Image forming apparatus

Abstract

To provide an image forming apparatus that can achieve both preventing the occurrence of an image defect and dew condensation and reducing the size of the image forming apparatus.SOLUTION: An image forming apparatus comprises: a reading unit; an image forming unit that forms an ejection space with the reading unit, and that has an image carrier, a fixing section that fixes a toner image to a sheet, and an ejection section that ejects the sheet in a sheet ejection direction toward the ejection space; and a first duct that extends in a first direction orthogonal to the rotation axis direction of the image carrier, and communicates with each other the ejection space and the outside surface of the image forming unit on the upstream side in the sheet ejection direction. The image forming unit has a second duct that extends in the rotation axis direction, and allows air for cooling the sheet ejected by the ejection section to pass therethrough. At least part of the first duct is arranged to overlap the second duct in a second direction orthogonal to the first direction and the rotation axis direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet.

Background Art

[0002] Conventionally, an image forming apparatus has been proposed that includes an image forming apparatus main body and a document reading apparatus provided above the image forming apparatus main body (see Patent Document 1). In such an image forming apparatus, water vapor generated inside the image forming apparatus main body is discharged from the sheet discharge port, or water vapor is generated from the discharged sheet. Further, this image forming apparatus forms a duct space between the upper surface of the image forming apparatus main body and the lower surface of the document reading apparatus, and the duct space communicates with the space formed between the image forming apparatus main body and the document reading apparatus and the back surface of the image forming apparatus. Then, a part of the water vapor filling the above space is discharged to the back surface of the image forming apparatus through the duct space by natural convection, suppressing the occurrence of dew condensation on the bottom surface of the document reading apparatus.

[0003] Also, conventionally, an air outlet is provided above the nip of a pair of discharge rollers that discharge a sheet, and an image forming apparatus has been proposed that suppresses the sticking of sheets due to the re-melting of toner on the sheet by blowing air from the air outlet onto the sheet (see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the image forming apparatus described in Patent Document 1, in order to provide a duct space between the image forming apparatus main body and the document reading apparatus, the image forming apparatus has been enlarged in the height direction by the amount of the duct space. Further, in the image forming apparatus described in Patent Document 2, it is necessary to arrange a duct for sending air to an air outlet provided above the nip of the discharge roller pair, and the image forming apparatus has been enlarged in the height direction by the amount of the duct.

[0006] Thus, when suppressing image defects and the occurrence of condensation associated with the re-melting of toner, the image forming apparatus has been enlarged, and it has not been possible to achieve both suppressing the occurrence of image defects and condensation and downsizing the image forming apparatus.

[0007] An object of the present invention is to provide an image forming apparatus capable of achieving both suppressing the occurrence of image defects and condensation and downsizing the image forming apparatus.

Means for Solving the Problems

[0008] The present invention relates to an image forming apparatus, comprising: a reading unit having a reading section for reading an image of a document; an image forming unit provided below the reading unit and forming a discharge space between the reading unit, the image forming unit including an image carrier for carrying a toner image to be transferred onto a sheet, a fixing unit for fixing the toner image onto the sheet by applying heat and pressure, and a discharge unit for discharging the sheet that has passed through the fixing unit in a sheet discharge direction toward the discharge space; a first duct extending in a first direction along the sheet discharge direction and orthogonal to the rotation axis direction of the image carrier, the first duct communicating the outer surface on the upstream side of the image forming unit in the sheet discharge direction with the discharge space; wherein the image forming unit has a second duct extending in the rotation axis direction through which air for cooling the sheet discharged by the discharge unit passes, and at least a part of the first duct is arranged to overlap the second duct in a second direction orthogonal to the first direction and the rotation axis direction.

Effects of the Invention

[0009] According to the present invention, it is possible to achieve both suppression of occurrence of image defects and condensation, and miniaturization of the image forming apparatus.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the present embodiment will be described with reference to the drawings. In the following description, the vertical, horizontal, front-back, and left-right positional relationships are defined based on the state where the image forming apparatus 100 is viewed from the front (the viewpoint in FIG. 1(a)). Further, hereinafter, the front-back direction (front-rear direction) of the image forming apparatus 100 is defined as the X-axis direction, the left-right direction of the image forming apparatus 100 is defined as the Y-axis direction, and the height direction of the image forming apparatus 100 is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are orthogonal to each other. Also, the X-axis direction as the first direction is a direction along the sheet discharge direction DD described later, and is a direction orthogonal to the rotation axis direction of the photosensitive drum 42 described later within the horizontal direction. The Y-axis direction is the rotation axis direction of the photosensitive drum 42 as an image carrier. The Z-axis direction as the second direction is the height direction of the image forming apparatus 100, and is a direction parallel to the vertical direction and the gravitational direction.

[0012] [Schematic Configuration of Image Forming Apparatus] FIG. 1(a) is a front view showing the image forming apparatus 100, and FIG. 1(b) is a cross-sectional view showing the A-A cross section of FIG. 1(a). The image forming apparatus 100 according to the present embodiment is an electrophotographic monochrome laser beam printer and is a multifunction printer having a document reading function.

[0013] Note that the image forming apparatus includes a printer, a copier, a facsimile machine, and a multifunction machine, and refers to an apparatus that forms an image on a sheet used as a recording medium based on image information input from an external PC or image information read from a document. In addition, in addition to the main body having an image forming function, the image forming apparatus may be connected with accessory devices such as an optional feeder and a sheet processing apparatus, and the entire system connected with such accessory devices is also a kind of image forming apparatus. Also, the document and the sheet include paper such as paper and envelopes, plastic films such as overhead projector sheets (OHT), cloth, and the like.

[0014] As shown in FIGS. 1(a) and 1(b), the image forming apparatus 100 includes a reading unit 2 that reads image data of a document, and an image forming unit 1 provided below the reading unit 2. The reading unit 2 is supported so as to be openable and closable with respect to the image forming unit 1 about an opening / closing axis provided at the rear and upper part of the image forming unit 1. The reading unit 2 includes a document glass table 2a on which a document is placed, and a reading unit 2b that optically scans the document placed on the document glass table 2a to read image information. Note that the reading unit 2 may have an ADF (Auto Document Feeder) that feeds a document placed on a document tray. The image information converted into an electronic signal by the reading unit 2 is transferred to a control unit (not shown) provided in the image forming unit 1.

[0015] The image forming unit 1 includes a feeding unit 5 that feeds a sheet P, an image forming unit 40 that forms an image on the sheet P, a fixing unit 7 that fixes the image on the sheet P, a pair of discharging rollers 8 as a discharging unit, and the like. A discharging space 10 where the sheet P is discharged is formed between the reading unit 2 and the image forming unit 1, and a discharging tray 9 on which the discharged sheet P is stacked is provided in the discharging space 10.

[0016] The image forming unit 40 includes a laser scanner 41, a photosensitive drum 42, a charging roller and a developing roller (not shown) arranged around the photosensitive drum 42, and a transfer roller 43 that forms a transfer nip 6 together with the photosensitive drum 42.

[0017] Next, the image forming operation of the image forming apparatus 100 configured as described above will be described. When the image data transmitted from a personal computer or the like (not shown) or the image data read by the reading unit 2 is input to the laser scanner 41, laser light corresponding to the image data is irradiated onto the photosensitive drum 42 from the laser scanner 41.

[0018] At this time, the surface of the photosensitive drum 42 is uniformly charged to a predetermined polarity and potential in advance by a charging roller, and an electrostatic latent image is formed on the surface by irradiating laser light from the laser scanner 41. The electrostatic latent image formed on the photosensitive drum 42 is developed by a developing roller, and a toner image is formed on the photosensitive drum 42.

[0019] In parallel with this image forming process, the sheet P placed on the sheet tray 5a of the feeding unit 5 is fed to the conveyance path CP by the pickup roller 5b. Then, the toner image on the photosensitive drum 42 is transferred at the transfer nip 6 to the sheet P fed by the pickup roller 5b by the transfer bias applied to the transfer roller 43. The sheet P onto which the toner image has been transferred is given predetermined heat and pressure by the fixing unit 7, and the toner is melted and fixed (fixed). The sheet P that has passed through the fixing unit 7 is discharged to the discharge tray 9 by the discharge roller pair 8.

[0020] [Discharge space] Next, the discharge space 10 will be described with reference to FIGS. 1(a) to 2(b). FIG. 2(a) is a perspective view showing the image forming apparatus 100. FIG. 2(b) is another perspective view showing the image forming apparatus 100. In FIGS. 2(a) and 2(b), the reading unit 2 is open with respect to the image forming unit 1.

[0021] As shown in FIGS. 1(a) and 1(b), a discharge space 10 is formed between the image forming unit 1 and the reading unit 2 through which the sheet P is discharged in the sheet discharge direction DD. The discharge space 10 is formed by the fact that when the reading unit 2 is closed with respect to the image forming unit 1, other than the opening 3 on the front side of the image forming apparatus 100, is covered by the image forming unit 1 and the reading unit 2.

[0022] More specifically, as shown in FIGS. 2(a) and 2(b), the discharge space 10 is formed by a discharge tray 9 on which the discharged sheet P is loaded, a rising surface 51, a first side surface 23a, a second side surface 23b, and the bottom surface 11 of the reading unit 2. The rising surface 51 extends in the Y-axis direction and the Z-axis direction. A sheet discharge port 51a through which the sheet P discharged by the discharge roller pair 8 passes is formed in the rising surface 51.

[0023] The discharge tray 9 as a loading surface extends upward as it goes downstream in the sheet discharge direction DD. The first side surface 23a is formed on one side (right side) of the discharge tray 9 in the Y-axis direction and extends in the X-axis direction and the Z-axis direction. The second side surface 23b is formed on the other side (left side) of the discharge tray 9 in the Y-axis direction and extends in the X-axis direction and the Z-axis direction. A side surface opening 25 as a second exhaust port is formed in the first side surface 23a.

[0024] Further, the image forming unit 1 has a side cover 24 that forms an outer surface, and the side cover 24 includes a back surface 24a as an outer surface on the upstream side in the sheet discharge direction DD of the image forming unit 1 as shown in FIG. 1(b). An intake louver 28 formed of a plurality of holes is provided on the inner right side surface of the side cover 24. Also, the image forming unit 1 has a top cover 52 that constitutes the top surface of the image forming unit 1, and a recess 52a recessed in a direction away from the bottom surface 11 of the reading unit 2 is provided in the top cover 52. The recess 52a and the bottom surface 11 of the reading unit 2 form a first duct 22 that extends in the X-axis direction, and the first duct 22 communicates the discharge space 10 with the back surface 24a of the image forming unit 1.

[0025] In the Y-axis direction, the width L1 of the first duct 22 is narrower than the width L2 of the discharge tray 9. The first duct 22 is arranged at a position closer to the second side surface 23b than the first side surface 23a in the Y-axis direction. More specifically, the first duct 22 is formed such that one end surface in the Y-axis direction is substantially flush with the second side surface 23b.

[0026] [Duct Structure and Airflow] Next, the duct structure and airflow formed in the image forming unit 1 will be described with reference to FIGS. 3(a) to 4(b). FIG. 3(a) is a perspective view showing the image forming unit 1 with the side cover 24 removed, and FIG. 3(b) is another perspective view showing the image forming unit 1 with the side cover 24 removed. FIG. 4(a) is a perspective view showing the dew condensation adhesion range of the image forming apparatus 200 according to the comparative example, and FIG. 4(b) is a perspective view showing the airflow and dew condensation adhesion range of the image forming apparatus 100 according to the present embodiment.

[0027] As shown in FIG. 3(a), the image forming unit 1 includes a fan 13, an intermediate duct 14, and a second duct 15. Here, the direction from the first side surface 23a (see FIG. 2(a)) to the second side surface 23b (see FIG. 2(b)) within the Y-axis direction is defined as the -Y direction as the first axis direction. The fan 13 and the intermediate duct 14 are arranged upstream in the -Y direction from the discharge space 10. For example, the fan 13 and the intermediate duct 14 are fixed to a side plate 53 which is a part of the frame of the image forming unit 1.

[0028] The fan 13 sends air toward the intermediate duct 14, and the intermediate duct 14 as the third duct extends in the Z-axis direction. In the present embodiment, the fan 13 is composed of a centrifugal fan, but is not limited thereto. For example, the fan 13 may be composed of an axial flow fan that sends air along the rotation axis direction of the blades.

[0029] The air (outside air) sucked in from the intake louver 28 (see Fig. 2(b)) by the fan 13 flows through the intermediate duct 14 as shown by the arrow A. As shown in Fig. 3(b), a branch portion 17 for branching the wind generated by the fan 13 is provided at the upper end portion of the intermediate duct 14. The wind flowing through the intermediate duct 14 branches at the branch portion 17 into the wind advancing in the direction of arrow B toward the second duct 15 and the wind advancing in the direction of arrow C toward the side opening 25 formed in the first side surface 23a through the side exhaust port 19 formed at the upper end portion of the intermediate duct 14. That is, the intermediate duct 14 guides a part of the wind generated by the fan 13 to the second duct 15.

[0030] The second duct 15 extends in the Y-axis direction, and the wind for cooling the sheet discharged by the discharge roller pair 8 passes through the inside. More specifically, the wind advancing in the direction of arrow B from the upper end portion of the intermediate duct 14 enters the second duct 15, and the wind in the -Y direction passes through the second duct 15. In other words, the fan 13 generates the wind in the -Y direction in the second duct 15.

[0031] The wind advancing in the -Y direction in the second duct 15 is directed in the direction along the sheet discharge direction DD by a plurality of straightening plates 16 provided in the second duct 15. A cooling exhaust port 18 for communicating the second duct 15 with the discharge space 10 is provided in the rising surface 51. The cooling exhaust port 18 as the first exhaust port may be formed integrally with the sheet discharge port 51a (see Fig. 2(a)) or separately.

[0032] Then, the wind whose direction has been changed in the direction along the sheet discharge direction DD by the plurality of straightening plates 16 is exhausted in the direction of arrow D toward the discharge space 10 through the cooling exhaust port 18. In this way, the wind exhausted in the direction of arrow D toward the discharge space 10 is taken as the first wind. The first wind cools the sheet P discharged into the discharge space 10 by the discharge roller pair 8. Then, the sheet P cooled by the first wind and discharged into the discharge space 10 is loaded on the discharge tray 9.

[0033] The sheet P stacked on the discharge tray 9 is cooled by the first wind and thus becomes equal to or lower than the remelting temperature of the toner. As a result, it is possible to suppress the sticking of sheets to each other and image defects caused by the remelting of the toner. Note that the wind flowing in the -Y direction through the second duct 15 may cool the sheet P inside the image forming unit 1 before being discharged into the discharge space 10. That is, the cooling exhaust port 18 may be formed in the second duct 15 to exhaust the wind for cooling the sheet P conveyed by the discharge roller pair 8.

[0034] On the other hand, the wind advancing in the direction of arrow C branched by the branch portion 17 is exhausted in the direction of arrow E from the side opening 25 toward the discharge space 10. Such wind advancing in the direction of arrow E is defined as the second wind. The direction of arrow E is a direction along the -Y direction, and the second wind (E) merges with the first wind (D) in the discharge space 10. Then, when the merged wind is defined as the third wind, as shown in FIG. 4(b), the third wind advances as indicated by arrow F.

[0035] Here, as shown in FIG. 4(a), the image forming apparatus 200 according to the comparative example will be described. The image forming apparatus 200 has a configuration that does not include the first duct 22 and the side opening 25 of the present embodiment described above. Therefore, in the image forming apparatus 200, the cooling air for cooling the sheet P is only the first wind (D) described above, and the first wind is exhausted into the discharge space 10 in the direction of arrow D. Then, the discharge space 10 is filled with the water vapor generated in the fixing unit 7 and the water vapor generated from the sheet P.

[0036] Since the image forming apparatus 200 does not have the first duct 22, the water vapor filling the discharge space 10 adheres as dew condensation to the bottom surface 11 of the reading unit 2. The dew condensation adhesion range shown by hatching in FIG. 4(a) is almost the same as the entire range of the bottom surface 11 forming the discharge space 10.

[0037] On the other hand, as shown in FIG. 4(b), in the present embodiment, the third wind indicated by the arrow F formed by the confluence of the first wind (D) and the second wind (E) hits the second side surface 23b. This is because the second wind (E) travels in the -Y direction. Then, a part of the wind hitting the second side surface 23b is exhausted to the back surface 24a side of the image forming unit 1 through the first duct 22, and the other part is exhausted from the opening 3 (see FIG. 1(b)) on the front side of the image forming apparatus 100 along the first side surface 23a.

[0038] As a result, the dew condensation adhesion range of the present embodiment indicated by hatching in FIG. 4(b) is dispersed over the first side surface 23a and the first duct 22, and a part of the reading unit 2. These dew condensation adhesion ranges are only on the -Y direction side (left side) of the discharge space 10 and are not on the Y direction side (right side) of the discharge space 10. Also, the dew condensation adhesion ranges located on the bottom surface 11 and the front side of the reading unit 2 are narrower than those in the comparative example shown in FIG. 4(a). Therefore, the risk of dew condensation adhering to the sheet P discharged by the discharge roller pair 8 and the user can be reduced, image defects can be reduced, and usability can be improved.

[0039] [Arrangement of the First Duct and the Second Duct] Next, with reference to FIGS. 1(a) and 5(a)(b), the arrangement of the first duct 22 and the second duct 15 will be described. FIG. 5(a) is a plan view showing the first duct 22 and the second duct 15 according to the present embodiment, and FIG. 5(b) is a plan view showing the first duct 22 and the second duct 15 according to Modification 1.

[0040] As shown in FIG. 1(a), in the present embodiment, the first duct 22 is arranged at the same height as the second duct 15 in the Z-axis direction. In the present embodiment, although the first duct 22 and the second duct 15 are arranged at the same height position, at least a part of the first duct 22 may be arranged so as to overlap the second duct 15 in the Z-axis direction. Also, as shown in FIG. 5(a), the first duct 22 is formed so as not to overlap the second duct 15 in the Y-axis direction. That is, the first duct 22 is arranged side by side with the second duct 15 in the Y-axis direction.

[0041] By arranging the first duct 22 and the second duct 15 as described above, the image forming apparatus 100 can be miniaturized particularly in the Z-axis direction. Further, since the sheet P can be cooled by the air passing through the second duct 15, image defects caused by toner remelting can be reduced. Further, while forming the first duct 22 in the image forming apparatus 100 and merging the second air flow (E) advancing in the -Y direction from the side opening 25 with the first air flow (D) advancing in the direction of arrow D, the dew condensation adhesion range can be narrowed and the occurrence of dew condensation can be suppressed. That is, it is possible to achieve both suppression of the occurrence of image defects and dew condensation and miniaturization of the image forming apparatus 100.

[0042] Further, since the second air flow (E) advancing in the -Y direction is merged with the first air flow (D) advancing in the direction of arrow D to create a forced convection (F), the cross-sectional area of the first duct 22 can be narrowed. And by miniaturizing the image forming apparatus 100, the degree of freedom of the installation location for the user can be expanded and the usability for the user can be improved.

[0043] <Modification Example 1> In Modification Example 1 shown in FIG. 5(b), the shape of the first duct 22 is changed. That is, in the first duct 22 shown in FIG. 5(b), the side communicating with the discharge space 10 is expanded in the Y-axis direction. That is, a part G of the first duct 22 is formed so as to overlap the second duct 15 in the Y-axis direction. Thereby, the amount of air flowing from the discharge space 10 into the first duct 22 increases, and the occurrence of image defects and dew condensation can be further suppressed.

[0044] <Modification Example 2> FIG. 6(a) is a front view showing the image forming apparatus 100 according to Modification Example 2, FIG. 6(b) is a front view showing the image forming apparatus 100 according to Modification Example 2, and FIG. 6(c) is a cross-sectional view showing the B-B cross section of FIG. 6(b).

[0045] In Modification 2, as shown in FIGS. 6(a) to 6(c), a reading recess 30 is formed on the bottom surface 11 of the reading unit 2. The reading recess 30 is recessed in a direction away from the top surface cover 52 of the image forming unit 1. Further, the reading recess 30 faces the recess 52a of the top surface cover 52, and at least a part of the reading recess 30 is arranged so as to overlap the recess 52a in the Y-axis direction.

[0046] And the first duct 22 according to Modification 2 is formed by the recess 52a and the reading recess 30. Thereby, the cross-sectional area of the first duct 22 according to Modification 2 can be enlarged compared to the first duct 22 (see FIG. 1(a)) of the present embodiment. Therefore, the amount of wind flowing from the discharge space 10 into the first duct 22 increases, and the occurrence of image defects and condensation can be further suppressed.

[0047] <Modification 3> FIG. 7(a) is a front view showing the image forming apparatus 100 according to Modification 3, and FIG. 7(b) is a perspective view showing the image forming apparatus 100 according to Modification 3. In Modification 3, as shown in FIGS. 7(a) and 7(b), a reading recess 130 is formed on the bottom surface 11 of the reading unit 2. The reading recess 130 is recessed in a direction away from the top surface cover 52 of the image forming unit 1.

[0048] The reading recess 130 is displaced in the Y-axis direction with respect to the reading recess 30 according to Modification 2. However, the reading recess 130 also faces the recess 52a of the top surface cover 52, and at least a part of the reading recess 130 is arranged so as to overlap the recess 52a in the Y-axis direction. Thereby, the same effect as in Modification 2 can be obtained, and the degree of design freedom can be improved.

[0049] <Modification 4> FIG. 8 is a perspective view showing the image forming apparatus 100 according to Modification 4. As shown in FIG. 8, an exhaust louver 31 is provided in an opening formed on the back surface 24a side of the first duct 22 according to Modification 4. Thereby, the design can be improved. <Other Embodiments>

[0050] In addition, in this embodiment, the air passing through the second duct 15 was advancing in the -Y direction, but it is not limited to this. For example, the fan 13 and the intermediate duct 14 may be provided on the -Y direction side (left side) of the discharge space 10 so that the air passing through the second duct 15 advances in the Y direction. In this case, it is preferable to arrange the first duct 22 at a position close to the first side surface 23a.

[0051] Further, the disclosure of this embodiment includes the following configuration examples and method examples. (Configuration 1) A reading unit having a reading unit for reading an image of a manuscript, An image forming unit provided below the reading unit and forming a discharge space between the image forming unit and the reading unit, the image forming unit including an image carrier carrying a toner image to be transferred to a sheet, a fixing unit for fixing the toner image to the sheet by applying heat and pressure, and a discharging unit for discharging the sheet that has passed through the fixing unit in a sheet discharge direction toward the discharge space. A first duct extending in a first direction along the sheet discharge direction and orthogonal to the rotation axis direction of the image carrier, and communicating an outer surface on the upstream side in the sheet discharge direction of the image forming unit with the discharge space. The image forming unit has a second duct through which air for cooling the sheet discharged by the discharging unit passes and extends in the rotation axis direction. At least a part of the first duct is arranged so as to overlap the second duct in a second direction orthogonal to the first direction and the rotation axis direction. An image forming apparatus characterized by the above. (Configuration 2) The image forming unit has a loading surface on which the sheet discharged by the discharging unit is loaded, a sheet discharge port through which the sheet discharged by the discharging unit passes, a rising surface extending in the direction of the rotation axis and the second direction, a first side surface formed on one side of the loading surface in the direction of the rotation axis, and a second side surface formed on the other side of the loading surface in the direction of the rotation axis. The discharge space is formed by the loading surface, the rising surface, the first side surface, the second side surface, and the bottom surface of the reading unit. In the direction of the rotation axis, the width of the first duct is narrower than the width of the loading surface. The image forming apparatus according to Configuration 1, characterized in that. (Configuration 3) The first duct is arranged at a position closer to the second side surface than the first side surface in the direction of the rotation axis. The image forming apparatus according to Configuration 2, characterized in that. (Configuration 4) When the direction from the first side surface to the second side surface within the direction of the rotation axis is defined as the first axis direction, The image forming unit has a fan that generates a wind in the first axis direction within the second duct. The image forming apparatus according to Configuration 3, characterized in that. (Configuration 5) The rising surface has a first exhaust port that communicates the second duct with the discharge space and exhausts a first wind for cooling the sheet discharged by the discharging unit toward the discharge space in the sheet discharge direction. The first side surface has a second exhaust port that communicates with the discharge space and exhausts a second wind, which is a part of the wind generated by the fan, toward the discharge space in the first axis direction. The first wind and the second wind merge in the discharge space. The image forming apparatus according to Configuration 4, characterized in that. (Configuration 6) The image forming unit has a third duct that guides the wind generated by the fan to the second duct. The fan and the third duct are arranged upstream of the discharge space in the first axial direction. The image forming apparatus according to Configuration 5, characterized in that. (Configuration 7) The air flowing through the third duct is branched into air flowing toward the second duct and air flowing toward the second exhaust port. The image forming apparatus according to Configuration 6, characterized in that. (Configuration 8) The image forming unit has a top cover facing the bottom surface of the reading unit, and a recess formed in the top cover and recessed in a direction away from the bottom surface. The first duct is formed by the bottom surface of the reading unit and the recess. The image forming apparatus according to any one of Configurations 2 to 7, characterized in that. (Configuration 9) The bottom surface of the reading unit has a reading recess recessed in a direction away from the top cover of the image forming unit. At least a part of the reading recess is arranged so as to overlap the recess in the rotational axis direction. The image forming apparatus according to Configuration 8, characterized in that. (Configuration 10) The first duct is formed so as not to overlap the second duct in the rotational axis direction. The image forming apparatus according to any one of Configurations 1 to 9, characterized in that. (Configuration 11) A part of the first duct is formed so as to overlap the second duct in the rotational axis direction. The image forming apparatus according to any one of Configurations 1 to 9, characterized in that. (Configuration 12) The first direction is a direction orthogonal to the rotational axis direction within the horizontal direction. The second direction is a direction parallel to the vertical direction. The image forming apparatus according to any one of Configurations 1 to 11, characterized in that.

Explanation of Signs

[0052] 1: Image forming unit / 2: Reading unit / 2b: Reading section / 7: Fixing section / 8: Discharge section (discharge roller pair) / 9: Loading surface (discharge tray) / 10: Discharge space / 11: Bottom surface / 13: Fan / 14: Third duct (intermediate duct) / 15: Second duct / 18: First exhaust port (cooling exhaust port) / 22: First duct / 23a: First side surface / 23b: Second side surface / 24a: Outer surface (rear surface) / 25: Second exhaust port (side opening) / 30, 130: Reading recesses / 42: Image carrier (photosensitive drum) / 51: Upright surface / 51a: Sheet discharge port / 52a: Recess / 100: Image forming apparatus / DD: Sheet discharge direction / G: Part / L1, L2: Width / X: First direction (X-axis direction) / Y: Second direction (Y-axis direction) / -Y: First axis direction (-Y direction) / Z: Third direction (Z-axis direction)

Claims

1. A reading unit having a reading section for reading an image of a document, An image forming unit provided below the reading unit and forming a discharge space between the reading unit and the image forming unit, the image forming unit including an image carrier for carrying a toner image to be transferred onto a sheet, a fixing section for fixing the toner image onto the sheet by applying heat and pressure, and a discharge section for discharging the sheet that has passed through the fixing section toward the discharge space in a sheet discharge direction, A first duct extending in a first direction along the sheet discharge direction and orthogonal to the rotation axis direction of the image carrier, the first duct communicating the outer surface on the upstream side in the sheet discharge direction of the image forming unit with the discharge space, The image forming unit has a second duct extending in the rotation axis direction and through which air for cooling the sheet discharged by the discharge section passes, At least a part of the first duct is arranged so as to overlap with the second duct in a second direction orthogonal to the first direction and the rotation axis direction, An image forming apparatus characterized by the above.

2. The image forming unit has a loading surface on which the sheet discharged by the discharge section is loaded, a sheet discharge port through which the sheet discharged by the discharge section passes, a rising surface extending in the rotation axis direction and the second direction, a first side surface formed on one side of the loading surface in the rotation axis direction, and a second side surface formed on the other side of the loading surface in the rotation axis direction, The discharge space is formed by the loading surface, the rising surface, the first side surface, the second side surface, and the bottom surface of the reading unit, In the rotation axis direction, the width of the first duct is narrower than the width of the loading surface, The image forming apparatus according to claim 1, characterized by the above.

3. The first duct is arranged at a position closer to the second side surface than the first side surface in the rotation axis direction, The image forming apparatus according to claim 2, characterized by the above.

4. When the direction from the first side surface to the second side surface within the rotation axis direction is defined as the first axis direction, The image forming unit has a fan for generating air flowing in the first axis direction within the second duct, The image forming apparatus according to claim 3, characterized by the above.

5. The rising surface has a first exhaust port that communicates the second duct with the discharge space and exhausts, in the sheet discharge direction, a first air current for cooling the sheet discharged by the discharge unit, toward the discharge space. The first side surface has a second exhaust port that communicates with the discharge space and exhausts, in the first axial direction, a second air current that is part of the air current generated by the fan, toward the discharge space. The first air current and the second air current merge in the discharge space. The image forming apparatus according to claim 4, characterized in that.

6. The image forming unit has a third duct that guides the air current generated by the fan to the second duct. The fan and the third duct are arranged upstream of the discharge space in the first axial direction. The image forming apparatus according to claim 5, characterized in that.

7. The air current flowing through the third duct branches into an air current toward the second duct and an air current toward the second exhaust port. The image forming apparatus according to claim 6, characterized in that.

8. The image forming unit has a top cover that faces the bottom surface of the reading unit, and a recess formed in the top cover and recessed in a direction away from the bottom surface. The first duct is formed by the bottom surface of the reading unit and the recess. The image forming apparatus according to claim 2, characterized in that.

9. The bottom surface of the reading unit has a reading recess recessed in a direction away from the top cover of the image forming unit. At least a part of the reading recess is arranged so as to overlap the recess in the rotational axis direction. The image forming apparatus according to claim 8, characterized in that.

10. The first duct is formed so as not to overlap the second duct in the rotational axis direction. The image forming apparatus according to claim 1, characterized in that.

11. A part of the first duct is formed so as to overlap the second duct in the rotational axis direction. The image forming apparatus according to claim 1, characterized in that.

12. The first direction is a direction orthogonal to the rotational axis direction within the horizontal direction. The second direction is a direction parallel to the vertical direction. The image forming apparatus according to any one of claims 1 to 11, characterized in that.

Images