Image forming device

Abstract

To solve the problem in which: when an image forming apparatus is configured to prevent contact of an operating unit with a sheet ejected with respect to the vertical direction in order to prevent ejected paper loading properties and printing accuracy from being impaired due to contact of the operating unit with an ejected or inverted sheet, a size of an apparatus body is increased.SOLUTION: An image forming apparatus comprises: an upper guide unit that is provided fixed to the image forming apparatus and guides a top face of a sheet ejected by a roller pair; a loading unit for loading the ejected sheet thereon at a position recessed from an upper exterior part of the image forming apparatus; and an operating unit that has a display. The upper guide unit extends to a downstream side in an ejection direction beyond the roller pair. The operating unit and the upper guide unit have portions that overlap each other. When seen from an axial direction of the roller pair, the upper guide unit and the operating unit are at positions through which a straight line passes, the straight line orthogonal to a surface passing through the axes of the roller pair and passing through a nip part of the roller pair.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Some image forming devices, such as printers and facsimiles, are provided with an operation unit for displaying information to a user or for the user to operate the device. The operation unit is located on the image forming device at a position outside the sheet stacking area in the sheet width direction, which is perpendicular to the sheet discharge direction, so as not to come into contact with the discharged sheets. Furthermore, from the perspectives of the size and design of the image forming device and preventing damage, it is desirable for the operation unit to be configured so that it does not protrude beyond the side of the device.

[0003] On the other hand, when an attempt is made to increase the size of an operation unit for the purpose of improving usability by increasing the amount of information displayed on the operation unit or adopting a touch panel, the operation unit tends to become larger. However, if the operation unit is enlarged and does not protrude from the side of the device, it may become difficult to position it outside the sheet stacking portion. In other words, the operation unit may protrude directly above the sheet stacking portion in the sheet width direction.

[0004] Therefore, a configuration has been proposed in which an arm unit is provided in the image forming apparatus to connect the upper part of the image forming apparatus with the operating unit, and even if the operating unit is provided above the stacking unit, the operating unit does not come into contact with the discharged sheets (Patent Document 1). In Patent Document 1, the arm unit is rotatable relative to the apparatus body, and by rotating the arm unit, the operating unit ensures a distance from the discharged sheets.

[0005] Also, a technique has been proposed in which the rotation path of the operating unit is positioned above the discharge path of the discharged sheets (Patent Document 2). In Patent Document 2, the operating unit is positioned so that it does not come into contact with the discharged sheets. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent 06341975 [Patent Document 2] Patent 06398307 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the methods described in Patent Documents 1 and 2, the arm unit and the operating unit are located at positions distant from the main body of the apparatus, which leads to an increase in the size of the image forming apparatus. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an image forming apparatus having an image forming section that forms an image on a sheet, the image forming apparatus including a pair of rollers that transport an image-formed sheet and discharge at least a portion of the sheet to the outside of the image forming apparatus, an upper guide section that is fixed to the image forming apparatus and guides an upper surface of the sheet discharged by the pair of rollers, a stacking section that is recessed from an upper exterior section of the image forming apparatus and stacks the discharged sheets, and a display section that displays information related to image formation, movable relative to the upper guide portion and an operating unit attached to an upper exterior part of the image forming apparatus for operating the image forming apparatus, wherein the upper guide unit extends downstream of the roller pair in the discharge direction of the sheet discharged by the roller pair, and the operating unit and the upper guide unit are aligned vertically. Look at and the rollers are arranged in a direction parallel to the axial direction of the roller pair. Look at When the roller pair is rotated, the operation unit and the upper guide unit are located at positions where a straight line that is perpendicular to a plane passing through the axes of the roller pair and passes through the nip portion of the roller pair passes through the straight line. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an image forming apparatus that is miniaturized while preventing the operation unit from interfering with the discharge of sheets when the operation unit is enlarged. [Brief explanation of the drawings]

[0010] [Figure 1] Schematic diagram of an image forming apparatus according to a first embodiment [Figure 2] FIG. 1 is a perspective view showing the arrangement of an operation unit in the first embodiment; [Figure 3] 1 is a top view of an image forming apparatus according to a first embodiment, viewed from a vertical direction. [Figure 4] FIG. 1 is a side view showing the configuration of an operation unit in the first embodiment. [Figure 5] FIG. 1 is a cross-sectional view illustrating a configuration of a sheet discharge unit in the first embodiment. [Figure 6] FIG. 5 is an enlarged view of the vicinity of the operation unit in the first embodiment. [Figure 7] FIG. 1 is a top view illustrating an example of packaging arrangement in an image forming apparatus according to a first embodiment. [Figure 8] FIG. 1 is a perspective view showing the shape of an upper guide portion in the first embodiment; [Figure 9] FIG. 10 is a cross-sectional view showing the relationship between the sheet discharge direction and the operation unit when the operation unit is in a first position in the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing the relationship between the sheet discharge direction and the operation unit when the operation unit is in a second position in the first embodiment. [Figure 11] 4 is a cross-sectional view showing the relationship between the state of the guide portion and the state of the detection portion in the first embodiment. [Figure 12] 1 is a cross-sectional view showing the relationship between the guide portion and the rotation trajectory of the detection portion in the first embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing the relationship between the guide portion and the sheets stacked on the stacking portion in the first embodiment. [Figure 14] FIG. 10 is a perspective view showing the shape of an upper guide portion in the second embodiment. [Figure 15] FIG. 10 is a top view of the image forming apparatus according to the second embodiment, viewed from the vertical direction. [Figure 16] FIG. 10 is a perspective view showing the shape of an upper guide portion in the third embodiment. [Figure 17]FIG. 10 is a top view of the image forming apparatus according to the third embodiment, viewed from the vertical direction. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Example 1] As an example of the configuration of an image forming apparatus according to the present invention for forming an image on a sheet, an embodiment in which the apparatus is applied to an electrophotographic laser beam printer will be specifically described. In this description, the overall configuration of the image forming apparatus according to the present invention will be described first, and then the configuration of a sheet discharge section of the image forming apparatus according to the present invention will be described.

[0012] FIG. 1 is a cross-sectional view showing the configuration of an example of an image forming apparatus according to an embodiment, when applied to an electrophotographic laser beam printer with a double-sided image forming function. FIGS. 2 and 3 are diagrams showing the layout of an operation unit 20 in this embodiment, with FIG. 2 being a perspective view and FIG. 3 being a top view of FIG. 2 as viewed from direction A, which is the vertical direction. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in this embodiment are not intended to limit the scope of the present invention to those alone. Furthermore, the image forming apparatus according to the present invention is not limited to laser beam printers, but may also be applied to other image forming apparatuses such as copiers and facsimiles.

[0013] 1 is broadly composed of a sheet feeding unit, an image forming unit, a fixing unit, a paper discharge / reversing unit, and a duplex conveying unit. The image forming apparatus 101 is equipped with a process cartridge 1 that is detachable from the main body of the apparatus. The process cartridge 1 is composed of a photosensitive drum 2 and process means such as a developing unit and a charging roller (not shown).

[0014] A scanner unit 3 is disposed vertically above the process cartridge 1, and exposes the photosensitive drum 2 based on an image signal. After the photosensitive drum 2 is charged to a predetermined negative potential by a charging roller (not shown), an electrostatic latent image is formed on it by the scanner unit 3. This electrostatic latent image is reverse-developed by a developing unit (not shown) inside the process cartridge 1, and negative toner is attached to form a toner image.

[0015] The sheet feeding unit is made up of a paper feed roller 4 attached to the image forming apparatus 101 and a paper feed cassette 5 that stores sheets and is detachable from the image forming apparatus main body 101. The sheets S stored in the paper feed cassette 5 are separated and fed one by one from the paper feed cassette 5 by the paper feed roller 4 that is rotated by the power of a paper feed drive unit (not shown). The fed sheet S is transported to a registration roller pair 7 by a transport roller pair 6, where skew correction is performed, and the sheet S is transported to the transfer unit.

[0016] In the transfer section, a bias voltage of positive polarity is applied by a bias applying means (not shown) to the transfer roller 8. As a result, the toner image is transferred as an unfixed image onto the sheet S conveyed to the transfer section.

[0017] The sheet S onto which the toner image has been transferred is transported to a fixing device 9 provided downstream of the transfer section in the transport direction of the sheet S. The fixing device 9 fixes the toner image transferred onto the sheet S, and has a heating roller 10 heated by a heater, which is a heating means (not shown), and a pressure roller 11, which is a pressure member that rotates while being pressed against the heating roller 10. The sheet S is sandwiched and transported in a fixing nip formed by the heating roller 10 and the pressure roller 11, and the toner image is fixed to the surface of the sheet S by applying heat and pressure.

[0018] The sheet S with the fixed toner image, i.e., the sheet S with the image formed thereon, is transported from the fixing device 9 to a paper discharge / reversal section. The paper discharge / reversal section has a triplet of rollers consisting of a drive roller 13 and driven rollers, a paper discharge roller 14 and a reversal roller 15. It also has a double-sided flapper 12. The drive roller 13 can rotate by receiving drive from a drive source (not shown), and the driven rollers, the paper discharge roller 14 and the reversal roller 15, each form a nip portion by contacting the drive roller 13, and are a pair of rollers that are driven to rotate by the rotation of the drive roller 13.

[0019] Among these roller pairs, the roller pair formed by the drive roller 13 and the discharge roller 14 is a discharge roller pair for discharging the sheet S to the stacking section 16. As shown in FIG. 2, the stacking section 16 is provided at a position recessed from the upper exterior part 19, and has a stacking surface 31 for stacking the discharged sheets. The stacking surface 31 has an inclined surface that is recessed most from the upper surface on the upstream side in the discharge direction of the sheet S and gradually becomes shallower toward the downstream side. In addition, the roller pair formed by the drive roller 13 and the reverse roller 15 is a reverse roller pair for discharging a portion of the sheet S outside the image forming apparatus 101 and then transporting the sheet S into the image forming apparatus 101. In this embodiment, the upper exterior part 19 forms the top cover of the image forming apparatus.

[0020] 5, in the case of single-sided image formation (single-sided printing), the double-sided flapper 12 waits at the position indicated by the solid line to guide the sheet S to a pair of discharge rollers formed by a drive roller 13 and a discharge roller 14. The transported sheet S is then discharged by the drive roller 13 and the discharge roller 14 onto a stacking unit 16 outside the image forming apparatus 101 for stacking the discharged sheets S.

[0021] In the case of double-sided image formation (double-sided printing), the double-sided flapper 12 waits at a position (dotted line position) where it guides the sheet S to a pair of reversing rollers formed by a drive roller 13 and a reversing roller 14, and the sheet S is conveyed to the pair of reversing rollers by the fixing device 9. The drive roller 13 is rotated in the reverse direction by a rotation direction switching means (not shown) when the trailing edge of the sheet S reaches a predetermined position. At this time, when the trailing edge of the sheet S reaches the predetermined position, a portion of the sheet S is discharged outside the image forming apparatus 101.

[0022] Due to the reverse rotation of the drive roller 13, the sheet S passes through the pair of duplex conveying rollers 17 and the pair of re-feed rollers 18, with the end that was on the upstream side in the discharge direction now at the front, and is re-sent in an inverted state with respect to the pair of registration rollers 7. Thereafter, as with single-sided printing, the second side of the sheet S is corrected for skew by the pair of registration rollers 7, transferred by the transfer roller 8, and fixed by the fixing device 9, and is discharged to the stacking section 16 by the drive roller 13 and the paper discharge roller 14, completing double-sided printing.

[0023] Next, the sheet discharge section according to the present invention will be described with reference to Figures 2 to 14. Note that in the following description, illustrations of fastening members such as screws will be omitted. An operation section 20 for operating the image forming apparatus 101 is disposed on an upper exterior section 19, which is part of the exterior surface of the image forming apparatus 101, and is provided with a display section 22 that displays information related to image formation, such as the number of sheets to be printed and the remaining amount of developer.

[0024] 3, the operation unit 20 is disposed so as to overlap the stacking unit 16 when viewed vertically. The operation unit 20 is disposed so as not to protrude outward from the side surface 33 of the image forming apparatus 101, that is, disposed inside the side surface 33. Furthermore, the operation unit 20 is located closer to the roller pair shown in FIG. 1 than the center of the image forming apparatus 101 in terms of the discharge direction of the sheet S. The operation unit 20 also overlaps with an upper guide unit, which will be described later, when viewed vertically.

[0025] 4 is a diagram showing the configuration of the operating unit, and is a side view of FIG. 2 as viewed from direction B. The operating unit 20 is supported by a holding unit 21 located on the upper exterior unit 19. The operating unit 20 is also configured to be rotatable relative to the holding unit 21 around a rotation center 23. The holding unit 21 is contained within the width of the upper exterior unit 19 in the width direction of the sheet S, which intersects with the conveyance direction of the sheet S, does not protrude toward the stacking unit 16, and does not overlap with an upper guide unit, which will be described later, when viewed vertically.

[0026] By providing the rotation center 23, when the operation unit 20 is attached to the upper exterior part 19, the operation unit 20 can take a first position in which it is disposed substantially parallel to the upper exterior part 19 as shown in FIG. 4(a). Also, as shown in FIG. 4(b), the operation unit 20 can take a second position in which it is rotated to the maximum angle at which it can rotate relative to the upper exterior part 19. By rotating the operation unit 20 in this manner, the user can easily see the operation unit when operating the image forming apparatus 101. Furthermore, the operation unit 20 can be fixed not only at the first position and the second position but also at any angle between them, allowing the user to rotate the operation unit 20 to an angle that is easy to use.

[0027] In the configuration of this embodiment, the display unit 22 has a touch sensor that allows the user to operate or give instructions to the image forming apparatus 101 by touching it. The display unit 22 may have only the function of displaying information related to image formation, etc., and may not have the function of an operation unit. Furthermore, the operation unit 20 may have a configuration in which the image forming apparatus 101 is operated by buttons, etc.

[0028] Fig. 5 is a cross-sectional view showing the configuration of the sheet discharge unit, seen from direction B in Fig. 2. The sheet discharge unit is equipped with a triple roller set consisting of a double-sided flapper 12 for guiding the sheet to a discharge path or a reverse path, a drive roller 13, a discharge roller 14, and a reverse roller 15.

[0029] Further, a stacking section 16 for stacking sheets S discharged by the driving roller 13 and the paper discharge rollers 14, and a lower guide section 25 for guiding the lower surface of the sheets S conveyed by the driving roller 13 and the reversing rollers 15 are provided.

[0030] The image forming apparatus 101 also has an upper guide portion 24 that is fixed to the image forming apparatus 101 and that guides the upper surface of the sheet S conveyed by the drive roller 13 and the reversing rollers 15. The upper guide portion 24 extends downstream in the discharge direction along the discharge direction of the sheet S that is discharged by the roller pair formed by the drive roller 13 and the reversing rollers 15. In this embodiment, the upper guide portion 24 and the upper surface cover 32 that covers the upper surface of the image forming apparatus 101 are separate members, but the upper guide portion 24 and the upper surface cover 32 may be formed integrally.

[0031] When the sheet S is conveyed to the drive roller 13 and the discharge roller 14 by the double-sided flapper 12, the sheet S is discharged and stacked on the stacking unit 16. When the sheet S is conveyed to the drive roller 13 and the reversing roller 15 by the double-sided flapper 12 located at the position indicated by the dotted line, the lower side of the sheet is guided by the lower guide unit 25 and the upper side of the sheet is guided by the upper guide unit 24, and a portion of the sheet S is conveyed to the outside of the apparatus above the stacking unit 16. Then, the drive roller 13 is rotated in the reverse direction by a rotation direction switching means (not shown), and the sheet S is reversed and conveyed into the apparatus.

[0032] 6 is an enlarged view of FIG. 5 showing the configuration in the front-to-rear direction of the device, which is a direction horizontal to the sheet discharge direction in the sheet discharge section. The size L1 of the operation unit 20 in the direction horizontal to the sheet discharge direction and the distance L2 from the drive roller 13 to the rear cover 26 have the relationship L1>L2. Therefore, the operation unit 20 is disposed closer to the front of the image forming apparatus 101 than the drive roller 13.

[0033] Furthermore, the distance L3 from the operation unit 20 to the rear cover 26 and the distance L4 from the rear surface of the frame 28 supporting the image forming unit (not shown) to the rear cover 26 are such that L3>L4. In other words, the operation unit 20 is disposed closer to the front side of the frame 28 than to the rear side of the apparatus in the horizontal direction. This is to ensure a receiving surface for the packaging material 29 when the image forming apparatus 101 is transported.

[0034] 7A and 7B are diagrams showing an example of the arrangement of packaging for an image forming apparatus 101 during transportation, with FIG. 7A being a top view seen from the vertical direction, and FIG. 7B being a view of FIG. 7A seen from direction B in FIG. 2. Note that FIG. 7B omits some components of the sheet discharge section that are not used in the explanation. As shown in FIG. 7A, packaging 29 is generally configured to receive the four corners of the image forming apparatus. Furthermore, as shown in FIG. 7B, the packaging placed between the operation unit 20 and the rear of the image forming apparatus 101 (part L3) is arranged so as to overlap with the frame 28 (part L5) when viewed from the vertical direction.

[0035] As a result, external forces are received by the frame 28 via the packaging material 29. In consideration of these points, in this embodiment, the arrangement of the operating unit 20 in the front-to-rear direction of the device, which is horizontal to the sheet discharge direction, is as shown in Figure 6.

[0036] Figure 8 shows the shape of the upper guide part, with Figure 8(a) being a perspective view and Figure 8(b) being a side view of Figure 8(a) as seen from direction C. Note that the upper guide part in Figure 8 does not include the shape for attaching to the upper cover 32 as the upper exterior part, lightening holes, etc.

[0037] 9 is an enlarged view of FIG. 5 showing the relationship between the trajectory of sheet S being inverted and conveyed in the sheet discharge section and operation unit 20. Line T1 as a first straight line is a straight line that is perpendicular to a plane passing through the center of drive roller 13 and the center of reverse roller 15 and passes through the nip portion between drive roller 13 and reverse roller 15, i.e., nip tangent T1. When viewed from the axial direction of drive roller 13 and reverse roller 15, nip tangent T1 is located at a position that passes through operation unit 20 and upper guide unit 24.

[0038] 9 is a line tangent to both the upper guide portion leading edge 24a, which is the most downstream point in the discharge direction of the sheet S of the upper guide portion 24, and the lower guide portion leading edge 25a, which is the contact point between the sheet S of the lower guide portion 25 and the upper guide portion 24. This line T2 is drawn so as to come closest to the operation portion 20 when the sheet S is discharged. Here, the upper guide portion leading edge 24a is the part of the upper guide portion 24 that is located most downstream in the discharge direction of the sheet S. When viewed from the axial direction of the roller pair, the line T2 does not pass through the operation portion 20, and therefore the sheet S that is reversed and transported does not come into contact with the operation portion 20.

[0039] Therefore, the sheet S is reversed and conveyed as follows: First, the sheet S is conveyed in the direction of line T1 by the drive roller 13 and the reversing roller 15. Next, because the upper guide portion 24 and line T1 overlap, the sheet S comes into contact with the upper guide portion 24. When the sheet S comes into contact with the upper guide portion 24, its direction of movement is changed and it is conveyed along the guide shape of the upper guide portion 24. Thereafter, while the lower surface of the sheet S is guided by the lower guide portion 25 and the upper surface by the upper guide portion 24, the sheet S is conveyed along the trajectory of line T2 so that part of the sheet S is discharged outside the apparatus.

[0040] Then, when the drive roller 13 is rotated in the reverse direction by a rotation direction switching means (not shown), the sheet S is inverted and transported into the device along the locus of line T2 while being guided by the lower guide portion 25 and the upper guide portion 24 in the same manner. As a result, the sheet S that is inverted and transported can be transported without coming into contact with the operation unit 20. Note that, as shown in FIG. 10 , even when the operation unit 20 is in the second position, the line T2 is located below the operation unit 20. Therefore, the sheet S that is inverted and transported can be transported without coming into contact with the operation unit 20, just like when the operation unit 20 is in the first position.

[0041] In other words, without the upper guide portion 24, the sheet S would come into contact with the operation portion 20, but the upper guide portion 24 prevents the discharged sheet S from coming into contact with the operation portion 20. In this embodiment, the drive roller 13 and the reversing rollers 15 are configured as a pair of reversing rollers that discharge a portion of the sheet S outside the image forming apparatus 101 and then transport the sheet S into the image forming apparatus 101, but this configuration is not limited to this. For example, the same effect can be obtained even if the pair of reversing rollers and the pair of discharging rollers are combined so that the drive roller 13 and the reversing rollers 15 not only reverse the sheet S but also function as a pair of discharging rollers to discharge the sheet S onto the stacking portion 16. The same effect can also be obtained with a pair of discharging rollers in an image forming apparatus that does not have a sheet reversing function and only performs single-sided printing.

[0042] Next, FIG. 11 is a cross-sectional view showing the relationship between the upper guide portion 24 and the swing-up state of the detection portion 30, which detects when the amount of sheets on the stacking portion has reached a predetermined amount. The detection portion 30 is located vertically lower than the upper guide portion 24. The detection portion 30 in FIG. 11 is in a state in which it has been swung up to the maximum amount. Even when the detection portion 30 is swung up to the maximum amount, a distance L6 is provided between the detection portion 30 and the upper guide portion 24, so that the detection portion 30 does not come into contact with the upper guide portion 24. In other words, when the number of sheets S stacked on the stacking portion 16 is at its maximum, the detection portion 30 does not come into contact with the upper guide portion 24. This prevents the detection portion 30 from contacting the upper guide portion 24 and blocking the conveyance path, even when the detection portion 30 is swung up to its maximum amount.

[0043] 12 is a cross-sectional view showing the relationship between the upper guide portion 24 and the rotation trajectory of the detection portion 30. Line 30a shows the rotation trajectory of the detection portion 30. When the end of the detection portion 30 is positioned most downstream in the discharge direction of the sheet S due to rotation, the end of the detection portion 30 is positioned upstream in the discharge direction of the sheet S from the tip end 24a of the upper guide portion by a distance L7.

[0044] Therefore, even if a sheet S is being inverted and conveyed while another sheet S is being discharged to the stacking unit 16, the inverted sheet S can be conveyed without coming into contact with the operation unit 20. Note that even when the operation unit 20 is in the second position, the line T2 is located below the operation unit 20. Therefore, the sheet S is conveyed without coming into contact with the operation unit 20, just like when the operation unit 20 is in the first position.

[0045] 13 shows the relationship between the upper guide portion 24 and the sheets S stacked in the stacking portion 16. The sheets S stacked in the stacking portion 16 represent a state in which they have reached a predetermined amount as determined by the detection portion 30. At this time, a distance L8 is provided between the stacked sheets S and the leading edge 24a of the upper guide portion. This allows the sheets S to be reversed and transported without coming into contact with the operation portion 20, and allows the sheets S to be stacked in the stacking portion 16 up to the amount determined by the detection portion 30.

[0046] In this way, by configuring the upper guide portion 24 and the operation portion 20 so that at least a portion of them overlap when viewed vertically, and by devising the position of the upper guide portion 24, it is possible to transport the sheet S without it coming into contact with the operation portion 20. The present invention makes it possible to provide an image forming apparatus that has a large operation portion and that is compact while preventing the operation portion from interfering with the discharge of the sheet.

[0047] [Example 2] Next, a second embodiment of the present invention will be described with reference to Figures 14 and 15. In this embodiment, the description of parts common to the first embodiment will be omitted. The difference from the first embodiment is the configuration of the guide unit. Figure 14 is a perspective view showing the shape of an upper guide unit 124 in the second embodiment of the present invention, and Figure 16 is a top view showing the relationship between the upper guide unit 124 and the operating unit when viewed from the vertical direction. Note that the shape of the upper guide unit 124 in Figure 14 does not include the shape for attachment to the top cover 32 as the upper exterior unit, lightening holes, etc. As can be seen from Figure 14, the guide unit tip 124a on the downstream side in the discharge direction of the sheet S of the upper guide unit 124 is only partially disposed in the sheet width direction perpendicular to the discharge direction of the sheet S.

[0048] Specifically, the distance that the upper guide portion 124 extends downstream along the discharge direction of the sheet S differs in the width direction of the sheet S that intersects with the discharge direction of the sheet S, and is longer at the end than at the center of the stacking portion 16 in the width direction of the sheet S.

[0049] 15, in the sheet width direction, the width of the upper guide portion tip 124a is longer by a distance R1 than the overlapping length between the stacking portion 16 and the operation portion 20. Therefore, it is possible to obtain the same effect as in the first embodiment, and the conveyed sheet S does not come into contact with the operation portion 20.

[0050] Furthermore, in this embodiment, unlike in the first embodiment, the tip 124a of the upper guide portion that regulates the position of the sheet S is not disposed across the entire width above the stacking portion 16 in the sheet width direction perpendicular to the discharge direction of the sheet S, but is disposed in a minimal manner so that the sheet S does not come into contact with the operation portion 20. This results in a configuration that improves the visibility and ease of removal of the sheet discharged to the stacking portion 16 compared to the first embodiment.

[0051] [Example 3] A third embodiment of the present invention will be described with reference to Figures 16 and 17. In this embodiment, descriptions of parts common to the first embodiment will be omitted. The difference from the first embodiment is the configuration of the guide unit. Figure 16 is a perspective view showing the shape of the reversing guide unit in the third embodiment of the present invention, and Figure 17 is a top view showing the relationship between the upper guide unit 224 and the operation unit 20 when viewed from the vertical direction. Note that the shape of the upper guide unit 224 in Figure 16 is a shape in which the shape for attachment to the top cover 32 as the upper exterior part, lightening holes, etc. are omitted.

[0052] 16, the guide portion tip 224a of the upper guide portion 224 on the downstream side in the discharge direction of the sheets S is only partially disposed in the sheet width direction perpendicular to the discharge direction of the sheets S. The guide portion tips 224a A1 and A2 protrude symmetrically in the sheet width direction. As in the second embodiment, the distance that the upper guide portion 224 extends downstream along the discharge direction of the sheets S varies in the width direction of the sheets S, and is longer at both ends of the stacking portion in the width direction of the sheets S than at the center.

[0053] Furthermore, in the sheet width direction, the width A1 of the upper guide tip 224a is longer by a distance R2 than the overlapping length between the stacking section 16 and the operation section 20. Therefore, it is possible to obtain the same effect as in the first and second embodiments, and the conveyed sheet S does not come into contact with the operation section 20.

[0054] In this embodiment, the upper guide portion 224 does not protrude as much in the center in the sheet width direction as compared to the left and right, and therefore, similar to embodiment 2, the visibility and ease of removal of the sheet discharged into the stacking portion 16 are improved. Also, in this embodiment, when the sheet S is guided by the upper guide portion 224 during conveyance, the shape of the upper guide portion tip 224a is symmetrical in the sheet width direction, so that the conveyance resistance is uniform on both sides in the sheet width direction.

[0055] Therefore, even when conveying paper types such as thick paper with a high basis weight, there is no difference in conveying resistance between the left and right sides of the sheet width direction. This improves sheet visibility and ease of removal, while also improving conveyance. Furthermore, in this embodiment, the shape of the upper guide portion 224 is symmetrical in the sheet width direction, so the appearance of the sheet is not easily impaired.

[0056] Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments. The present invention is not limited to the above, and various modifications are possible based on the technical concept of the present invention. [Explanation of symbols]

[0057] 1 Process cartridge 2 Photosensitive drum 3 Scanner Unit 4 Paper feed roller 5 Paper cassette 10 Heating roller 11 Pressure roller 12 Double-sided flapper 13 Drive roller 14 Paper ejection roller 15 Reverse roller 16 Loading section 19 Upper exterior part 20 Control section 23 Rotation center 24, 124, 224 Upper guide 29 Packaging material 30 Detection unit 101 Image forming device

Claims

1. An image forming apparatus having an image forming unit that forms an image on a sheet, a pair of rollers that convey an image-formed sheet and discharge at least a portion of the sheet to the outside of the image forming apparatus; an upper guide portion that is fixed to the image forming apparatus and that guides an upper surface of the sheet discharged by the roller pair; a stacking section provided at a recessed position in an upper exterior section of the image forming apparatus, for stacking discharged sheets; an operating unit for operating the image forming apparatus, the operating unit having a display unit for displaying information related to image formation and attached to the upper exterior unit of the image forming apparatus so as to be movable relative to the upper guide unit; Equipped with the upper guide portion extends downstream of the roller pair in the sheet discharge direction of the sheet discharged by the roller pair, the operating portion and the upper guide portion each have a portion that overlaps with each other when viewed in the vertical direction, An image forming apparatus characterized in that, when viewed in the axial direction of the roller pair, the operating unit and the upper guide unit are located at positions where a straight line passes that is perpendicular to a plane passing through the axes of each of the roller pair and passes through the nip portion of the roller pair.

2. 2. The image forming apparatus according to claim 1, wherein the operation unit allows the user to operate the image forming apparatus by touching the display unit.

3. The image forming apparatus according to claim 1 or 2, characterized in that the operation unit is located inside the side of the image forming apparatus in the sheet width direction that intersects with the discharge direction, and on the roller pair side of the center of the image forming apparatus in the discharge direction.

4. 4. The image forming apparatus according to claim 1, wherein the operating unit is held by a holding portion located on the upper exterior portion, and the operating unit is held rotatably relative to the holding portion around a rotation center.

5. 5. The image forming apparatus according to claim 1, wherein the operation unit and the stacking unit have portions that overlap each other when viewed vertically.

6. 6. The image forming apparatus according to claim 1, further comprising a lower guide portion that guides a lower surface of the sheet discharged by the pair of rollers.

7. The image forming apparatus of claim 6, characterized in that, when viewed in the axial direction of the roller pair, a straight line passing through the tip of the lower guide portion, which is the contact point between the lower guide portion and the sheet, and the tip of the upper guide portion, which is the most downstream in the discharge direction of the upper guide portion, does not pass through the operating unit.

8. An image forming apparatus as described in any one of claims 1 to 7, characterized in that the distance extending of the upper guide portion along the sheet discharge direction differs in the sheet width direction intersecting with the sheet discharge direction, and the end portion is longer in the sheet width direction than the central portion of the stacking portion.

9. 9. The image forming apparatus according to claim 1, wherein the pair of rollers is a pair of reversing rollers for discharging a part of the sheet to the outside of the image forming apparatus and then transporting the sheet into the image forming apparatus.

10. the image forming apparatus has a detection unit for detecting the amount of sheets stacked on the stacking unit, the detection portion is located lower than the upper guide portion in the vertical direction, An image forming apparatus as described in any one of claims 1 to 9, characterized in that the downstream tip of the detection section in the sheet discharge direction is located upstream in the sheet discharge direction of the upper guide section, which is located most downstream in the sheet discharge direction of the upper guide section.

11. 11. The image forming apparatus according to claim 10, wherein the detection unit does not come into contact with the upper guide unit when the number of sheets stacked on the stacking unit is at its maximum.

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