imaging device

Abstract

The present application relates to an image forming apparatus including an image forming section, a sheet discharging section, and a sheet stacking section. The stacking section includes a first member including an inclined surface inclined upward toward a downstream side in a sheet discharging direction, and a second member including a stacking surface on which discharged sheets are stacked, which protrudes upward from the inclined surface. The second member is rotatable relative to the first member about a fulcrum disposed upstream of the stacking surface with respect to the sheet discharging direction. The second member is rotatable in a direction in which the stacking surface is moved downward about the fulcrum in accordance with an increase in the number of sheets stacked on the stacking surface.

Description

[0001] This application is a divisional application of the invention patent application entitled "Imaging Device", filed on September 30, 2020, with application number 202011060175.3. Technical Field

[0002] The present invention relates to an imaging apparatus for forming images on a sheet. Background Technology

[0003] In imaging devices such as printers, copiers, or multifunction machines, sheets on which images are formed by inkjet printing units or electrophotographic mechanisms are stacked on an ejection tray via ejection roller pairs.

[0004] Japanese Patent Application Publication No. 2000-38247 discloses an imaging device in which a rib guide is provided, the rib guide protruding upward from a discharge tray and sheets to be stacked on the rib guide. The rib guide is lowered according to the number of sheets stacked on it.

[0005] The rib guide rotates with its downstream end relative to the sheet discharge direction as a fulcrum. As the number of sheets stacked on the rib guide increases and the rib guide decreases in height, the tilt angle of the rib guide relative to the horizontal plane increases. As a result, when the number of sheets stacked on the rib guide is large, the newly discharged sheet is susceptible to the large feed resistance from the sheets already stacked on the rib guide during its discharge through the discharge rollers. The newly discharged sheet is subject to the large sheet resistance from the already stacked sheets, thus the newly discharged sheet is prone to positional deviation. Therefore, there is a possibility of poor alignment of the stacked sheets. Summary of the Invention

[0006] The main objective of this invention is to provide an imaging device in which the alignment of the stacked sheets remains good even when the number of stacked sheets increases.

[0007] According to one aspect of the present invention, an imaging apparatus is provided, comprising: an imaging unit configured to form an image on a sheet; an ejection unit configured to eject the sheet on which the image is formed by the imaging unit; and a stacking unit configured to stack the sheet ejected by the ejection unit in a state where an upstream end of the sheet relative to the sheet ejection direction is lower than a downstream end of the sheet relative to the sheet ejection direction, wherein the stacking unit comprises: a first member including an inclined surface inclined upward toward a downstream side of the sheet ejection direction; and a second member including a stacking surface protruding upward from the inclined surface and on which the ejected sheet is stacked, wherein the second member is rotatable relative to the first member about a fulcrum disposed upstream of the stacking surface relative to the sheet ejection direction; wherein, according to an increase in the number of sheets stacked on the stacking surface, the second member is rotatable about the fulcrum in a direction of downward movement along the stacking surface.

[0008] Other features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the imaging device according to Embodiment 1.

[0010] Figure 2 This is a perspective view of the discharge tray (first discharge tray) in Embodiment 1 on the upper (front) surface side.

[0011] Figure 3 This is a perspective view of the discharge tray (first discharge tray) in Embodiment 1 on the lower (back) surface side.

[0012] Figure 4 This is a cross-sectional view of the discharge tray in Example 1 (in standby state).

[0013] Figure 5 This is a cross-sectional view of the discharge tray in Example 1 (fully filled).

[0014] Figure 6 This is a cross-sectional view showing the state of the sheet discharge operation in Embodiment 1.

[0015] Figure 7 This is a cross-sectional view showing the movement of the sheet discharged onto the discharge tray in Embodiment 1.

[0016] Figure 8 This is a cross-sectional view showing the state of multiple sheets stacked in Embodiment 1.

[0017] Figure 9 This is a cross-sectional view showing the state of multiple sheets stacked in the comparative (reference) example.

[0018] Figure 10This is a perspective view of the movable tray in Example 2. Detailed Implementation

[0019] Exemplary embodiments for carrying out the present invention will now be described with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the imaging device 100 according to Embodiment 1. The main component 101 of the imaging device 100 houses the imaging section 140, which is an intermediate transfer cascade type electro-camera mechanism, wherein four imaging stations 1Y, 1M, 1C and 1K for forming toner images of four colors are arranged along the intermediate transfer belt 145.

[0021] In each imaging station 1Y, 1M, 1C, and 1K, toner images are formed through electrophotographic processing. Specifically, the photosensitive component 141, serving as the image carrier, is pre-charged uniformly by a charger, and then scanned and exposed using light emitted from the exposure device 142, thereby writing (forming) an electrostatic latent image on the surface of the photosensitive component 141. This electrostatic latent image is developed into a toner image by charged toner particles supplied from the developing device 143. The toner image carried on the photosensitive component 141 is temporarily transferred by the primary transfer roller 144 to the intermediate transfer belt 145, which serves as the intermediate transfer component. At this time, the yellow, magenta, cyan, and black toner images formed by each imaging station 1Y, 1M, 1C, and 1K are superimposed on the intermediate transfer belt 145, thereby forming a full-tone toner image. This full-tone toner image is carried on the intermediate transfer belt 145 and fed to the secondary transfer section 130.

[0022] In parallel with this imaging process, a feeding process for the sheet S, which serves as the recording material, is performed. With the sheet S stacked on a lifting device included in the sheet feeding apparatus, the sheet S is housed in a cassette that can be inserted into and pulled out of the main assembly 101 of the imaging apparatus 100. Incidentally, various sheet materials of different sizes and materials can be used as the sheet S, such as paper including plain paper and thick paper, plastic film, cloth, surface-treated sheet materials such as coated paper, and specially shaped sheet materials such as envelopes or index paper. Based on the progress of the imaging operations performed by the imaging stations 1Y, 1M, 1C, and 1K, the sheet S housed in the cassette is fed sheet by sheet by sheet via the feeding unit 110, which serves as the feeding device.

[0023] The sheet S fed by the feeding unit 110 is conveyed to the skew correction device 120 through the conveying channel, where skew correction and timing correction are performed, and then it is sent to the secondary transfer section 130. The secondary transfer section 130 is a clamping part formed by an inner secondary transfer roller 131 and an outer secondary transfer roller 132 that are opposite each other and simultaneously clamp the intermediate transfer belt 145. The toner image carried on the intermediate transfer belt 145 is transferred onto the sheet S under mechanical pressing pressure and electrostatic load bias applied at the secondary transfer section 130.

[0024] The sheet S passing through the secondary transfer section 130 is conveyed to the fixing device 150. The fixing device 150 includes a pair of rotatable members that are rotatable while holding the sheet S, and a heat source such as a halogen lamp, which heats and presses the toner image on the sheet S while feeding it. As a result, the toner particles melt and are then fixed, thereby fixing the toner image onto the sheet S. The sheet S with the fixed image is guided by a first baffle 151, which serves as a switching member, to a channel toward the first discharge roller 160 (lower discharge path) or to a channel toward the second discharge roller 161 (upper discharge path).

[0025] As the designated discharge location for the sheet S on which the image is formed, the imaging apparatus 100 of this embodiment is provided with a first discharge tray 170 and a second discharge tray 171. The sheet S, guided to the lower discharge path, is discharged by the first discharge roller 160 to the outside of the main assembly 101 and stacked on the first discharge tray 170. The sheet S, guided to the upper discharge path, is discharged by the second discharge roller 161 to the outside of the main assembly 101 and stacked on the second discharge tray 171. The first discharge roller 160 and the first discharge tray 170 constitute a first discharge section 190, and the second discharge roller 161 and the second discharge tray 171 constitute a second discharge section 191. The first discharge section 190 and the second discharge section 191 are each examples of sheet discharge devices for discharging the sheet S.

[0026] On the other hand, in the case of double-sided printing, the sheet S with the image on the first side is guided to the upper discharge path by the first baffle 151, and then folded back by the reverse operation of the second discharge roller 161. After the sheet S is folded back, the second baffle 152 guides the sheet S to the double-sided feed path 180. Then, the sheet S, which reaches the skew movement correction device 120 again through the double-sided feed path 180, undergoes a similar process to the first side to form an image on the second side, and is then discharged onto the first discharge tray 170 or the second discharge tray 171.

[0027] Incidentally, the first discharge tray 170 and the second discharge tray 171 each include an inclined surface that slopes upward relative to the vertical direction toward the downstream side (to the left in the figure) relative to the sheet discharge direction. Therefore, the sheet S discharged on each discharge tray returns to the upstream side relative to the sheet discharge direction by its own weight and aligns in contact with the alignment reference wall provided on the main assembly 101 of the equipment.

[0028] Furthermore, the imaging device 100 of this embodiment has a so-called in-device discharge type structure, wherein a sheet discharge space is provided between the imaging unit 140 and the image reading device 102 disposed at the upper part of the main device assembly 101 relative to the vertical direction. Of the first discharge tray 170 and the second discharge tray 171 disposed at the upper and lower sections of this discharge space, the first discharge tray 170 disposed at the lower section is mounted at the upper part of the main device assembly 101. Incidentally, the image reading device 102 is a device that reads image information by scanning the original document using an image sensor unit provided with a pickup element, and transmits the image information to the control circuit of the main device assembly 101.

[0029] [Exit tray]

[0030] In the following description, the first discharge section 190, which is a sheet discharge device, will be described. In the description below, the first discharge tray 170 and the first discharge roller 160 will be simply referred to as "discharge tray 170" and "discharge roller 160," respectively. Furthermore, the direction of movement of the sheet discharged from the discharge roller 160 relative to the horizontal direction is referred to as the "sheet discharge direction D1," and the axial direction of the discharge roller 160 (the direction perpendicular to the vertical direction and the sheet discharge direction D1) is referred to as the "width direction D2."

[0031] Figure 2 This is a perspective view of the discharge tray 170 as seen from the top (front) side. Figure 3 This is a perspective view of the discharge tray 170 as seen from the lower surface (back side). The discharge tray 170, as the stacking section in this embodiment, is a tray unit including a fixed tray 20 and a movable tray 21. The fixed tray 20 serves as a first member forming a first stacking surface, and the movable tray 21 serves as a second member forming a second surface and is movable relative to the fixed member. The sheet S discharged by the discharge roller 160 is stacked on these fixed trays 20 and movable trays 21.

[0032] On the front side of the fixed tray 20 ( Figure 2The movable tray 20 has an upper surface 20s constituting a first stacking surface and a plurality of slits 20b arranged from the upstream end relative to the sheet discharge direction D1 toward the center portion along the width direction D2. As described later, the arcuate ribs 21d of the movable tray 21 protrude from each of the slits 20b provided in the upper surface 20s. Incidentally, on the upper surface 20s, at positions corresponding to each of the slits 20b relative to the width direction D2, a plurality of guide ribs 20g extend along the sheet discharge direction D1. That is, the arcuate ribs 21d of the movable tray 21 and the guide ribs 20g of the fixed tray 20 are arranged along the sheet discharge direction D1.

[0033] On the back side of the fixed tray 20 ( Figure 3 The rotating hole 20d is located at the upstream end relative to the sheet discharge direction, and two fixed tray hooks 20e, each equipped with a force-applying spring 22, are located at the center portion relative to the sheet discharge direction. Furthermore, the fixed tray 20 connects to the main equipment assembly 101 via four mounting portions 20c. Figure 1 The parts to be joined are mounted on the imaging device and fixed to the main component 101 of the device.

[0034] The movable tray 21 is provided with a plurality of arcuate ribs 21d forming a second stacking surface. Figure 2 The plurality of arcuate ribs 21d are positioned relative to the width direction D2 at locations corresponding to the slit 20b of the fixed tray 20, and at least a portion of the arcuate ribs extend from the upstream end of the movable tray 21 toward the downstream end relative to the sheet discharge direction D1. Furthermore, the upper end of each arcuate rib 21d is inclined upward toward the downstream side of the sheet discharge direction D1 and bends in a generally arcuate shape, such that the angle of inclination of the arcuate rib relative to the horizontal plane decreases toward the downstream side of the sheet discharge direction D1. Incidentally, in this embodiment, nine arcuate ribs 21d are provided. The distance (interval) M between adjacent arcuate ribs 21d in the width direction among the five central arcuate ribs 21d is narrower than the distance (interval) N between adjacent (two) arcuate ribs 21d in the width direction on each of the opposite sides.

[0035] In addition, the movable tray 21 is on the back side of the fixed tray 20 ( Figure 3 The portion includes a plate-shaped main body 21f connecting multiple arcuate ribs 21d, two rotation axes 21a serving as rotation fulcrums for the movable tray 21, and two movable tray hooks 21b. Each arcuate rib 21d extends upward from the plate-shaped main body 21f relative to the vertical direction and can protrude upward from the fixed tray 20 through the slit 20b of the fixed tray 20.

[0036] Two rotating shafts 21a are provided at the upstream end of the movable tray 21 relative to the sheet discharge direction D1, and are respectively engaged in the rotating holes 20d of the fixed tray 20. Thus, the movable tray 21 is configured to rotate relative to the fixed tray 20 about a rotating axis extending in the width direction D2 (i.e., an imaginary straight line passing through the two rotating shafts 21a). Two movable tray hooks 21b are provided at the downstream end of the movable tray 21 relative to the sheet discharge direction D1. A force-applying spring 22 is installed between each of the two sets of movable tray hooks 21b and the fixed tray hooks 20e, and the force-applying spring 22 applies force to the movable tray hooks 21b to bring them closer to the fixed tray hooks 20e (i.e., applies force upwards to the movable tray 21). Incidentally, at the downstream end of the movable tray 21 relative to the sheet discharge direction D1, an abutment portion 21c is provided that can contact the back of the fixed tray 20. Figure 4 and 5 The contact part 21c contacts the fixed tray 20 at the position ( Figure 4 () is the upper limit position of the rotation range of the movable tray 21.

[0037] The discharge tray 170, assembled as described above, is mounted on the main equipment assembly 101 via four mounting portions 20c of the fixing tray 20. Incidentally, the discharge tray 170 (and the second discharge tray 171 located above the discharge tray 170) can be installed in and removed from the main equipment assembly 101, and by removing the two discharge trays from the main equipment assembly 101, space for installing post-processing devices is ensured in the discharge space within the imaging equipment 100.

[0038] [Details of the tray shape]

[0039] Next, the shape and operation of the stacked surface formed by the discharge tray 170, including the movable tray 21, will be described. Figure 4 This is a cross-sectional view of the discharge tray 170 when the movable tray 21 is in a standby state. Figure 5 This is a cross-sectional view of the discharge tray 170 when the movable tray 21 is in its maximum rotation state. However, the standby state refers to the state where no sheets are stacked on the discharge tray 170, and the maximum rotation state refers to the state where the movable tray 21 has rotated downwards the most from its standby state position. The position of the movable tray 21 in the standby state is the first position in this embodiment, and the position of the movable tray 21 in the maximum rotation state is the second position in this embodiment. Furthermore, in the following description, "upstream" or "downstream" refers to the positional relationship on the upstream or downstream side relative to the sheet discharge direction D1.

[0040] The first stacking surface WX is formed by the fixed tray 20 from position W to position X. Position W is the upstream end of the region in which the fixed tray 20 can support the lower surface of the sheet via its upper surface, relative to the sheet discharge direction D1, and position X is the downstream end of the region relative to the sheet discharge direction D1.

[0041] The second stacking surface YZ is formed by the arcuate ribs 21d of the movable tray 21 from position Y to position Z. That is, in this embodiment, the second stacking surface YZ is an imaginary surface that connects the upper ends of a plurality of arcuate ribs arranged in the width direction. Position Y is the position of the upstream end relative to the sheet discharge direction D1 in the region where the arcuate ribs 21d can support the lower surface of the sheet, and position Z is the position of the downstream end relative to the sheet discharge direction D1 in the same region.

[0042] The movable tray 21 is arranged to be offset upstream of the discharge tray 170 relative to the sheet discharge direction D1. For example, the midpoint V (midpoint between position Y and position Z) of the second stack surface relative to the sheet discharge direction D1 is upstream of the midpoint U (midpoint between position W and position X) of the first stack surface, which is also the midpoint of the entire discharge tray 170. The distance from the upstream end of the first stack surface WX to the upstream end of the second stack surface YZ is shorter than the distance from the downstream end of the first stack surface WX to the downstream end of the second stack surface YZ (WY...). <XZ)。

[0043] The upstream end (Y) of the second stacking surface YZ is located in the upstream end region of the discharge tray 170. For example, when the extent of the stacking surface of the discharge tray 170 is divided into four equal parts relative to the sheet discharge direction D1, the upstream end (Y) of the second stacking surface YZ is located upstream of the upstream quartering point Q1. On the other hand, the downstream end (Z) of the second stacking surface YZ extends downstream of the middle position U of the discharge tray 170 relative to the sheet discharge direction D1. However, when the extent of the stacking surface of the discharge tray 170 is divided into four equal parts relative to the sheet discharge direction D1, the downstream end (Z) of the second stacking surface YZ is located upstream of the downstream quartering point Q3.

[0044] The pivot point P of the movable tray 21 is located near the upstream end of the discharge tray 170. Specifically, the pivot point P is located upstream of the intermediate position U of the discharge tray 170 relative to the sheet discharge direction D1, and the distance from the pivot point P to position W is less than the distance from the pivot point P to the intermediate position U. In other words, the pivot point P is located upstream of the upstream quarter point Q1 of the stacking surface of the discharge tray 170 relative to the sheet discharge direction D1.

[0045] Furthermore, the pivot point P of the movable tray 21 is located near the upstream end of the movable tray 21 itself. Specifically, the pivot point P is located upstream of the intermediate position V of the movable tray 21 relative to the sheet discharge direction D1, and the distance from the pivot point P to position Y is less than the distance from the pivot point P to the intermediate position V. In other words, when the range of the second stacking surface is divided into four equal parts relative to the sheet discharge direction D1, the pivot point P is located upstream of the upstream four-part division point q1 of the second stacking surface of the movable tray 21 relative to the sheet discharge direction D1.

[0046] Incidentally, in the illustrated construction example, the pivot point P of the movable tray 21 is located closer to the upstream end of the discharge tray 170 within the aforementioned range and the upstream end of the movable tray 21 itself within the aforementioned range. For example, the distance (PW) from the pivot point P to the upstream end (W) of the discharge tray 170 relative to the sheet discharge direction D1 is less than 1 / 8 of the entire first stack surface (WX) of the discharge tray 170. Furthermore, the distance (PY) from the pivot point P to the upstream end (Y) of the second stack surface YZ relative to the sheet discharge direction D1 is less than 1 / 8 of the entire second stack surface (YZ) of the discharge tray 170.

[0047] In the standby state, the first stacking surface WX and the second stacking surface YZ are each freely inclined surfaces that are tilted upward relative to the vertical direction on the downstream side relative to the sheet discharge direction D1. That is, the fixed tray 20 and the movable tray 21 are tilted in the standby state, thereby generating a force for returning the sheet discharged on the discharge tray 170 to the upstream side relative to the sheet discharge direction.

[0048] The tilt angles of the first stacked surface WX and the second stacked surface YZ will be described in detail. The average tilt angle of the first stacked surface WZ differs between the upstream portion 91 (W to Z) located on the upstream side of the downstream end of the second stacked surface YZ and the downstream portion 92 (Z to X) located on the downstream side of the downstream end of the second stacked surface YZ. When the tilt angle in the upstream portion 91 (W to Z) of the first stacked surface WX is θa (degrees) and the tilt angle in the downstream portion 92 (Z to X) of the first stacked surface WX is θb (degrees), θa > θb is satisfied. Incidentally, in this embodiment, the upstream and downstream portions of the first stacked surface WX are each formed as planar shapes tilted at a specific tilt angle θa or θb. When the tilt angle in each portion is not a specific angle, θa and θb each refer to the average tilt angle.

[0049] The second stacked surface YZ is configured such that at least a portion of its upstream tilt angle is greater than the tilt angle θa of the first stacked surface WX in the upstream portion where the positions of the second stacked surface YZ and the first stacked surface overlap with each other relative to the sheet discharge direction D1. That is, when the tilt angle θc (degrees) of the tangent of the arcuate rib 21d relative to the horizontal plane is θc, the tilt angle θc gradually decreases from the upstream side to the downstream side. In this case, the structure ensures that at least in the upstream end region where the tilt angle θc of the second stacked surface YZ is maximized, θc > θa is satisfied. In other words, when the tilt angle θc of the second stacked surface YZ in the upstream end region of the second stacked surface YZ is θcmax, θcmax is a value greater than θa.

[0050] In the construction example shown, the settings are configured such that θa = 20 (degrees), θb = 6 (degrees), and θcmax = 32 (degrees). However, the tilt angle of the stacked surfaces is not limited to this, but can be appropriately changed according to the assumed material and size of the main sheet used, the surface properties of the material constituting the discharge tray 170, etc.

[0051] When no sheets are stacked on the discharge tray 170, the movable tray 21 remains in a ready-to-use state in which the second stacking surface YZ protrudes most upward from the first stacking surface WX due to the force applied by the force spring. At this time, as... Figure 4 As shown, the entire second stacking surface YZ is located above the first stacking surface WX. The movable tray 21 rotates downwards according to the force from above, i.e., according to the weight of the extruded sheet, as... Figure 5 As shown by arrow B in the diagram, the force applied by the force-applying spring 22 is set such that even when a small force is applied, the abutment portion 21c of the movable tray 21 remains in contact with the fixed tray 21, thus reducing the likelihood of vibration noise.

[0052] On the other hand, the force applied by the force spring 22 is set such that when a certain number or more sheets are stacked on the discharge tray 170, the movable tray 21 rotates to its maximum rotation state according to the weight of the sheets. As described later, when the number of stacked sheets is small, the second stacking surface YZ with a greater inclination supports the sheets, resulting in a greater return force acting on the sheets and thus achieving higher alignment. When the number of stacked sheets increases, the lower end 21g of the movable tray 21 contacts the mounting surface 210 of the main assembly 101 of the device, thereby limiting the downward rotation of the movable tray 21, and thus the movable tray 21 is in its maximum rotation state. At this time, the force spring 22 is in its maximum extension state, but it is set so that the extended force spring 22 does not fall within the range of plastic deformation. By making such a setting, the function of the force spring 22 will not be impaired even if the movable tray 21 is rotated incorrectly by human error. Furthermore, in the maximum rotation state, the second stacking surface retracts downward from the first stacking surface at least from the middle position V of the second stacking surface to the downstream end (Z).

[0053] Regarding the movable tray 21 constructed as described above, its pivot point is located at the upstream end of the discharge tray 170 relative to the sheet discharge direction, such that the tilt angle θc of the second stacking surface YZ gradually approaches the tilt angle θa from θcmax as the number of stacked sheets increases. Therefore, as the number of stacked sheets increases, the return force acting on the sheets caused by the second stacking surface YZ decreases. On the other hand, as the second stacking surface YZ decreases, the tilt of the sheets at the portion supported by the second stacking surface YZ decreases. That is, the attitude of the sheet bundles stacked on the discharge tray 170 is close to the horizontal plane, and the position of the lower surface of the sheet bundles is lowered. Therefore, as described later, even if the number of sheets stacked on the tray increases, the sheets can be discharged smoothly.

[0054] Incidentally, the tilt angle θb in the downstream portion 92 of the fixed tray 20 is set to be smaller than the tilt angle θa and the maximum tilt angle (θcmax) in the upstream portion 91. This is to prevent the discharge tray 170 from occupying an excessively large area relative to the vertical direction, and in this embodiment, to ensure space for the second discharge tray 171 positioned above the discharge tray 170 and the sheet to be stacked thereon. In the downstream portion 92, which serves as a support, when discharging a long sheet along the sheet discharge direction, the discharge tray supports the downstream portion of the long sheet above the second stacking surface YZ of the movable tray 21. Furthermore, the tilt angle θb of the downstream portion 92 is set to a small value, so for relatively large sheets, it is possible to suppress the increase of feed resistance applied to the sheet from the stacking surface during sheet discharge, thus preventing incorrect discharge. However, the reason why the tilt angle θb is not set below 0 in the downstream portion of the fixed tray 20 is that a return force should be applied to the sheet even at any position of the discharge tray 170.

[0055] Incidentally, the fixed tray 20 and movable tray 21 constituting the first stacking surface WX and the second stacking surface YZ each include ribs extending in the sheet discharge direction, and in particular, the second stacking surface is formed by arcuate ribs 21d. Such ribs effectively reduce the feed resistance exerted on the sheet from the tray surface when the sheet is discharged onto the discharge tray 170. Furthermore, the second stacking surface YZ is curved such that the degree of inclination decreases towards the downstream side, thus preventing the formation of large steps or grooves that would cause the sheet to jam at the boundary between the second stacking surface YZ and the first stacking surface, regardless of the rotation angle of the movable tray 21.

[0056] Furthermore, the arcuate ribs 21d of the movable tray 21 protrude slightly upward from the first stacking surface WX near the upstream end position Y and the downstream end position Z of the second stacking surface YZ (i.e., protruding upward from the guide ribs of the fixed tray 20). By forming the arcuate ribs 21d at a slightly higher height, the front and rear ends of the sheet relative to the sheet discharge direction can be prevented from being stuck by the longitudinal ends of the slits 20b of the fixed tray 20. Moreover, each slit 20b is formed with a tapered shape relative to the downstream end of the sheet discharge direction, so that its shape narrows towards the downstream side. In this way, even if the movable tray 21 is rotated downward from the standby state and a new sheet is discharged with the downstream end of each arcuate rib 21d located below the corresponding slit 20b, the sheet can be prevented from being stuck by the downstream end of the slit 20b.

[0057] Furthermore, the first stacking surface WX is formed by the upper surface of the fixed tray 20, which is a plate-like member extending in both the sheet discharge direction and the width direction. The second stacking surface YZ is formed by a rib-like member that protrudes through a slit provided in the plate-like member and extends in the sheet discharge direction. Therefore, when the movable tray 21 is in a standby state, most of the opening of the slit 20b is closed by the arcuate rib 21d. When the movable tray 21 rotates downward due to the weight of the sheet, at least a portion of the opening of the slit 20b is closed by the sheet. Therefore, by providing openings for the movable tray 21 to move upward and downward relative to the fixed tray 20, the possibility of foreign objects falling onto the back side of the discharge tray 170 can be suppressed.

[0058] Incidentally, the fixed tray 20 is provided with a removal groove 20a for allowing sheet removal therefrom. The removal groove 20a extends at its end relative to the width direction D2 toward the side of the discharge tray 170 (the front side of the imaging device). Furthermore, the removal groove 20a is positioned relative to the sheet discharge direction D1 at a location overlapping with the movable tray 21, and is formed as a recessed shape such that the upper surface 20s of the fixed tray 20 is recessed downstream. To allow the user to access the sheet via the removal groove 20a, the portion of the arcuate rib 21d overlapping with the removal groove 20a at a position relative to the width direction D2 is formed only outside the removal groove 20a relative to the sheet discharge direction D1. Incidentally, the inclination angle of the downstream sidewall surface of the removal groove 20a is also set to an angle capable of preventing the front end of the sheet from being jammed.

[0059] Furthermore, each slit 20b provided in the fixed tray 20 has a minimum necessary length, and the fixed tray 20 is formed as a continuous member relative to the width direction D2 at each of the upstream and downstream sides relative to the movable tray 21. This not only has the advantage of ensuring the rigidity of the fixed tray 20, but also has the advantage of taking into account the flowability of the shape when the fixed tray 20 is prepared by injection molding of a resin material. An example of a resin material is PC + ABS (a copolymer of polycarbonate and acrylonitrile-butadiene-styrene resin). Incidentally, the fixed tray 20 can be a single member as a whole, but it can also be, for example, a combination of upstream and downstream portions molded as separate members.

[0060] [Operation of the movable tray]

[0061] The state of the discharge tray 170, constructed as described above, will be described when the sheet is discharged onto the stacked surface of the discharge tray. Figure 6 This is a cross-sectional view of the first discharge section 190, showing the state during the discharge of the first sheet S via the discharge roller 160. Figure 7This is a cross-sectional view of the first discharge section 190, showing the state in which the discharged first sheet S is aligned with the stacking surface of the discharge tray 170.

[0062] like Figure 6 As shown, the discharge roller 160 is configured to discharge the sheet S in an upwardly inclined posture relative to the horizontal direction relative to the downstream side of the sheet discharge direction D1. In other words, the discharge roller 160 includes a pair of rollers arranged at a clamping angle (an angle relative to the direction perpendicular to the axis between rollers) in which the sheet is discharged slightly upward. Furthermore, the discharge roller 160 is provided with a stiffness-improving member, which imparts stiffness to the sheet S by bending (in a wavy shape) when viewed from the downstream side of the sheet discharge direction D1. Therefore, the sheet S is discharged from the position where it is clamped by the discharge roller 160 towards the downstream side of the sheet discharge direction D1 while following an arc-shaped trajectory toward its leading edge. The sheet S contacts the movable tray 21 of the discharge tray 170, which is in a ready state, at its leading edge in position P1, and moves while sliding on the fixed tray 20 and the movable tray 21, and then the rear end of the sheet is fed out by the discharge roller 160.

[0063] like Figure 7 As shown, the sheet S, whose rear end is fed out, returns upstream (arrow R) in the sheet discharge direction according to the inclination of the stacking surface of the discharge tray 170, particularly the inclination of the stacking surface (second stacking surface) formed by the movable tray 21. Then, the sheet S is stopped by bringing its rear end relative to the sheet discharge direction D1 against the alignment wall 162 provided on the main assembly 101 of the equipment. The alignment wall 162 is a reference surface that aligns the sheet position by contacting the rear end of the sheet S discharged on the discharge tray 170.

[0064] As the first sheet S moves toward the alignment wall 162, the behavior of the first sheet S is affected by the magnitude of the frictional force acting between the sheet S and the stacked surface of the discharge tray 170. With respect to the second sheet S, the effect of friction between the sheet S and the discharge tray 170 decreases; instead, the effect between the sheets increases.

[0065] The aforementioned position P1 (assuming the front end of the first sheet first contacts the stacking surface of the discharge tray 170) is preferably located at a certain distance from the discharge roller 160 in the sheet discharge direction D1, and is preferably at a height substantially the same as the height of the clamping portion of the discharge roller 160. Furthermore, the movable tray 21 is configured such that the orientation of the sheet S at its front end and the contact angle between the sheet S and the second stacking surface are not too large. Regarding the movable tray 21 in this embodiment, in the standby state, the degree of inclination gradually decreases from the maximum inclination angle (32 degrees) at the upstream end towards the downstream side, and the inclination angle at the downstream end is approximately equal to the inclination angle (6 degrees) of the fixed tray 20 at the downstream portion. By adopting this configuration, the feed resistance applied to the sheet S from the stacking surface is suppressed, and the maximum number of sheets that can be stacked on the discharge tray 170 is ensured, thereby enabling stable discharge of sheets with lower stiffness and improving the alignment of the stacked sheets.

[0066] Incidentally, the sheets discharged by the discharge roller 160 include sheets such as recycled paper and tissue paper, and these sheets tend to exhibit increased curvature (curling) at the ends, for example, under high humidity conditions. [The text abruptly ends here, likely due to an incomplete sentence or missing information.] Figure 8 and 9 This describes a situation where relatively large quantities of sheets with a high degree of curl are stacked together. Figure 8 This is a cross-sectional view of the first discharge section 190 and the second discharge section 191 with multiple rolled sheets stacked on the discharge tray 170. Figure 9 This is a cross-sectional view of the first discharge section 190 and the second discharge section 191 with the movable tray 21 fixed in the standby position, as a reference example. However, in this embodiment, Figure 8 and 9 The sheet quantities shown are not intended to specify the actual number of sheets.

[0067] In the imaging apparatus of this embodiment, both small-sized sheets, such as A4 size sheets, and large-sized sheets, such as A3 size sheets, can be used. Curling occurs in both sizes, but the curled sheet is raised at its ends corresponding to the degree of curvature. Specifically, the small-sized sheet is shorter than the large-sized sheet, thus, due to the curling, the sheet easily forms a steeply inclined surface. Furthermore, as described above, the stacking surface of the discharge tray 170 is configured such that the inclination angle of the upstream side relative to the sheet discharge direction is greater than the inclination angle of the downstream side relative to the sheet discharge direction. The small-sized sheet is primarily supported by the more inclined upstream stacking surface, making the curling effect of the sheet more likely to occur due to the synergistic effect with the inclination of the stacking surface.

[0068] exist Figure 8In the case of small-sized sheets S, stacked in a curled state. With the rear end of the sheet contacting the alignment wall 162 relative to the sheet discharge direction D1, the front end of the sheet is located upstream of the downstream end of the movable tray 21. The sheet S is curled such that the lower surface (the surface opposite to the stacking surface of the discharge tray 170), which serves as the image surface, has a protruding shape. Therefore, the stacked bundle T of the sheet S contacts the stacking surfaces of the fixed tray 20 and the movable tray 21 at the middle inclined portion and is supported by the stacking surfaces of the fixed tray 20 and the movable tray 21. On the other hand, the stacked bundle T is lifted at the end relative to the sheet discharge direction D1.

[0069] Here, by stacking the weight of the bundle T, the movable tray 21 rotates downward from its standby position. Figure 6 and 7 This causes a portion of the arcuate rib of the movable tray 21 to retract downwards from the upper surface of the fixed tray 20 through the slit. Furthermore, compared to the standby state, the inclination of the stacking surface formed by the movable tray 21 becomes gentler. In other words, by increasing the stacking amount of the stacked bundles, at least a portion of the second stacking surface retracts downwards from the first stacking surface, thus reducing the inclination of the second stacking surface relative to the horizontal plane. Therefore, even if the discharged sheet S is curled, the discharge space on the discharge tray 170 is prevented from being occupied by stacked bundles T consisting of a relatively small amount of sheet S.

[0070] Incidentally, in Figure 9 In the illustrated example, the movable tray 21 is secured in a ready-to-go position using a spacer 203, so that the inclination and height of the second stacking surface remain unchanged even as the weight of the stacked bundles T increases. Therefore, when the discharged sheet S curls, the downstream end of the sheet rises, causing the discharge space on the discharge tray 170 to be occupied by the stacked bundles T consisting of a relatively small amount of sheet S.

[0071] In this case, with Figure 8Compared to the state where the movable tray 21 is rotated, the contact angle of the front end of the sheet S discharged from the discharge roller 160 contacting the upper surface of the stack bundle T is larger. As a result, the sheet S collides with the upper surface of the stack bundle T and is easily subjected to greater forces. Furthermore, when the sheet S is discharged while sliding on the upper surface of the stack bundle T (especially on the curled portion at the downstream end of the stack bundle T), the feed resistance increases. As a result, there is a possibility that the sheet S cannot be satisfactorily fed out of the discharge roller 160, and thus the rear end of the sheet S remains in the clamping portion of the discharge roller 160 and does not fall onto the discharge tray 170 (with the rear end tilted). In addition, when a subsequent sheet arrives at the discharge roller 160 while the rear end of the current sheet is held near the clamping portion of the discharge roller 160, there is a possibility that the front end of the subsequent sheet collides with the rear end of the current sheet, and thus the current sheet and the subsequent sheet cannot be discharged correctly.

[0072] On the other hand, in this embodiment, as described above, the movable tray 21 rotates around a pivot point located near the upstream end of the discharge tray 170, thereby reducing the height of the upper surface of the stacked bundles T. This not only ensures discharge space but also minimizes the tilt of the stacked bundles T. Thus, compared to... Figure 9 Compared to the reference example shown, the resistance experienced by the discharged sheet is reduced, thereby suppressing improper discharge and thus enabling smooth discharge of the sheet.

[0073] Furthermore, in this embodiment, an in-equipment discharge type structure is adopted, thereby limiting the height of the discharge space of the discharge tray 170. In this case, the structure in which the movable tray 21 rotates around a pivot point located near the upstream end of the discharge tray 170 has the advantage of ensuring discharge space. In particular, in this embodiment, a second discharge tray 171 serving as a second (another) discharge section is provided above the discharge tray 170, which serves as a first stacking section, thus having a greater advantage in ensuring discharge space. In this embodiment, the gap (interval) M between the five central arcuate ribs 21d is narrow, allowing sheets with a relatively small dimension in the width direction to be stably supported by the central arcuate ribs 21d.

[0074] [Example 2]

[0075] In Embodiment 2, instead of the construction of Embodiment 1 in which the movable tray 21 rotates by the weight of the sheet, an example of a construction of a drive source for driving and rotating the movable tray 21 will be described. Hereinafter, elements whose construction and function are similar to those in Embodiment 1 are indicated by reference numerals or symbols common to Embodiments 1 and 2, and their descriptions will be omitted.

[0076] Figure 10This is a perspective view showing the movable tray 21 and its drive structure in this embodiment. The movable tray 21 has sector gears 21e and 21e at two positions relative to the width direction at its downstream end opposite to the rotation shaft 21a relative to the sheet discharge direction D1. The sector gears 21e and 21e are connected to the input / output shaft 220 via output gears 222 and 222. At the end of the input / output shaft 220, an input gear 221 is provided that meshes with the gear 211 of the rotary motor 212, which serves as the drive source. Therefore, the movable tray 21 is driven by the gear system through the forward and reverse rotation of the rotary motor 212, thereby causing the movable tray 21 to rotate upward and downward.

[0077] As the rotary motor 212, a stepper motor can be appropriately used. In this case, the rotation amount of the movable tray 21, i.e., the tilt angle of the movable tray 21, can be set to any value with high precision, regardless of the weight of the sheet on the tray. Therefore, depending on factors such as whether the environment is a high-humidity environment that easily causes sheet curling or whether the stacking height of each sheet is large, the rotation amount of the movable tray 21 can be set differently even when the number of sheets stacked is the same. That is, an appropriate rotation amount can be set according to the operating conditions of the imaging device.

[0078] By using a sensor to detect the position of the movable tray 21 (e.g., a switch to detect whether the movable tray 21 is in a standby position), the rotation of the movable tray 21 can be controlled with high precision. Furthermore, a sensor is provided above the movable tray 21 to detect the height of the upper surface of the sheet bundles stacked on the discharge tray 170, and the rotation of the movable tray 21 is controlled based on the detection result, thereby allowing precise control of the height of the upper surface of the sheet bundles.

[0079] Incidentally, in this embodiment, the rotary motor 212 serves as the drive source, and the movable tray 21 is driven by... Figure 10 The gear transmission mechanism shown is used for rotation, but other drive structures can also be used.

[0080] (Modified Implementation Example)

[0081] In embodiments 1 and 2 described above, the inclined surface is formed by the upper surface 20s of the fixed tray 20 and the stacked surface is formed by a plurality of arcuate ribs 21d disposed on the movable tray 21. However, it is also possible to adopt a configuration in which the inclined surface is formed by a plurality of rib-like members and the stacked surface is disposed on a plate-like member including a slit (through which the rib-like members pass).

[0082] Alternatively, instead of the arc-shaped rib 21d, ribs may be provided that each has an upper end portion consisting of a curved portion other than the arc shape. Moreover, in this case, the upper end portion of each rib can be appropriately inclined upward toward the downstream side of the sheet discharge direction D1 in the standby state and can be appropriately bent (including the portion bent into a zigzag shape), so that the inclination angle relative to the horizontal plane becomes smaller toward the downstream side of the sheet discharge direction D1.

[0083] Furthermore, this embodiment describes an imaging device including an electrophotographic imaging unit; however, the present invention is also effective in other types of imaging devices. For example, in imaging devices that include an inkjet printing unit as an imaging unit, there is a situation where the sheet curls as an image is formed; therefore, the present invention is suitable for application in such cases.

[0084] As an imaging device, an imaging device including a sheet processing unit can also be used, in which a sheet with an image formed by the imaging unit is received and then punched, folded, etc.

[0085] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An imaging device, comprising: An imaging unit configured to form an image on a sheet; The discharge section is configured to discharge a sheet on which the imaging section forms an image along the sheet discharge direction; and The stacking section is where the sheets discharged from the discharge section are stacked. The stacking section includes: (1) A first member, the first member comprising an inclined surface that slopes upward toward a downstream side in the sheet discharge direction, wherein the inclined surface of the first member comprises a slit; and (2) Ribs, wherein the discharged sheets are stacked on the stacked surface of the ribs that project upward from the inclined surface through the slits, wherein the ribs are movable relative to the first member to change the amount by which the ribs project from the inclined surface. The first component is provided with a groove that is recessed downward below the inclined surface and extends in the width region of the discharged sheet relative to the sheet width direction perpendicular to the sheet discharge direction. The ribs and the grooves overlap each other in the sheet discharge direction, and the ribs are arranged such that the downstream end of the ribs in the sheet discharge direction is located downstream of the grooves in the sheet discharge direction.

2. The imaging device according to claim 1, wherein, When the sheet is not stacked on the stack, the rib tilts upstream toward the sheet discharge direction.

3. The imaging device according to claim 1, wherein, The first component includes a support portion capable of supporting the sheet on the downstream side of the rib relative to the sheet discharge direction, and The sheet is supported by the stacked surfaces of the ribs and the support portion.

4. The imaging device according to claim 3, wherein, The support has multiple ribs, and sheets are stacked on the ribs.

5. The imaging apparatus of claim 1, further comprising an alignment portion configured to align the sheet, the alignment portion contacting an upstream end of the sheet stacked on the rib relative to the sheet discharge direction.

6. The imaging device according to claim 1 further includes a force-applying part, the force-applying part being configured to apply force to the rib in a direction that moves upward along the rib.

7. The imaging apparatus of claim 1, further comprising a drive motor configured to move the rib thereby changing the amount by which the rib protrudes through the opening from the inclined surface.

8. The imaging device according to claim 7, wherein, The drive motor moves the rib to a position that depends on the operating conditions of the imaging device.

9. The imaging device according to claim 7, wherein, Even when the number of sheets stacked is the same, the drive motor moves the ribs, causing the ribs to protrude differently depending on the operating conditions of the imaging device.

10. The imaging apparatus according to claim 1, further comprising an image reading device disposed above the stack and configured to read image information from the original document.

11. The imaging device according to claim 10, wherein, The first component includes a retaining rib that contacts the sheet. The fixing ribs are configured to guide and support the discharged sheet. In the sheet discharge direction, when the area of ​​the sheet supported by the first member is divided into four equal parts relative to the sheet discharge direction, the upstream end of the area of ​​the sheet supported by the rib is located upstream of the four equal division points on the upstream side. In the sheet discharge direction, the downstream end of the region where the sheet is supported by the rib is located downstream of the middle position of the region where the sheet is supported by the first member. Wherein, in the sheet discharge direction, the distance from the downstream end of the region where the sheet is supported by the rib to the downstream end of the region where the sheet is supported by the first member is longer than the distance from the upstream end of the region where the sheet is supported by the first member to the upstream end of the region where the sheet is supported by the rib. The image reading device is configured to overlap with the rib in the horizontal direction and, relative to the sheet discharge direction, to overlap with the fixing rib downstream of the downstream end of the rib. The ribs and the fixing ribs are arranged at different positions in the width direction of the sheet, which is perpendicular to the sheet discharge direction. Wherein, the ribs and the fixing ribs are arranged to overlap each other in position relative to the sheet discharge direction, and The fixing rib is continuous in the sheet discharge direction from the upstream side of the downstream end of the slit to the downstream side of the downstream end of the slit.

12. The imaging device according to claim 1, wherein, The first component includes a retaining rib, wherein the retaining rib is configured to guide and support the discharged sheet. Wherein, the position of the fixing rib relative to the sheet discharge direction overlaps with the rib, and The downstream end of the fixing rib in the sheet discharge direction is located downstream of the groove in the sheet discharge direction.

13. The imaging device according to claim 12, wherein, The first component includes another rib that extends along the sheet discharge direction and projects upward, and The fixing rib overlaps with the groove, the rib and the other rib relative to the sheet discharge direction.

14. The imaging device according to claim 13, wherein, In the state where the rib protrudes upwards most from the inclined surface, the top of the rib is higher than the top of the fixed rib at a predetermined position in the sheet discharge direction.

15. The imaging device according to claim 1, wherein, The first component includes a support portion downstream of the inclined surface, and The support portion is located below an imaginary surface obtained by extending the inclined surface, and the support portion is configured as a support sheet. The ribs of the first component are continuously arranged from the inclined surface to the support portion in the sheet discharge direction.

16. The imaging device according to claim 1, wherein, The distance from the upstream end of the stacked surface to the upstream end of the stacked portion relative to the sheet discharge direction is less than the distance from the upstream end of the stacked surface to the middle position of the stacked portion relative to the sheet discharge direction.

17. The imaging device according to claim 1, wherein, The first component includes a retaining rib, wherein the retaining rib is configured to guide and support the discharged sheet. Wherein, the position of the fixing rib relative to the sheet discharge direction overlaps with the rib, and The rib is positioned relative to the sheet discharge direction and overlaps with the groove.

18. The imaging device according to claim 17, wherein, The first component includes a support portion downstream of the inclined surface. The support portion is located below an imaginary surface obtained by extending the inclined surface, and the support portion is configured as a support sheet. The fixing ribs are disposed on the inclined surface and the support portion, and are continuously disposed in the sheet discharge direction.

19. The imaging device according to claim 1, wherein, The groove is inclined in the sheet width direction at its downstream edge in the sheet discharge direction, thereby positioning itself downstream in the sheet discharge direction toward the outer side of the sheet width direction.

20. The imaging device according to claim 1, wherein, The groove includes a bottom portion and an inclined portion connecting the bottom portion and the inclined surface, the inclined portion being inclined upward in the sheet discharge direction downstream of the sheet discharge direction, and Wherein, the tilt angle of the tilted portion relative to the horizontal plane is greater than the tilt angle of the tilted surface relative to the horizontal plane.

21. The imaging device according to claim 1, wherein, The groove extends to the end of the first member in the width direction of the sheet.

22. The imaging device according to claim 1, in, The first component includes a retaining rib that contacts the sheet. The ribs are arranged such that their positions relative to the sheet discharge direction overlap with both the groove and the fixing rib. The fixing rib is positioned so that it overlaps with the groove relative to the width of the sheet.

23. The imaging apparatus of claim 1, further comprising a motor configured to move the rib, thereby changing the amount by which the rib protrudes from the inclined surface. in, The motor is located downstream of the groove in the sheet discharge direction.

24. The imaging apparatus of claim 1, further comprising a motor configured to move the rib, thereby changing the amount by which the rib protrudes from the inclined surface. in, The motor is configured such that the gear of the motor is located downstream of the groove in the sheet discharge direction.

25. An imaging device, comprising: An imaging unit configured to form an image on a sheet; The discharge section is configured to discharge a sheet on which the imaging section forms an image along the sheet discharge direction; and The stacking section is where the sheets discharged from the discharge section are stacked. The stacking section includes: (1) A first member, the first member comprising an inclined surface that slopes upward toward a downstream side in the sheet discharge direction, wherein the inclined surface of the first member comprises a slit; and (2) Ribs, wherein the discharged sheets are stacked on the stacked surface of the ribs that project upwards from the inclined surface through the slits. The rib is movable relative to the first member, thereby changing the amount by which the rib protrudes from the inclined surface. The first component has a recessed portion that is recessed downward below the inclined surface and extends to the end of the first component in the sheet width direction perpendicular to the sheet discharge direction. When viewed from above, the sheets on the recessed portion and the stacked portion overlap each other, and The rib and the recess are positioned relative to each other in the sheet discharge direction, and the rib is arranged such that the downstream end of the rib in the sheet discharge direction is located downstream of the recess in the sheet discharge direction.

26. The imaging apparatus of claim 25, further comprising a motor configured to move the rib, thereby changing the amount by which the rib protrudes from the inclined surface. in, The motor is located downstream of the recess in the sheet discharge direction.

27. The imaging apparatus of claim 25, further comprising a motor configured to move the rib, thereby changing the amount by which the rib protrudes from the inclined surface. in, The motor is configured such that the gear of the motor is located downstream of the recess in the sheet discharge direction.

28. An imaging device, comprising: An imaging unit configured to form an image on a sheet; The discharge section is configured to discharge a sheet on which the imaging section forms an image along the sheet discharge direction; A stacking member, the stacking member including an inclined portion that is inclined upward toward a downstream side in the sheet discharge direction and configured to stack sheets discharged from the discharge portion; as well as A wall portion, the wall portion being configured to contact the rear end of the sheets stacked on the stacking member in the sheet discharge direction. The stacking member is provided with a downwardly recessed removal groove, which is configured to allow a user to access sheets stacked on the stacking member. Wherein, the upstream edge of the removal groove in the sheet discharge direction is spaced apart from the wall portion, and the upstream edge of the removal groove extends along the sheet width direction, and Wherein, the downstream edge of the removal groove in the sheet discharge direction is inclined relative to the sheet width direction, such that the downstream edge is positioned towards the outside in the sheet width direction and downstream in the sheet discharge direction.

29. The imaging device according to claim 28, further comprising: A protruding member, which extends upward through an opening provided in the stacking member and is configured to extend along the sheet discharge direction, such that sheets discharged from the discharge portion are stacked on the protruding member. A motor configured to move the protruding member, thereby changing the amount by which the protruding member protrudes from the stacked members. Wherein, the width of the opening provided in the stacking member in the sheet width direction perpendicular to the sheet discharge direction is narrower than the width of the sheet to be discharged. Wherein, the width of the protruding member in the width direction of the sheet is narrower than the width of the sheet to be discharged, and In the sheet discharge direction, the upstream edge of the removal groove is located downstream of the upstream end of the opening and the upstream end of the protruding member, and the downstream edge of the removal groove is located upstream of the downstream end of the opening and the downstream end of the protruding member.

Images