Stacking device and imaging apparatus

Abstract

The present disclosure relates to a stacking device detachably attached to an apparatus body of an image forming apparatus, the stacking device having an abutting member that abuts against recording material, and a stack of recording material stacked on the stacking device, the image forming apparatus including a first support unit that supports the recording material from a lower side of the recording material, and a second support unit that supports an end portion of the recording material in an attaching / detaching direction of the stacking device. The second support unit includes a corresponding region, and a position of the corresponding region in a width direction orthogonal to the attaching / detaching direction coincides with an abutting position at which the abutting member abuts against the recording material. At least the corresponding region has a height in a direction orthogonal to the attaching / detaching direction and the width direction that is lower than a height of the abutting member. The present disclosure also relates to an image forming apparatus.

Description

[0001] This divisional application is based on Chinese patent application No. 201910761687.3, filed on August 19, 2019, entitled "Stacking Device and Imaging Apparatus", which claims priority to Japanese earlier application 2018-155806 filed on August 22, 2018. Technical Field

[0002] The present invention relates to a stacking device on which sheets are stacked, and the stacking device is disposed in an imaging device or in a sheet post-processing device installed in an imaging device. Background Technology

[0003] Traditionally, sheet ejection stacking units are installed as stacking devices in imaging equipment or sheet post-processing devices, with sheets of recording material stacked on the ejection stacking unit. The ejection stacking unit includes: a sheet stacking unit on which sheets are stacked; and a transport unit that ejects sheets onto the sheet stacking unit. As an example of a stacking device, a device is known in which a rear end wall provided on the upstream end side (rear end side of the sheet) in the transport direction of the stacked sheets is integrated with the sheet stacking unit and can be separated from the transport unit. For example, this configuration is effective in creating space for a user to access jammed sheets during paper jam clearance. Japanese Patent Application Publication No. 2002-274727 discloses a stacking device that, in addition to the integrated rear end wall and sheet stacking unit, includes an abutment member that abuts against the sheets stacked on the sheet stacking unit. The abutting member is configured to abut against the sheets stacked on the sheet stacking unit from above, such that the abutting position of the sheets changes according to the height of the stacked sheets. However, in the device configuration disclosed in Japanese Patent Application Publication No. 2002-274727, when the sheet stacking unit and the rear end wall separate from the transport unit during paper jam removal to return to their original positions, the rear end wall and the abutting member interfere with each other. Therefore, in Japanese Patent Application Publication No. 2002-274727, a cam shape is provided in the portion of the rear end wall that contacts the abutting member to avoid interference, such that the abutting member moves along the cam shape when the rear end wall returns to its original position. However, since the abutting member moves in continuous contact with the cam shape, in the event of an impact (e.g., when the rear end wall returns to its original position with a violent movement), the abutting member may break and fail to follow the cam shape. Summary of the Invention

[0004] However, a stacking device is known, which, for example, includes a detection mark for detecting the height of the sheets stacked on the sheet stacking unit, in addition to a sheet pressing member configured to press the sheets stacked on the sheet stacking unit. Similar to the sheet pressing member, the detection mark is also configured such that the abutment position of the sheets changes according to the height of the stacked sheets. Therefore, a problem similar to that of the device with the sheet pressing member occurs when the sheet stacking unit and the rear end wall separate from the transport unit during paper jam clearance to return to their original position.

[0005] Therefore, the present invention was made in view of this situation. That is, an object of the present invention is to provide a stacking device that can be detachably attached to the device body of an imaging device without damaging the abutting members against the recording material stacked on the stacking device, even when the stacking device is attached to or detached from the device body by violent pulling or returning of the stacking device.

[0006] To achieve the aforementioned objective, a stacking device is provided, which is detachably attached to the device body of an imaging apparatus including a device body having abutting members against stacked recording material, and recording material discharged from the device body is stacked on the stacking device, the stacking device comprising:

[0007] A first support unit, the first support unit supporting the recording material from below; and

[0008] A second support unit supports the end of the recording material along an attachment / removal direction, which is the direction in which the stacking device is attached to and detached from the device body.

[0009] The second support unit includes a corresponding area, and the position of the corresponding area in the width direction orthogonal to the attachment / removal direction coincides with the abutment position where the abutment member abuts against the recording material.

[0010] Wherein, at least the height of the corresponding region in a direction orthogonal to the attachment / removal direction and the width direction is lower than the height of the abutment member.

[0011] To achieve the aforementioned objective, the imaging device according to the present invention comprises:

[0012] An imaging unit that forms an image on a recording material;

[0013] The aforementioned stacking device, and

[0014] Abutting member abuts against recording material stacked on the stacking device.

[0015] To achieve the aforementioned objective, the imaging device according to the present invention comprises:

[0016] An imaging unit that forms an image on a recording material;

[0017] A stacking device on which recording material on which an image is formed by the imaging unit is stacked, and which is detachably attached to the device body of the imaging device, the stacking device comprising: a first support unit supporting the recording material from below; and a second support unit supporting an end of the recording material in an attachment / removal direction, the stacking device being attached to and detached from the device body in the attachment / removal direction;

[0018] Control unit, which controls the transfer of the recording material in the imaging device;

[0019] A first abutting member abuts against recording material stacked on the stacking device, and is configured such that the abutting position against the recording material stacked on the stacking device changes according to the height of the stacked recording material; and

[0020] A second abutting member abuts against recording material stacked on the stacking device, and is configured such that the abutting position against the recording material stacked on the stacking device is positioned closer to the end supported by the second support unit than the abutting position between the first abutting member and the recording material, and varies according to the height of the stacked recording material.

[0021] The control unit performs control such that the transfer of the recording material to the stacking device stops when either the first abutting member or the second abutting member abuts the recording material at its maximum height position, at which the recording material can be supported by the second support unit in a direction orthogonal to the attachment / removal direction and the width direction of the recording material.

[0022] According to the present invention, a stacking device can be provided that can be detachably attached to the device body of an imaging device without damaging the abutting members against the recording material stacked on the stacking device, even when the stacking device is attached to or detached from the device body by violent pulling or returning the stacking device.

[0023] Further features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 It is a schematic cross-sectional view of the imaging equipment and the sheet post-processing device;

[0025] Figure 2A and Figure 2B It is a schematic cross-sectional view of the sheet post-processing device separated from the imaging equipment;

[0026] Figure 3A and Figure 3B This is an exemplary illustrative diagram showing the periphery of the first stacked unit according to Embodiment 1;

[0027] Figure 4A and Figure 4B This is an exemplary illustrative diagram showing the periphery of the first stacked unit when the segmented portion does not have a comb-like shape;

[0028] Figure 5A and Figure 5B This is an exemplary illustrative diagram showing the periphery of the first stacking unit according to Embodiment 2;

[0029] Figure 6A and Figure 6B This is an exemplary illustrative diagram showing the process of attaching the sheet post-processing apparatus according to Embodiment 2 to the equipment body;

[0030] Figure 7A and Figure 7B This is an exemplary illustrative diagram showing the periphery of the first stacking unit according to Embodiment 3; and

[0031] Figure 8A and Figure 8B This is an exemplary illustration diagram showing the possible states that may occur when the second full load detection flag 131 is not present. Detailed Implementation

[0032] Hereinafter, embodiments (examples) of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments can be appropriately varied depending on the construction of the device to which the present invention is applied, various conditions, etc. Therefore, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments are not intended to limit the scope of the present invention to the following embodiments.

[0033] Example 1

[0034] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 A schematic cross-sectional view of a monochrome digital printer is shown as an example of an imaging device to which the present invention is applied. Figure 1 In the accompanying drawings, reference numeral 100 refers to the imaging device body (hereinafter referred to as the device body). A sheet post-processing apparatus 200 is attached to the upper left portion of the device body 100. The sheet post-processing apparatus 200 corresponds to the stacking apparatus of this embodiment. That is, the imaging device of this embodiment includes the device body 100 and the sheet post-processing apparatus 200. In this embodiment, the device body 100 is the only structural component of the imaging device other than the sheet post-processing apparatus 200.

[0035] In the following description and the parts shown in the accompanying drawings, the directions up, down, left, and right are the directions assumed to be in the normal installation state when the imaging device is mounted on a horizontal surface.

[0036] The device body 100 includes an imaging unit 101. Reference numeral 102 is a sheet feeding unit that feeds a sheet into the imaging unit 101, and reference numeral 103 is a fixing unit that fixes an image onto the sheet.

[0037] Here, the imaging unit 101 includes along... Figure 1 The imaging unit 101 forms a toner image on the sheet S according to the imaging process. The image unit 101 includes a photosensitive drum 111 that rotates clockwise, an exposure device 112, and a charging roller 113, a developing device 114, and a transfer roller 115 arranged substantially sequentially along the rotation direction of the photosensitive drum 111.

[0038] In other words, firstly, after the surface of the photosensitive drum 111, which serves as the image carrier, is uniformly charged to a predetermined polarity by the charging roller 113, image data based on the image to be formed on the sheet S, which serves as the recording material, is used by the exposure device 112 to form a latent image on the photosensitive drum 111. The developing device 114 causes toner to adhere to the latent image formed on the surface of the photosensitive drum 111 as a toner image. The toner image formed on the photosensitive drum 111 is transferred to the transfer clamping section formed by the transfer roller 115 and the photosensitive drum 111. Furthermore, the sheet S, which serves as the recording material, is delivered from the sheet feed cassette 105 by the sheet feed roller 106. The delivered sheet S passes through the transfer guide 109 and the alignment roller 110, and is then transferred to the transfer clamping section formed by the transfer roller 115 and the photosensitive drum 111, which serves as the image carrier. In the transfer clamping section, a high voltage of the opposite polarity to the normal charging polarity of the toner is applied, and the toner image on the photosensitive drum 111 is transferred onto the sheet S. The imaging process is performed in this manner. Afterwards, the sheet S with the transferred toner image is transferred to the fixing unit 103, described later, and heated and pressurized by the fixing roller 116 and the pressure roller 117, thereby fixing the toner image onto the sheet S.

[0039] The sheet feeding unit 102 includes a sheet feeding cassette 105 (in which multiple sheets S, as recording material for printing, are stored in a stacked state), a sheet feeding roller 106, a transport guide 109, an alignment roller 110, etc. The fixing unit 103 includes a fixing roller 116, a pressure roller 117 abutting against the fixing roller 116, and a transport roller 118. Reference numeral 119 indicates a first sheet transport path, and the sheet leaving the transport roller 118 is transported while being guided by the first sheet transport path 119.

[0040] The first transmission path switching component 120 and the second transmission path switching component 121 are disposed in the first sheet transmission path 119. The positions shown by the solid lines in the figure are the original positions of the first transmission path switching component 120 and the second transmission path switching component 121.

[0041] When the first transfer path switching member 120 switches from the position shown by the solid line in the figure to the position shown by the dashed line via an actuator (not shown) and remains in that position, the sheet S is transferred to the sheet post-processing device 200 while being guided by the second sheet transfer path 122. A reversing roller 123 and a discharge roller 124 are disposed in the first sheet transfer path 119. The sheet S discharged from the discharge roller 124 is stacked on the first stacking unit 201 corresponding to the first support unit, positioned on the top surface of the sheet post-processing device 200 and supported from the bottom. A first full-load detection mark 125, serving as a detection unit, is disposed above the first stacking unit 201 to detect whether the sheet has been stacked on the first stacking unit 201 to a predetermined height or higher. During the period when the first full-load detection mark 125 detects that the sheet has been stacked to a predetermined height or higher, the control unit 300 executes control to stop the transfer of the sheet S to the first stacking unit 201 until the sheet S on the first stacking unit 201 is removed. The control unit 300 performs various operations of the imaging device, including transferring the sheet S within the imaging device.

[0042] Next, the operation when printing images on both sides of the sheet S will be described. The sheet S is transported while being guided to the first sheet transport path 119, and the rear end of the sheet passes the distal end of the second transport path switching member 121. The second transport path switching member 121 is switched from the position shown by the solid line in the figure to the position shown by the dashed line by an actuator (not shown) and remains in that position. Then, the rotation directions of the reversing roller 123 and the discharge roller 124 are reversed, thereby transporting the sheet S to the refeed transport path 126. The refeed transport path 126 merges with the transport guide 109 on the upstream side of the alignment roller 110, and the sheet S is transported again to the imaging unit 101.

[0043] Next, the structure of the sheet post-processing apparatus 200 will be described. Reference numeral 202 indicates the third sheet transport path, which receives and transports sheet S from the second sheet transport path 122. The sheet S transported by the third sheet transport path 202 is discharged to the intermediate processing tray 203. The sheet S discharged to the intermediate processing tray 203 is aligned one after another in each direction by the width alignment unit 204 and the transport direction alignment unit 205. After a predetermined number of sheets S are stacked on the intermediate processing tray 203, the upstream ends of the stacked sheets S are pushed by a discharge unit (not shown), thereby discharging the stacked sheets S and stacking them on a second stacking unit 206. The second stacking unit 206 is configured to move vertically in the vertical direction (direction of gravity). Furthermore, when it is desired to perform post-processing such as binding on the sheet S, after a predetermined number of sheets S are stacked on the intermediate processing tray 203, post-processing is performed using the post-processing unit 207, and the processed sheet is discharged to the second stacking unit 206. A sheet surface detection mark 208 is disposed above the second stacking unit 206. When the sheet surface detection mark 208 detects that the sheet S has been stacked on the second stacking unit 206 to a predetermined height, the second stacking unit 206 moves downward by a predetermined amount. When the second stacking unit 206 repeatedly moves downward and a sensor (not shown) detects that the second stacking unit 206 has reached its lower limit position, a full-load state is detected. In this case, the control unit 300 does not transfer the sheet S to the second stacking unit 206 until the sheet S on the second stacking unit 206 is removed. In this embodiment, the transfer reference position is the center of the sheet, and the sheet S is transferred to the first stacking unit 201 or the second stacking unit 206 such that the center position in the direction orthogonal to the transfer direction of the sheet S (width direction) follows the transfer reference position.

[0044] The sheet post-processing apparatus 200 is attached to the equipment body 100, and an interface unit 210 is provided between them. A track (not shown) is formed in the interface unit 210, and the sheet post-processing apparatus 200 is detachably attached to the equipment body 100 (attached to the equipment body or detached from the equipment body).

[0045] Figure 2A The sheet post-processing apparatus 200, having a first stacking unit 201 and a second rear end wall 212, is shown in a state where it is moved to separate from the apparatus body 100. Figure 2B The diagram illustrates a state where a portion of the transport guide is released to clear a paper jam, with the sheet post-processing unit 200 separated from the equipment body 100. Within the equipment body 100, the first transport guide unit 128 is configured to be movable as shown, allowing the user to access the first sheet transport path 119 downstream of the second transport path switching member 121. When a paper jam clearing operation is to be performed, the first full-load detection flag 125 is also configured as shown... Figure 2B The device is movable and does not impede the movement of the first transfer guiding unit 128. In this way, the sheet post-processing apparatus 200 is separated from the device body 100 to create space where the transfer guiding unit 128 can move and space where the user can access and remove the stuck sheet. To remove the stuck sheet, as... Figure 2A and Figure 2B As shown, the paper jam removal operation can be performed with the sheet post-processing device 200 moved to a state separate from the equipment body 100. Alternatively, the sheet post-processing device 200 can be completely detached from the equipment body 100 for easier operation.

[0046] Figure 3A This is a cross-sectional view of the periphery of the first stacking unit 201. Figure 3B yes Figure 3A The left view shows a first rear end wall 129 positioned vertically below the discharge roller 124, and a second rear end wall 212 positioned vertically below the first rear end wall. The first rear end wall 129 corresponds to a body-side support unit that supports the sheet S stacked on a first stacking unit 201 corresponding to the first support unit on the equipment body side, and is configured to integrate with the first transfer guide unit of the equipment body 100. The second rear end wall 212 corresponds to a second support unit that supports the end of the sheet S stacked on the first stacking unit 201 in an attachment / removal direction, which is the direction in which the sheet post-processing device 200 is attached to and removed from the equipment body 100. The second rear end wall 212 is configured to integrate with the first stacking unit 201 of the sheet post-processing device 200. When the sheet post-processing device 200 is attached to the equipment body 100, the sheet post-processing device 200... Figure 3A The sheet post-processing device moves in the direction indicated by arrow A, and when the sheet post-processing device 200 is separated from the device body, the sheet post-processing device moves in the direction indicated by arrow B.

[0047] like Figure 3B As shown, the second rear end wall 212 is disposed below the first rear end wall 129. The vertical direction in which the first rear end wall 129 and the second rear end wall 212 are arranged is orthogonal to both the attachment / removal direction of the sheet post-processing apparatus 200 to and from the equipment body 100 and the sheet width direction. In this embodiment, the attachment / removal direction of the sheet post-processing apparatus 200 to and from the equipment body 100 is along the vertical direction of the sheet width direction. Figure 3A The Y-axis extends in the left and right directions, and the sheet width direction is indicated by the direction along the Y-axis. Figure 3B The X-axis extends in a left-right direction. That is to say, Figure 3A and Figure 3BThe vertical direction extending along the Z-axis is orthogonal to the attachment / removal direction of the sheet post-processing apparatus 200 relative to the equipment body 100 and the width direction of the sheet S. The boundary portion (the portion having the shape to be divided when the sheet post-processing apparatus 200 is removed from the equipment body 100 (hereinafter referred to as the dividing portion)) has a partially comb-like shape. That is, the dividing portion is configured such that the uneven uneven portion formed in the first rear end wall 129 in the vertical direction and the uneven uneven portion formed in the second rear end wall 212 in the vertical direction engage with each other. Specifically, a plurality of body-side protrusions 129a protruding downward toward the second rear end wall 212 are formed at intervals along the width direction of the sheet S on the first rear end wall 129 as protrusions. A plurality of body-side recesses 129b concave upward are formed at intervals between the plurality of body-side protrusions 129a along the width direction of the sheet S. On the other hand, a plurality of protruding portions 212c protruding upward toward the first rear end wall 129 are formed at intervals along the width direction of the sheet S on the second rear end wall 212 as protruding portions. A plurality of recessed portions 212e recessed downward are formed at intervals between the plurality of protruding portions 212c along the width direction of the sheet S as recessed portions. The uneven structure of the first rear end wall 129 and the uneven structure of the second rear end wall 212 are configured such that the body-side protruding portion 129a enters the recessed portion 212e and the protruding portion 212c enters the body-side recessed portion 129b. That is, the body-side protruding portion 129a of the first rear end wall 129 and the protruding portion 212c of the second rear end wall 212 are arranged alternately along the width direction of the sheet S. In this way, the regions where the rear end of the sheet S stacked on the first stacking unit 201 is supported only by the second rear end wall 212, the regions where the rear end of the sheet S is supported by both the first rear end wall 129 and the second rear end wall 212, and the regions where the rear end of the sheet S is supported only by the first rear end wall 129 are sequentially formed along the stacking direction of the sheet S. In other words, the regions where the rear end of the sheet S stacked on the first stacking unit 201 can be supported by the first rear end wall 129 extend downward in the vertical direction (the stacking direction of the sheet S) so as to overlap with the regions where the rear end of the sheet S can be supported by the second rear end wall 212. The advantages of this configuration will be described later.

[0048] Reference numeral 125 is a first full-load detection mark and corresponds to the detection unit as described above. The first full-load detection mark 125 rotates about the mark rotation center 130 (a rotation axis extending along the width direction of the sheet S). Figure 3AReference numeral 125a indicates a first full-load detection mark in its original position (i.e., initial position), and reference numeral 125b indicates a first full-load detection mark at the position where a full-load stack of sheet S is detected (hereinafter referred to as the full-load detection position). When sheet S is stacked on the first stacking unit 201, the first full-load detection mark 125 abuts against the stacked sheets, thereby raising the mark portion at the distal end of the first full-load detection mark 125. That is, the position abutting against sheet S changes according to the height of the sheets stacked on the first stacking unit 201. Furthermore, as Figure 3A As shown, the first full-load detection mark 125 has a base portion 125e formed near the mark rotation center 130, which serves as the base of arms 125-1-1 to 125-4 (described later). Furthermore, as... Figure 3B As shown, the first full-load detection mark 125 has arms 125-1-1 to 125-4 extending from a base portion 125e near the mark rotation center 130 toward the surface of the sheet S stacked on the first stacking unit 201, and abutting against the sheet S at multiple locations along the width direction of the sheet. Since the base portion 125e is positioned close to the mark rotation center 130, the arms 125-1-1 to 125-4 rotate around the mark rotation center 130. Furthermore, the arm 125-4 is formed at a transfer reference position of the sheet S. Therefore, in this embodiment, the sheet S is transferred such that the center position of the sheet S in the width direction is aligned with the position of the arm 125-4. In this embodiment, the arms 125-1-1 to 125-3-2 are arranged in pairs on the outer side of the arm 125-4 along the width direction of the sheet to handle three sizes of sheet S. First, pairs of arms 125-1-1 and 125-1-2 are formed on the outer side of arm 125-4 to process sheet S having the smallest size among the sizes that can be processed in this embodiment. Arm 125-2-1 is disposed on the outer side of arm 125-1-1 and arm 125-2-2 is disposed on the outer side of arm 125-1-2 to process sheet S with a width greater than the smallest size sheet S (having a second smallest size). Furthermore, arm 125-3-1 is formed on the outer side of arm 125-2-1 and arm 125-3-2 is formed on the outer side of arm 125-2-2 to process sheet S with a width greater than the second smallest size sheet S (having a largest size in this embodiment).

[0049] The distal ends of arms 125-1-1 to 125-4, serving as first abutment portions 125c, abut against the surface of the sheet S stacked on the first stacking unit 201 at multiple locations. Furthermore, the portions of arms 125-1-1 to 125-4 that form the surface between the first abutment portion 125c and the base portion 125e near the mark rotation center 130 are second abutment portions 125d1-1 to 125d4, which abut against the ends of the sheet S transported from the device body in the transport direction. More specifically, second abutment portion 125d1-1 is formed in arm 125-1-1, and second abutment portion 125d1-2 is formed in arm 125-1-2. Second abutment portion 125d2-1 is formed in arm 125-2-1, and second abutment portion 125d2-2 is formed in arm 125-2-2. The second abutting portion 125d3-1 is formed in the arm 125-3-1, and the second abutting portion 125d3-2 is formed in the arm 125-3-2. The second abutting portion 125d4 is formed in the arm 125-4.

[0050] The arms 125-1-1 to 125-3-2 of the first full-load detection mark 125 have a so-called approximately trapezoidal shape, such that when viewed from the attachment / removal direction, the width near the first abutment portion 125c in the sheet width direction is larger than the width near the base portion 125e. That is, when viewed from the attachment / removal direction, the second abutment portions 125d1-1 to 125d3-2 also have an approximately trapezoidal shape, the second abutment portion being the portion of the arms 125-1-1 to 125-3-2 that serves as the surface between the base portion 125e and the first abutment portion 125c. The width of the sheet S that can abut against the second abutment portion, according to the size of the sheet S, is ensured to be the width of the second abutment portions 125d1-1 to 125d3-2 near the first abutment portion 125c along the sheet width direction. This is correct regardless of whether the sheet S moves obliquely at the corner of its end in the transport direction.

[0051] Therefore, regardless of whether the sheet S moves obliquely in the surface portion of the arms 125-1-1 to 125-3-2 extending from the base portion 125e to the first abutment portion 125c, the second abutment portions 125d1-1 to 125d3-2 can abut against the corner portion of the sheet S.

[0052] Furthermore, it will be described how sheet S abuts against the second abutting portions 125d1-1 to 125d3-2 when sheet S is being transported. For example, when sheet S is being transported normally, the corner portion of the end of sheet S in the transport direction abuts against the second abutting portion corresponding to the size of sheet S. The portion of the corner portion of sheet S located inside the end in the transport direction abuts against the second abutting portion located inside the second abutting portion in the sheet width direction, substantially simultaneously with the corner portion. For example, the case where the corner portion abuts against the second abutting portion 125d3-1 and the second abutting portion 125d3-2 will be discussed. The portion of sheet S located inside the corner portion in the sheet width direction abuts against the second abutting portions located inside the two second abutting portions in the sheet width direction.

[0053] On the other hand, when sheet S is conveyed at an angle, the downstream portion of the corner portion of sheet S abuts against one of the paired second abutting portions according to the size of sheet S. Then, the ends of sheet S in the conveying direction sequentially abut against the second abutting portions located inside the second abutting portions in the sheet width direction relative to the corner portions. Finally, the corner portions of sheet S that have not yet abutted against the second abutting portions abut against the other of the paired second abutting portions according to the size of sheet S.

[0054] In this embodiment, due to design limitations of the imaging device, the mounting position of the components forming the arm including the first full-load detection mark 125 is restricted. Therefore, the position of the base portions 125e of the arms 125-1-1 to 125-3-2 of the first full-load detection mark 125 is also restricted. Consequently, the width of the second abutment portions 125d1-1 to 125d3-2 near the base portion 125e in the sheet width direction is smaller than the width near the first abutment portion 125c in the sheet width direction. Furthermore, the tilt angle during sheet tilting varies depending on the size of the sheet S. Therefore, considering these facts, the second abutment portions 125d1-1 to 125d3-2 have the following... Figure 3B The approximate trapezoidal shape shown allows the end surface of sheet S in the transport direction to abut against the second abutment portion.

[0055] Furthermore, as the positions of the second abutting portions 125d1-1 to 125d3-2 relative to the second abutting portion 125d4, which serves as the boundary, progress outward in the sheet width direction, the width of the second abutting portion in the sheet width direction gradually increases. Specifically, the width of the second abutting portion 125d2-1 is greater than the width of the second abutting portion 125d1-1, and the width of the second abutting portion 125d2-2 is greater than the width of the second abutting portion 125d1-2. Furthermore, the width of the second abutting portion 125d3-1 is greater than the width of the second abutting portion 125d2-1, and the width of the second abutting portion 125d3-2 is greater than the width of the second abutting portion 125d2-2. This is because as the size of the sheet S increases, the displacement of the corner portion at the distal end in the transport direction of the sheet S increases when the sheet S moves obliquely. Therefore, even when the displacement of the corner portion increases, the corner portion of the sheet S can still abut against the second abutting portion.

[0056] The advantages arising from the fact that the second abutment portions 125d1-1 to 125d3-2 are set in the arms 125-1-1 to 125-3-2 of the first full load detection mark 125 will be described.

[0057] When the second abutment portion formed in the arm of the first full load detection mark 125 has an elongated (narrow) shape, the area of ​​the portion abutting the sheet S is reduced, the width of the corner supporting the sheet S is reduced, or the abutment portion abuts with a small width at a position offset from the corner of the end of the sheet S. In this case, the sheet S may be damaged, causing the force acting on the abutment sheet S to be concentrated in a local area and the corners to be folded.

[0058] However, in this embodiment, as described above, regardless of whether the sheet S moves at an angle, the generally trapezoidal portion of the second abutment portion abuts against the corner portion of the end of the sheet S in the transport direction. Therefore, even during the transport of the sheet S, the second abutment portion continues to maintain surface contact with the sheet S, and the force acting on the sheet S is distributed rather than concentrated in a localized area, thus reducing the burden on the sheet S. Therefore, it is possible to prevent the sheet S from being discharged in a corner-folded state.

[0059] As described above, the first full-load detection mark 125 has a plurality of first abutting portions 125c arranged along the width direction of the sheet. That is, the first full-load detection mark 125 abuts against the stacked sheet S at multiple locations along the width direction of the sheet, rather than at one location. In this embodiment, although the first full-load detection mark 125 abuts against the stacked sheet S at a total of seven locations, the number of abutting locations is not limited to this. The number of portions abutting against the sheet S is not particularly limited, as long as the first full-load detection mark 125 can abut against the stacked sheet S in a wide area while aligning with the left and right ends and the center portion along the width direction of the sheet. For example, the number of portions abutting against the sheet S on the left and right sides relative to the center of the first abutting portion 125c can be changed from three to two, so that the first full-load detection mark 125 abuts against the stacked sheet S at a total of five locations.

[0060] Furthermore, the sheet S stacked on the first stacking unit 201 reaches its maximum height that can be stacked on the first stacking unit 201, and the first full load detection mark 125 (first abutment portion 125c) rises to the full load detection position. In this way, the state of the sensor (not shown) is switched to detect a full load state. Here, in this embodiment, the full load detection position of the first full load detection mark 125 is set such that the sensor detects a full load state before the height of the rear end of the sheet S stacked on the first stacking unit 201 (the end abutted by the second rear end wall 212) exceeds the height α of the second rear end wall 212.

[0061] Figure 3A The double-dotted line indicates the height of sheet S when a full load is detected. That is, when sheet S is stacked to the height of the double-dotted line, the control unit 300 stops transferring sheet S to the first stacking unit 201. Figure 3A In the middle, the movement trajectory of the upper end surface 212a of the second rear end wall 212 is indicated by a dashed line. Figure 3BIn the diagram, the height of the upper end surface 212a in a direction orthogonal to the attachment / removal direction of the sheet post-processing device 200 relative to the equipment body 100 and the sheet width direction (vertical direction) is indicated by α. When the sheet post-processing device 200 is detachably attached to the equipment body 100 (attached to or separated from it), the upper end surface 212a moves along the dotted line. During this movement, the upper end surface 212a of the second rear end wall 212, which serves as the second support unit, is configured to be located on a side lower than the lowest surface (first abutment portion 125c) of the first full-load detection mark 125a in its original position. That is, the height α of the upper end surface 212a is lower than the height of the lowest surface of the first full-load detection mark 125. The positional relationship between the upper end surface 212a and the lowest surface of the first full-load detection mark 125 does not depend on whether the sheet S is stacked on the first stacking unit 201. Figure 3A As shown, the height of the first full-load detection mark 125b when the sheet S is detected to be fully loaded, as indicated by the double-dotted line, is further higher than the first full-load detection mark 125a at its original position. That is, this is because the height of the first full-load detection mark 125 (first abutment portion 125c) of the stacked sheet S becomes higher than the upper end surface 212a of the second rear end wall 212.

[0062] Due to the above-described structure, the following advantages are achieved. First, compared to a structure where the second rear end wall 212 remains on the device body and only the sheet stacking unit (i.e., the first stacking unit 201) is separated (which is considered a type of stacking device structure), in this embodiment, the first stacking unit 201 and the second rear end wall 212 are integrated. Furthermore, the second rear end wall 212 is positioned at a height higher than the height at which the full load state of the sheet S is detected. Therefore, even when the sheet post-processing device 200 separates from the device body 100 while the sheet S is stacked to its full stacking height, it is possible to prevent the stacked sheets from falling into the space created by the separation. Therefore, the need to remove the stacked sheets before performing the separation operation can be eliminated.

[0063] Even when the sheet post-processing device 200 is attached to and separated from the equipment body 100, the upper end surface 212a of the second rear end wall 212 remains at a position lower than the lowest surface of the first full-load detection mark 125, which serves as a detection unit. Furthermore, as... Figure 3BAs shown, the first full-load detection mark 125 and the second rear end wall 212 are configured not to overlap when viewed from the attachment / removal direction of the sheet post-processing apparatus 200 relative to the equipment body 100. Therefore, during the movement of the sheet post-processing apparatus 200 relative to the equipment body 100, the first full-load detection mark 125 and the second rear end wall 212 do not contact each other, and the first full-load detection mark 125 will not be damaged due to interference with the second rear end wall 212.

[0064] Although the second rear end wall 212 of this embodiment has a structure in which the height (height of the upper end surface 212a) throughout the entire sheet width direction is lower than the lowest surface of the first full load detection mark 125, it is not limited thereto. That is, the area that coincides with the first full load detection mark 125 in the sheet width direction when viewed from the attachment / removal direction is defined as the corresponding area of ​​the second rear end wall 212, which corresponds to the position where the first full load detection mark 125 abuts against the recording material. The area that does not coincide with the first full load detection mark 125 in the sheet width direction when viewed from the attachment / removal direction is defined as the non-corresponding area of ​​the second rear end wall 212 relative to the first full load detection mark 125. When the area is defined in this way, the height of the second rear end wall 212, at least in the corresponding area, may be lower than the lowest surface of the first full load detection mark 125.

[0065] Due to the comb-like shape, the area of ​​the first rear end wall 129 that can support the rear end of the sheet S stacked on the first stacking unit 201 can extend downward to overlap with the area of ​​the second rear end wall 212 that can support the rear end of the sheet S. This configuration provides the following advantages. For example, due to wind pressure and other factors that occur when the sheet post-processing device 200 separates from the device body 100 with the sheet S stacked on it, a portion of the stacked sheet S may extend beyond the second rear end wall 212, causing it to slide and fall into the gap between the first and second rear end walls 129 and 212. In this example, the body-side protrusion 129a of the first rear end wall 129, extending further downward relative to the upper end surface 212a of the second rear end wall 212, abuts against the end of the protruding sheet S that extends beyond the first rear end wall 129, and prevents the sheet S from further entering the gap.

[0066] Here, as a comparative example to more easily describe the advantages, in Figure 4A and Figure 4B An exemplary illustrative diagram is shown of the periphery of the first stacked unit 201 when the division between the first rear end wall 129 and the second rear end wall 212 does not have a comb-tooth shape. Figure 4AThis is a cross-sectional view of the periphery of the first stacking unit 201 when the segmented portion does not have a comb-like shape (for reference, the construction of the body-side protrusion 129a, which is not provided in this comparative example, is indicated by dashed lines). Figure 4B yes Figure 4A The left view. (e.g.) Figure 4A and Figure 4B As shown, if the partition between the first rear end wall 129 and the second rear end wall 212 is flat, the following problem may occur when the sheet post-processing apparatus 200 is separated from the equipment body 100. That is, the sheet S stacked on the first stacking unit 201 may float due to wind pressure and may enter through the gap in the partition, such as... Figure 2B The space formed when the sheet post-processing device 200 is separated from the equipment body 100.

[0067] However, as Figure 4A As indicated by the dashed lines, in the partition between the first rear end wall 129 and the second rear end wall 212 in this embodiment, a portion of the first rear end wall 129 (the body-side protrusion 129a) extends to prevent the sheet S from entering the space. That is, due to the body-side protrusion 129a formed in the first rear end wall 129, no gap is formed for the sheet S to enter towards the inside of the partition, or the gap is small. Therefore, it is possible to prevent the stacked sheet S from entering the gap in the partition.

[0068] Example 2

[0069] Reference Figure 5A and Figure 5B Description of Example 2. Figure 5A This is a cross-sectional view of the periphery of the first stacking unit 201 according to this embodiment. Figure 5B yes Figure 5A Left view. Constructions identical to those in Embodiment 1 will be indicated by the same reference numerals, and their detailed description will be omitted.

[0070] like Figure 5B As shown, in this embodiment, the second rear end wall 212 forms a wall with two different heights, including a portion with an upper end surface 212a having a height of α and a portion with an upper end surface 212b having a height of β. The height α of the upper end surface 212a is the same as the height of the upper end surface 212a shown in Embodiment 1, and is lower than the lowest surface of the first full load detection mark 125.

[0071] like Figure 5BAs shown, the first full-load detection mark 125 has a partially notched shape, rather than a mark portion that abuts against the stacked sheets in the entire sheet width direction. At the location where the first full-load detection mark 125 forms a notch, the second rear end wall 212 has a wall portion including an upper end surface 212b, the height β of which is greater than the height α of the upper end surface 212a. Conversely, at the location where the first full-load detection mark 125 has a mark portion (first abutting portion 125c) abutting against the stacked sheets S, the second rear end wall 212 has a wall portion including an upper end surface 212a of height α.

[0072] In Embodiment 2, the comb tooth shape is partially formed in the segment between the first rear end wall 129 and the second rear end wall 212. The comb tooth shape of Embodiment 2 is configured such that a body-side recessed portion 129c and a protruding portion 212d are added to the comb tooth shape of Embodiment 1, wherein the body-side recessed portion 129c is deeper than the body-side recessed portion 129b, and the protruding portion 212d is higher (β-α) than the protruding portion 212c and is configured to enter the body-side recessed portion 129c.

[0073] In other words, similar to Embodiment 1, in the region of the second rear end wall 212 in the sheet width direction, the region whose position in the sheet width direction coincides with the position of the first full load detection mark 125 is defined as the corresponding region of the second rear end wall 212, and the corresponding region corresponds to the first full load detection mark 125. When the region is defined in this way, the height of the corresponding region in a direction orthogonal to the attachment / removal direction and the width direction is lower than the height of the lowest surface of the first full load detection mark 125. The height of the corresponding region corresponds to Figure 5B The height α of the upper end surface 212a is specified. Furthermore, regions whose position in the sheet width direction does not correspond to the position of the first full-load detection mark 125 are defined as non-corresponding regions of the second rear end wall 212 relative to the first full-load detection mark 125. When the region is defined in this way, the non-corresponding region is higher than the lowest surface of the first full-load detection mark 125. The height of the non-corresponding region corresponds to... Figure 5B The height β of the upper end surface 212b is specified. In other words, in this embodiment, the first full-load detection mark 125 and the second rear end wall 212 are configured so that they do not overlap when viewed from the attachment / removal direction of the sheet post-processing device 200 relative to the device body 100. Therefore, when the sheet post-processing device 200 is attached to or separated from the device body 100, the first full-load detection mark 125 and the second rear end wall 212 do not interfere with each other.

[0074] In this embodiment, the second rear end wall 212 has an upper end surface 212b with a height of β and an upper end surface 212a with a height of α, wherein the height α corresponds to the maximum height of the stacked sheets S and is less than the height β. Due to this construction, the stacking state of the sheets S can be stabilized.

[0075] Figure 5A The diagram shows a state in which sheet S, curled (hereinafter referred to as tilted and curled) in a direction inclined against the rear end wall, is stacked on a first stacking unit 201. In the figure, the double-dotted line indicates the height of the stacked sheet S when a fully loaded state of sheet S is detected. Furthermore, the dashed lines indicate the positions of the upper end surfaces 212b and 212a of the second rear end wall 212. As described above, compared to Embodiment 1, in this embodiment, the difference between the height of the upper end surface 212b of the second rear end wall 212 and the height of sheet S when a fully loaded state of sheet S is detected is increased.

[0076] In this state, in Embodiment 1, when the sheet post-processing device 200 is detached from the device body 100, since the rear end of the sheet is not supported, the sheet S stacked above the upper end surface 212a may slip and fall from the sheet post-processing device 200. Conversely, in Embodiment 2, since the wall portion having an upper end surface 212b that is higher than the upper end surface 212a can support the rear end of the curled sheet S stacked above it, the stacking state of the sheet S can be stabilized during the attachment / removal of the sheet post-processing device 200.

[0077] Figure 6A and Figure 6B An intermediate state is shown, in which the sheet post-processing device 200 attaches to the device body 100 with the tilted, curled sheet stacked to a full load state. Figure 6A The state is shown before the upper end surface 212b passes through the lateral side of the first full load detection mark 125, and Figure 6B The diagram shows the state after the upper end surface 212b passes through the lateral side of the first full load detection mark 125. As described above, the first full load detection mark 125 and the second rear end wall 212 do not interfere with each other. However, some sheets stacked on top (S1 and S2 in the figure) may come into contact with the first full load detection mark 125. However, only a few sheets can straddle the first full load detection mark 125, and the possibility of the first full load detection mark 125 being damaged is very small.

[0078] As described above, in this embodiment, the difference between the height of the upper end surface of the second rear end wall 212 and the height of the sheet when the sheet S is detected to be fully loaded is greater than the difference in Embodiment 1. Therefore, even when the sheet S with its rear end tilted and curled is stacked on the first stacking unit 201, advantages similar to those mentioned in Embodiment 1 are obtained.

[0079] Even when no curling occurs in the stacked sheets S, the significant advantages unique to Embodiment 2 are still attainable. For example, in addition to the advantage of the comb-like shape of the dividing portion between the first rear end wall 129 and the second rear end wall 212 described in Embodiment 1, the higher height of the upper end surface 212b prevents the sheet S from straddling the second rear end wall 212. Compared to Embodiment 1, according to Embodiment 2, it is not necessary to set the upper limit height of the maximum number of stackable sheets S to the height of the upper end surface 212a, and the maximum number of stackable sheets S can be increased.

[0080] Example 3

[0081] Reference Figure 7A and Figure 7B Description of Example 3. Figure 7A This is a cross-sectional view of the periphery of the first stacking unit 201 according to this embodiment. Figure 7B yes Figure 7A Left view. Constructions identical to those in Embodiments 1 and 2 will be indicated by the same reference numerals, and their detailed descriptions will be omitted.

[0082] like Figure 7B As shown, in this embodiment, similar to Embodiment 2, the second rear end wall 212 forms a wall with two different heights, including a portion with an upper end surface 212a having a height α and a portion with an upper end surface 212b having a height β. The height α of the upper end surface 212a is the same as the height of the upper end surface 212a shown in Embodiments 1 and 2, and is lower than the lowest surface of the first full load detection mark 125. The height β of the upper end surface 212b is the same as the height of the upper end surface 212b shown in Embodiment 2, and is higher than the height α of the upper end surface 212a. Similar to Embodiment 2, at the location where the first full load detection mark 125 forms a notch, the second rear end wall 212 has a wall portion including the upper end surface 212b, the height β of which is higher than the height α of the upper end surface 212a.

[0083] In this embodiment, the first full-load detection mark 125 is a first detection unit, and it also includes a second full-load detection mark 131 corresponding to the second detection unit. The second full-load detection mark 131, abutting against the upper surface of the stacked sheet S at the top, is located on the side closer to the rear end portion of the sheet S (closer to the second rear end wall 212) in the conveying direction of the sheet S (the attachment / removal direction of the sheet post-processing device 200) than the first full-load detection mark 125. In this embodiment, the paired second full-load detection marks 131 are disposed outside the arms 125-4 of the first full-load detection mark 125 in the sheet width direction, and abut against the sheet S at two positions in the sheet width direction. Regarding the position in the sheet width direction, the second full-load detection mark 131 is disposed at a position consistent with the upper end surface 212a of the second rear end wall 212 at a height α.

[0084] exist Figure 7A In the figure, reference numeral 131a indicates the second full-load detection mark 131 at its original position, and reference numeral 131b indicates the mark at the position where the full-load state of the sheet S is detected. The second full-load detection mark 131 rotates about the mark rotation center 130 (a rotation axis extending in the width direction of the sheet S). When the sheet S is stacked on the first stacking unit 201, the distal end (abutment portion 131c) of the second full-load detection mark 131 is raised by the stacked sheet S. When the distal end (abutment portion 131c) of the mark is raised to the full-load detection position, the state of the sensor (not shown) is switched and the full-load state is detected. Furthermore, in the second full-load detection mark 131, similar to the first full-load detection mark 125, arms 131-1 and 131-2 extend from the base portion 131e near the mark rotation center 130 toward the sheet S stacked on the first stacking unit 201. The distal ends of arms 131-1 and 131-2 are abutment portions 131c.

[0085] When the sensor detects that the sheet S is fully stacked on the first stacking unit 201 using at least the first full load detection flag 125 or the second full load detection flag 131, the control unit 300 stops transferring the sheet to the first stacking unit 201.

[0086] Here, the function of the second full load detection flag 131 will be described.

[0087] A second full-load detection mark 131 is provided to more accurately detect a portion of the sheet S stacked on the first stacking unit 201 that is closer to the rear end than the first full-load detection mark 125 abutting against it, which cannot be detected by the first full-load detection mark 125. More specifically, for example, as Figure 7AAs shown, a second full-load detection mark 131 is provided to more accurately detect the state of the sheet S stacked on the first stacking unit 201 when the sheet S curls up closer to the rear end than the abutment position of the first full-load detection mark 125. As described above, the abutment position between the second full-load detection mark 131 and the sheet S stacked on the first stacking unit 201 is located closer to the rear end of the sheet S in the transport direction of the sheet S than the abutment position between the first full-load detection mark 125 and the sheet S. Therefore, the state of the portion closer to the rear end than the abutment position between the sheet S and the first full-load detection mark 125 can be detected more accurately.

[0088] When the portion of the sheet S near the rear end of the sheet stacked on the first stacking unit 201 abuts against the second full load detection mark 131 and the abutting portion 131c rises to the full load detection position, the sensor changes state to detect the full load state and stops conveying the sheet.

[0089] The second full load detection mark 131 has a bent portion 131d in the portion near the abutment portion 131c, which is the distal end of arms 131-1 and 131-2. The bent portion 131d bends in the opposite direction to the direction in which it returns from a position offset from a predetermined attachment position relative to the equipment body 100 of the sheet post-processing device 200 to the predetermined attachment position. Furthermore, even when the rear end of the sheet S stacked on the first stacking unit 201 abuts the second full load detection mark 131 in its original position (initial position), the bent portion 131d bends at an angle and length from the portion near the abutment portion 131c so that the rear end of the stacked sheet S does not straddle the second full load detection mark 131. In other words, the bent portion 131d bends from the portion near the abutting portion 131c at an angle and length such that when the sheet post-processing device 200 is reattached, the abutting portion 131c rises by abutting against the sheet S stacked on the first stacking unit 201 to abut against the upper surface of the stacked sheet S at the top.

[0090] The advantages of the bent portion 131d will be described. For example, the following situation will be discussed: by reattaching the sheet post-processing device 200 from a position shifted relative to the device body 100, the sheet S in the sheet post-processing device 200 is stacked on the first stacking unit 201 to a height where the sheet S abuts against the abutting portion 131c of the second full load detection mark 131. In this case, if the bent portion 131d were not present, the rear end of the sheet S stacked on the first stacking unit 201 might straddle the second full load detection mark 131.

[0091] However, if the bent portion 131d exists, it can prevent the rear end of the sheet S stacked on the first stacking unit 201 from straddling the second full load detection mark 131 when the sheet post-processing device 200 is reattached. Therefore, when the user reattaches the sheet post-processing device 200 from a position shifted relative to the device body 100 from a predetermined attachment position, the user can eliminate the need to, for example, return the sheet S straddling the second full load detection mark 131 to the initial position of the first stacking unit 201.

[0092] like Figure 7B As shown, unlike the arms 125-1-1 to 125-3-2 of the first full-load detection mark 125, the arms 131-1 and 131-2 of the second full-load detection mark 131 are not approximately trapezoidal in shape. The first full-load detection mark 125 is configured to align with the width of the sheet S and the corner of the end of the sheet S in the transport direction as a countermeasure against corner folding of the sheet S, and has an approximately trapezoidal shape, the width of which allows the first full-load detection mark 125 to abut against the corner even when the sheet S is tilted. Conversely, the second full-load detection mark 131 is configured to more accurately detect a portion of the sheet S stacked on the first stacking unit 201 that is closer to the rear end than the abutment position of the first full-load detection mark 125, which cannot be detected by the first full-load detection mark 125. In other words, the purpose of the second full load detection mark 131 is different from that of the first full load detection mark 125, and the second full load detection mark 131 does not need to be against the corner of the sheet S and does not need to be aligned with the width of the sheet S.

[0093] Next, we will refer to Figure 7A Describe how to set the full load detection position of the second full load detection flag 131.

[0094] First, when the stacked sheets S are flat, the second full load detection mark 131, as the second full load detection mark 131a, is located at its original position and slightly higher than the second full load detection mark 131a. Figure 7A The portion indicated by the double-dotted line indicates that the second full-load detection mark 131 does not abut against the sheet S. That is, before the second full-load detection mark 131 abuts against the sheet S, the full-load state is detected by the first full-load detection mark 125, and the sheet transport is stopped. On the other hand, when the stacked sheet S tilts and curls, for example, as... Figure 7A As shown, the second full-load detection mark 131 can abut against the sheet S before the first full-load detection mark 125 abuts against the sheet S. When the curled sheets S are stacked continuously, the rear end of the sheet S may extend beyond the height β of the upper end surface 212b of the second rear end wall 212. The full-load position of the second full-load detection mark 131 is set such that the state of the sensor is switched to stop the sheet transfer before this state is formed.

[0095] like Figure 7A As shown, the case where a tilted, curled sheet S is stacked on the first stacking unit 201 will be discussed. In this embodiment, the abutment position between the stacked sheet and the second full-load detection mark 131 is positioned closer to the end of the sheet supported by the second rear end wall 212 than the abutment position between the stacked sheet and the first full-load detection mark 125. Therefore, when the sheet curls to tilt against the second rear end wall 212, the second full-load detection mark 131 detects a full-load state before the first full-load detection mark 125 detects a full-load state. Figure 7B As shown, similar to the first full-load detection mark 125a, the lowest surface of the second full-load detection mark 131a at its original position is set higher than the upper surface 212a of the second rear end wall 212. Therefore, even when the sheet post-processing device 200 is attached to or removed from the device body 100, the first full-load detection mark 125a and the second full-load detection mark 131a will not interfere with the second rear end wall 212.

[0096] In embodiments 1 and 2, only the first full-load detection flag 125 is set as a flag to detect whether the sheet S is completely stacked on the first stacking unit 201, and the height state of the stacked sheet S can be detected only at one position in the transport direction of the sheet S. Therefore, for example, when the curling state of the sheet S is weaker than Figure 5A and Figure 5B When the sheet S curls to the extent indicated and closer to the rear end than the contact position of the first full load detection mark 125, there is a possibility that the first full load detection mark 125 may not detect the curling state. In other words, the problem is that it is difficult to determine whether the side of the sheet S closer to the rear end than the contact position of the first full load detection mark 125 has curled to the point that the height of the rear end exceeds the height of the second rear end wall 212. Therefore, in this embodiment, the second full load detection mark 131 is provided near the end of the sheet supported by the second rear end wall 212. By doing so, the state of the stacked sheets can be detected more accurately and the full load state can be detected more reliably.

[0097] As described above, the following advantages are achieved due to the construction of this embodiment. When the second full-load detection mark 131 is further provided as described above, the state of the stacked sheets can be detected more accurately and the full-load state can be detected more reliably. Furthermore, similar to Embodiments 1 and 2, during the attachment and disassembly of the sheet post-processing apparatus 200, the first full-load detection mark 125 and the second full-load detection mark 131 do not come into contact with the second rear end wall 212 and will not be damaged due to mutual interference with the second rear end wall 212. In addition, due to the advantage of the comb-tooth shape of the dividing portion between the first rear end wall 129 and the second rear end wall 212, similar to Embodiments 1 and 2, it is possible to prevent the sheet from falling into the space formed when the sheet post-processing apparatus 200 is separated from the equipment body 100.

[0098] Consider the following scenario: the sheet post-processing device 200 is attached to the equipment body 100 when the tilted, curled sheet S is stacked to a full load state. In this case, compared to the configuration of Embodiment 2, the incidence of a portion of the stacked sheet straddling the full load detection mark or the number of straddling sheets can be reduced. Of course, the first full load detection mark 215 and the second full load detection mark 131 will not be damaged when the sheet post-processing device 200 is attached to and removed from the equipment body 100.

[0099] Furthermore, even when the rear end of the stacked sheets is tilted against the rear end wall 212, the following advantages can be obtained. (Refer to...) Figure 8A and 8B The advantages are described, illustrating the possible states when the second full-load detection mark 131 is absent. If the second full-load detection mark 131 is absent and a portion of sheet S closer to its rear end than the abutment position between sheet S and the first full-load detection mark 125 cannot be detected, the following situations may occur as examples. The first situation is, as follows... Figure 8A As shown, the rear end of the sheet S stacked on the first stacking unit 201 rolls into the gap between the first rear end wall 129 and the lower roller of the discharge roller 124. The second case is as follows... Figure 8B As shown, the rear end of the sheet S stacked on the first stacking unit 201 blocks the discharge opening of the discharge roller 124. Figure 8A and Figure 8BIn the diagram, the sheet S causing the aforementioned problem is indicated by a thick line. However, as in this embodiment, when the second full-load detection mark 131 is further provided, it is raised to the full-load detection position (reference numeral 131b) before this state is formed. Therefore, the sensor can detect the full-load state and stop the sheet transfer. That is, the second full-load detection mark 131 detects the state of the sheet S more accurately and stops the sheet transfer before a portion of the sheet S closer to the rear end than the abutment position between the sheet S and the first full-load detection mark 125 is stacked to a height β above the upper end surface 212b. Therefore, problems such as paper jams can be prevented. The "full-load state" mentioned herein refers to a state in which additional sheets S are not allowed to be stacked on the first stacking unit 201, and the number of stacked sheets S considered to be in a "full-load state" varies depending on the curling state of the sheet S. That is, if the sheet S is flat and without any curling, more sheets are stacked, and as the size of the curling increases, the number of stacked sheets decreases.

[0100] Although the invention has been described with reference to embodiments 1 to 3, its application is not limited to stacking devices attached to and detached from a device body, the stacking device including a detection mark for detecting the height of stacked sheets. For example, the invention can be applied to stacking devices attached to and detached from a device body, the device body including an abutting member that abuts against the stacked sheets from above to press the sheets in order to stabilize the state of the sheets stacked on the stacking device.

[0101] While 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 following claims should be given the broadest interpretation in order to cover all such modifications and equivalent structures and functions.

Claims

1. An imaging device, the imaging device comprising: Equipment body; An imaging unit configured to form an image on a recording material; A transmission device configured to transmit recording material; A stacking device on which recording material discharged from the device body is stacked, and the stacking device is detachably attached to the device body, the stacking device comprising: a first support unit configured to support the recording material from below; and a second support unit configured to support an end of the recording material in an attachment / removal direction, the stacking device being attached to and detached from the device body in the attachment / removal direction; A control unit configured to control the transmission of the recording material; A first abutting member, configured to abut against recording material stacked on the stacking device, wherein the first abutting member is rotatable about a rotation axis, and the first abutting member includes a central arm located at a central position of the recording material in the direction of the rotation axis, and a pair of arms configured to contact the corners of the recording material; and A second abutting member is configured to abut against recording material stacked on the stacking device, and the abutting position between the second abutting member and the recording material is positioned closer to the end supported by the second support unit than the abutting position between the first abutting member and the recording material. The second abutting member is rotatable about the axis of rotation, and the direction of the second abutting member relative to the axis of rotation is located between the pair of arms. The control unit is configured to control the transfer of the recording material such that the transfer of the recording material to the stacking device stops when either the first abutting member or the second abutting member abuts against the recording material at its maximum height position supported by the stacking device; and Specifically, when the stacked recording material is flat, the first abutment member detects a full load state and stops the transmission of the recording material before the second abutment member abuts against the stacked recording material; and when the stacked recording material is tilted and curled, the second abutment member abuts against the stacked recording material before the first abutment member abuts against the stacked recording material, and the second abutment member detects the full load state before the first abutment member detects the full load state.

2. The imaging device according to claim 1, in, The second support unit is configured such that it does not overlap with the first abutment member and the second abutment member when viewed from the attachment / removal direction.

3. The imaging device according to claim 1, in, The first abutment member is configured to be raised from its first original position by contact with recording material stacked on the stacking device. The second support unit includes a first corresponding region, and the position of the first corresponding region corresponds to the position of the first abutting member that abuts against the recording material when the stacking device is attached to the device body in the width direction orthogonal to the attachment / removal direction. The height of the first corresponding region in the orthogonal direction orthogonal to the attachment / removal direction and the width direction is lower than the height of the lowest surface of the first abutting member when the stacking device is attached to the device body and the first abutting member is in the first original position.

4. The imaging device according to claim 3, in, The second abutment member is configured to be raised from its second original position by contact with the recording material stacked on the stacking device. The second support unit includes a second corresponding region, and the position of the second corresponding region corresponds to the position of the second abutment member that abuts against the recording material in the width direction when the stacking device is attached to the device body, and the height of the second corresponding region in the orthogonal direction is lower than the height of the lowest surface of the second abutment member when the stacking device is attached to the device body and the second abutment member is in the second original position.

5. The imaging device according to claim 4, in, The second support unit has a non-corresponding region, wherein the position of the non-corresponding region in the width direction does not correspond to the position of the first corresponding region and the position of the second corresponding region, and the height of the non-corresponding region in the orthogonal direction is higher than (i) the height of the abutment position between the first abutment member and the recording material and (ii) the height of the abutment position between the second abutment member and the recording material.

6. The imaging device according to claim 1, wherein, The second support unit is configured to abut against the rear end of the recording material stacked on the first support unit.

7. The imaging device according to claim 1, wherein, The shape of the first abutment member is different from the shape of the second abutment member.

8. The imaging device according to any one of claims 3 to 5, wherein the imaging device further comprises: A body-side support unit is disposed in the device body to support the ends of recording materials stacked on the stacking device along the attachment / removal direction. The second support unit is positioned on the lower side relative to the main body-side support unit in the orthogonal direction. The second support unit includes a plurality of protruding portions, which are spaced apart along the width direction to protrude toward the body-side support unit. The body-side support unit includes multiple body-side protrusions, which are spaced apart along the width direction to protrude toward the second support unit. The plurality of protruding portions and the plurality of body-side protruding portions are arranged alternately along the width direction.

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