Media Loading Device

Abstract

To enable a medium loading device to load media in a U-shape even when the loading amount increases. [Solution] A first stacking unit (10) is configured to load a portion of one side of media M in a width direction (D2) perpendicular to the ejection direction of the media M. A loading platform (12) of the first stacking unit (10) rotates about a first support shaft (S1) so that, when a pressed portion (11) is pressed, the angle of inclination with respect to the horizontal increases, and the height of the end portion on the one side increases. A second stacking unit (20) is configured to load a portion of the other side of media M in the width direction (D2). A loading platform (22) of the second stacking unit (20) rotates about a second support shaft (S2) so that, when a pressed portion (21) is pressed, the angle of inclination with respect to the horizontal increases, and the height of the end portion on the other side increases.

Description

[Technical Field]

[0001] The present invention relates to a medium loading device on which media are loaded. [Background technology]

[0002] Conventionally, a paper output tray has been proposed in which an angle-adjustable support member is provided between the bottom surface of the paper output tray and the side fence in order to load paper that tends to curl upward in a convex shape in a downward convex shape (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-175717 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, paper discharged from an image forming apparatus tends to curl into an inverted U-shape (convex upward) due to ink adhesion, which can easily cause uneven stacking in the paper width direction. When stacking paper that curls into such an inverted U-shape, the paper can be stacked in a U-shape by using a U-shaped (concave upward) stacking surface (for example, the support member described above).

[0005] However, when the paper load on a U-shaped stacking surface is small, the sheets are stacked in a U-shape, almost parallel to the stacking surface. However, as the load of paper, particularly low-rigidity paper, increases, the total air gap between the sheets in the widthwise center increases, causing the sheets to gradually become flatter. As a result, when the load is large, it becomes difficult for air gaps to form between newly stacked sheets. This increases the likelihood of friction between sheets, making it difficult for new sheets to slide over the existing sheets when ejected onto the stacking tray, and making it more likely for the leading edge of the paper to shift position.

[0006] An object of the present invention is to provide a medium stacking device that can stack media in a U-shape even when the stacking amount increases. [Means for solving the problem]

[0007] In one aspect, the medium loading device includes a first loading section and a second loading section, each of which loads a portion of a medium. The first loading section loads a portion of one side of the medium in a width direction perpendicular to the ejection direction of the medium. The second loading section loads a portion of the other side of the medium in the width direction. The first loading section has a pressed portion that is pressed by the medium, and a loading platform that rotates about a first support shaft so that, when the pressed portion is pressed, the inclination angle with respect to the horizontal increases and the height of the end of the one side in the width direction increases. The second loading section has a pressed portion that is pressed by the medium, and a loading platform that rotates about a second support shaft so that, when the pressed portion is pressed, the inclination angle with respect to the horizontal increases and the height of the end of the other side in the width direction increases. [Effects of the Invention]

[0008] According to this aspect, the media can be stacked in a U-shape even when the load amount increases. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing an internal configuration of an image forming apparatus including a medium stacking device according to an embodiment; [Figure 2] 2 is a top view of the medium stacking device as seen from a direction II in FIG. 1. [Figure 3] 3 is a right side view of the medium stacking device as seen from direction III in FIG. 1. [Figure 4] 10 is a right side view showing the medium stacking device in an embodiment with an increased stack amount. FIG. [Figure 5] 1 is a right side view showing a medium stacking device in one embodiment with a highly rigid medium (cardboard) stacked thereon. [Figure 6]FIG. 10 is a right side view showing the medium stacking device in a comparative example with a small stack amount. [Figure 7] FIG. 10 is a right side view showing the medium stacking device in a comparative example when the stacking amount is large. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A medium stacking device according to an embodiment of the present invention will now be described with reference to the drawings.

[0011] FIG. 1 is a diagram showing the internal configuration of an image forming apparatus 100 including a medium stacking device 1 according to an embodiment.

[0012] The image forming apparatus 100 shown in FIG. 1 includes a medium supply unit 101, a feed roller 102, multiple pairs of conveying rollers 103, a suction conveying unit 104, an image forming unit 105, conveying path switching units 106 and 107, a discharge unit 108, and a medium stacking device 1. The up-down, front-rear, and left-right directions shown in FIG. 1 and in FIGS. 2 to 7 (described later) are examples for the convenience of explanation, assuming that the discharge direction D1 of the medium M is the right direction. In the example of FIG. 1, the medium stacking device 1 is tilted downward in the discharge direction D1, but the plan view of FIG. 2 and the right side views of FIGS. 3 to 7 show the up-down, front-rear, and left-right directions when the medium stacking device 1 (medium stacking device 201 in the comparative examples of FIGS. 6 and 7) is positioned horizontally. In FIG. 1, the circulating conveying path of the medium M in the medium stacking device 1 is indicated by a two-dot chain line, and the reverse conveying path of the medium M is indicated by a dashed line.

[0013] As shown in FIG. 1, media M before image formation are loaded in a medium supply unit 101. As an example, the media M are sheet-like media M such as paper sheets. The medium supply unit 101 is disposed integrally with the image forming apparatus 100, but may also be disposed separately from the image forming apparatus 100. A feed roller 102 feeds out and transports the uppermost medium M among the multiple sheets of media M loaded in the medium supply unit 101. Multiple pairs of transport rollers 103 are disposed within the image forming apparatus 100 and nip and transport the medium M. The suction transport unit 104 is disposed opposite the image forming unit 105. The suction transport unit 104 transports the medium M by, for example, a belt while suctioning the medium M. The feed roller 102, the multiple pairs of transport rollers 103, and the suction transport unit 104 are examples of a transport unit that transports the medium M.

[0014] The image forming unit 105 has, for example, a line-head type inkjet head (not shown) for each color used in image formation. Note that the image forming method of the image forming unit 105 may be a method other than the inkjet method, such as stencil printing. The transport path switching unit 106 is, for example, a flipper, and switches the transport path of the medium M on which an image has been formed by the image forming unit 105 between a transport path leading to the medium loading device 1 and a circulating transport path (shown by a two-dot chain line). The transport path switching unit 107 is, for example, a flipper, and switches the circulating transport path of the medium M between a transport path leading to the discharge unit 108 and a transport path leading to a reversing transport path (shown by a dashed line). The discharge unit 108 is loaded with media M that are not discharged to the medium loading device 1. Note that the medium M is turned over in the reversing transport path and transported again to the image forming unit 105, where an image is formed on the opposite side.

[0015] 2 (a top view seen from direction II in FIG. 1) and FIG. 3 (a right side view seen from direction III in FIG. 1), the medium stacking device 1 includes a first stacking section 10, a second stacking section 20, two first guides 31, 31, two second guides 32, 32, a base 40, an end fence 50, a pair of side fences 60, 70, a first support shaft S1, and a second support shaft S2. Note that in FIG. 2, the medium M is shown by an imaginary line (two-dot chain line), and in FIG. 3, the end fence 50 is not shown.

[0016] The first stacking section 10 is loaded with a portion of one side (front side) of the medium M in the width direction D2 perpendicular to the discharge direction D1 of the medium M. The second stacking section 20 is loaded with a portion of the other side (rear side) of the medium M in the width direction D2. In this manner, a portion of the medium M is loaded on each of the first stacking section 10 and the second stacking section 20. The medium M loaded on the first stacking section 10 and the second stacking section 20 is, as described above, the medium M on which an image has been formed by, for example, the image forming apparatus 100.

[0017] Each of the first stacking unit 10 and the second stacking unit 20 has a pressed portion 11, 21, a stacking table 12, 22, and two arms 13, 13, 23, 23. As shown in FIG. 1 , the first stacking unit 10 and the second stacking unit 20 are inclined downward in the direction D1 in which the media M are discharged from the image forming device 100. As a result, the media M discharged from the image forming device 100 slides over the topmost media M already stacked and hits the end fence 50 of the media stacking device 1.

[0018] The pressed portions 11, 21 are, for example, rod-shaped extending in the discharge direction D1 and are pressed by the loaded media M. As will be described later, the pressed portions 11, 21 rotate around the first support shaft S1 or the second support shaft S2 as a rotation center when pressed by the media M, so it is preferable that they have a cylindrical shape so that the shape of the contact area with the media M is constant regardless of the rotation position. The pressed portions 11, 21 can also be called drive rods.

[0019] The loading platforms 12, 22 are connected to the pressed parts 11, 21 by arms 13, 13, 23, 23 provided on both ends of the pressed parts 11, 21 in the discharge direction D1. The angle formed between the arms 13, 13, 23, 23 and the loading platforms 12, 22 (loading surfaces as upper surfaces) is preferably, for example, 90 degrees or more and 135 degrees or less.

[0020] 4, the loading platform 12 of the first loading unit 10 is located on the one side (front side) in the width direction D2 of the pressed portion 11. The loading platform 12 rotates about the first support shaft S1 so that, as the pressed portion 11 is pressed, the inclination angle with respect to the horizontal increases and the height of the end of the loading platform 12 on the one side (front side) in the width direction D2 increases. When the loading platform 12 rotates, the entire first loading unit 10, including the pressed portion 11 and the arms 13, 13, rotates.

[0021] Similarly, the loading platform 22 of the second loading unit 20 is located on the other side (rear side) in the width direction D2 of the pressed portion 21. The loading platform 22 rotates about the second support shaft S2 so that, as the pressed portion 21 is pressed, the inclination angle with respect to the horizontal increases and the height of the end of the loading platform 22 on the other side (rear side) in the width direction D2 increases. When the loading platform 22 rotates, the entire second loading unit 20, including the pressed portion 21 and the arms 23, 23, rotates.

[0022] The first support shaft S1 and the second support shaft S2 are disposed at both ends of the loading platforms 12, 22 in the discharge direction D1, and extend parallel to the discharge direction D1. The first support shaft S1 and the second support shaft S2 are not particularly limited, but may be, for example, held by a holding portion protruding upward from the upper surface of the base platform 40 (described later) and inserted into the first loading unit 10 or the second loading unit 20, or may be provided on the first loading unit 10 or the second loading unit 20 themselves and held by a recess in the upper surface of the base platform 40.

[0023] Two notches 12a are provided at the front end of the loading platform 12 to avoid interference with first guides 31, 31 and a side fence 60, which will be described later. Furthermore, two notches 22a are provided at the rear end of the loading platform 22 to avoid interference with second guides 32, 32 and a side fence 70, which will be described later. Note that in order to avoid interference between the loading platforms 12, 22 and the first guides 31, 31 or the second guides 32, 32 or the side fences 60, 70, the loading platforms 12, 22 may be provided with through holes extending in the vertical direction, or grooves may be provided on the upper surfaces of the loading platforms 12, 22.

[0024] 3, when the amount of media M loaded is small (at least when no media M is loaded), the first guides 31, 31 protrude upward from the stacking table 12 of the first stacking unit 10 to come into contact with the media M. The height of the first guides 31, 31 increases toward the one side (front side) in the width direction D2.

[0025] Furthermore, when the amount of media M loaded is small (at least when no media M is loaded), the second guides 32, 32 protrude upward from the loading table 22 of the second stacking unit 20 to come into contact with the media M. Furthermore, the height of the second guides 32, 32 increases as they approach the other side (rear side) in the width direction D2.

[0026] Therefore, when the load amount of media M is small, media M are loaded on the first guides 31, 31 and the second guides 32, 32. Note that when the load amount of media M is small, the first guides 31, 31 and the second guides 32, 32 protrude upward from the loading tables 12, 22, and the positions of the loading tables 12, 22 in the first stacking unit 10 and the second stacking unit 20 when no media M are loaded may be restricted by an elastic body such as a torsion spring and a rotation restricting unit so that the height of the loading tables 12, 22 increases the further away from the center of the media M in the width direction D2. In the example of FIGS. 2 and 3, the first guides 31, 31 and the second guides 32, 32 have a rectangular parallelepiped shape whose upper surface increases in height the further away from the center of the media M in the width direction D2, but the shapes of the first guides 31, 31 and the second guides 32, 32 are not particularly limited. Furthermore, although an example has been described in which two first guides 31, 31 and two second guides 32, 32 are arranged in each of the first stacking section 10 and the second stacking section 20, any number of first guides 31, 31 and second guides 32, 32 may be arranged in each of the first stacking section 10 and the second stacking section 20, and the number may be one or more. Furthermore, when only media M with particularly low rigidity are stacked, it is also possible to omit the arrangement of the first guides 31, 31 and the second guides 32, 32.

[0027] The base table 40 holds the first support shaft S1 and the second support shaft S2 as described above. The base table 40 is disposed below the first stacking unit 10 and the second stacking unit 20. The base table 40 may have a horizontal, flat plate shape, but is curved to have an upward concave shape. The base table 40 may also have a shape such as a V-shape. The base table 40 can be omitted, but it is preferable that it be disposed in the medium stacking device 1.

[0028] 2, the leading edge of the medium M discharged in the discharge direction D1 from the image forming apparatus 100 abuts against the end fence 50, which regulates the position of the medium M in the discharge direction D1. The end fence 50 is preferably movable in the discharge direction D1 in accordance with the size of the medium M. Furthermore, when the medium loading device 1 is positioned horizontally, the end fence 50 may function as an offset guide that changes the position of the loaded medium M in the discharge direction D1 at a specified timing, such as a print job.

[0029] The side fences 60, 70 are disposed opposite each other in the width direction D2 and regulate the position in the width direction D2 of the medium M. The side fences 60, 70 are preferably movable in the width direction D2 in accordance with the size of the medium M, etc.

[0030] Here, a medium stacking device 201 in a comparative example will be described with reference to FIGS.

[0031] As shown in Figure 6, the medium stacking device 201 includes a stacking table 210 and a pair of side fences 220, 230. The stacking table 210 is shaped so that its top surface is concave upward. As a result, when the amount of media M stacked is small, the total air layer A (shown by the dashed line) between the media M in the center in the width direction D2 is small, so the media M are stacked in a U-shape approximately parallel to the stacking surface. As a result, the center in the width direction D2 of the topmost medium M is lower by a sufficient height h1 than the imaginary horizontal line V connecting both ends of the media M in the width direction D2.

[0032] On the other hand, as shown in FIG. 7, when the amount of loaded media M increases, the total air layer A (shown by the dashed line) between the media M in the center in the width direction D2 increases, causing the media M to become more flat. As a result, the center in the width direction D2 of the uppermost media M is lower by a height h2 than the imaginary horizontal line V connecting both ends of the media M in the width direction D2, and this height h2 is an insufficient height that is shorter than the height h1 described above. Accordingly, when the amount of loaded media M is large, it is difficult for the air layer A to form between newly loaded media M. As a result, friction between the media M is more likely to occur, making it difficult for newly loaded media M to slide over the already loaded media M, and the leading edge of the media M in the discharge direction D1 is more likely to shift position.

[0033] 4, when the amount of loaded media M increases, the pressed portions 11, 21 of the first stacking unit 10 and the second stacking unit 20 are pressed strongly, causing the loading tables 12, 22 to rotate about the first support shaft S1 or the second support shaft S2 so that the angle of inclination with respect to the horizontal increases. Therefore, even when the amount of loaded media M increases, the media M can be maintained in a U-shape, and friction between newly loaded media M is less likely to occur, making it easier for newly loaded media M to slide over already loaded media M, and making it easier to align the leading edges of the media M in the discharge direction D1.

[0034] Furthermore, as shown in FIG. 5, if the medium M is thick paper C (e.g., cardboard) and has high rigidity, the thick paper C is guided by the first guides 31, 31 and the second guides 32, 32, so that the pressed portions 11, 21 are not pressed strongly even when the load is large. Therefore, when thick paper C, which has high rigidity and is therefore less likely to create an air layer (see air layer A in FIG. 7 for the comparative example), is loaded, the tilt angle of the stacking tables 12, 22 is kept from becoming too large, preventing the thick paper C from forming an extremely large U-shape. Therefore, the U-shape of the thick paper C can be maintained regardless of the load amount. Furthermore, because the thick paper C easily slides along the downward slope of the medium stacking device 1 in the discharge direction D1, the leading edge of the medium M is less likely to shift position in the discharge direction D1.

[0035] As explained above, it is desirable that the medium loading device 1 be inclined downward in the discharge direction D1, but the heights of the first stacking unit 10, second stacking unit 20, etc. may be constant in the discharge direction D1. Furthermore, the medium loading device 1 may be provided with a lifting mechanism that raises and lowers the first stacking unit 10 and second stacking unit 20 based on the amount of media M loaded, in order to keep the height of the stacking surface of the media M close to constant. In this case, only parts of the medium loading device 1, such as the first stacking unit 10, second stacking unit 20, first guides 31, 31, second guides 32, 32, and base 40, may be raised and lowered, while other parts of the medium loading device 1, such as the end fence 50 and side fences 60, 70, may be arranged so that they cannot be raised or lowered.

[0036] Furthermore, in the above description, the medium loading device 1 is arranged integrally with the image forming apparatus 100, but it may also be arranged separately from the image forming apparatus 100. Furthermore, the medium loading device 1 may not be loaded with the medium M on which the image has been formed in the image forming apparatus 100, but may be loaded with a processing device that performs processing other than image formation on the medium M, or with the medium M discharged from a conveying device that conveys the medium M.

[0037] In the present embodiment described above, the medium stacking device 1 includes a first stacking section 10 and a second stacking section 20, each of which holds a portion of the medium M. The first stacking section 10 holds a portion of the medium M on one side (front side) in the width direction D2 perpendicular to the discharge direction D1 of the medium M. The second stacking section 20 holds a portion of the medium M on the other side (rear side) in the width direction D2. The first stacking section 10 has a pressed portion 11 that is pressed by the medium M, and a loading platform 12 that rotates about a first support shaft S1 so that, when the pressed portion 11 is pressed, the angle of inclination with respect to the horizontal increases and the height of the end portion on the one side in the width direction D2 increases. The second loading section 20 has a pressed portion 21 that is pressed by the medium M, and a loading platform 22 that rotates around the second support axis S2 so that when the pressed portion 21 is pressed, the inclination angle with respect to the horizontal increases and the height of the end on the other side in the width direction D2 increases.

[0038] As a result, even if the air gap between the media M in the center in the width direction D2 (see air gap A in FIG. 6 for the comparative example) increases as the amount of media M loaded increases, increasing the inclination angle of the loading trays 12, 22 relative to the horizontal can prevent the media M from becoming flat. Therefore, according to this embodiment, the media M can be loaded in a U-shape even if the amount of media M loaded increases. Furthermore, because the media M can be stably loaded in a U-shape, air gaps can be formed between the media M even if the amount of media M loaded increases. Therefore, friction between the media M is less likely to occur, making it easier for the ejected media M to slide over the media M already loaded on the loading trays 12, 22, and making it easier to align the leading edges of the media M in the ejection direction D1.

[0039] In addition, in this embodiment, the medium loading device 1 further includes first guides 31, 31 that protrude upward from the loading table 12 of the first loading section 10 when at least no medium M is loaded, thereby contacting the medium M, and that become higher as they move toward the one side (front side) in the width direction D2, and second guides 32, 32 that protrude upward from the loading table 22 of the second loading section 20 when at least no medium M is loaded, thereby contacting the medium M, and that become higher as they move toward the other side (rear side) in the width direction D2.

[0040] Incidentally, when the medium M is a type of medium such as cardboard C with high rigidity, the U-shape of the medium M is likely to be maintained even when the load is large. In this embodiment, the cardboard C is easily guided by the first guides 31 and the second guides 32, so the pressed portions 11 and 21 are not strongly pressed by the cardboard C, preventing the cardboard C from forming an extremely large U-shape (a shape in which the central portion sinks significantly more than both ends in the width direction D2), which can result in bending, damage, and stacking irregularities. In this manner, in this embodiment, the inclination of the stacking trays 12 and 22 can be adjusted depending on the type of medium M (plain paper, cardboard C, etc.). Because the cardboard C is easily slidable in accordance with the downward inclination of the medium stacking device 1 in the discharge direction D1, the leading edge of the medium M is unlikely to shift in the discharge direction D1 even if the inclination of the stacking trays 12 and 22 is not increased depending on the load amount.

[0041] In this embodiment, the medium stacking device 1 further includes a base table 40. The base table 40 holds the first support shaft S1 and the second support shaft S2, and is disposed below the first stacking unit 10 and the second stacking unit 20.

[0042] This stabilizes the airflow below the first stacking unit 10 and the second stacking unit 20 compared to an embodiment in which the base table 40 is omitted, making it easier to align the stacking positions of the media M. Also, the user can fold the entire media stacking device 1, including the first stacking unit 10 and the second stacking unit 20, along with the image forming apparatus 100, by simply pushing the base table 40.

[0043] The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components without departing from the spirit of the invention in the implementation stage. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all of the components shown in the embodiments may be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention. The invention as set forth in the claims of the present application as originally filed is set forth below.

[0044] [Appendix 1] a first stacking section and a second stacking section, each of which is configured to stack a portion of the medium; the first stacking section stacks a portion of one side of the medium in a width direction perpendicular to the ejection direction of the medium, the second stacking section stacks a portion of the medium on the other side in the width direction, the first stacking unit has a pressed portion that is pressed by the medium, and a stacking table that rotates about a first support shaft so that the pressed portion is pressed to increase its inclination angle with respect to the horizontal and increase the height of the end portion on one side in the width direction; The second stacking unit has a pressed portion that is pressed by the medium, and a stacking table that rotates about a second support shaft so that the pressed portion increases in inclination angle with respect to the horizontal and the height of the other end in the width direction increases. A medium loading device.

[0045] [Appendix 2] a first guide that protrudes upward from the loading platform of the first loading section when at least the media are not loaded, thereby contacting the media, and that increases in height toward the one side in the width direction; a second guide that protrudes upward from the loading platform of the second loading section when at least the media are not loaded, thereby contacting the media, and that increases in height as it goes to the other side in the width direction; 2. The medium loading device according to claim 1, further comprising:

[0046] [Appendix 3] a base table that holds the first support shaft and the second support shaft and is disposed below the first loading section and the second loading section. 3. A medium loading device according to claim 1 or 2. [Explanation of symbols]

[0047] 1 Media loading device 10 First loading section 11 Pressed part 12 Loading platform 12a Notch 13 Arm 20 Second loading section 21 Pressed part 22 Loading platform 22a Notch 23 Arm 31 First Guide 32 Second Guide 40 Base 50 End Fence 60,70 Side fence 100 Image forming device 101 Media supply section 102 Feed roller 103 conveying roller pair 104 Suction conveying section 105 Image forming unit 106,107 Conveyor path switching unit 108 Discharge section 201 Media loading device (comparison example) A Air layer C. Cardboard D1 Discharge direction D2 width direction h1,h2 height M medium S1 1st spindle S2 2nd spindle V Virtual horizon

Claims

1. a first stacking section and a second stacking section, each of which is configured to stack a portion of the medium; the first stacking section stacks a portion of one side of the medium in a width direction perpendicular to the ejection direction of the medium, the second stacking section stacks a portion of the medium on the other side in the width direction, the first stacking unit has a pressed portion that is pressed by the medium, and a stacking table that rotates about a first support shaft so that the pressed portion is pressed to increase its inclination angle with respect to the horizontal and increase the height of the end portion on the one side in the width direction, The second stacking unit has a pressed portion that is pressed by the medium, and a stacking table that rotates about a second support shaft so that the pressed portion increases in inclination angle with respect to the horizontal and the height of the other end in the width direction increases. A medium loading device.

2. a first guide that protrudes upward from the loading platform of the first loading section when at least the media are not loaded, thereby contacting the media, and that increases in height toward the one side in the width direction; a second guide that protrudes upward from the loading platform of the second loading unit when at least the medium is not loaded, thereby contacting the medium, and that increases in height as it approaches the other side in the width direction; The media loading device of claim 1 , further comprising:

3. a base table that holds the first support shaft and the second support shaft and is disposed below the first loading section and the second loading section.

3. The medium loading device according to claim 1 or 2.

Images