Medium discharge device, medium conveyance device and image forming device

Abstract

To provide a medium discharge device which has a loading unit on which a medium is likely to be loaded properly, to provide a medium conveyance device and to provide an image forming device.SOLUTION: A medium discharge device includes: a discharge part for discharging a medium; and a loading unit capable of loading a medium discharged from the discharge part. The loading unit includes: a first loading surface positioned on a rear end side of the discharged medium; a first portion having an extension part extending from the first loading surface; and a second portion having a second loading surface positioned on a tip side of the discharged medium. The first portion extends in the first direction which inclines upward as it is separated from the discharge part. The second portion extends in the second direction different from the first direction from a gap between an upstream side end part of the first loading surface and a downstream side end part of the extension part, in the medium discharge direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a medium ejection device, a medium transport device, and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art There are known image forming apparatuses equipped with a medium discharge device having a stacking unit capable of stacking media discharged from a discharge section. One example of this type of apparatus is a printing apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-233666. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-3471 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional media ejection devices, including the technology described in Patent Document 1, when curled or other distorted media is ejected, it may not be possible for the media to be properly held in the stacking unit and may not be properly stacked.

[0005] An object of the present invention is to provide a medium ejection device, a medium transport device, and an image forming apparatus that have a loading unit that makes it easy to properly load media. [Means for solving the problem]

[0006] In order to solve the above problems, the medium discharging device of the first disclosure has a discharging unit that discharges a medium, and a stacking unit capable of stacking the medium discharged from the discharging unit. The stacking unit has a first stacking surface located on the rear end side of the discharged medium, a first portion having an extending portion extending from the first stacking surface, and a second portion having a second stacking surface located on the front end side of the discharged medium. The first portion extends in a first direction that slopes upward as it moves away from the discharging unit, and the second portion extends in a second direction different from the first direction from between the upstream end of the first stacking surface and the downstream end of the extending portion in the discharging direction of the medium.

[0007] The medium conveying device of the second disclosure has the medium discharging device of the first disclosure, a medium tray capable of storing a medium, and a supply unit capable of supplying the medium stored in the medium tray. When the length of the maximum size medium that can be stored in the medium tray in the supply direction of the medium by the supply unit is L_max, the length L from the end of the extending portion on the opposite side of the discharging unit to the discharging unit satisfies L_max / 2 < L ≦ L_max×2 / 3.

[0008] The image forming apparatus of the third disclosure is an image forming apparatus that forms an image on the surface of a medium, and includes an image forming unit that forms an image on the medium, a fixing unit that fixes the image formed by the image forming unit to the medium, and a medium discharging means corresponding to the medium discharging device of the first disclosure that discharges the medium after image fixing by the fixing unit.

Advantages of the Invention

[0009] According to the present disclosure, even when a medium with distortion such as curl is discharged, it can be appropriately held and stacked on the stacking unit.

Brief Description of the Drawings

[0010] [Figure 1] It is an internal configuration schematic diagram schematically showing the internal configuration of the image forming apparatus according to the first embodiment. [Diagram 2]1 is a diagram showing an internal configuration of an image forming apparatus according to a first embodiment. [Diagram 3] FIG. 1 is a configuration diagram showing a configuration of a medium stacking unit according to a first embodiment (part 1). [Figure 4] FIG. 2 is a diagram showing the configuration of the medium stacking unit according to the first embodiment (part 2). [Diagram 5] 5A and 5B are explanatory diagrams illustrating a method of holding a reverse-curled medium when it is discharged in the first embodiment. [Figure 6] FIG. 4 is an explanatory diagram for explaining a holding method when a medium with a positive curl is discharged in the first embodiment. [Figure 7] FIG. 4 is an explanatory diagram illustrating a method of holding a cylindrically curled medium when the medium is discharged in the first embodiment. [Figure 8] 13 is a configuration diagram showing the configuration of a first stack portion and a protruding portion according to a second embodiment. FIG. [Figure 9] 13 is an explanatory diagram illustrating how media are stacked in a media stacking unit according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (A) First embodiment Hereinafter, a first embodiment of a medium ejection device, a medium conveying device, and an image forming apparatus according to the present disclosure will be described in detail with reference to the drawings.

[0012] (A-1) Configuration of the First Embodiment (A-1-1) Configuration of Image Forming Apparatus Fig. 1 is a schematic diagram showing the internal configuration of an image forming apparatus according to the first embodiment. Fig. 2 is a schematic diagram showing the internal configuration of an image forming apparatus according to the first embodiment.

[0013] The image forming apparatuses in FIGS. 1 and 2 have the same basic components, and FIG. 1 is a schematic diagram showing the internal configuration of the image forming apparatus in FIG.

[0014] 1 and 2, an image forming apparatus 100 according to a first embodiment is a color printer that employs an electrophotographic system and forms a color image on the surface of a medium P. The image forming apparatus 100 has various components arranged inside a housing formed in a substantially box shape.

[0015] In the following description, the right end portion in FIG. 1 is regarded as the front of image forming apparatus 100, and the up / down direction, left / right direction, and front / rear direction are defined as viewed from the front of image forming apparatus 100.

[0016] The image forming apparatus 100 is connected to a higher-level device such as a computer device, and upon receiving a print instruction or print data from the higher-level device, the image forming apparatus 100 forms an image on the surface of the medium P. The image forming apparatus 100 may include a display operation unit that receives operation inputs and displays various information, for example.

[0017] 1 and 2, the image forming apparatus 100 according to the first embodiment has a media storage tray 20 storing a media P, a pickup roller 31, a conveying roller 32, a media conveying path 30, a conveying roller 33, a belt support roller 41, a belt drive roller 42, a belt unit 40, image forming units 50K, 50Y, 50M, 50C, a fixing unit 60, a conveying roller 34, a conveying roller 35, a discharge roller 36 as a discharge section, and a media stacking unit 10 as a stacking unit.

[0018] Here, the medium ejection device of the present disclosure has an ejection roller 36 as an ejection section, and a medium stacking unit 10 as a stacking unit.

[0019] In addition to the media discharge device of the present disclosure, the media conveying device of the present disclosure has a media storage tray 20 as a media tray, and a media supply mechanism including a pickup roller 31, a media conveying path 30, conveying rollers 32-35, a belt support roller 41, a belt drive roller 42, and a belt unit 40 as a supply section.

[0020] The medium transport path 30 is a transport path from the medium storage tray 20 to the discharge of the medium P on which an image has been formed, and is formed in a substantially S-shape.

[0021] In the medium transport path 30, the side of the medium storage tray 20 is the "upstream side" along the transport direction of the medium P, and the side of the discharge rollers 36 that discharge the medium P is the "downstream side". Also, locations other than the medium transport path 30 (for example, after the medium P is discharged) will be described as the upstream side and downstream side along the transport direction of the medium P.

[0022] The image forming apparatus 100 is a rear discharge type image forming apparatus in which the medium P after image formation is discharged to the rear of the apparatus. In other words, the medium stacking unit 10 functions as a rear discharge tray.

[0023] The pickup roller 31 picks up the media P stored in the medium storage tray 20 one by one, and sends the media P to the medium transport path 30.

[0024] The transport rollers 32, 33, 34, and 35 transport the medium P along the medium transport path 30 in the direction of the arrow H shown in FIG.

[0025] The belt unit 40 is an endless belt, and is supported by a belt support roller 41, a belt drive roller 42, and transfer rollers of the image forming units 50K, 50Y, 50M, and 50C. The belt unit 40 transports the medium P along the medium transport path 30 while each of the image forming units 50K, 50Y, 50M, and 50C is transferring a toner image onto the medium P.

[0026] The belt drive roller 42 is rotated by a motor (not shown) to drive the belt unit 40 .

[0027] The belt support roller 41 is a driven roller, and rotates together with the belt unit 40 .

[0028] The image forming units 50K, 50Y, 50M, and 50C correspond to the colors black (K), yellow (Y), magenta (M), and cyan (C), respectively, and each includes a toner cartridge, a photosensitive drum, an LED head, a transfer roller, and the like.

[0029] The arrangement order of the image forming units 50K, 50Y, 50M, and 50C and the toner colors of the respective image forming units are not limited to those shown in Fig. 1. In other words, the toner colors of the image forming units 50 may be colors other than black (K), yellow (Y), magenta (M), and cyan (C), and the multiple image forming units 50 may have toner of the same color.

[0030] Each of the image forming units 50K, 50Y, 50M, and 50C transfers a toner image formed on the surface of the photosensitive drum onto the medium P transported by the belt unit 40. The medium P to which the toner image has been transferred is transported to the fixing unit 60 by the belt unit 40.

[0031] The fixing unit 60 applies heat and pressure to the medium P onto which the toner image has been transferred, thereby fixing the toner image to the medium P.

[0032] The discharge rollers 36 transport the medium P after the fixing process to the medium accumulation unit 10. As illustrated in Fig. 1 and Fig. 2, the discharge rollers 36 are formed as a pair of two roller members 36a and 36b. The position where the pair of roller members 36a and 36b come into contact with each other and sandwich the medium P is also called the nip position or nip point. The discharge rollers 36 are disposed so that a common tangent at the nip position of the pair of roller members 36a and 36b is directed toward the top surface of the image forming apparatus 100 (diagonally upward).

[0033] The discharge rollers 36 can set the discharge direction of the medium P as a common tangent at the nip position of the two roller members 36a and 36b, and the common tangent is set to be on the upper surface side of the image forming apparatus 100. In other words, the discharge rollers 36 are disposed so that the discharge direction of the medium P (common tangent) is the upper surface of the apparatus.

[0034] The medium stacking unit 10 is for stacking the media P transported along the medium transport path 30.

[0035] (A-1-2) Configuration of media accumulation unit Next, the configuration of the medium stacking unit 10 according to the first embodiment will be described in detail with reference to FIGS.

[0036] As illustrated in FIG. 2, the medium stacking unit 10 has a first portion located on the trailing end side of the discharged medium P and a second portion located on the leading end side of the discharged medium P.

[0037] The first portion has a first stack portion 12 as a first loading portion and a protruding portion 11 as an extension portion. The first portion is provided so as to incline upward as it moves away from the position of the discharge roller 36. The upward direction in which the first portion is inclined is also referred to as the "first direction."

[0038] The second portion also has a second stack portion 13 as a second loading portion. The second portion extends in a direction different from the first direction in the discharge direction of the medium P from between an upstream end of a first stack surface 121 as a first loading surface described below and a downstream end of the protruding portion 11 as an extension portion. The direction in which the second portion extends is also referred to as the "second direction."

[0039] The first stack unit 12 guides the medium P from the discharge rollers 36 and holds the discharged medium P. The first stack unit 12 is a plate-shaped member located downstream of the discharge rollers 36. As illustrated in Fig. 2, the first stack unit 12 has a first stack surface 121 as a first loading surface located on the rear end side of the discharged medium P, and a rotation shaft 122 as a second rotation shaft.

[0040] The rotating shaft 122 is provided at one end of the first stack unit 12 (the lower end in FIG. 2) and is supported on the rear side of the device. By rotating the rotating shaft 122, the first stack unit 12 can be pulled out from the device housing or stored in the device housing. The structure of the first stack unit 12 is not limited to that shown in FIG. 2, and the first stack unit 12 may be fixed and not stored. In addition, the first and second parts can be stored in the device body by rotating the second stack unit 13 about a rotating shaft (first rotating shaft) 133 described later and then rotating the second stack unit 13 about a rotating shaft (second rotating shaft) 122 relative to the device body. In addition, the axis position of the rotating shaft 122 may be any position depending on the design requirements. In this way, other configurations are possible as long as they can achieve both storage ability and loading ability.

[0041] The first stack surface 121 is a surface that guides the discharged medium P further downstream and holds the medium P. The first stack surface 121 is a gentle slope having an angle equal to or larger than (i.e., equal to or greater than) the angle of the common tangent of the discharge roller 36 with respect to the vertical upward direction (hereinafter referred to as "vertically upward"). The angle α (0<α<90°) of the first stack surface 121 with respect to the vertically upward direction is held at an arbitrary opening angle (opening angle) of the first stack section 12 pulled out from the device (see FIG. 3).

[0042] Although the first stack surface 121 is illustrated as being flat, it may be, for example, an upwardly convex curved surface.

[0043] The protrusion 11 is a member that gently bends the leading end of the medium P, which is guided by the first stack unit 12 and moves further downstream, from the leading end 111 of the protrusion 11 as a starting point, and drops the rear end of the medium P discharged from the discharge roller 36 onto the first stack surface 121 of the first stack unit 12 by its own weight. When the leading end of the medium P that approaches the leading end 111 of the protrusion 11 bends downward, the leading end of the medium P sags. Therefore, even if the medium P is curled, the rear end of the medium P discharged from the discharge roller 36 can be dropped onto the first stack surface 121 of the first stack unit 12. This allows the medium P to be held normally and accumulated normally. The leading end 111 of the protrusion 11 functions as an inflection point.

[0044] The protruding portion 11 exists on an extension line of the first stack surface 121 of the first stack section 12. That is, as illustrated in FIG. 3, the installation angle of the protruding portion 11 with respect to the vertically upward direction is set to be approximately the same as the installation angle α of the first stack surface 121. The installation angle of the protruding portion 11 can be set in the range of −5° to +5° with respect to the installation angle α of the first stack surface 121. This can reduce friction between the first stack surface 121 and the media P, making it difficult for the leading ends of the media to get caught, and enabling proper placement.

[0045] Here, the reason for providing the protrusion 11 will be explained. As described above, since the common tangent corresponds to the discharge direction of the discharge rollers 36, the discharge rollers 36 are arranged so as to discharge the medium P in an obliquely upward direction, that is, the angle θ of the common tangent with respect to the vertically upward direction is set to be an acute angle (0<θ<90°).

[0046] For example, there is a strong demand for space saving in a rear discharge type image forming device 100 that discharges medium P from the rear of the device, and to solve this problem, the discharge angle of the discharge roller 36 (i.e., the angle θ of the common tangent of the discharge roller 36) is made acute to ensure space on the rear side.

[0047] However, if the discharge angle of the discharge roller 36 (i.e., the angle θ of the common tangent line of the discharge roller 36) is set small, when the curl of the discharged medium P is strong, there is a problem that the medium P cannot be normally held and accumulated, and the medium P may fall. For example, in the case of the medium P curled on the upper surface side, the rear end of the medium P stays on or rides over the discharge roller 36, and normal holding and accumulation cannot be achieved.

[0048] Therefore, in the first embodiment, since the medium accumulation unit 10 includes the protruding portion 11, the tip 111 of the protruding portion 11 becomes an inflection point, moves to the downstream side, and gently bends the tip of the medium P that has passed beyond the tip 111, so that the rear end of the medium P discharged from the discharge roller 36 falls onto the first stack surface 121 of the first stack portion 12 by its own weight.

[0049] Thereby, the rear end of the medium P from the discharge roller 36 can be dropped onto the first stack surface 121, and the tip of the medium P that has passed beyond the tip 111 of the protruding portion 11 hangs down, enabling normal holding and accumulation of the medium P.

[0050] Next, the position of the tip 111 of the protruding portion 11 will be described. The position of the tip 111 of the protruding portion 11 is desirably a position where the rear end of the medium P discharged from the discharge roller 36 falls onto the first stack surface 121 by its own weight while supporting the medium P moving to the downstream side. Also, the position of the tip 111 of the protruding portion 11 desirably determines the position of the inflection point according to the medium length along the conveyance direction of the medium P.

[0051] Therefore, for example, as illustrated in FIG. 3, if the length from the nip position of the discharge roller 36 to the position of the tip 111 of the protruding portion 11 is “L”, the position of the tip 111 of the protruding portion 11 is set such that (medium length / 2) < L ≤ (medium length × 2 / 3).

[0052] In other words, when the length of the largest-size medium that can be stored in the medium tray in the supply direction of the medium P is defined as L_max, the length L from the end of the protruding portion 11 as the extending portion on the side opposite to the discharge roller 13 to the discharge roller 13 satisfies L_max / 2 < L ≤ L_max×2 / 3.

[0053] Thereby, with the inflection point at a position of at least the rear half of the length of the medium in the conveyance direction, the leading end of the medium P can be bent downward. Since the risk of poor loading increases as the length of the medium increases, in a form where the position of the leading end 111 of the protruding portion 11 cannot be adjusted, it may be set according to the maximum medium size available as the standard size of the medium tray.

[0054] In the first embodiment, as illustrated in FIG. 4, an example is given where the protruding portion 11 is a plate-like member and is fixed to the central portion in the width direction of the other end (for example, the upper end portion) of the first stacking portion 12.

[0055] However, as described above, if the leading end of the medium P passing through the protruding portion 11 can be bent at the leading end 111 of the protruding portion 11 and the trailing end of the medium P discharged from the discharge roller 36 can be dropped onto the first stacking surface 121 by its own weight, the configuration of the protruding portion 11 is not limited to the configuration illustrated in FIG. 4. For example, the protruding portion 11 may be a rod-shaped member, or may be a triangular shape obtained by bending a rod-shaped member into a triangle. When the former rod-shaped member is used as the protruding portion 11, the end of the rod-shaped member can be the position of the leading end 111. When the latter triangular-shaped member is used as the protruding portion 11, the position of a certain vertex of the triangular shape can be the position of the leading end 111.

[0056] Also, as illustrated in FIG. 4, the protruding portion 11 has a stacking surface 112 as a third stacking surface for stacking the discharged medium P. Here, when the value of the length in the width direction of the first stacking surface 121 as the first stacking surface is defined as W1 (this is also referred to as the "first width"), the value W2 of the length in the width direction of the stacking surface 112 as the third stacking surface (this is referred to as the "second width") is smaller than W1.

[0057] The second stack section 13 is a member that holds the leading end of the medium P that hangs down beyond the leading end 111 of the protrusion 11. The second stack section 13 is a plate-like member that is connected to the other end (e.g., the upper end) of the first stack section 12. For example, the second stack section 13 may be formed of two plate-like members 13a and 13b that support both ends of the medium P to be discharged, as illustrated in FIG. 4. Of course, the number of members of the second stack section 13 is not limited as long as it can support the leading end of the medium P.

[0058] The second stack unit 13 has a second stack surface 131 as a second loading surface located on the leading end side of the discharged medium P, a support portion 132, and a rotation shaft 133 as a first rotation shaft.

[0059] The support portion 132 is pivotally supported on the other end portion (eg, the upper end portion) of the first stack portion 12.

[0060] The rotation shafts 133 are located at both ends in the width direction, and the second stack unit 13 is provided so as to be rotatable about the rotation shafts 133 as a center.

[0061] The second stack surface 131 receives the leading end of the medium P and holds the medium P. The angle β of the second stack surface 131 is held at an arbitrary opening angle (opening angle) of the second stack unit 13 journaled on the first stack unit 12 (see FIG. 3).

[0062] Although the second stack surface 131 is illustrated as being flat, it may be, for example, a curved surface that is convex downward. The second stack surface 131 may be inclined upward as it is away from the discharge roller 36, and in order to save space, the angle with respect to the horizontal direction may be in the range of 0° to 20°, for example, and it is further preferable that the angle with respect to the horizontal direction is in the range of 10° to 20°.

[0063] In order to facilitate the holding of the leading ends of the hanging media P by the protrusion 11 and the accumulation of the media P, the angle β of the second stack surface 131 is made larger than the angle α of the first stack surface 121. The angle β may also be horizontal. In other words, the relationship between the angles α and β can be any angle within the range of α<β≦90°.

[0064] (A-2) Operation of the First Embodiment Next, the operation of holding the media P by the media stacking unit 10 according to the first embodiment will be described.

[0065] Here, we will explain the types of curl that can occur in the discharged medium P. Curling towards the side on which an image is formed is called "positive curl," curling towards the side on which an image is not formed is called "negative curl," and when both ends of the width of the medium P in the transport direction curl towards one side to form a cylinder, it is called "cylindrical curl."

[0066] Although three types of curl are exemplified here, the types of curl are not limited to these, and the present invention can also be applied to a case where a medium P having multiple types of curl is discharged.

[0067] FIG. 5 is an explanatory diagram for explaining a method of holding the reverse curled medium P when it is discharged.

[0068] The image is formed on the upper surface of the discharged medium P. If reverse curl occurs in the medium P, the medium P is discharged with its leading and trailing ends curled downward.

[0069] When the reverse curled medium P is discharged from the discharge rollers 36, the medium P is guided by the first stack section 12 and moves further downstream. Then, when the medium P passes the tip 111 of the protruding section 11, the tip 111 becomes an inflection point, and the medium P bends gently downward from the tip 111 as a starting point, and the tip of the medium P is held on the second stack surface 131.

[0070] Thereafter, the leading end of the medium P is held on the second stack surface 131, and the trailing end of the medium P falls from the discharge rollers 36 onto the first stack surface 121 due to its own weight, and is held on the first stack surface 121.

[0071] FIG. 6 is an explanatory diagram for explaining a method of holding a positively curled medium P when it is discharged.

[0072] The image is formed on the upper surface of the discharged medium P. If a positive curl occurs in the medium P, the medium P is discharged with its leading and trailing ends curled upward.

[0073] When the medium P discharged from the discharge roller 36 passes over the tip 111 of the protrusion 11, the tip 111 becomes an inflection point, and the medium P bends gently downward from the tip 111 as a starting point, and the tip of the medium P is held on the second stack surface 131.

[0074] Thereafter, the leading end of the medium P is held on the second stack surface 131, and the trailing end of the medium P falls from the discharge rollers 36 onto the first stack surface 121 due to its own weight, and is held on the first stack surface 121.

[0075] 7 is an explanatory diagram for explaining a method of holding the discharged cylindrically curled medium P. In FIG. 7, the discharged medium P is shown in a see-through state.

[0076] When a cylindrical curl occurs in the medium P, the medium P is discharged with both ends of the width of the medium P aligned along the upper surface side.

[0077] The discharged medium P is curled into a cylindrical shape, and is discharged with strong stiffness of the medium P. When the medium P passes the tip 111 of the protrusion 11, the tip 111 becomes an inflection point, the medium P bends gently from the tip 111 of the protrusion 11, and the tip of the medium P hangs down to the second stack surface 131.

[0078] Both lateral ends of the medium P hang down from the width direction of the protruding portion 11 onto the second stack surface 131, and the rear end of the medium P falls from the discharge rollers 36 onto the first stack surface 121 due to its own weight.

[0079] (A-3) Effects of the First Embodiment As described above, according to the first embodiment, the protrusion creates an inflection point, which enables stacking while maintaining alignment for various media curls. In this case, by positioning the inflection point at a position more than halfway through the length of the media, it is possible to prevent the rear end side from falling completely from the discharge roller onto the stack surface, or from bouncing up and being pushed out to the next page discharge, thereby preventing the stacking from deteriorating.

[0080] Furthermore, according to the first embodiment, since it is composed of two components, a first stack section and a second stack section, the leading edge of the ejected medium passes over the first stack surface, thereby reducing friction with the stack surface before and after the medium is ejected, making it easier for the medium to be stacked properly.

[0081] Furthermore, according to the first embodiment, the discharge route where the paper is discharged with the print side facing up is located at the rear of the device, but as the discharge angle is set higher along with miniaturization, it becomes difficult to ensure stackability. To address this issue, the second stack surface has a structure in which it is pivotally supported by the first stack surface, so that the opening angle of the second stack surface can be set with stackability in mind while the first stack surface is aligned with the discharge angle, thereby realizing space saving in the stack section while ensuring stackability.

[0082] (B) Second embodiment Next, a second embodiment of a medium ejection device and an image forming apparatus according to the present disclosure will be described in detail with reference to the drawings.

[0083] (B-1) Configuration of the second embodiment The image forming apparatus of the second embodiment is basically the same as the image forming apparatus 100 of the first embodiment, but the configuration of the first stack portion and the protrusion portion in the media accumulation unit differs from that of the first embodiment.

[0084] Therefore, the second embodiment will also be described using Figures 1 to 7 of the first embodiment, and the configurations of the first stack portion 12A and the protruding portion 11A will be described in detail using Figures 8 and 9. In the second embodiment, these are referred to as the first stack portion 12A and the protruding portion 11A.

[0085] FIG. 8 is a configuration diagram showing the configuration of a first stack portion 12A and a protruding portion 11A according to the second embodiment.

[0086] 8, the first stack unit 12A of the second embodiment has a first stack surface 121, a slide guide unit 124, a fitting unit 125 provided at an end of the slide guide unit 124, and a biasing member 126.

[0087] The protruding portion 11A in the second embodiment is, for example, a plate-like member, and has a tip 111 and a plurality of fitted portions 113.

[0088] For example, the first stack section 12A is a hollow plate-like member, and has a first stack surface 121 as an upper member and a slide guide section 124 as a lower member.

[0089] The protruding portion 11A is inserted into a first stack portion 12A of the hollow member, and is configured to be slidable in the transport direction of the medium P or the opposite direction.

[0090] The protrusion 11A, which can slide relative to the first stack section 12A, has a plurality of mating portions 113 on one surface (e.g., the bottom surface), and as the protrusion 11A slides, one of the mating portions 113 engages with the sliding guide section 124 and mating portion 125, thereby fixing the tip 111 of the protrusion 11A at a predetermined length.

[0091] In other words, even if the length of the medium P used is different, the length of the tip 111 of the protruding portion 11A can be adjusted according to the length of the medium.

[0092] 8 shows an example in which six fitted portions 113 are provided and the length of tip 111 can be adjusted in six stages, but the number of fitted portions 113 is not limited to this. Also, in FIG. 8, fitted portions 113 are recessed and fitting portions 125 are protruding, but the opposite may be true, with fitted portions 113 being protruding and fitting portions 125 being recessed. Also, fitted portions 113 may be provided at positions that correspond to standard sizes of media, and the corresponding standard sizes may be displayed so that the user can position them.

[0093] FIG. 9 is an explanatory diagram illustrating how media are accumulated in the media accumulation unit 10 according to the second embodiment.

[0094] As shown in Fig. 9(A), when multiple media P are discharged in succession, the media P are accumulated in a bundle. If the bundle thickness (bundle height) exceeds a certain level, the media P discharged subsequently will not fit on the bundle, and will not be able to be accumulated or will fall. In addition, there is a problem that it becomes difficult to maintain the angle of the protrusion 11A due to the weight of the bundle.

[0095] Therefore, in the second embodiment, the protruding portion 11A is rotatably held relative to the first stack portion 12A, and the pressing force (biasing force) of the biasing member 126 supports the protruding portion 11A from below toward above.

[0096] 9(B), even if a large number of media P are discharged and the stack of media P is accumulated on protruding portion 11A, protruding portion 11A can rotate gently in the direction of arrow A (i.e., from top to bottom). Therefore, the height of the stack can be gradually lowered according to the thickness of the stack, and the accumulation of media P can be maintained.

[0097] 9(B), even if the protruding portion 11A is lowered due to the weight of the stack, the angle of the protruding portion 11A can be maintained by the biasing member 126 biasing the protruding portion 11A. Note that the biasing member 126 may not be provided and may be realized by the elastic force of the first stack portion 12A.

[0098] (B-2) Effects of the Second Embodiment As described above, according to the second embodiment, by rotating the protrusion toward the stack surface due to a certain weight of the paper stack, a targeted inflection point can be set when stacking a small number of sheets, and even if the inflection point changes depending on the height of the paper stack, the risk of the leading edge of the ejected paper generating friction on the top surface of the paper stack can be reduced.

[0099] This makes it possible to ensure stable stackability without contributing to the stack amount.

[0100] (C) Other embodiments Although various modified embodiments have been mentioned in the first and second embodiments described above, the present disclosure can also be applied to the following modified embodiments.

[0101] (C-1) Although an example of an application of the image forming apparatus according to the present disclosure to a color printer has been described, the present disclosure is not limited to this and can also be applied to devices such as copy machines and MFPs.

[0102] (C-2) As explained in the first and second embodiments above, the protrusion is not limited to being a plate-like member as exemplified in FIG. 4, but may be a rod-like member, or a rod-like member bent into a triangle, a rectangle, etc.

[0103] (C-3) In the second embodiment, the protruding portion is slidable relative to the first stack portion, but various configurations can be widely applied to the configuration of the sliding mechanism of the protruding portion. Also, the protruding portion is not limited to a sliding type, and may be one that rotates relative to the first stack portion and can be folded.

[0104] Furthermore, the protruding portion may be formed physically integrally with the first stack portion.

[0105] (C-4) In the first and second embodiments described above, the medium is a single sheet of paper, but the medium may be a roll of paper, and the cut medium may be discharged after image formation. In this case, the discharged medium may curl, but the same effects as those described in the first and second embodiments can be obtained. [Explanation of symbols]

[0106] 100...image forming apparatus, 10...medium stacking unit, 11 and 11A...protruding portion, 111...tip, 112...loading surface, 113...engaged portion, 12 and 12A...first stack portion, 121...first stack surface, 122...rotating shaft, 124...slide guide portion, 125...engaging portion, 126...urging member, 13...second stack portion, 13a and 13b...plate-shaped members, 131...second stack surface, 132...support portion, 133...rotating shaft, 20...medium storage tray, 30...medium transport path, 31...pickup roller, 32-35...transport rollers, 36...discharge roller, 36a and 36b...roller member, 40...belt unit, 41...belt support roller, 42...belt drive roller, 50 (50C, 50K, 50M, 50Y)...image forming unit, 60...fixing unit.

Claims

1. a discharge unit that discharges the medium; a loading unit capable of loading the medium discharged from the discharge unit; having The loading unit is a first portion having a first stacking surface located on a rear end side of the ejected media and an extension portion extending from the first stacking surface; a second portion having a second stacking surface located on a leading end side of the ejected medium; having The first portion extends in a first direction that slopes upward as it moves away from the discharge portion, The second portion extends in a second direction different from the first direction from between an upstream end of the first stacking surface and a downstream end of the extension portion in a direction in which the medium is discharged. A medium ejection device.

2. the first loading surface has a first width in a width direction perpendicular to the first direction, a third stacking surface formed by the extension portion and on which the medium is stacked has a second width in the width direction that is smaller than the first width, The extension portion is positioned in the middle of the area through which the medium is discharged in the width direction. The medium ejection device according to claim 1 .

3. the second stacking surfaces are formed on both ends of an area in the width direction into which the medium is discharged, The second portion is provided so as to be rotatable about a first rotation axis provided at each end in the width direction. The medium ejection device according to claim 1 .

4. The discharge unit is provided in the device body, The loading unit is The second part is rotated about the first rotation axis and then rotated about a second rotation axis relative to the device body, so that the second part can be freely stored in the device body. The medium ejection device according to claim 3 .

5. The length of the extension portion in the first direction is changeable. The medium ejection device according to claim 2 .

6. The angle at which a third stacking surface on which the media is stacked in the extension portion extends relative to the angle at which the first stacking surface extends in a direction away from the discharge portion is between −5° and +5°. The medium ejection device according to claim 2 .

7. The second placement surface is inclined upward as it moves away from the discharge portion. The medium ejection device according to claim 1 .

8. The extension portion is a rod-shaped member that is located at the center in the width direction of the medium to be discharged. The medium ejection device according to claim 1 .

9. The medium ejection device according to claim 1 , wherein the first portion is rotatably disposed relative to the first stacking portion and has a biasing member that biases the extension portion against the weight of the ejected stack of media.

10. The medium ejection device according to claim 1 ; a media tray capable of storing media; a supply unit capable of supplying media stored in the media tray; having When the length of the medium of the maximum size that can be stored in the medium tray in the supply direction of the medium by the supply unit is L_max, The length L from the end of the extension portion opposite the discharge portion to the discharge portion is L_max / 2 <L≦ L_max×2 / 3 A medium conveying device, characterized in that

11. An image forming apparatus for forming an image on a surface of a medium, comprising: an image forming unit for forming an image on the medium; a fixing unit that fixes the image formed by the image forming unit onto the medium; a medium ejection unit corresponding to the medium ejection device according to claim 1, which ejects the medium after the image is fixed by the fixing unit; An image forming apparatus comprising:

Images