, and the cost of the image forming apparatus 10 can also be reduced.

[0038] <Second Embodiment> Next, a second embodiment of the present invention will be described in detail with reference to FIGS. 4 to 6. In this embodiment, the configuration is different from the first embodiment in that a cover 200 is mounted instead of the discharge device 100. However, for the other components of the image forming apparatus 10, since they are the same as those in the first embodiment, the same reference numerals are used and the detailed description thereof is omitted. In this embodiment, the image forming system 2 includes the same image forming apparatus 10 as in the first embodiment and a cover 200.

[0039] FIG. 4 is a perspective view of the image forming apparatus 10 in the first embodiment with the cover 200 mounted thereon, FIG. 5 is a cross-sectional view of the image forming apparatus 10 with the cover 200 mounted thereon, and FIG. 6 is a cross-sectional view of the image forming apparatus 10 with the cover 200 removed. As shown in FIG. 3, by removing the discharge device 100 from the image forming apparatus 10, as shown in FIGS. 4 and 5, a detachable cover 200 can be mounted on the upper part of the image forming apparatus 10 instead of the discharge device 100.

[0040] The cover 200 has a second inversion path P7 connected to the first inversion path P3 in a state where the cover 200 is mounted on the image forming apparatus 10. Thereby, in a state where the cover 200 is mounted on the image forming apparatus 10, a retraction path is formed by the first inversion path P3 and the second inversion path P7 to retract the rear end of the sheet S conveyed in the first direction D1 downstream of the second connection position X2. The second inversion path P7 has a downstream end in the second direction connected to the communication port 15 and is formed substantially horizontally upward from above toward the front direction F upstream. Thereby, it is not necessary to expand the cover 200 upward, and the thickness of the cover 200 can be reduced.

[0041] As shown in FIG. 6, the cover 200 has a mounting portion 203. The mounting portion 203 has a mounting surface 204 and a convex portion 205 that protrudes convexly downward from the mounting surface 204. When the mounting portion 203 is mounted on the mounted portion 11, the cover 200 is mounted on the image forming apparatus 10. A guide portion 205a is formed at the lower end portion of the convex portion 205. In a state where the cover 200 is mounted on the image forming apparatus 10, the guide portion 205a closes the opening 14a, and the guide member 14 of the image forming apparatus 10 forms the main body discharge path P2 together with the guide portion 205a.

[0042] [Sheet conveyance path during sheet discharge] Next, the configuration of the sheet conveyance path in a state where the cover 200 is mounted on the image forming apparatus 10 will be described with reference to FIG. 5. As shown in FIG. 5, in a state where the cover 200 is mounted, the communication port 107 and the discharge switching portion 101 of the first embodiment are not provided. For this reason, the sheet S is always conveyed to the main body discharge tray 41 through the main body discharge path P2 without branching from the main body conveyance path P1 to the discharge device 100 during sheet conveyance. Therefore, as shown in FIG. 6, the cover 200 is provided with a guide portion 205a for guiding the sheet S in the main body conveyance path P1 and the main body discharge path P2.

[0043] During re-conveyance, similar to the first embodiment, by rotating the reverse roller pair 51 forward, the sheet S conveyed through the first reverse path P3 is temporarily conveyed in the first direction D1 from the communication port 15 to the cover 200 outside the image forming apparatus 10 through the second reverse path P7. Then, by rotating the reverse roller pair 51 backward, the sheet S is conveyed in the second direction D2 for drawing the sheet S into the image forming apparatus 10.

[0044] As described above, according to the image forming system 2 of the present embodiment, the discharge switching unit 101 that switches the discharge destination of the sheet S is not provided in the image forming apparatus 10. Therefore, when a sheet jam occurs in the main body discharge path P2, the main body conveyance path P1, or the communication port 15, the sheet can be easily processed by removing the cover 200. In addition, since the number of parts of the image forming apparatus 10 can be reduced, the occurrence rate of sheet jams can be decreased and the stability can be improved, and the cost of the image forming apparatus 10 can also be reduced. Further, since the cover 200 has only the guide portion 205a and the second inversion path P7, it can have a simple configuration.

[0045] Also, it is possible to make the configuration of the image forming apparatus 10 common when the discharge device 100 is mounted and when the cover 200 is mounted. Thereby, the number of parts of the image forming apparatus 10 can be reduced and the configuration can be simplified.

[0046] <Third Embodiment> Next, a third embodiment of the present invention will be described in detail with reference to FIG. 7. In this embodiment, the configuration is different from that of the first embodiment in that a discharge device 300 is mounted instead of the discharge device 100. However, since the other image forming apparatus 10 is the same as that of the first embodiment, the same reference numerals are used and the detailed description is omitted. In this embodiment, the image forming system 3 includes the same image forming apparatus 10 as that of the first embodiment and a discharge device 300.

[0047] As shown in FIG. 7, the discharge device 300 has a second inversion path P8 connected to the first inversion path P3 in a state where it is mounted on the image forming apparatus 10. Thereby, in a state where the discharge device 300 is mounted on the image forming apparatus 10, a retraction path is formed that retracts the rear end of the sheet S conveyed in the first direction D1 by the first inversion path P3 and the second inversion path P8 to a position downstream of the second connection position X2. The second inversion path P8 has a downstream end in the second direction connected to the communication port 15 and is formed substantially horizontally upward from above toward the front direction F upstream. Thereby, it is not necessary to expand the discharge device 300 upward, and the discharge device 300 can be made thinner.

[0048] The discharging device 300 includes a second discharging roller pair R2 that discharges the sheet S, an optional discharging path P9 that conveys the sheet S from the first connection position X1 to the second discharging roller pair R2, a switching unit 301, and an optional discharging tray 302. The optional discharging path P9 is an example of a second conveyance path. When the discharging device 300 is mounted on the image forming apparatus 10, it is connected to the main body conveyance path P1 and conveys the sheet S from the first connection position X1 of the main body conveyance path P1 to the second discharging roller pair R2. The discharge switching unit 101 is an example of a guide portion and guides the sheet conveyed in the main body conveyance path P1 to the optional discharging path P9. That is, in the present embodiment, the switching unit 301 is a member that switches the conveyance direction of the sheet S at the first connection position X1, but is provided at the second position so as to always guide the sheet to the optional discharging path P9 during sheet conveyance. The sheet S is discharged from the second discharging roller pair R2 to the optional discharging tray 302 and stacked thereon. The optional discharging tray 302 is provided in a sheet accommodating space from the second discharging roller pair R2 toward the main body discharging tray 41 and can stack a large amount of the sheet S.

[0049] As described above, according to the image forming system 3 of the present embodiment, the switching unit 301 that switches the discharge destination of the sheet S is not provided in the image forming apparatus 10. Therefore, when a sheet jam occurs in the main body discharge path P2, the main body conveyance path P1, or the communication port 15, the sheet can be easily processed by removing the discharging device 300. In addition, since the number of components of the image forming apparatus 10 can be reduced, the occurrence rate of sheet jams can be decreased, the stability can be improved, and the cost of the image forming apparatus 10 can be reduced.

[0050] Further, according to the image forming system 3 of the present embodiment, the optional discharging tray 302 can be disposed lower than in the first embodiment, and a second inversion path P8, which is a part of a retracting path formed in the discharging device 300, extends forward. Therefore, it is possible to reduce the size of the image forming apparatus 10 compared to the first embodiment.

[0051] Note that, in the above-described embodiment, the switching unit 301 is movable and is positioned at the second position, but the present invention is not limited to this. For example, instead of the switching unit 301, a fixed and immovable guide may be attached to guide the sheet conveyed in the main body conveyance path P1 to the optional discharge path P9.

[0052] <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described in detail with reference to FIG. 8. In this embodiment, the configuration is different from that of the first embodiment in that a multi-stage discharge device 400 is attached instead of the discharge device 100. However, for the other image forming apparatuses 10, since they are the same as those in the first embodiment, the same reference numerals are used and the detailed description is omitted. In this embodiment, the image forming system 4 includes the same image forming apparatus 10 as that in the first embodiment and a discharge device 400.

[0053] As shown in FIG. 9, the discharge device 400 has a first discharge tray 411, a second discharge tray 412, and a third discharge tray 413 arranged vertically. In this discharge device 400, the sheet S sent from the image forming apparatus 10 can be distributed and discharged to each of the first discharge tray 411, the second discharge tray 412, and the third discharge tray 413. Here, the discharge device 400 has a second discharge unit 410 that discharges the sheet S. The second discharge unit 410 includes a second discharge roller pair R2, a third discharge roller pair R3, and a fourth discharge roller pair R4, which will be described later.

[0054] The second discharge roller pair R2 discharges the sheet to the first discharge tray 411. The discharge device 400 has a discharge path P11 for discharging the sheet S conveyed from the image forming apparatus 10 to the first discharge tray 411. The discharge path P11 is an example of a second conveyance path that conveys the sheet S from the first connection position X1 to the second discharge roller pair R2.

[0055] The third discharge roller pair R3 discharges the sheet onto the second discharge tray 412. The discharge device 400 has a discharge path P12 for discharging the sheet S conveyed from the image forming apparatus 10 onto the second discharge tray 412, and a second switching unit 402. The discharge path P12 can be connected to the discharge path P11 at the third connection position X3, and is an example of a sixth conveyance path that conveys the sheet S from the third connection position X3 to the third discharge roller pair R3. The second switching unit 402 is provided in the middle of the discharge path P11 and is switched by rotation between a third position (shown by a broken line in FIG. 8) and a fourth position (shown by a solid line in FIG. 8). When the second switching unit 402 is in the third position, it guides the sheet S from the image forming unit 30 toward the second discharge roller pair R2 via the discharge path P11. When the second switching unit 402 is in the fourth position, it guides the sheet S from the image forming unit 30 toward the third discharge roller pair R3 via the discharge path P12.

[0056] The fourth discharge roller pair R4 discharges the sheet onto the third discharge tray 413. The discharge device 400 has a discharge path P13 for discharging the sheet S conveyed from the image forming apparatus 10 onto the third discharge tray 413, and a third switching unit 403. The discharge path P13 can be connected to the discharge path P12 at the fourth connection position X4, and is an example of a seventh conveyance path that conveys the sheet S from the fourth connection position X4 to the fourth discharge roller pair R4. The third switching unit 403 is provided in the middle of the discharge path P12 and is switched by rotation between a fifth position (shown by a broken line in FIG. 8) and a sixth position (shown by a solid line in FIG. 8). When the third switching unit 403 is in the fifth position, it guides the sheet S from the image forming unit 30 toward the third discharge roller pair R3 via the discharge path P12. When the third switching unit 403 is in the sixth position, it guides the sheet S from the image forming unit 30 toward the fourth discharge roller pair R4 via the discharge path P13.

[0057] In a state where the discharge device 400 is attached to the image forming apparatus 10, it has a second inversion path P10 connected to the first inversion path P3. As a result, in a state where the discharge device 400 is attached to the image forming apparatus 10, a retraction path is formed by the first inversion path P3 and the second inversion path P10 to retract the rear end of the sheet S conveyed in the first direction D1 downstream of the second connection position X2. The second inversion path P10 has its downstream end in the second direction connected to the communication port 15 and is formed linearly upstream. In the present embodiment, since it has three-stage first discharge trays 411, second discharge trays 412, and third discharge trays 413, it has a high height, and the second inversion path P10 can be made long, enabling it to handle long-sized sheets as well.

[0058] As described above, according to the image forming system 4 of the present embodiment, the switching unit 401 for switching the discharge destination of the sheet S is not provided in the image forming apparatus 10. Therefore, when a sheet jam occurs in the main body discharge path P2, the main body conveyance path P1, or the communication port 15, the sheet can be easily processed by removing the discharge device 400. Also, since the number of components of the image forming apparatus 10 can be reduced, the occurrence rate of sheet jams can be decreased, improving stability, and cost reduction of the image forming apparatus 10 can also be achieved.

[0059] Also, according to the image forming system 4 of the present embodiment, since a part of the retraction path formed in the discharge device 400, that is, the second inversion path P10, has a longer configuration than in the first embodiment, it is possible to handle long sheets.

Explanation of Reference Numerals

[0060] 1…Image forming system, 10…Image forming apparatus, 11…Mounting part, 12…Mounting surface, 13…Recessed part, 14…Guide member (first guide member), 30…Image forming unit (image forming part), 51…Inversion roller pair, 100…Discharge device, 101…Discharge switching part (first switching part, switching part), 103…Mounting part, 104…Mounting surface, 105…Protrusion, 106…Guide member (second guide member), 110…Second discharge part, 200…Cover, 301…Discharge switching part (guide part), 402…Second switching part, 403…Third switching part, 410…Second discharge part, D1…First direction, D2…Second direction, P1…Main body conveyance path (first conveyance path), P2…Main body discharge path (first conveyance path), P3…First inversion path (third conveyance path, retraction path), P4…Re-conveyance path (fourth conveyance path), P5…Option discharge path (second conveyance path), P6…Second inversion path (fifth conveyance path, retraction path), P11…Discharge path (second conveyance path), P12…Discharge path (sixth conveyance path), P13…Discharge path (seventh conveyance path), R1…First discharge roller pair (first discharge part), R2…Second discharge roller pair, R3…Third discharge roller pair, R4…Fourth discharge roller pair, S…Sheet, X1…First connection position, X2…Second connection position, X3…Third connection position, X4…Fourth connection position

Claims

1. An image forming apparatus having an image forming unit that forms an image on a sheet, and a discharging device detachably mounted on the upper part of the image forming apparatus, comprising: The image forming apparatus has a first discharging unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharging unit inside the image forming apparatus; The discharging device has a second discharging unit that discharges the sheet, and a second conveyance path that is connectable to the first conveyance path when mounted on the image forming apparatus and conveys the sheet from the first conveyance path to the second discharging unit, and a first switching unit that switches between a first position for guiding the sheet from the image forming unit toward the first discharging unit via the first conveyance path and a second position for guiding the sheet from the image forming unit toward the second discharging unit via the second conveyance path; An image forming system characterized by the above.

2. The discharging device has a mounting portion, The image forming apparatus has a mounted portion on which the discharging device is mounted when the mounting portion is mounted, The mounting portion has a mounting surface and a convex portion protruding convexly downward from the mounting surface, The mounted portion has a mounted surface that supports the mounting surface when the mounting portion is mounted, and a concave portion that is recessed concavely downward from the mounted surface and into which the convex portion is fitted, The first switching unit is provided at the lower end of the convex portion. The image forming system according to claim 1, characterized by the above.

3. The image forming apparatus has a first guide member that forms the first conveyance path together with the first switching unit located at the first position, The discharging device has a second guide member that forms the second conveyance path together with the first switching unit located at the second position. The image forming system according to claim 1, characterized by the above.

4. The image forming apparatus has a third conveyance path that branches from the first conveyance path upstream in the sheet conveyance direction from a first connection position where the second conveyance path is connected to the first conveyance path, and a pair of reversing rollers that reverse and convey the conveyance direction of the sheet conveyed in a first direction by the third conveyance path in a second direction opposite to the first direction. A fourth conveyance path that is connected to the third conveyance path at a second connection position upstream of the inversion roller pair in the first direction, and that re-conveys a sheet that has been conveyed in the third conveyance path and whose conveyance direction has been inverted to the second direction by the inversion roller pair to the image forming unit. The discharge device has a fifth conveyance path that is connected to the third conveyance path in a state where the discharge device is attached to the image forming apparatus. In a state where the discharge device is attached to the image forming apparatus, a retraction path is formed by the third conveyance path and the fifth conveyance path to retract the trailing edge of a sheet conveyed in the first direction downstream of the second connection position. The image forming system according to claim 1, characterized in that.

5. The first discharge unit has a first discharge roller pair. The image forming system according to claim 1, characterized in that.

6. The second discharge unit has a second discharge roller pair. The image forming system according to claim 1, characterized in that.

7. The second discharge unit further has a third discharge roller pair that discharges a sheet. The discharge device has a sixth conveyance path that can be connected to the second conveyance path at a third connection position and that conveys a sheet from the third connection position to the third discharge roller pair, and a second switching unit that switches between a third position that guides a sheet from the image forming unit toward the second discharge roller pair via the second conveyance path and a fourth position that guides a sheet from the image forming unit toward the third discharge roller pair via the sixth conveyance path. The image forming system according to claim 6, characterized in that.

8. The second discharge unit further has a fourth discharge roller pair that discharges a sheet. The discharge device has a seventh conveyance path that can be connected to the sixth conveyance path at a fourth connection position and that conveys a sheet from the fourth connection position to the fourth discharge roller pair, and a third switching unit that switches between a fifth position that guides a sheet from the image forming unit toward the third discharge roller pair via the sixth conveyance path and a sixth position that guides a sheet from the image forming unit toward the fourth discharge roller pair via the seventh conveyance path. The image forming system according to claim 7, characterized in that.

9. An image forming apparatus having an image forming unit that forms an image on a sheet, a first discharge unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharge unit inside the image forming apparatus, a discharge device that is detachably attached to the upper part of the image forming apparatus, a second discharge unit that discharges the sheet, a second conveyance path that can be connected to the first conveyance path when the discharge device is attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharge unit, a switching unit that switches between a first position that guides the sheet from the image forming unit toward the first discharge unit via the first conveyance path and a second position that guides the sheet from the image forming unit toward the second discharge unit via the second conveyance path, characterized in that it is a discharge device.

10. An image forming unit that forms an image on a sheet, a first discharge unit that discharges the sheet, a first conveyance path that conveys the sheet from the image forming unit to the first discharge unit inside the image forming apparatus, a second discharge unit that discharges the sheet, a second conveyance path that can be connected to the first conveyance path when the discharge device is attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharge unit, a switching unit that switches between a first position that guides the sheet from the image forming unit toward the first discharge unit via the first conveyance path and a second position that guides the sheet from the image forming unit toward the second discharge unit via the second conveyance path, a mounting portion to which the discharge device can be mounted, a cover that is detachably attached to the mounting portion with the discharge device removed, characterized in that it is an image forming apparatus.

11. An image forming apparatus having an image forming unit that forms an image on a sheet, a discharge device that is detachably attached to the upper part of the image forming apparatus, wherein the image forming apparatus has a first discharge unit that discharges the sheet, and a first conveyance path that conveys the sheet from the image forming unit to the first discharge unit inside the image forming apparatus, wherein the discharge device has a second discharge unit that discharges the sheet, a second conveyance path that is connected to the first conveyance path when the discharge device is attached to the image forming apparatus and conveys the sheet from the first conveyance path to the second discharge unit, and a guiding unit that guides the sheet conveyed in the first conveyance path to the second conveyance path, characterized in that it is an image forming system.

Images