Paper ejection device and image forming apparatus

Abstract

The objective is to provide a paper ejection device and an image forming apparatus that can reliably hold down paper according to the degree of curling of the paper, and can prevent the curled paper from getting caught between the two arms of the paper holding member. [Solution] The paper discharge device 71 comprises a device body 3 and a paper holding member 80. The paper holding member 80 is made of an elastically deformable material and has two arms 81, 81 arranged at a predetermined distance apart in the width direction W perpendicular to the discharge direction X of the paper P. When the paper P is discharged from the discharge port 73, the arm elastically deforms so that it contacts the paper P and the distance L1 between the tips of the two arms 81, 81 changes due to the transport force of the paper P.

Description

Technical Field

[0001] The present disclosure relates to a paper discharge device and an image forming apparatus such as a copying machine, a multifunction peripheral, a printer, and a facsimile machine.

Background Art

[0002] In a paper discharge device provided in an image forming apparatus, due to factors such as a change in the moisture content of the paper caused by heating during saddling or fixing, a U-shaped curl (so-called shrimp warp) may occur in which both ends in the width direction W orthogonal to the paper discharge direction X are curved downward or upward (see FIG. 13). In the example shown in FIG. 13, an example of a curl in which both ends are curved upward (an example in which the shrimp warp is convex downward) is shown. Further, if the discharged paper is stacked on the paper discharge tray while being curled in a U shape, there are concerns about a decrease in stacking property and an inability to obtain a predetermined number of stacked sheets. Specifically, when the discharged paper is stacked on the paper discharge tray while being curled in a U shape, the paper floats from the tray surface of the paper discharge tray, and the paper is stacked in a state where a gap is formed. Therefore, although the actual number of sheets is small, the full detection sensor is turned on, and it is erroneously detected that the paper on the paper discharge tray is full, resulting in a disadvantage that a predetermined number of stacked sheets cannot be obtained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding this point, as a conventional paper discharge device, for example, there is one having a configuration as shown in FIG. 14.

[0005] Figure 14 is a reference diagram showing a state in which a sheet of paper P is caught in a paper holding member 200 of a conventional paper ejection device.

[0006] A conventional paper ejection device shown as a reference in Figure 14 includes a paper holding member 200 having two arms 210, 210. The two arms 210, 210 are arranged at a predetermined distance apart in the width direction W, which is perpendicular to the ejection direction X of the paper P.

[0007] In the conventional paper ejection device shown in Figure 14, for example, when paper P that has curled due to heating during fixing is ejected, the paper P tries to return to its planar shape (try to spread in the width direction W) within the two arms 210, 210, and may get caught between the two arms 210, 210 of the paper holding member 200. Note that although the example shown in Figure 14 shows paper P that has curled upwards, the same applies to paper P that has curled downwards.

[0008] Furthermore, if the paper P gets caught between the two arms 210, 210 of the paper holding member 200, the curled paper P may block the discharge opening, potentially causing a paper jam as the paper P cannot be smoothly discharged from the opening.

[0009] To address these challenges, image forming apparatuses have been provided that are equipped with a paper-holding member to suppress problems caused by the curling of the discharged paper. For example, Patent Document 1 discloses an image forming apparatus equipped with a sheet-end guide (paper-holding member) that holds down both ends of the paper when it is discharged.

[0010] More specifically, the image forming apparatus of Patent Document 1 is equipped with two sheet tip guides provided between the document reading unit and the main body of the image forming apparatus to guide the leading edge of the upper surface of the sheet (paper) discharged by the paper discharge roller, and the spacing between the two sheet tip guide pieces widens as they move downstream in the direction of sheet discharge. In the image forming apparatus of Patent Document 1, even if a narrow sheet of paper that enters inside the left and right paper discharge tip guides and is not guided by the paper discharge tip guides is discharged at a slight angle with respect to the transport direction, it is designed so that it does not get caught on the inner edge of the paper discharge tip guide (see the third sentence of paragraph

[0046] of Patent Document 1).

[0011] In this configuration, the two sheet-tip guide pieces (the two arms of the paper-holding member) are spaced further apart as they move downstream in the paper discharge direction. This prevents the paper from getting caught between the two arms of the paper-holding member, even if the paper tries to return to a flat position within the two arms when it is discharged. However, because the paper-holding member maintains a widened gap between its two arms even as the paper moves in the discharge direction, it cannot reliably hold down the paper according to the degree of its curvature.

[0012] Therefore, the present disclosure aims to provide a paper ejection device and an image forming apparatus that can reliably hold down paper according to the degree of curling of the paper, and can prevent the curled paper from getting caught between the two arms of the paper holding member. [Means for solving the problem]

[0013] To solve the aforementioned problems, the paper discharge device according to the present disclosure comprises a device body having a discharge port for discharging paper and a paper discharge tray for stacking the paper discharged from the discharge port, and a paper pressing member that contacts the paper discharged from the discharge port, wherein the paper pressing member is made of an elastically deformable material and has two arms arranged at a predetermined distance apart in a width direction perpendicular to the paper discharge direction, and when the paper is discharged from the discharge port, it contacts the paper and elastically deforms so that the distance between the tips of the two arms changes due to the transport force of the paper. Furthermore, the image forming apparatus according to the present disclosure is characterized by comprising the paper discharge device according to the present disclosure. [Effects of the Invention]

[0014] According to this disclosure, it is possible to provide a paper ejection device and an image forming apparatus that can reliably hold down paper according to the degree of curling of the paper, and can prevent the curled paper from getting caught between the two arms of the paper holding member. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view showing a schematic configuration of an image forming apparatus equipped with a paper ejection device according to an embodiment of the present disclosure. [Figure 2] This figure shows the arrangement of the discharge port and paper holding member of an image forming apparatus equipped with a paper discharge device according to the first embodiment of this disclosure. [Figure 3] Figure 2 is a front view showing the paper-holding member. [Figure 4] Figure 2 is a perspective view showing the paper-holding member when paper is ejected from the image forming apparatus. [Figure 5] This figure shows the deformation of the paper-holding member before and after Figure 2. [Figure 6] This figure shows the arrangement of the discharge port and paper holding member of an image forming apparatus equipped with a paper discharge device according to the second embodiment of this disclosure. [Figure 7] Figure 6 is a front view showing the deformation of the paper-holding member before and after the deformation. [Figure 8] It is a diagram showing the discharge port of an image forming apparatus provided with a paper discharge device according to the third embodiment of the present disclosure, and the arrangement of the paper pressing member. [Figure 9] It is a front view showing before and after the deformation of the paper pressing member in FIG. 8. [Figure 10] It is a front view and a plan view showing a paper pressing member according to the fourth embodiment of the present disclosure. [Figure 11] It is a perspective view showing the state before and after the deformation of an example of the paper pressing member in FIG. 10. [Figure 12] It is a perspective view showing the state before and after the deformation of another example of the paper pressing member in FIG. 10. [Figure 13] It is a reference diagram showing a state where the paper is curled on the paper discharge tray. [Figure 14] It is a reference diagram showing a state where the paper is sandwiched by the paper pressing member in the conventional paper discharge device. [Embodiments for Carrying Out the Invention]

[0016] Hereinafter, an image forming apparatus 1 provided with a paper discharge device 71 according to an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0017] [Image Forming Apparatus] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 1 provided with a paper discharge device 71 according to the present embodiment.

[0018] In the following description, the vertical direction in the state where the image forming apparatus 1 is installed will be referred to as the "vertical direction H". Also, the upper side in the vertical direction H will be referred to as "upper side H1" and the lower side as "lower side H2".

[0019] As shown in Figure 1, the image forming apparatus 1 is a multifunction device having copying, scanning, facsimile, and printing functions. As shown in Figure 1, the image forming apparatus 1 includes a document feeder 2, a main unit 3, and a paper ejection device 71.

[0020] The image forming apparatus 1 transmits the image of the original document G read by the image reading unit 10 to an external source. The image forming apparatus 1 also forms an image on paper P, such as recording paper, in color or monochrome, based on the image of the original document G read by the image reading unit 10 or the image received from an external source. The image forming apparatus 1 may be a monochrome image forming apparatus. The image forming apparatus 1 may also be a color image forming apparatus of another form.

[0021] The document feeder 2 is supported by the main body 3 (image reading unit 10) so as to be openable and closable. The document feeder 2 includes a document tray 2a on which documents G are placed, and a document output tray 2b on which the output documents G are stacked. The document feeder 2 transports one or more documents G placed on the document tray 2a one by one onto the document reading unit 12 in the image reading unit 10, and outputs them to the document output tray 2b.

[0022] The main unit 3 comprises an image reading unit 10, an optical scanning device 20, an image forming unit 30, an intermediate transfer belt device 40, a secondary transfer device 50, a fixing device 60, a paper transport path S, a paper feed cassette 70, and a paper ejection device 71. As shown in Figure 1, the main unit 3 has a configuration in which the image reading unit 10, image forming unit 30, paper feed cassette 70, paper ejection device 71, etc. are housed inside the housing 4. The main unit 3 also constitutes the main unit of the paper ejection device 71.

[0023] The image reading unit 10 reads the document G transported by the document feeder 2. The image reading unit 10 is also provided with a document tray 11 on which the document G is placed. The image reading unit 10 reads the document G placed on the document tray 11. When the document feeder 2 is opened, the document tray 11 above the image reading unit 10 H1 is opened, allowing the document G to be placed manually. The image reading unit 10 generates image data by either reading the document G transported by the document feeder 2 with the scanning optical system 13 positioned at a reading position below the document reading unit 12 H2, or by scanning the document G placed on the document tray 11 with the scanning optical system 13.

[0024] Image forming apparatus 1 handles image data corresponding to color images using black (K), cyan (C), magenta (M), and yellow (Y), or monochrome images using a single color (for example, black). The image forming unit 30 is equipped with four developing devices 31, four photoreceptor drums 32, four drum cleaning devices 33, and four chargers 34 for forming four types of toner images, each corresponding to black, cyan, magenta, and yellow, forming four image stations Pa, Pb, Pc, and Pd.

[0025] The charger 34 uniformly charges the surface of the photoreceptor drum 32 to a predetermined potential. The light scanning device 20 exposes the surface of the photoreceptor drum 32 to form an electrostatic latent image. The developing device 31 develops the electrostatic latent image on the surface of the photoreceptor drum 32 to form a toner image on the surface of the photoreceptor drum 32. The drum cleaning device 33 removes and recovers residual toner from the surface of the photoreceptor drum 32. Through the above series of operations, toner images of each color are formed on the surface of each photoreceptor drum 32.

[0026] The intermediate transfer belt device 40 includes intermediate transfer rollers 41, an endless intermediate transfer belt 42, an intermediate transfer drive roller 43, an intermediate transfer driven roller 44, and a cleaning device 45. Four intermediate transfer rollers 41 are provided inside the intermediate transfer belt 42 to form four different toner images corresponding to each color. The intermediate transfer rollers 41 transfer the toner images of each color formed on the surface of the photoreceptor drum 32 to the intermediate transfer belt 42, which moves in a circular motion direction C.

[0027] The intermediate transfer belt 42 is stretched over the intermediate transfer drive roller 43 and the intermediate transfer driven roller 44. In the image forming apparatus 1, the toner images of each color formed on the surface of each photoreceptor drum 32 are sequentially transferred and superimposed onto the surface of the intermediate transfer belt 42 to form a color toner image on the surface of the intermediate transfer belt 42.

[0028] The secondary transfer device 50 has a transfer nip section TN between the secondary transfer roller 51 and the intermediate transfer belt 42, and transports the paper P that has been transported through the paper transport path S by gripping it in the transfer nip section TN. When the paper P passes through the transfer nip section TN, the toner image on the surface of the intermediate transfer belt 42 is transferred by the secondary transfer device 50 and transported to the fuser device 60. The cleaning device 45 removes and collects waste toner that remains on the surface of the intermediate transfer belt 42 without being transferred to the paper P.

[0029] The fixing device 60 includes a fixing belt 61 and a pressure roller 62 that rotate with the paper P in between. The fixing device 60 heats and pressurizes the paper P, on which the toner image has been transferred, between the fixing belt 61 and the pressure roller 62, thereby fixing the toner image to the paper P. Although not shown in Figure 1, the fixing device 60 has components other than the fixing belt 61 and the pressure roller 62.

[0030] The paper ejection device 71 includes an ejection roller 65, a paper ejection tray 72, and a paper holding member 80.

[0031] The paper transport path S is equipped with a transport roller 63, a registration roller 64, and an discharge roller 65. The transport roller 63 facilitates the transport of the paper P. The registration roller 64 temporarily stops the paper P and aligns the leading edge of the paper P. The registration roller 64 then transports the temporarily stopped paper P in accordance with the timing of the toner image on the intermediate transfer belt 42.

[0032] The paper feed cassette 70 is a cassette for storing paper P used for image formation, and is located below H2 of the optical scanning device 20. The paper P is pulled out of the paper feed cassette 70 by the pickup roller 66 and transported to the paper transport path S. The paper P transported to the paper transport path S passes through the secondary transfer device 50 and the fixing device 60, is transported to the discharge roller 65, and is discharged into the paper discharge tray 72 of the paper discharge device 71.

[0033] Although Figure 1 shows only one paper feed cassette 70, the system is not limited to this configuration. Multiple paper feed cassettes 70 may be provided, each loaded with a different type of paper P. Furthermore, if the image forming apparatus 1 is to perform image formation on both the front and back surfaces of the paper P, it transports the paper P in the reverse direction from the discharge roller 65 to the sheet reversal path Sr. The image forming apparatus 1 reverses the front and back surfaces of the paper P that has been transported in the reverse direction and guides it back to the registration roller 64. The image forming apparatus 1 then forms an image on the back surface of the paper P guided to the registration roller 64 in the same way as the front surface, and transports it to the paper discharge tray 72.

[0034] [First Embodiment] Next, a first embodiment of the present disclosure will be described. Figure 2 is a diagram showing the arrangement of the discharge port 73 and the paper holding member 80A(80) of an image forming apparatus 1 equipped with a paper discharge device 71A(71) according to the first embodiment of the present disclosure. Figure 3 is a front view showing the paper holding member 80A of Figure 2. Figure 4 is a perspective view showing the paper holding member 80A when paper P is discharged into the paper discharge tray 72 in the image forming apparatus 1 of Figure 2. Figure 5 is a diagram showing the paper holding member 80A of Figure 2 before and after the change.

[0035] Figures 3, the upper left of Figure 5, and the upper right of Figure 5 show the paper-holding member 80A viewed from a direction perpendicular to the virtual plane containing the two arms 81, 81 (front view direction B in Figure 2). In this specification, the view of the paper-holding member from front view direction B will be simply referred to as the "front view."

[0036] As shown in Figure 2, a space SP is formed inside the cylinder of the device body 3 where paper P on which toner images have been transferred (images recorded) is stored. Below space SP H2 is the paper output tray 72 of the paper output device 71A. In this example, the device body 3 of the paper output device 71A has the lower surface H2 of space SP (lower surface 71a) formed by the paper output tray 72, and the upper surface H1 of space SP (upper surface 71b) formed by the lower surface H2 of the image reading unit 10.

[0037] The discharge roller 65 comprises a drive roller 65a on the upper H1 side and a driven roller 65b on the lower H2 side. The paper P on which the toner image has been transferred is discharged into the paper discharge tray 72 from between the drive roller 65a and the driven roller 65b. Therefore, the space between the drive roller 65a and the driven roller 65b can be said to be the discharge port 73 through which the paper P is discharged.

[0038] As shown in Figure 2, in the paper discharge device 71A of this embodiment, the paper retaining member 80A is attached to the device body 3 above the discharge port 73 at a height H1. More specifically, the paper retaining member 80A is attached to the surface of the device body 3 facing the paper discharge tray 72 (upper surface 71b). In other words, the position where the paper retaining member 80A is attached to the device body 3 (mounting position A, specifically about 50 mm from the discharge port 73) is located on the upper surface 71b.

[0039] In this embodiment, the mounting position A of the paper holder member 80A is shown to be below H2 of the image reading unit 10, but the mounting position may be set at other locations. In this example, the mounting position A is set to a position about 50 mm from the discharge port 73, but for example, the mounting position may be set to a position above the discharge port and adjacent to the discharge port.

[0040] The paper-holding member 80A is made of an elastically deformable material. As shown in Figure 3, the paper-holding member 80A has two arms 81, 81, a connecting part 83, and a mounting part 84. As shown in Figure 4, the two arms 81, 81 are arranged side by side in a direction perpendicular to the paper discharge direction X (width direction W). The two arms 81, 81 also extend along the longitudinal direction N, which is perpendicular to the width direction W. Each arm 81, 81 has a contact part 82 that contacts the paper P. The contact part 82 is, for example, the surface of the arm 81 that contacts the paper P. The contact part 82 is, for example, the edge of the arm 81 that contacts the paper P. Each arm 81, 81 contacts the paper P at its respective contact part 82. As shown in Figure 3, the connecting part 83 connects the two arms 81, 81. The paper-holding member 80A has two arm portions 81, 81 connected at right angles to both ends of a connecting portion 83 that runs along the width direction W.

[0041] The total length L2 (see Figure 3) of the paper holding member 80A from its upper end 80a to its lower end 80b is smaller than the distance L3 (see Figure 2) between the upper surface 71b and the lower surface 71a of the paper ejection device 71. As shown in Figure 2, when the paper holding member 80A is mounted at mounting position A and placed on the paper ejection device 71, its own weight causes it to be in a position along the vertical direction (up and down direction H).

[0042] In other words, the paper holding member 80A is capable of holding down the paper P discharged from the discharge port 73 from above H1 with its own weight and / or rotational load. As a result, the paper discharge device 71A can hold down the vicinity of both ends in the width direction W of the paper P (paper P discharged from the discharge port 73) on the paper discharge tray 72, thereby suppressing problems such as a decrease in stackability caused by the curvature (bend) of the paper P.

[0043] The paper-holding member 80A swings when it comes into contact with the paper P discharged from the discharge port 73. More specifically, the paper-holding member 80A is supported on the device body 3 so as to be rotatable around a pivot axis along the width direction W. In this example, the mounting portion 84 is provided in the center of the connecting portion 83 in the width direction W. The paper-holding member 80A is supported so as to be suspended from the device body 3 by the mounting portion 84 being attached to the upper surface 71b of the device body 3.

[0044] As shown in Figure 4, when the paper P is discharged from the discharge port 73 (not shown in Figure 4, see Figure 2) toward the paper discharge tray 72, the contact portion 82 comes into contact with the paper P. Also, as the paper P is discharged in the discharge direction X, the paper P moves in the discharge direction X while in contact with the contact portion 82. The paper holding member 80A elastically deforms in accordance with the load applied to the contact portion 82 due to the frictional resistance with the paper P moving in the discharge direction X, changing (in this example, increasing) the distance L1 between the tips of the two arms 81, 81 (see the upper right diagram of Figure 5). Here, the paper holding member 80A rotates freely due to contact with the paper P, but this rotation may have a load necessary for the paper holding member 80A to elastically deform.

[0045] As described above, the paper ejection device 71A according to the first embodiment comprises a device body 3 and a paper holding member 80A. The device body 3 has an ejection port 73 for ejecting paper P on which a toner image has been transferred, and a paper ejection tray 72 on which the paper P ejected from the ejection port 73 is stacked. The paper holding member 80A contacts the paper P ejected from the ejection port 73. The paper holding member 80A is made of an elastically deformable material and has two arm portions 81, 81, a connecting portion 83, and a mounting portion 84. The two arm portions 81, 81 are aligned in the width direction W perpendicular to the ejection direction X of the paper P. The connecting portion 83 connects the two arm portions 81. The mounting portion 84 is attached to the device body 3 above H1 above the ejection port 73. When the paper P is discharged from the discharge port 73, the paper holding member 80A elastically deforms so that the distance L1 between the tips of the two arms 81, 81 changes (in this example, it increases) as it contacts the paper P while the transport force of the paper P is applied to it. After the paper P has passed (after contact with the paper P has ended), the paper holding member 80A returns to its original shape (shape before deformation) or approximately its original shape (shape approximately before deformation).

[0046] The paper-holding member can be made of, for example, an elastic flat plate. The paper-holding member can be made of, for example, a resin material. Polycarbonate or polyethylene terephthalate (PET) can be suitably used as the resin material. The paper-holding member holds the paper down by its own weight and / or rotational load. In this example, the paper-holding member 80A is a plate-shaped member with two arms 81, 81 (at least the contact portion 82 that contacts the paper P) extending in a direction perpendicular to the thickness direction M. Here, the thickness direction M is a direction perpendicular to both the longitudinal direction N and the width direction W (see the left diagram in Figure 5). The arms 81, 81 of the paper-holding member 80A are suspended such that the distance from the discharge port 73 in the discharge direction X is approximately equal (so that the leading edge P1 of the conveyed paper P contacts simultaneously or approximately simultaneously). The arms 81, 81, connecting portion 83, and mounting portion 84 of the paper-holding member 80A are integrally formed. The paper-holding member 80A can be formed by die-cutting a plate-shaped resin member.

[0047] According to this embodiment, the paper-holding member 80A can change the distance L1 between the tips of the two arms 81, 81 in accordance with the load on the contact portion 82 that contacts the paper P when the paper P is discharged from the discharge port 73. This ensures that the paper P is held down reliably according to the degree of curvature of the curved paper P. Furthermore, the contact portion 82 of the two arms 81, 81 can hold down the vicinity of both ends of the upper surface Pu in the width direction W of the paper P. This effectively prevents a decrease in the paper-holding action of the paper-holding member 80A when the upper surface Pu of the paper P contacts the two arms 81, 81. At this time, the distance L1 between the tips of the two arms 81, 81 changes due to the transport force of the discharged paper P, making it less likely for the paper P to get caught between the two arms 81, 81.

[0048] Therefore, the paper ejection device 71A can reliably hold down the paper P according to the degree of curling of the curled paper P, and the paper holding member 80A can suppress inconveniences such as a decrease in stackability caused by the curling, while also suppressing paper jams by preventing the paper P from getting caught in the paper holding member 80A.

[0049] As shown in Figure 3, the mounting portion 84 is provided with a pair of projections 85, 85 that serve as pivot axes along the width direction W. Also, as shown in Figure 2, the upper surface 71b of the device body 3 is provided with a bearing portion 74 having an insertion portion 75 through which the projections 85, 85 can be inserted. Each projection 85, 85 is inserted into the insertion portion 75 of the bearing portion 74. As a result, the paper holder member 80A is supported while suspended from the upper surface 71b. Furthermore, the projections 85, 85 can rotate circumferentially relative to the insertion portion 75. Therefore, the paper holder member 80A is rotatable while suspended from the device body 3.

[0050] Thus, the paper-holding member 80A is rotatable relative to the main body of the device 3.

[0051] As a result, in the paper ejection device 71A, when the paper P ejected from the ejection port 73 hits the paper retaining member 80A, the paper retaining member 80A is pushed by the paper P and swings around the pivot axis (projections 85, 85), ensuring that the paper P is reliably guided to the paper ejection tray 72 below the paper retaining member 80A H2.

[0052] As shown in Figure 3, in this embodiment, the paper-holding member 80A is equipped with a bent portion 86 where the load is more likely to concentrate (bending stress is smaller) than in other parts. When the paper P is discharged from the discharge port 73, the paper-holding member 80A contacts the upper surface Pu of the paper P and bends along the bent portion 86 as the paper P moves, and elastically deforms so that the distance L1 between the two arm portions 81, 81 changes (in this example, it becomes larger).

[0053] As a result, the paper ejection device 71A can make it easier for the upper surface Pu of the paper P to bend at the bending portion 86 due to the frictional resistance as it passes through the contact portion 82 of the arms 81, 81, and consequently, the paper holding member 80A can be appropriately elastically deformed. Furthermore, the paper ejection device 71A can easily control the deformation pattern when the paper P comes into contact with the arms 81, 81 (the angle of the arms 81, 81, which widens or narrows as it moves downstream in the ejection direction X (in this example, it widens)) by setting the position and angle of the bending portion 86.

[0054] As shown in Figure 3, in this embodiment, the bent portion 86 is provided at two locations on both sides of the connecting portion 83, with the mounting portion 84 in between. Note that the paper ejection device of this disclosure is not limited to this embodiment, and the position and number of bent portions can be selected in various ways.

[0055] The bent portion 86 is, for example, a portion that is more elastically deformable than other portions. The bent portion 86 is, for example, a portion that is less rigid than other portions and is more elastically deformable. The bent portion 86 can be formed, for example, as a fold where load is more likely to concentrate than other portions. The bent portion 86 can be formed, for example, by pre-folding it, or / or by making it thinner than other portions. The bent portion 86 can be formed, for example, as a constricted portion.

[0056] In this embodiment, when the paper P is discharged from the discharge port 73, the paper holding member 80A elastically deforms so that the distance L1 between the two arms 81, 81 increases as the paper P moves, while contacting the upper surface Pu of the paper P.

[0057] As shown in Figure 3, in this embodiment, the two bent portions 86, 86 are formed at an angle with respect to the direction in which the connecting portion 83 extends (width direction W). More specifically, as shown in the upper right view of Figure 5, in this embodiment, the two bent portions 86, 86 are inclined with respect to the width direction W such that the separation distance L1 increases as the paper P is discharged from the discharge port 73 towards the downstream side in the discharge direction X.

[0058] As shown in the upper left of Figure 5, when the paper-holding member 80A is not bent at the bent portions 86, 86, the two arm portions 81, 81 provided at both ends of the connecting portion 83 along the width direction W appear perpendicular to the width direction W. Also, as shown in the lower left of Figure 5, when the paper-holding member 80A is not bent at the bent portions 86, 86, it appears straight in side view.

[0059] As the paper P moves in the discharge direction X while in contact with the contact portion 82, the paper holding member 80A rotates, and a load is generated on the paper holding member 80A due to frictional resistance with the paper P. In addition, the bent portions 86, 86 are folds where the load is more likely to concentrate than in other parts. Therefore, as shown in the upper right and lower right figures of Figure 5, the paper holding member 80A bends so that both ends of the connecting portion 83 tilt forward, with the bent portions 86, 86 as the boundary. At this time, the arm portions 81, 81 connected to both ends of the connecting portion 83 are inclined to spread outward in the width direction W as they move downstream in the discharge direction X. As a result, the paper holding member 80A elastically deforms so that the distance L1 between the tips of the two arm portions 81, 81 increases.

[0060] Thus, when the paper P is discharged from the discharge port 73, the paper holding member 80A of this embodiment elastically deforms so that the distance L1 between the tips of the two arms 81, 81 increases as the paper P moves while contacting the upper surface Pu of the paper P. In other words, when the paper P is discharged in a curved state, even if the paper P tries to return to a planar direction within the two arms 81, 81, the paper holding member 80A of this embodiment elastically deforms so as the paper P moves, releasing the paper P between the two arms 81, 81.

[0061] As a result, the paper holding member 80A makes it less likely for the paper P to get caught between the two arms 81, 81. Therefore, the paper ejection device 71A can suppress paper jams by preventing the paper P from getting caught in the paper holding member 80A while suppressing the inconvenience caused by the paper bending of the paper in the paper holding member 80A.

[0062] [Second Embodiment] Next, an image forming apparatus 1 equipped with a paper ejection device 71B(71) according to the second embodiment of this disclosure will be described. Figure 6 is a diagram showing the arrangement of the ejection port 73 and the paper holding member 80B(80) of the image forming apparatus 1 equipped with the paper ejection device 71B according to the second embodiment of this disclosure. Figure 7 is a front view (a front view seen from the front viewing direction B in Figure 6) showing the deformation of the paper holding member 80B in Figure 6 before and after.

[0063] As shown in Figure 6, the paper ejection device 71B according to the second embodiment includes a paper holding member 80B. The main body 3 of the paper ejection device 71B has the same configuration as the main body 3 of the paper ejection device 71A according to the first embodiment. On the other hand, the paper holding member 80B of the paper ejection device 71B has a different configuration from the paper holding member 80A of the first embodiment. In the following description of the second embodiment, the differences from the paper holding member 80A will be the main focus, and the same components will be described using the same reference numerals as in the first embodiment, and detailed explanations will be omitted.

[0064] The paper-holding member 80B is made of an elastically deformable material. As shown in the left diagram of Figure 7, the paper-holding member 80B, like the paper-holding member 80A of the first embodiment, has two arms 81, 81, a connecting part 83, a mounting part 84, and two bending parts 86, 86. Furthermore, when the paper P is discharged from the discharge port 73, the paper-holding member 80B elastically deforms so that it contacts the paper P and the distance L1 between the tips of the two arms 81, 81 changes (in this example, it becomes smaller) due to the transport force of the paper P. The paper-holding member 80B also returns to its original shape (shape before deformation) or approximately its original shape (shape approximately before deformation) after the paper P has passed (after contact with the paper P has ended).

[0065] As shown in the left diagram of Figure 7, in this embodiment, the two bent portions 86, 86 are formed at an angle with respect to the direction in which the connecting portion 83 extends. More specifically, in this embodiment, the two bent portions 86, 86 are inclined with respect to the width direction W such that the distance L1 between them decreases as they move downstream in the discharge direction X when the paper P is discharged from the discharge port 73.

[0066] As shown in the left diagram of Figure 7, when the paper-holding member 80B is not bent at the bent portions 86, 86, the two arm portions 81, 81 provided at both ends of the connecting portion 83 along the width direction W appear to be perpendicular to the width direction W.

[0067] As the paper P moves in the discharge direction X while in contact with the arms 81,81, the paper holding member 80B rotates, and a load is generated on the paper holding member 80B due to frictional resistance with the paper P. In addition, the bent portions 86,86 are folds where the load tends to concentrate more than in other parts. Therefore, as shown in the right diagram of Figure 7, the paper holding member 80B bends so that both ends of the connecting portion 83 tilt forward, with the bent portions 86,86 as the boundary. At this time, the arms 81,81 connected to both ends of the connecting portion 83 are inclined to move inward as they move downstream in the discharge direction X. As a result, the paper holding member 80B elastically deforms so that the distance L1 between the tips of the two arms 81,81 becomes smaller.

[0068] Thus, when the paper P is discharged from the discharge port 73, the paper holding member 80B of this embodiment elastically deforms so that the distance L1 between the tips of the two arms 81, 81 decreases as the paper P moves while contacting the upper surface Pu of the paper P. In other words, even if the paper P tries to enter the two arms 81, 81 when the paper P is discharged in a curved state, the paper holding member 80B of this embodiment elastically deforms so as the paper P moves so that it is difficult for the paper P to enter between the two arms 81, 81 of the paper holding member 80A.

[0069] As a result, the paper P is less likely to enter between the two arms 81, 81 of the paper holding member 80B, thus making it less likely for the paper P to get caught. Therefore, the paper ejection device 71B can suppress paper jams by preventing paper P from getting caught in the paper holding member 80B while suppressing problems caused by the paper bending of the paper in the paper holding member 80B.

[0070] [Third Embodiment] Next, a paper ejection device 71C(71) according to the third embodiment of this disclosure will be described. Figure 8 is a diagram showing the arrangement of the ejection port 73 and the paper holding member 80C(80) of an image forming apparatus 1 equipped with the paper ejection device 71C according to the third embodiment of this disclosure. Figure 9 is a front view showing the deformation of the paper holding member 80C in Figure 8 before and after.

[0071] As shown in Figure 8, the paper ejection device 71C according to the third embodiment includes a paper retaining member 80C. The main body 3 of the paper ejection device 71C has the same configuration as the main body 3 of the paper ejection device 71A according to the first embodiment. On the other hand, the paper retaining member 80C of the paper ejection device 71C has a different configuration from the paper retaining member 80A of the first embodiment. In the following description of the third embodiment, the differences from the paper retaining member 80A will be the main focus, and the same components will be described using the same reference numerals as in the first embodiment, and detailed explanations will be omitted.

[0072] The paper-holding member 80C is made of an elastically deformable material. As shown in the left diagram of Figure 9, the paper-holding member 80C, like the paper-holding member 80A of the first embodiment, has two arms 81, 81, a connecting part 83, and a mounting part 84. Furthermore, when the paper P is discharged from the discharge port 73, the paper-holding member 80C elastically deforms so that it contacts the paper P and the distance L1 between the tips of the two arms 81, 81 changes (in this example, it becomes smaller) due to the transport force of the paper P. The paper-holding member 80C also returns to its original shape (shape before deformation) or approximately its original shape (shape approximately before deformation) after the paper P has passed (after contact with the paper P has ended).

[0073] As shown in the left diagram of Figure 9, in the paper-holding member 80C, the connecting portion 83 and / or mounting portion 84 (connecting portion 83 in this example) has a curved portion 87 that is curved in a substantially arc shape in the longitudinal direction N between the two arm portions 81, 81 (in this example, the mounting portion 84 side in the longitudinal direction N is curved convexly).

[0074] As the paper P moves in the discharge direction X while in contact with the arms 81, 81, the paper holding member 80C rotates, and the frictional resistance with the paper P causes a load to be placed on the curved portion 87 of the paper holding member 80C. Therefore, as shown in the right diagram of Figure 9, the paper holding member 80C bends so that the upstream surface of the curved portion 87 in the discharge direction X becomes convex. As the curved portion 87 bends in this way, the tips of the arms 81, 81 move inward in the width direction W to compensate for the difference in distance between the inner circumference 87a and the outer circumference 87b of the curved portion 87 caused by the bending. At this time, the arms 81, 81 connected to both ends of the curved portion 87 (connecting portion 83) are inclined to move inward as they move downstream in the discharge direction X. As a result, the paper holding member 80C undergoes elastic deformation so that the distance L1 between the tips of the two arms 81, 81 becomes smaller. Furthermore, the curved portion 87 may be a curved portion that is more elastically deformable than other parts.

[0075] In this way, when the paper P is discharged from the discharge port 73, the paper holding member 80C contacts the upper surface Pu of the paper P, and as the paper P moves, the curved portion 87 bends, and the member elastically deforms such that the distance L1 between the tips of the two arm portions 81, 81 changes (in this example, it becomes smaller).

[0076] As a result, the paper holding member 80C makes it less likely for the paper P to get caught between the two arms 81, 81. Therefore, the paper ejection device 71C can suppress paper jams by preventing the paper P from getting caught in the paper holding member 80C while suppressing the inconvenience caused by the paper bending of the paper in the paper holding member 80C.

[0077] [Fourth Embodiment] Next, a paper-holding member 80D(80) according to the fourth embodiment of this disclosure will be described. The left figure of Figure 10 is a front view of the paper-holding member 80D, and the right figure of Figure 10 is a plan view of the paper-holding member 80D (a plan view seen from the plan view direction E in the left figure of Figure 10). Figures 11 and 12 are perspective views showing an example and another example of the paper-holding member 80D(80) according to the fourth embodiment before and after deformation, respectively. Figure 11 shows the paper-holding member 80D in a state where the curved portion 88 protrudes forward X1 in the discharge direction X. Figure 12 shows the paper-holding member 80D in a state where the curved portion 88 protrudes backward X2 in the discharge direction X. In Figure 11, the left figure shows the paper-holding member 80D in contact with the leading edge P1 of the paper P, and the right figure shows the paper-holding member 80D pressing down on the upper surface Pu of the paper P. In Figure 12, the left figure shows the state in which the paper holding member 80D is in contact with the leading edge P1 of the paper P, and the right figure shows the state in which the paper holding member 80D is pressing down on the upper surface Pu of the paper P.

[0078] In the following description of the fourth embodiment, the focus will be on the differences from the paper-holding member 80A, and for the same components, the same reference numerals used in the first embodiment will be used, and detailed explanations will be omitted.

[0079] The paper-holding member 80D is made of an elastically deformable material. As shown in the left diagram of Figure 10, the paper-holding member 80D, like the paper-holding member 80A of the first embodiment, has two arm portions 81, 81, a connecting portion 83, and a mounting portion 84. As shown in the right diagram of Figure 10, in the paper-holding member 80D, the connecting portion 83 and / or the mounting portion 84 (mounting portion 84 in this example) are curved portions 88 formed in a shape that is curved in a substantially arc shape in the thickness direction M. In the example shown in Figure 11, the paper-holding member 80D is arranged so that the curved portion 88 protrudes forward X1 in the discharge direction X. In the example shown in Figure 12, the paper-holding member 80D is arranged so that the curved portion 88 protrudes backward X2 in the discharge direction X.

[0080] As shown in the right-hand diagram of Figure 10, the paper-holding member 80D has a configuration in which the connecting portion 83 is bent in a plan view. Therefore, as shown in Figures 11 and 12, before contact with the paper P, at least a portion of the two arms 81, 81 of the paper-holding member 80D is inclined in the discharge direction X relative to the leading edge P1 of the paper P. As shown in the left-hand diagram of Figure 11, when the curved paper P is discharged from the discharge port 73 (not shown in Figure 11), the leading edge P1 of the paper P first comes into contact with the arms 81. Then, as shown in the right-hand diagram of Figure 11, when the paper P is discharged from the discharge port 73 (not shown in Figure 11), the paper-holding member 80D (80) comes into contact with the upper surface Pu of the paper P, and as the paper P moves, the contact portion 82 moves in a direction along the upper surface Pu of the paper P. As a result, the paper-holding member 80D undergoes elastic deformation such that the distance L1 between the two arms 81, 81 changes (increases in the right-hand diagram of Figure 11).

[0081] In the example shown in Figure 11, the paper holding member 80D is inclined in the discharge direction X such that the outer side of the two arm portions 81, 81 in the width direction W is closer to the discharged paper P than the inner side. Specifically, the connecting portion 83 and / or the mounting portion 84 (mounting portion 84 in this example) constitute the curved portion 88, which is curved so that the upstream surface in the discharge direction X is concave.

[0082] With this configuration, in the paper-holding member 80D shown in Figure 11, when the paper P is discharged from the discharge port 73, the two arms 81, 81 move outwards in the width direction W (outward D1) as the paper P moves, while contacting the upper surface Pu of the paper P, and bending so that the contact portion 82 follows the upper surface Pu of the paper P (see the right diagram in Figure 11). As a result, the paper-holding member 80D shown in Figure 11 elastically deforms so that the distance L1 between the tips of the two arms 81, 81 increases. In other words, even if the paper P tries to return to a planar direction within the two arms 81, 81 when the curved paper P is discharged, the paper-holding member 80D shown in Figure 11 elastically deforms as the paper P moves, releasing the paper P between the two arms 81, 81.

[0083] On the other hand, in the example shown in Figure 12, the paper holding member 80D is inclined in the discharge direction X such that the inner side of the two arm portions 81, 81 in the width direction W is closer to the discharged paper P than the outer side. Specifically, the connecting portion 83 and / or the mounting portion 84 (mounting portion 84 in this example) constitute the curved portion 88, which is curved so that the upstream surface in the discharge direction X is convex.

[0084] With this configuration, in the paper-holding member 80D shown in Figure 12, when the paper P is discharged from the discharge port 73, the two arms 81, 81 move inward (inward D2) in the width direction W, with the contact portion 82 bending so that it follows the upper surface Pu of the paper P as the paper P moves (see the right diagram in Figure 12). As a result, the paper-holding member 80D shown in Figure 12 elastically deforms so that the distance L1 between the tips of the two arms 81, 81 becomes smaller. In other words, even if the paper P tries to enter between the two arms 81, 81 when the paper P is discharged in a curved state, the paper-holding member 80D shown in Figure 12 elastically deforms as the paper P moves so that it is difficult for the paper P to enter between the two arms 81, 81.

[0085] [Fifth Embodiment] Incidentally, in the paper-holding member described in Patent Document 1, the leading edge of the ejected paper comes into contact with the two arms of the paper-holding member at a position inward from the optimal position in the width direction (for example, the end in the width direction). As a result, the initial paper-holding effect when the leading edge of the paper comes into contact with the two arms may be reduced. Furthermore, if the paper-holding member is configured so that the two arms come into contact with the leading edge of the ejected paper at the optimal position in the width direction, the distance between the two arms of the paper-holding member becomes too wide, and in this case as well, the paper-holding effect when the top surface of the paper comes into contact with the two arms may be worsened.

[0086] In this regard, the paper-holding member 80 (80A to 80D) according to this embodiment (the first to fourth embodiments) has two arm portions 81, 81 that extend along the longitudinal direction N, which is perpendicular to the width direction W.

[0087] This allows the leading edge P1 of the ejected paper P to contact the two arms 81, 81 of the paper holding member 80 at the optimal position in the width direction W (for example, the end in the width direction W) at the beginning of contact with the paper P. This effectively prevents a decrease in the paper holding action of the paper holding member 80. Subsequently, the contact portions 82 of the two arms 81, 81 can press down on the vicinity of both ends of the upper surface Pu of the paper P in the width direction W. This effectively prevents a decrease in the paper holding action of the paper holding member 80 when the upper surface Pu of the paper P contacts the two arms 81, 81. At this time, the distance L1 between the tips of the two arms 81, 81 changes due to the transport force of the ejected paper P, making it less likely for the paper P to get caught between the two arms 81, 81.

[0088] While embodiments of the paper ejection device and image forming apparatus of this disclosure have been described above, the paper ejection device and image forming apparatus of this disclosure are not limited to the embodiments described above.

[0089] For example, although the two arms 81, 81 are provided on the device body 3 via a connecting portion 83 and a mounting portion 84, the two arms 81, 81 may be provided on the device body 3 without using the connecting portion 83 and the mounting portion 84.

[0090] This disclosure is not limited to the embodiments described above and can be implemented in various other ways. Therefore, these embodiments are merely illustrative in all respects and should not be constrained. The scope of this disclosure is defined by the claims and is not restricted by the text of the specification. Furthermore, any variations or modifications within the equivalent scope of the claims are all within the scope of this disclosure. [Explanation of symbols]

[0091] 1. Image forming apparatus 3. Main unit of the device 65 Discharge Roller 65a Drive roller 65b Driven roller 71 Paper ejection device 71A Paper ejection device 71B Paper ejection device 71C Paper ejection device 72 Paper output trays 73 Outlet 80 Paper holding member 80 Paper holding member 80A Paper holding member 80B Paper holding member 80C Paper holding member 80b lower end 81 Arm 82 Contact part 83 Connecting part 84 Mounting part 86. Bending section 87 Curved section 88 Curved section L1 separation distance P Paper Pu top surface W (width direction) X Ejection direction

Claims

1. A device body having a paper discharge port for discharging paper, and a paper discharge tray for stacking the paper discharged from the discharge port, It comprises a paper-holding member that contacts the paper being discharged from the discharge port, The aforementioned paper-holding member is It is made of an elastically deformable material, It has two arms arranged at a predetermined distance apart in the width direction perpendicular to the paper discharge direction, A paper discharge device characterized in that, when the paper is discharged from the discharge port, the two arms elastically deform so that the distance between their tip ends changes due to the transport force of the paper while in contact with the paper.

2. A paper ejection device according to claim 1, A paper ejection device characterized in that the paper holding member is rotatable relative to the main body of the device.

3. A paper ejection device according to claim 1, The aforementioned paper-holding member is It has a bent section where stress is more likely to concentrate than in other parts, A paper discharge device characterized in that, when the paper is discharged from the discharge port, it contacts the upper surface of the paper and bends along the bending portion as the paper moves, and elastically deforms so that the distance between the two arms changes.

4. A paper ejection device according to claim 1, The paper dispensing device is characterized in that the paper holding member, when the paper is discharged from the discharge port, contacts the upper surface of the paper and elastically deforms such that the distance between the two arms increases as the paper moves.

5. A paper ejection device according to claim 1, The paper dispensing device is characterized in that, when the paper is discharged from the discharge port, the paper holding member elastically deforms so as the paper moves, while contacting the upper surface of the paper, that the distance between the two arms decreases.

6. A paper ejection device according to claim 1, The aforementioned paper-holding member is A connecting part that connects the two aforementioned arm parts, It further includes a mounting portion that is attached to the main body of the device above the aforementioned discharge port, The connecting portion and / or the mounting portion is provided with a curved portion formed in a shape that curves in the longitudinal direction of the two arms, A paper discharge device characterized in that, when the paper is discharged from the discharge port, the curved portion elastically deforms such that the distance between the two arms in the width direction changes as the paper moves while contacting the upper surface of the paper.

7. A paper ejection device according to claim 1, The aforementioned paper-holding member is A paper discharge device characterized in that, before contact with the paper, the contact portions of the two arms that contact the paper are inclined in the discharge direction with respect to the leading edge of the paper, and when the paper is discharged from the discharge port, the contact portions move in a direction along the upper surface of the paper as the paper moves while contacting the upper surface of the paper, thereby elastically deforming so that the distance between the two arms changes.

8. A paper ejection device according to claim 6, The aforementioned paper-holding member is A connecting part that connects the two aforementioned arm parts, It further includes a mounting portion that is attached to the main body of the device above the aforementioned discharge port, A paper discharge device characterized in that the connecting portion and / or the mounting portion are provided with a curved portion formed in a shape that curves in the thickness direction of the paper holding member.

9. A paper ejection device according to claim 1, A paper ejection device characterized in that the two arms extend along a longitudinal direction which is perpendicular to the width direction.

10. An image forming apparatus characterized by comprising a paper ejection device according to any one of claims 1 to 9.

Images