Sheet feeding device and image forming apparatus

Abstract

The invention provides a sheet feeding device and an image forming apparatus. The sheet feeding apparatus includes: a stacking portion; a rotary feeding member configured to feed the sheet in a sheet feeding direction; a first separation portion including a separation surface; and a detachable unit including a second separation portion. The separating surface intersects the sheet feeding direction and intersects the rotation axis direction of the rotary feeding member, and a direction extending from the separating surface toward the rotary feeding member is defined as a protruding direction. The second separation portion is located downstream of the separation surface in the protruding direction in a state in which the detachable unit is attached to the first separation portion. In a state in which the detachable unit is attached to the first separation portion, another portion of the detachable unit other than the second separation portion is located upstream of the separation surface in the protruding direction.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a sheet feeding apparatus that feeds a sheet and an image forming apparatus including the sheet feeding apparatus. BACKGROUND

[0002] Japanese Patent Application Publication No. 2022-001517 proposes a sheet feeding apparatus that includes an inclined member including an inclined surface and a separation sheet unit that is detachably attached to the inclined member. The separation sheet unit includes a plurality of separation sheets and a support portion that supports the plurality of separation sheets. The support portion includes a top surface that is formed flush with the inclined surface in a state where the separation sheet unit is attached to the inclined member. A sheet fed by a feeding roller slides on the inclined surface of the inclined member, the top surface of the support portion, and the plurality of separation sheets of the separation sheet unit, so that the sheet is separated one by one from other sheets.

[0003] The plurality of separation sheets described in Japanese Patent Application Publication No. 2022-001517 are formed to protrude more than the inclined surface of the inclined member and the top surface of the support portion that supports the separation sheets. Therefore, the plurality of separation sheets are worn out earlier than the inclined surface of the inclined member and the top surface of the support portion, both of which serve as separation surfaces. The separation sheet unit is a unit in which the support portion and the plurality of separation sheets are integrally formed with each other. Therefore, in a case where one separation sheet unit is replaced by another separation sheet unit, the top surface of the support portion that has not been worn out is also replaced by the top surface of another support portion along with the replacement of the one separation sheet unit. SUMMARY

[0004] According to a first aspect of the present disclosure, a sheet feeding apparatus includes: a stacking portion on which sheets are stacked; a rotary feeding member configured to feed the sheets stacked on the stacking portion toward an image forming portion in a sheet feeding direction; a first separation portion including a separation surface that is disposed to be in contact with the sheets fed by the rotary feeding member; and a detachable unit that is detachably attached to the first separation portion, the detachable unit including a second separation portion that is in contact with the sheets fed by the rotary feeding member to separate the sheets one by one together with the separation surface. A direction intersecting the sheet feeding direction, intersecting a direction of an axis of rotation of the rotary feeding member, and extending from the separation surface toward the rotary feeding member is defined as a protruding direction. In a state where the detachable unit is attached to the first separation portion, the second separation portion is located downstream of the separation surface in the protruding direction. In the state where the detachable unit is attached to the first separation portion, another portion of the detachable unit other than the second separation portion is located upstream of the separation surface in the protruding direction.

[0005] According to a second aspect of the present disclosure, a sheet feeding apparatus includes a stack portion on which sheets are stacked, a rotary feeding member configured to feed the sheets stacked on the stack portion toward an image forming portion in a sheet feeding direction, a first separation portion including a separation surface provided to be in contact with the sheets fed by the rotary feeding member, and a detachable unit detachably attached to the first separation portion, the detachable unit including a second separation portion in contact with the sheets fed by the rotary feeding member to separate the sheets one by one together with the separation surface. A direction intersecting the sheet feeding direction and intersecting a direction of an axis of rotation of the rotary feeding member and extending from the separation surface toward the rotary feeding member is defined as a protruding direction. In a state where the detachable unit is attached to the first separation portion, the second separation portion is located downstream of the separation surface in the protruding direction. In the state where the detachable unit is attached to the first separation portion, another portion of the detachable unit other than the second separation portion is configured not to be in contact with the sheets fed by the rotary feeding member.

[0006] The features of the present disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. The following description of the embodiments is described with examples. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a whole schematic view of an image forming apparatus of a first embodiment.

[0008] Figure 2A is a perspective view of a sheet feeding apparatus in a state where a cartridge is attached to an apparatus main body.

[0009] Figure 2B is a perspective view of a cartridge detached from an apparatus main body and a surrounding configuration of the cartridge.

[0010] Figure 3A is a perspective view of a sheet separation unit attached to a separation wall.

[0011] Figure 3B is a perspective view of a state where the sheet separation unit is being detached from the separation wall.

[0012] Figure 3C is a perspective view of a state where the sheet separation unit has been detached from the separation wall.

[0013] Figure 4 is a perspective view of a state where a part of the sheet separation unit attached to the separation wall is cut off.

[0014] Figure 5A is a perspective view of a sheet separation unit of a second embodiment.

[0015] Figure 5Bis a perspective view showing a state in which the sheet separation unit is detached from the separation wall.

[0016] Figure 6 is a perspective view showing a state in which a part of the sheet separation unit attached to the separation wall is cut off.

[0017] Figure 7A is a perspective view showing a state in which the locking member and the sheet separation unit of the third embodiment are assembled to the separation wall.

[0018] Figure 7B is a perspective view showing a state in which the locking member and the sheet separation unit are detached from the separation wall.

[0019] Figure 8A is a perspective view showing a state in which the cover of the fourth embodiment is located in the closed position.

[0020] Figure 8B is a perspective view showing a state in which the cover is located in the open position.

[0021] Figure 8C is a perspective view showing a state in which the sheet separation unit is detached from the separation wall.

[0022] Figure 9A is a perspective view showing a state in which the cover of the fifth embodiment is located in the closed position.

[0023] Figure 9B is a perspective view showing a state in which the cover is located in the open position.

[0024] Figure 9C is a perspective view showing a state in which the sheet separation unit is detached from the separation wall.

[0025] Figure 10 is a perspective view showing a state in which a part of the sheet separation unit and the cover attached to the separation wall are cut off.

[0026] Figure 11A is a perspective view showing a modification of the fifth embodiment in which the separation wall and the sheet separation unit are provided in the device main body.

[0027] Figure 11B is a perspective view showing a modification of the fifth embodiment in a state in which the cassette is pulled out in the direction indicated by the arrow B.

[0028] Figure 12A is a perspective view showing a state in which the cover of the sixth embodiment is located in the closed position.

[0029] Figure 12B is a perspective view showing a state in which the cover is located in the open position.

[0030] Figure 12Cis a perspective view showing a state in which the sheet separation unit is detached from the separation wall.

[0031] Figure 13 is a diagram showing one example of an image forming apparatus having a configuration of the sixth embodiment.

[0032] Figure 14A is a diagram showing a positional relationship among the sheet separation portion, the separation slope, and the inclined surface of the first embodiment.

[0033] Figure 14B is a diagram showing a state in which the sheets are separated one by one from other sheets by the sheet separation portion and the separation slope. DETAILED DESCRIPTION

[0034] First Embodiment

[0035] Overall Configuration

[0036] First, the first embodiment of the present disclosure will be described. The image forming apparatus 1 is an electrophotographic laser beam printer. As shown in Figure 1 the image forming apparatus 1 includes an image forming portion 80 that forms an image on a sheet S, a sheet feeding device 90, and a fixing device 31. Note that examples of the image forming apparatus include a printer, a copier, a facsimile, and a multifunction printer, and the image forming apparatus forms an image on a sheet serving as a recording medium in accordance with image information transmitted from an external personal computer or read from a file. In addition, there are cases where an auxiliary device such as an optional feeder, an image reading device, or a sheet processing device is attached to a main body of the image forming apparatus having an image forming function. In this case, the entire system in which the auxiliary device is attached to the main body of the image forming apparatus is also a type of the image forming apparatus.

[0037] The image forming portion 80 includes four process cartridges PY, PM, PC, and PK, and a scanner 21. The four process cartridges form yellow (Y), magenta (M), cyan (C), and black (K) four-color toner images, respectively.

[0038] Note that the four process cartridges PY, PM, PC, and PK have the same configuration except that they generate images of different colors. Therefore, only the configuration and the image forming process of the process cartridge PY will be described, and the description of the process cartridges PM, PC, and PK will be omitted.

[0039] The process cartridge PY includes a photosensitive drum 22, a charging roller (not shown), and a developing roller 23. The photosensitive drum 22 has an organic photoconductive layer coated on the outer surface of an aluminum cylinder, and is driven to rotate by a drive motor (not shown). In addition, the image forming section 80 includes an intermediate transfer belt 25 wound around a drive roller 25a and a tension roller 25b, and primary transfer rollers 24Y, 24M, 24C, and 24K provided on the inner side of the intermediate transfer belt 25.

[0040] The fixing device 31 includes a fixing roller 31a heated by a heater (not shown), and a pressure roller 31b in pressure contact with the fixing roller 31a. The sheet feeding device 90 is provided in the lower portion of the image forming apparatus 1, and includes a cassette 11 that supports a sheet S, and a pickup roller 12 that is a rotating feeding member that feeds the sheet S. Examples of the sheet S can include paper such as a sheet for various uses or an envelope, a plastic film such as a sheet for an overhead projector (OHP), and a cloth sheet. In addition, a feeding belt can be used instead of the pickup roller 12. For example, the feeding belt can convey the sheet while using air suction to adhere the sheet.

[0041] Next, the image forming operation of the image forming apparatus 1 configured in this way will be described. If the scanner 21 receives an image signal from an apparatus such as a personal computer (not shown), the scanner 21 emits a laser beam generated in accordance with the image signal to the photosensitive drum 22 of the process cartridge PY.

[0042] Since the surface of the photosensitive drum 22 has been uniformly charged with a predetermined polarity and potential by the charging roller in advance, if the surface is irradiated with the laser beam from the scanner 21, an electrostatic latent image is formed on the surface of the photosensitive drum 22. The electrostatic latent image formed on the photosensitive drum 22 is developed by the developing roller 23, so that a yellow (Y) toner image is formed on the photosensitive drum 22.

[0043] Similarly, the photosensitive drums of the process cartridges PM, PC, and PK are also irradiated with the laser beam from the scanner 21, so that magenta (M), cyan (C), and black (K) toner images are formed on the respective photosensitive drums. The respective color toner images formed on the respective photosensitive drums are transferred to the intermediate transfer belt 25 by the primary transfer rollers 24Y, 24M, 24C, and 24K, and are conveyed to the secondary transfer roller 26 by the intermediate transfer belt 25 driven to rotate by the drive roller 25a. Note that the image forming process for a single color is performed at the time when the corresponding color toner image is superimposed on the upstream toner image that has been primarily transferred to the intermediate transfer belt 25.

[0044] Meanwhile, the sheet S stored in the cassette 11 of the sheet feeding device 90 is fed by the pickup roller 12 and conveyed to the registration roller pair 15 via the conveyance guide 10 and the conveyance roller pair 14. The skew of the sheet S is corrected by the registration roller pair 15, and then the sheet S is conveyed at a predetermined conveyance timing. Then, the full-color toner image on the intermediate transfer belt 25 is transferred onto the sheet S by applying a secondary transfer bias to the secondary transfer roller 26.

[0045] Then, the sheet S on which the toner image has been transferred is applied with predetermined heat and pressure by the fixing roller 31a and the pressure roller 31b of the fixing device 31, so that the toner is melted and fixed (fused). The sheet S that has passed through the fixing device 31 is discharged to the discharge tray 34 by the discharge roller pair 32.

[0046] Sheet feeding device

[0047] Next, with reference to Figures 2A-4 The sheet feeding device 90 is described. Figure 2A is a perspective view showing the sheet feeding device 90 in a state in which the cassette 11 is attached to the device main body 1A. Figure 2B is a perspective view showing the cassette 11 and the surrounding configuration of the cassette 11 detached from the device main body 1A. Figure 3A is a perspective view showing the sheet separation unit 62 attached to the separation wall 60. Figure 3B is a perspective view showing a state in which the sheet separation unit 62 is being detached from the separation wall 60. Figure 3C is a perspective view showing a state in which the sheet separation unit 62 has been detached from the separation wall 60. Figure 4 is a perspective view showing a state in which a part of the sheet separation unit 62 attached to the separation wall 60 is cut off.

[0048] As shown in Figure 1 and Figure 2A The cassette 11 of the sheet feeding device 90 is attached to the device main body 1A of the image forming device 1 so that the cassette 11 can be pulled out from the device main body 1A. The cassette 11 of the present embodiment can be pulled out toward the front of the paper surface. Figure 1 The cassette 11 as a pull-out unit includes the cassette frame 9, the tray 50, the separation wall 60, and the sheet separation unit 62. The tray 50 serves as a stacking portion on which the sheets S are stacked.

[0049] As shown in Figure 2AAs shown, the device main body 1A includes a roller rotation shaft 12s that is rotatably supported. In addition, the pickup arm 12a is pivotally supported by the roller rotation shaft 12s. The pickup arm 12a rotatably supports the pickup roller 12. In addition, the device main body 1A includes a roller drive shaft 44 that is driven and rotated by the motor Ml. A gear 45 is fixed to the roller drive shaft 44, and in a state in which the cassette 11 is attached to the device main body 1A, rotation of the gear 45 is transmitted to the pickup roller 12 via an idler gear train 43, the roller rotation shaft 12s, and a pickup gear train 42.

[0050] Further, a lift input shaft 54 is rotatably supported by one end portion of the cassette frame 9. In a state in which the cassette 11 is attached to the device main body 1A, the lift input shaft 54 is driven and rotated by a lift motor M2 provided in the device main body 1A. In addition, a lift input gear 53 is fixed to the lift input shaft 54, and engages with a sector-shaped lift gear 51. The lift gear 51 rotates together with a lift plate 51a provided below the tray 50. The tray 50 is pressed upward by the lift plate 51a by rotation of the lift plate 51a driven by the lift motor M2, and is pivoted upward about a pivot shaft 50a. By this operation, the sheet S stacked on the tray 50 is lifted to a position at which the sheet S can be fed by the pickup roller 12.

[0051] Next, the configuration of components of the sheet feed device 90 near the separation wall 60 will be described with reference to Figures 2B-4 It should be noted that Figure 4 is a perspective view for describing the configuration of components near the separation wall 60. In Figure 4 , Figure 3A A portion of the upper portion of the separation wall 60 shown is cut away, and the remaining portion of the separation wall 60 is viewed from the side opposite the side from which the separation wall 60 is viewed Figure 3A The remaining portion of the separation wall 60 is viewed from the side opposite the side from which the separation wall 60 is viewed

[0052] As shown in Figure 2B and Figure 3A The cassette frame 9 of the cassette 11 holds the separation wall 60. The separation wall 60, which is a first separation portion, includes a separation slope 60a that is a separation surface, which is provided so as to be contactable with the sheet S fed by the pickup roller 12. As shown in Figure 3CAs shown, the separation ramp 60a includes a first inclined surface 30L and a second inclined surface 30R arranged side by side in the width direction W described below. An opening 66 is formed between the first inclined surface 30L and the second inclined surface 30R in the separation wall 60. The opening 66 opens in a direction perpendicular to the separation ramp 60a, that is, it opens downstream in the protrusion direction PD described below. The sheet separation unit 62, described below, is inserted into the opening 66. It should be noted that the separation wall 60 may not be a single component. For example, the separation wall 60 may be composed of a first component including the first inclined surface 30L and a second component including the second inclined surface 30R. In other cases, the separation wall may include other components besides the first and second components.

[0053] A pair of retaining parts 65L and 65R are attached to the opening 66. In the following description, as... Figure 2A and Figure 2B As shown, the width direction of the sheet S, which is orthogonal to the sheet feed direction FD (which is the direction in which the pick-up roller 12 feeds the sheet S), is called the width direction W. In other words, the width direction W intersects the sheet feed direction FD. Furthermore, the width direction W is parallel to the rotation axis of the pick-up roller 12; that is, the width direction W is the direction of the rotation axis of the pick-up roller 12. For a pair of components arranged side-by-side in the width direction W, from the perspective of the separation slope 60a, the component on the left is labeled with the symbol "L," and the component on the right is labeled with the symbol "R." Since each component in a pair has the same construction, only one component of this pair is described, and the description of the other component is appropriately omitted.

[0054] Both retaining components 65L and 65R have a sheet contact surface 65a. The sheet contact surface 65a is located upstream of the separation ramp 60a in the protrusion direction PD. The protrusion direction PD intersects the feed direction FD and the width direction W, and extends from the separation ramp 60a toward the pick-up roller 12. In other words, the sheet contact surface 65a is located further away from the feed path 17 in the protrusion direction PD than the separation ramp 60a (see...). Figure 1 The feeding path 17 serves as the conveying path for the sheet S fed by the pick-up roller 12. That is, the sheet contact surface 65a is located upstream of the separation ramp 60a in the protruding direction PD. Therefore, the sheet contact surface 65a hardly obstructs the contact between the sheet S and the separation ramp 60a.

[0055] The retaining members 65L and 65R, which act as limiting components, are supported by the separation wall 60, allowing the retaining members 65L and 65R to move in the width direction W. Specifically, the retaining members 65L and 65R can... Figure 3A The position shown is the same as Figure 3B andFigure 3C The sheet separating unit 62 slides between the indicated separation positions. In the holding position, the holding members 65L and 65R hold the sheet separating unit 62 to prevent it from being removed from the separating wall 60 after being inserted into the opening 66. By sliding the holding member 65L in the direction indicated by arrow A1 and the holding member 65R in the direction indicated by arrow A2, the holding members 65L and 65R move to... Figure 3B and Figure 3C The separation positions are shown. Arrow A1 indicates a direction parallel to the width direction W, and the retaining member 65L separates from the retaining member 65R in this direction. Arrow A2 indicates a direction parallel to the width direction W, and the retaining member 65R separates from the retaining member 65L in this direction. The retaining position, as a limiting position, is a position closer to the center of the separating wall 60 in the width direction W. The separation position, as a permissible position, is a position further away from the center of the separating wall 60 in the width direction W compared to the retaining position. That is, the retaining members 65L and 65R move from the retaining position toward the separation position in the direction in which the retaining members 65L and 65R separate from each other.

[0056] The retaining members 65L and 65R cover a portion of the opening 66 in the retaining position, and increase the opening area of ​​the opening 66 by moving from the retaining position to the separating position. Therefore, in the separating position, the retaining members 65L and 65R release the sheet separating unit 62 and allow the sheet separating unit 62 to be detached from the separating wall 60.

[0057] The sheet separation unit 62 includes a pair of sheet separation portions 63L and 63R, which are detachably attached to the separation wall 60 and, together with the separation ramp 60a, separate the sheets S one by one by contacting the sheets S fed by the pick-up roller 12. The sheet separation portions 63L and 63R are located downstream of the separation ramp 60a in the protrusion direction PD. In other words, with the sheet separation unit 62 attached to the separation wall 60, the sheet separation portions 63L and 63R protrude further toward the feed path 17 than the separation ramp 60a. Therefore, the sheet separation portions 63L and 63R more easily abut against the sheets S passing through the feed path 17 compared to the separation ramp 60a.

[0058] It should be noted that in this embodiment, a pair of sheet separation portions 63L and 63R constitute the sheet separation portion 63 as the second separation portion. The sheet separation portion 63 may not be a pair of sheet separation portions 63L and 63R. For example, the sheet separation portion 63 may be composed of a single sheet separation portion or three or more sheet separation portions. Preferably, one or more sheet separation portions are arranged symmetrically about the center of the feed path 17 in the width direction W.

[0059] In this embodiment, asFigure 3C As shown, the sheet separation unit 62, which is a detachable unit, includes a first end FE and a second end SE formed in the width direction W. A sheet separation section 63L, serving as a first sheet separation section, is located closer to the first end FE than the second end SE. A sheet separation section 63R, serving as a second sheet separation section, is located closer to the second end SE than the first end FE. The sheet separation sections 63L and 63R are symmetrically arranged about the center of the feed path 17 in the width direction W.

[0060] Furthermore, the sheet separation unit 62 includes an inclined surface 62e disposed in the width direction W between a pair of sheet separation portions 63L, 63R. The inclined surface 62e is located upstream of the separation ramp 60a in the protrusion direction PD. In other words, the amount of protrusion of the inclined surface 62e toward the feed path 17 is less than the amount of protrusion of the separation ramp 60a toward the feed path 17. Therefore, although the inclined surface 62e faces the feed path 17, the inclined surface 62e does not abut against the sheet S passing through the feed path 17. In addition, when the sheet separation unit 62 is attached to the separation wall 60, the portion of the sheet separation unit 62, excluding the sheet separation portions 63L, 63R and including the inclined surface 62e, does not contact the sheet S fed by the pick-up roller 12. This is because when the sheet separation unit 62 is attached to the separation wall 60, the portion of the sheet separation unit 62, excluding the sheet separation portions 63L, 63R, is upstream of the separation ramp 60a in the protrusion direction PD.

[0061] Incidentally, the separation slope 60a of the separation wall 60 alone is insufficient to separate sheets with low rigidity (basis weight), such as thin paper, from other sheets individually. Therefore, to improve the separation performance of the sheet S, the sheet separation portions 63L and 63R both have surfaces with protrusions and depressions, or are made of a material with a coefficient of friction higher than that of the separation slope 60a and the sheet contact surface 65a. Thus, if a sheet S with low rigidity, such as thin paper, is fed by the pickup roller 12 and conveyed via the feed path 17, and is in contact with the sheet separation portions 63L and 63R in addition to contacting the separation slope 60a, then the sheet S is also separated from other sheets individually.

[0062] It should be noted that, in this embodiment, the sheet separation portions 63L and 63R are defined as the portions of the sheet separation unit 62 that protrude more towards the feed path 17 in the protrusion direction PD compared to the separation ramp 60a, when the sheet separation unit 62 is attached to the separation wall 60. Preferably, at least a portion of the sheet separation portions 63L and 63R has a greater coefficient of friction than the separation ramp 60a. For example, the separation ramp 60a may be made of a resin material, and at least a portion of the sheet separation portions 63L and 63R may be made of a material such as rubber, which has a greater coefficient of friction than the resin material. In this case, if only the rubber-made portion of the sheet separation portions 63L and 63R wears, that portion of the sheet separation portions 63L and 63R can be replaced with another portion.

[0063] In this embodiment, as Figure 3C As shown, in the width direction W, the width D1 of the opening 66 is longer than the distance D2 between the sheet separation portion 63L, which serves as the first separation piece, and the sheet separation portion 63R, which serves as the second separation piece. Therefore, since the opening 66 has a large opening area, the sheet separation unit 62 can be easily attached to the opening 66, thereby improving the operability of replacing the sheet separation unit 62.

[0064] like Figure 3B and Figure 4 As shown, the abutment portions 61L and 61R, and the propulsion member 64 are disposed near the opening 66 and on the rear side of the separation slope 60a of the separation wall 60. The sheet separation unit 62 includes a pair of unit abutment surfaces 62aL and 62aR, which serve as the abutted portions that can abut against the abutment portions 61L and 61R of the separation wall 60. The propulsion member 64 includes a compression coil spring 64a supported by, for example, the separation wall 60, and a plate member 64b fixed to the compression coil spring 64a and capable of abutting against the sheet separation unit 62.

[0065] The unit abutment surfaces 62aL and 62aR of the sheet separation unit 62 abut against the abutment portions 61L and 61R of the separation wall 60 when the sheet separation unit 62 is inserted into the opening 66 and advanced by the pushing member 64. In this way, the sheet separation unit 62 is positioned relative to the separation wall 60. In other words, with the sheet separation unit 62 attached to the separation wall 60, the pushing member 64 advances the sheet separation unit 62 toward the feed path 17 in the protrusion direction PD. In this state, the unit abutment surfaces 62aL and 62aR are located upstream of the abutment portions 61L and 61R in the protrusion direction PD.

[0066] The surfaces of the sheet separation sections 63L and 63R wear due to sliding friction between them and the sheet S. If the wear of the sheet separation sections 63L and 63R increases, the uneven surface shape of the sections becomes flat, reducing the resistance to separation and decreasing the height of the sections. Therefore, it becomes impossible to maintain the proper protrusion of the sheet separation sections 63L and 63R relative to the separation ramp 60a, leading to a deterioration in separation performance. Therefore, if many sheets S have been fed and the separation performance has deteriorated due to the wear of the sheet separation sections 63L and 63R, the sheet separation unit 62, including the sheet separation sections 63L and 63R, needs to be replaced with another sheet separation unit.

[0067] Replacement of sheet separation unit

[0068] Next, refer to Figures 3A-3C Describe a method for replacing the sheet separation unit 62. For example... Figure 3A As shown, in order to remove the sheet separation unit 62 from the separation wall 60 of the box 11, the user approaches the sheet separation unit 62 from the side facing the separation ramp 60a. With the sheet separation unit 62 attached to the separation wall 60, the sheet separation unit 62 is restricted from being removed from the separation wall 60 by the retaining members 65L and 65R located in the retaining position.

[0069] In the following description, the side closer to the center of the feed path 17 in the width direction W is referred to as the inner side, while the side farther from the center of the feed path 17 in the width direction W is referred to as the outer side. Figure 4 As shown, with the sheet separation unit 62 attached to the separation wall 60, the end portion 621L of the unit abutment surface 62aL is located outside the edge portion 611L of the abutment portion 61L in the width direction W. Similarly, the end portion 621R of the unit abutment surface 62aR is located outside the edge portion 611R of the abutment portion 61R in the width direction W. That is, in the width direction W, the distance D5 between the end portions 621L and 621R is longer than the gap between the edge portions 611L and 611R, meaning the distance D5 between the end portions 621L and 621R is longer than the width D1 of the opening 66. Therefore, the sheet separation unit 62 is advanced by the pushing member 64 in the protruding direction PD, causing the unit abutment surfaces 62aL and 62aR to press against the abutment portions 61L and 61R and be held by the separation wall 60.

[0070] Furthermore, when the retaining components 65L and 65R are in the retaining position, the distance D6 between the retaining components 65L and 65R in the width direction W is shorter than the width D1 and the distance D5. In this case, the width of the opening 66 is not the aforementioned width D1, but the distance D6. If the retaining components 65L and 65R are in the retaining position and the width of the opening 66 is the distance D6, even if the orientation of the sheet separation unit 62 changes in the space SP where the push member 64 is provided, the unit abutment surfaces 62aL and 62aR will not pass through the opening 66. Therefore, the removal of the sheet separation unit 62 from the separation wall 60 is restricted. If the retaining components 65L and 65R are in the separation position and the width of the opening 66 is the width D1, if the orientation of the sheet separation unit 62 changes in the space SP where the push member 64 is provided, the unit abutment surfaces 62aL and 62aR can pass through the opening 66.

[0071] First, the user orients the retaining component 65L, which is in the retaining position, towards... Figure 3B The arrow A1 indicates the direction of movement, and the retaining member 65R in the holding position is oriented towards... Figure 3B The retaining members 65L and 65R are moved in the direction indicated by arrow A2 to position them in the separated position. This operation increases the opening area of ​​the opening 66. In other words, the width of the opening 66 in the width direction W increases from a distance D6 to a width D1. In this way, the sheet separation unit 62 is released from the locking of the retaining members 65L and 65R.

[0072] Then, the user changes the orientation of the sheet separation unit 62 by pressing it into the space SP, overcoming the thrust of the propulsion component 64. Specifically, the user presses the sheet separation unit 62, causing the unit abutment surfaces 62aL, 62aR to separate from the abutment portions 61L, 61R of the separation wall 60. Furthermore, the user tilts the sheet separation unit 62 relative to the protrusion direction PD and the width direction W, thus pulling one of the unit abutment surfaces 62aL, 62aR out of the opening 66. Afterward, the user pulls the entire sheet separation unit 62 out of the opening 66 by pulling the other of the unit abutment surfaces 62aL, 62aR out of the opening 66. In this way, as... Figure 3C As shown, the sheet separation unit 62 is removed from the separation wall 60.

[0073] To assemble the sheet separating unit 62 onto the separating wall 60, the above process is performed in the reverse order of removing the sheet separating unit 62 from the separating wall 60. First, with components 65L and 65R in the separated position, the user inserts the sheet separating unit 62 into the opening 66. In this operation, the user first inserts one of the unit abutment surfaces 62aL and 62aR into the opening 66 by tilting the sheet separating unit 62 relative to the protrusion direction PD and the width direction W. Then, the user inserts the other of the unit abutment surfaces 62aL and 62aR into the opening 66 while simultaneously returning the sheet separating unit 62 to a position where it is positioned parallel to the width direction W. Through this operation, the sheet separating unit 62 is inserted into the opening 66 until it reaches the position where the unit abutment surfaces 62aL and 62aR face the abutment portions 61L and 61R of the separating wall 60.

[0074] The user then moves the retaining components 65L and 65R to the retaining position, thereby preventing the sheet separating unit 62 from detaching from the separating wall 60. In this case, if the user removes their hand from the sheet separating unit 62, the sheet separating unit 62 is pushed forward by the pushing component 64, causing the unit abutting surfaces 62aL and 62aR to abut the abutting portions 61L and 61R. In this way, the sheet separating portions 63L and 63R of the sheet separating unit 62 are positioned with high precision relative to the separating wall 60.

[0075] As described above, in this embodiment, with the sheet separation unit 62 attached to the separation wall 60, the portion of the sheet separation unit 62 other than the sheet separation portions 63L and 63R does not contact the sheet S fed by the pick-up roller 12.

[0076] Next, we will refer to Figure 14A and Figure 14B The positional relationship between the sheet separation sections 63L and 63R, the separation slope 60a, and the inclined surface 62e is described when the sheet separation unit 62 is attached to the separation wall 60. Figure 14A This is a diagram showing the positional relationship between the sheet separation portions 63L and 63R, the separation slope 60a, and the inclined surface 62e of the first embodiment. Figure 14B This diagram shows the state in which the sheet is separated from other sheets one by one by the sheet separation sections 63L and 63R and the separation slope 60a. Figure 14A and Figure 14B This is a diagram showing the sheet separation sections 63L and 63R, the separation slope 60a, and the inclined surface 62e viewed in the width direction W.

[0077] like Figure 14AAs shown, the sheet separating portions 63L and 63R of the sheet separating unit 62 protrude more in the protrusion direction PD compared to the separating inclined surface 60a. Furthermore, the inclined surface 62e of the sheet separating unit 62 is located upstream of the separating inclined surface 60a in the protrusion direction PD. Additionally, as... Figure 3A As shown, the inclined surface 62e of the sheet separation unit 62 is disposed between the sheet separation portions 63L and 63R in the width direction W. The first inclined surface 30L of the separation inclined surface 60a is disposed on the outer side of the sheet separation portion 63L, while the second inclined surface 30R is disposed on the outer side of the sheet separation portion 63R.

[0078] Therefore, as Figure 14B As shown, if a sheet S1, such as thin paper or ordinary paper, is fed by the pick-up roller 12, the sheet S1 is conveyed along the sheet feeding direction FD while in contact with the sheet separating sections 63L and 63R. In this case, the sheet S2 below the sheet S1 can be fed together with the top sheet S1. The sheet S2, fed together with the sheet S1, comes into contact with the sheet separating sections 63L and 63R. The frictional force between the sheet separating sections 63L and 63R and the sheet S2 is greater than the frictional force between the sheet S1 and the sheet S2. Therefore, the sheet S2 is intercepted by the sheet separating sections 63L and 63R, and only the sheet S1 is fed by the pick-up roller 12. In this way, the sheet S1 and the sheet S2 are separated.

[0079] Furthermore, when conveying high-rigidity sheets such as thick paper, the sheet separation sections 63L and 63R are pressed by the fed sheet. Therefore, the sheet separation unit 62 can overcome the thrust of the pushing member 64 and move upstream in the protruding direction PD. Even in this case, because the separation ramp 60a bears the load of the sheet, the sheet separation sections 63L and 63R will not move upstream of the separation ramp 60a in the protruding direction PD. In other words, the sheet can be separated from other sheets one by one by the sheet separation sections 63L and 63R, which become flush with each other, and the separation ramp 60a.

[0080] Therefore, the only parts of the sheet separation unit 62 that wear due to sliding friction between the sheet separation unit 62 and the sheet S are the sheet separation portions 63L and 63R. Therefore, the sheet separation unit 62 is replaced with another sheet separation unit only when the sheet separation portions 63L and 63R need replacement. Thus, the sheet separation unit 62 can be replaced with another sheet separation unit while the separation wall 60, including the separation ramp 60a, is retained in the sheet feeding device 90 (device body 1A). Furthermore, the sheet separation unit 62 can be replaced with another sheet separation unit at an appropriate time. In other words, the timing of the replacement of the sheet separation unit 62 by another sheet separation unit is not affected by any part of the sheet separation unit 62 other than the sheet separation portions 63L and 63R. That is, it is possible to prevent any component of the sheet separation unit 62 other than the sheet separation portions 63L and 63R that does not need replacement from being replaced by another component. In addition, since the sheet separation unit 62 does not include an inclined surface flush with the separation slope 60a, the size and cost of the sheet separation unit 62 can be reduced.

[0081] Furthermore, in this embodiment, the sheet separating unit 62 can be easily attached to and removed from the separating wall 60 simply by sliding the holding members 65L and 65R in the width direction W. Additionally, the sheet separating unit 62 is advanced by the pushing member 64, and with the sheet separating unit 62 attached to the separating wall 60, the unit abutting surfaces 62aL and 62aR abut against the abutting portions 61L and 61R. Therefore, the sheet separating unit 62 is positioned with high precision relative to the separating wall 60. Through this operation, the accuracy of the relative position between the sheet separating portions 63L and 63R and the separating inclined surface 60a is increased, and the sheet separating portions 63L and 63R are located at positions that protrude more towards the feed path 17 in the protrusion direction PD compared to the separating inclined surface 60a. Therefore, sheet S can be reliably separated from other sheets one by one through sheet separation sections 63L, 63R and separation slope 60a, and failures during conveying, such as multiple feeds, can be reduced.

[0082] The thrust of the pushing member 64 is set to be greater than the contact pressure generated when a sheet S with low stiffness, such as thin paper, contacts the sheet separation unit 62, and less than the contact pressure generated when a sheet S with high stiffness, such as thick paper, contacts the sheet separation unit 62. Therefore, when the sheet separation unit 62 is pressed by a sheet S with high stiffness (basis weight), such as thick paper, the sheet separation unit 62 can overcome the thrust of the pushing member 64 and move in the direction separating the unit abutment surfaces 62aL, 62aR from the abutment portions 61L, 61R. In this case, since the separation slope 60a bears the load of the sheet S even when the high-stiffness sheet S is conveyed, it is possible to prevent the sheet separation portions 63L, 63R from retracting upstream of the separation slope 60a in the protruding direction PD. Therefore, the surfaces of the sheet separation portions 63L and 63R and the separation slope 60a of the sheet separation unit 62 become flush with each other, so that the sheet S can be separated from other sheets one by one through the sheet separation portions 63L and 63R and the separation slope 60a.

[0083] It should be noted that in this embodiment, both the separation slope 60a and the sheet contact surface 65a are formed as flat surfaces. However, this disclosure is not limited thereto. For example, both the separation slope 60a and the sheet contact surface 65a may include a plurality of ribs extending along the conveying direction of the sheet S.

[0084] Second Embodiment

[0085] Next, a second embodiment of this disclosure will be described. In the second embodiment, the retaining members 65L and 65R of the first embodiment are not provided, and locking hooks 162aL and 162aR are formed in the sheet separation unit 62. Therefore, components that are the same as those in the first embodiment are omitted in the drawings, or will be described using the same reference numerals as indicated in the drawings.

[0086] Figure 5A This is a perspective view showing the sheet separation unit 162 of the second embodiment. Figure 5B This is a perspective view showing the sheet separation unit 162 removed from the separation wall 60. Figure 6 This is a perspective view showing the sheet separation unit 162 with a portion of the separation wall 60 cut off.

[0087] like Figures 5A-6 As shown, the sheet separation unit 162, which is a detachable unit, includes a pair of sheet separation portions 63L and 63R, a pair of arms 62bL and 62bR, and a pair of locking hooks 162aL and 162aR. The locking hooks 162aL and 162aR, which are abutted portions, are formed at the ends of the pair of arms 62bL and 62bR, respectively.

[0088] If the sheet separating unit 162 is inserted into the opening 66 of the separating wall 60, the locking hooks 162aL and 162aR are pressed by the edge of the opening 66, causing the arms 62bL and 62bR to elastically deform. If the sheet separating unit 162 is inserted into the opening 66 until it reaches the attachment position, the locking hooks 162aL and 162aR disengage from the edge of the opening 66, causing the arms 62bL and 62bR to elastically return to their original position. Therefore, the sheet separating unit 162 is advanced by the pushing member 64, and in the state where the sheet separating unit 162 is attached to the separating wall 60, the locking hooks 162aL and 162aR abut against and engage with the abutting portions 61L and 61R. Therefore, the sheet separating unit 162 is positioned relative to the separating wall 60 with high precision. In addition, since the locking hooks 162aL and 162aR are locked by the abutment portions 61L and 61R, the sheet separation unit 162 is restricted from being removed from the separation wall 60.

[0089] Similarly, in this embodiment, with the sheet separation unit 162 attached to the separation wall 60, the portion of the sheet separation unit 162 other than the sheet separation portions 63L and 63R does not contact the sheet S fed by the pick-up roller 12.

[0090] Therefore, the same effect as the first embodiment can be achieved with a simple construction. When the sheet separation unit 162 is removed from the separation wall 60, the user can pull the sheet separation unit 162 out from the opening 66 by elastically deforming the arms 62bL and 62bR to move the arms 62bL and 62bR closer to each other.

[0091] Third Embodiment

[0092] Next, a third embodiment of this disclosure will be described. In the third embodiment, locking members 70L and 70R are provided instead of the retaining members 65L and 65R of the first embodiment. Therefore, components identical to those in the first embodiment are omitted in the drawings, or will be described using the same reference numerals as indicated in the drawings.

[0093] Figure 7A This is a perspective view showing the locking components 70L, 70R and the sheet separation unit 62 of the third embodiment assembled to the separation wall 60. Figure 7B This is a perspective view showing the locking components 70L, 70R and the sheet separation unit 62 removed from the separation wall 60.

[0094] like Figure 7A and Figure 7BAs shown, locking components 70L and 70R, which serve as limiting components, are detachably fixed to the separation wall 60 via screws 71L and 71R. With the sheet separation unit 62 assembled to the separation wall 60, the user inserts the sheet separation unit 62 into the opening 66 with the locking components 70L and 70R removed from the separation wall 60. In this case, the user inserts the sheet separation unit 62 into the opening 66 until the sheet separation unit 62 reaches the position where the unit abutment surfaces 62aL and 62aR of the sheet separation unit 62 face the abutment portions 61L and 61R of the separation wall 60.

[0095] The user then secures the locking components 70L and 70R to the separation wall 60, preventing the sheet separation unit 62 from detaching from the separation wall 60. In this case, if the user removes their hand from the sheet separation unit 62, the sheet separation unit 62 is advanced by the pushing component 64, causing the unit abutment surfaces 62aL and 62aR to abut the abutment portions 61L and 61R. In this way, the sheet separation portions 63L and 63R of the sheet separation unit 62 are positioned with high precision relative to the separation wall 60. Through this operation, the accuracy of the relative position between the sheet separation portions 63L and 63R and the separation ramp 60a is increased, and the sheet separation portions 63L and 63R are located at a position where they protrude more towards the feed path 17 in the protrusion direction PD compared to the separation ramp 60a. Therefore, sheet S can be reliably separated from other sheets one by one through sheet separation sections 63L, 63R and separation slope 60a, and failures during conveying, such as multiple feeds, can be reduced.

[0096] In addition, since the locking components 70L and 70R are securely fixed to the separation wall 60 by screws 71L and 71R, the sheet separation unit 62 is not easily removed from the separation wall 60 except when the sheet separation unit 62 is replaced by another sheet separation unit.

[0097] Fourth embodiment

[0098] Next, a fourth embodiment of this disclosure will be described. In the fourth embodiment, a cover 67 is provided instead of the retaining members 65L and 65R of the first embodiment. Therefore, components identical to those in the first embodiment are omitted in the drawings, or will be described using the same reference numerals as indicated in the drawings.

[0099] Figure 8A This is a perspective view showing the cover 67 of the fourth embodiment in the closed position. Figure 8B This is a perspective view showing the cover 67 in the open position. Figure 8C This is a perspective view showing the sheet separation unit 62 detached from the separation wall 60.

[0100] like Figures 8A-8CAs shown, the cover 67 is supported such that it can pivot relative to the separating wall 60 about a rotation axis 67a, and the cover 67 can be opened and closed relative to the separating wall 60. The cover 67 includes a sheet contact surface 67b that can contact the sheet S fed by the pick-up roller 12, and openings 67cL and 67cR formed in the sheet contact surface 67b as second openings. Figure 8A As shown, with the cover 67 in the closed position, the sheet contact surface 67b is arranged side-by-side with the separation ramp 60a in the width direction W. In this case, the sheet contact surface 67b is located upstream of the separation ramp 60a in the protrusion direction PD. In other words, in the protrusion direction PD, the amount of protrusion of the sheet contact surface 67b toward the feed path 17 is less than the amount of protrusion of the separation ramp 60a toward the feed path 17. Therefore, the sheet contact surface 67b does not obstruct the contact between the sheet S and the separation ramp 60a.

[0101] Openings 67cL and 67cR are formed at positions corresponding to the positions where the sheet separation portions 63L and 63R of the sheet separation unit 62 are attached to the separation wall 60. Furthermore, the openings 67cL and 67cR are formed such that, with the sheet separation unit 62 attached to the separation wall 60, the sheet separation portions 63L and 63R protrude from the openings 67cL and 67cR.

[0102] The cover 67 can open and close the opening 66, which serves as the first opening. (Example) Figure 8B As shown, the cover 67 opens the opening 66 by rotating it from the closed position to the open position. In this state, as described in the first embodiment, the sheet separation unit 62 can be inserted into the opening 66 and removed from the separation wall 60.

[0103] It should be noted that, in this embodiment, when the sheet separation unit 62 is inserted into the opening 66 and pushed forward by the pushing member 64, the unit abutment surfaces 62aL and 62aR of the sheet separation unit 62 abut against the abutment portions 61L and 61R of the separation wall 60. If the cover 67 is in the closed position, the sheet separation portions 63L and 63R of the sheet separation unit 62 protrude from the openings 67cL and 67cR of the cover 67 toward the feed path 17, respectively. Through this operation, the accuracy of the relative position between the sheet separation portions 63L and 63R and the separation slope 60a is increased, and the sheet separation portions 63L and 63R are located downstream of the separation slope 60a in the protrusion direction PD. Therefore, the sheet S can be reliably separated from other sheets one by one by the sheet separation portions 63L and 63R and the separation slope 60a, and failures during multiple feeds can be reduced.

[0104] As described above, this embodiment also produces the same effect as the first embodiment. Furthermore, in this embodiment, the opening 66, with its large opening area, can be opened by moving the cover 67 from the closed position to the open position. Therefore, the sheet separation unit 62 can be replaced through this opening 66. This facilitates easy replacement of the sheet separation unit 62, improving its operability. Additionally, the cover 67 includes a sheet contact surface 67b, which, when the cover 67 is in the closed position, is arranged parallel to the sheet separation portions 63L and 63R and the separation slope 60a in the width direction W. Therefore, even if the opening 66 is made large, it will not affect the separation performance of the sheet S, allowing the sheet S to be properly separated from other sheets one by one.

[0105] It should be noted that in this embodiment, both the separation slope 60a and the sheet contact surface 67b are formed as flat surfaces. However, this disclosure is not limited thereto. For example, both the separation slope 60a and the sheet contact surface 67b may include a plurality of ribs extending along the conveying direction of the sheet S.

[0106] Fifth embodiment

[0107] Next, a fifth embodiment of this disclosure will be described. In the fifth embodiment, the arrangement of the cover 67 in the fourth embodiment is changed. Therefore, components identical to those in the fourth embodiment are omitted in the drawings, or will be described using the same reference numerals as indicated in the drawings.

[0108] Figure 9A This is a perspective view showing the state of the cover 167 in the closed position according to the fifth embodiment. Figure 9B This is a perspective view showing the cover 167 in the open position. Figure 9C This is a perspective view showing the sheet separation unit 62 detached from the separation wall 60. Figure 10 It is a perspective view showing a portion of the sheet separation unit 62 attached to the separation wall 60 and the cover 167 being cut off.

[0109] like Figure 9A and Figure 9B As shown, the separation slope 60a of the separation wall 60 includes openings 60bL and 60bR as third openings, through which sheet separation portions 63L and 63R protrude. Figures 9A-9CAs shown, the cover 167 is supported such that it can pivot relative to the separating wall 60 about a rotation axis 167a, and can be opened and closed relative to the separating wall 60. The cover 167 is located on the rear side of the separating ramp 60a and can open and close the opening 166 located on the rear side of the separating ramp 60a. That is, the opening 166 opens in a direction opposite to the feed path 17 relative to the separating ramp 60a. In other words, the opening 166 opens towards the upstream side in the protruding direction PD. Figure 9B and Figure 9C As shown, the cover 67 opens the opening 166 by rotating it from the closed position to the open position. In this state, as described in the first embodiment, the sheet separating unit 62 can be inserted into the opening 166 and detached from the separating wall 60. That is, in this embodiment, the sheet separating unit 62 is attached to and detached from the separating wall 60 from the rear (opposite) side of the separating ramp 60a. However, the construction for positioning the sheet separating unit 62 relative to the separating wall 60 is the same as that in the first embodiment.

[0110] In this embodiment, as Figure 9C As shown, in the width direction W, the width D3 of the opening 166 is greater than the distance D2 between the sheet separation portions 63L and 63R (refer to...). Figure 9A Therefore, since the opening 166 has a large opening area, the sheet separation unit 62 can be easily attached to the opening 166, thereby improving the operability of replacing the sheet separation unit 62.

[0111] like Figure 9B and Figure 9C As shown, in order to remove the sheet separation unit 62 from the separation wall 60 of the box 11, the user opens the cover 167 to the open position and approaches the sheet separation unit 62 from the rear side of the separation slope 60a. The opening 166, which has a large opening area, can be opened by opening the cover 167, thereby allowing the sheet separation unit 62 to be replaced through the opening 166.

[0112] Then, as Figure 9C and Figure 10 As shown, the user pulls the sheet separation unit 62 forward, separating the unit's contact surfaces 62aL and 62aR from the contact portions 61L and 61R of the separation wall 60. Through this operation, as... Figure 9C As shown, the sheet separation unit 62 can be detached from the separation wall 60.

[0113] To assemble the sheet separating unit 62 onto the separating wall 60, the above process is performed in the reverse order of removing the sheet separating unit 62 from the separating wall 60. First, with the cover 167 in the open position, the user inserts the sheet separating unit 62 into the opening 166. In this case, the user inserts the sheet separating unit 62 into the opening 166 until the sheet separating unit 62 reaches the position where the unit abutment surfaces 62aL and 62aR of the sheet separating unit 62 face the abutment portions 61L and 61R of the separating wall 60.

[0114] Then, as Figure 9A As shown, the user moves the cover 167 to the closed position, thereby preventing the sheet separation unit 62 from detaching from the separation wall 60. The pushing member 64 is supported by the cover 167. Therefore, if the user moves the cover 167 from the open position to the closed position, the sheet separation unit 62 is pushed forward by the pushing member 64, so that the unit abutting surfaces 62aL and 62aR abut against the abutting portions 61L and 61R.

[0115] In this configuration, the sheet separating portions 63L and 63R of the sheet separating unit 62 protrude from the openings 60bL and 60bR of the separating ramp 60a, respectively. In other words, after the sheet separating unit 62 is inserted into the opening 166 and the cover 167 is closed, the sheet separating portions 63L and 63R protrude from the openings 60bL and 60bR toward the feed path 17. This operation increases the accuracy of the relative position between the sheet separating portions 63L and 63R and the separating ramp 60a, placing them downstream of the separating ramp 60a in the protrusion direction PD. Therefore, the sheet S can be reliably separated from other sheets one by one via the sheet separating portions 63L and 63R and the separating ramp 60a, reducing failures during multiple feeds.

[0116] In this embodiment, the opening 166, which has a large opening area and is located on the rear side of the separation slope 60a, can be opened by opening the cover 167 from the closed position to the open position. This allows for the replacement of the sheet separation unit 62 through the opening 166. Therefore, even if the opening cannot be located on the separation slope 60a side or the replacement operation cannot be performed from the separation slope 60a side, the replacement of the sheet separation unit 62 can be easily performed, thereby improving the operability of the replacement. Furthermore, since the opening 166 and the cover 167 are located on the rear side of the separation slope 60a, even if the opening 166 is manufactured to be large, the opening 166 will not affect the separation performance of the sheet S, allowing the sheet S to be properly separated from other sheets one by one.

[0117] Figure 11AThis is a perspective view of a modified example of the fifth embodiment, showing the separation wall 60 and the sheet separation unit 62 disposed in the device body 1A. Figure 11B This is a perspective view showing a modified example of the fifth embodiment with box 11 pulled out in the direction indicated by arrow B. (As shown) Figure 11A and Figure 11B As shown, if the separation wall 60 and the sheet separation unit 62 are located within the main body 1A of the device, it may be difficult to access and replace the sheet separation unit 62 from the separation ramp 60a side due to the structure and space constraints. Even with such a configuration, since the opening 166 and the cover 167 are located on the rear side of the separation ramp 60a, the replacement of the sheet separation unit 62 can be easily performed, thereby improving the operability of the replacement.

[0118] It should be noted that in this embodiment, the separation slope 60a is formed as a flat surface. However, this disclosure is not limited thereto. For example, the separation slope 60a may include a plurality of ribs extending along the conveying direction of the sheet S.

[0119] Sixth Embodiment

[0120] Next, a sixth embodiment of the present disclosure will be described. In the sixth embodiment, the arrangement of the cover 167 and the opening 166 of the fifth embodiment is changed. Therefore, components that are the same as those in the fifth embodiment are omitted in the drawings, or will be described using the same reference numerals as indicated in the drawings.

[0121] Figure 12A This is a perspective view showing the cover 267 of the sixth embodiment in the closed position. Figure 12B This is a perspective view showing the cover 267 in the open position. Figure 12C This is a perspective view showing the sheet separation unit 62 detached from the separation wall 60.

[0122] like Figure 12A and Figure 12B As shown, the separation slope 60a of the separation wall 60 includes openings 60bL and 60bR, through which sheet separation portions 63L and 63R protrude. Figures 12A-12C As shown, the cover 267 is supported such that it can pivot relative to the separating wall 60 about a rotation axis 267a, and can be opened and closed relative to the separating wall 60. The cover 267 is disposed in the top surface 60c of the separating wall 60, and can open and close the opening 266 disposed in the top surface 60c. That is, the opening 266 opens in the vertical direction. Figure 12B and Figure 12CAs shown, the cover 267 opens the opening 266 by rotating it from the closed position to the open position. In this state, as described in the first embodiment, the sheet separating unit 62 can be inserted into the opening 266 and detached from the separating wall 60. That is, in this embodiment, the sheet separating unit 62 is attached to and detached from the separating wall 60 from the upper surface 60c of the separating slope 60a. However, the construction for positioning the sheet separating unit 62 relative to the separating wall 60 is the same as that in the first embodiment.

[0123] In this embodiment, as Figure 12B As shown, in the width direction W, the width D4 of the opening 266 is longer than the distance D2 between the sheet separation section 63L and the sheet separation section 63R. Therefore, since the opening 266 has a large opening area, the sheet separation unit 62 can be easily attached to the opening 266, thereby improving the operability of replacing the sheet separation unit 62.

[0124] In order to remove the sheet separation unit 62 from the separation wall 60 of the box 11, as follows Figure 12B and Figure 12C As shown, the user opens the cover 267 to the open position and approaches the sheet separation unit 62 from the top surface 60c side of the separation wall 60. The opening 266, which has a large opening area, can be opened by opening the cover 267, allowing the sheet separation unit 62 to be replaced through the opening 266.

[0125] Then, as Figure 12C The user pulls the sheet separation unit 62 upwards, separating the unit's contact surfaces 62aL and 62aR from the contact portions 61L and 61R of the separation wall 60. This operation allows the sheet separation unit 62 to be detached from the separation wall 60.

[0126] To assemble the sheet separating unit 62 onto the separating wall 60, the above process is performed in the reverse order of removing the sheet separating unit 62 from the separating wall 60. First, with the cover 267 in the open position, the user inserts the sheet separating unit 62 into the opening 266. In this case, the user inserts the sheet separating unit 62 into the opening 266 until the sheet separating unit 62 reaches the position where the unit abutment surfaces 62aL and 62aR of the sheet separating unit 62 face the abutment portions 61L and 61R of the separating wall 60.

[0127] Then, as Figure 12AAs shown, the user moves the cover 267 to the closed position, thereby preventing the sheet separation unit 62 from detaching from the separation wall 60. In this case, if the user removes their hand from the sheet separation unit 62, the sheet separation unit 62 is pushed forward by the pushing member 64, causing the unit abutting surfaces 62aL and 62aR to abut against the abutting portions 61L and 61R. The pushing member 64 is supported by the separation wall 60. In this case, the sheet separation portions 63L and 63R of the sheet separation unit 62 protrude from the openings 60bL and 60bR of the separation slope 60a, respectively. Through this operation, the accuracy of the relative position between the sheet separation portions 63L and 63R and the separation slope 60a is increased, and the sheet separation portions 63L and 63R are located downstream of the separation slope 60a in the protrusion direction PD. Therefore, sheet S can be reliably separated from other sheets one by one through sheet separation sections 63L, 63R and separation slope 60a, and failures during conveying, such as multiple feeds, can be reduced.

[0128] As described above, the same effect as in the first embodiment can be achieved in this embodiment. Furthermore, in this embodiment, the opening 266, which has a large opening area and is formed in the top surface 60c of the separation wall 60, can be opened by opening the cover 267 from the closed position to the open position. Therefore, the sheet separation unit 62 can be replaced through the opening 66. Thus, even if the opening cannot be provided on the side of the separation slope 60a or the rear side of the separation slope 60a, the replacement of the sheet separation unit 62 can be easily performed, thereby improving the operability of the replacement. In addition, since the opening 266 and the cover 267 are provided in the top surface 60c of the separation wall 60, even if the opening 266 is manufactured to be large, the opening 266 will not affect the separation performance of the sheet S, allowing the sheet S to be properly separated from other sheets one by one.

[0129] Figure 13 This is a diagram illustrating an example of an image forming apparatus 1B having a configuration according to the sixth embodiment. Figure 13 As shown, a sheet feeding device 190 with the same structure as the sheet feeding device 90 is disposed below the sheet feeding device 90 and is connected to the image forming apparatus 1B. In this case, the sheet S fed from the lower sheet feeding device 190 is conveyed upward through the conveying path 18 disposed in the upper sheet feeding device 90.

[0130] In this configuration, since the conveying path 18 is located behind the separation slope 60a of the separation wall 60 of the sheet feeding device 90, it is difficult to provide an opening behind the separation slope 60a and perform the replacement operation of the sheet separation unit 62 through this opening. Furthermore, there are cases where the outer surface of the image forming apparatus is located behind the separation slope 60a of the separation wall 60. In this case, it is also difficult to provide a large opening behind the separation slope 60a for the replacement operation of the sheet separation unit 62.

[0131] However, in this embodiment, since the opening 266 and the cover 267 are provided in the top surface 60c of the separation wall 60, the sheet separation unit 62 can be easily replaced, thereby improving the operability of replacement.

[0132] It should be noted that in this embodiment, the separation slope 60a is formed as a flat surface. However, this disclosure is not limited thereto. For example, the separation slope 60a may include a plurality of ribs extending along the conveying direction of the sheet S.

[0133] Other embodiments

[0134] It should be noted that in the above embodiments, the pushing member 64 pushes the sheet separation unit to position the sheet separation unit relative to the separation wall 60. However, the construction of the pushing member 64 is not limited to this. As mentioned above, the pushing member 64 may include a compression coil spring 64a supported by, for example, the separation wall 60, and a plate member 64b fixed to the compression coil spring 64a and capable of abutting against the sheet separation unit 62. In other cases, the pushing member 64 may be constructed solely of elastic components such as springs, rubber, or sponges.

[0135] Furthermore, in the above embodiments, the separation wall 60 may be as described in reference. Figure 2A and Figure 2B It is set in box 11 as described, or as can be referenced. Figure 11A and Figure 11B It is arranged in the main body 1A of the device as described.

[0136] Furthermore, although the above embodiments have been described with respect to the use of electrophotographic image forming apparatus 1, this disclosure is not limited thereto. For example, this disclosure can also be applied to inkjet image forming apparatuses that form images on sheets by ejecting ink from nozzles.

[0137] In this disclosure, the removable unit can be replaced by another removable unit while the separation surface is left in the sheet feeding device.

[0138] Although this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A sheet feeding device, comprising: Stacking section, on which sheets are stacked; A rotating feeder is configured to feed the sheet stacked on the stacked portion toward the image forming portion in a sheet feeding direction; A first separation section, the first separation section including a separation surface configured to contact the sheet fed by the rotary feeding member; as well as A detachable unit, detachably attached to the first separating portion, includes a second separating portion that contacts the sheets fed by the rotary feeding member to separate the sheets one by one together with the separating surface. The direction that intersects the sheet feeding direction, intersects the rotation axis direction of the rotating feeding component, and extends from the separation surface toward the rotating feeding component is defined as the protruding direction. With the detachable unit attached to the first separating part, the second separating part is located downstream of the separating surface in the protruding direction, and With the detachable unit attached to the first separation part, another part of the detachable unit, excluding the second separation part, is located upstream of the separation surface in the protruding direction.

2. The sheet feeding device according to claim 1, wherein, The first separation part includes an opening, into which the detachable unit to be attached is inserted.

3. The sheet feeding device according to claim 2, wherein, The opening faces downstream in the protruding direction.

4. The sheet feeding device according to claim 2, wherein, The opening faces the upstream side in the protruding direction.

5. The sheet feeding device according to claim 2, wherein, The opening is vertical.

6. The sheet feeding device according to claim 2, wherein, The detachable unit is included at a first end and a second end in the direction of the rotation axis. The second separation section includes: A first sheet separation portion is disposed at a position closer to the first end than the second end in the direction of the rotation axis; and The second sheet separation section is disposed at a position closer to the second end than the first end in the direction of the rotation axis, and The width of the opening is longer than the distance between the first sheet separation portion and the second sheet separation portion in the direction of the rotation axis.

7. The sheet feeding device according to claim 2, further comprising a limiting member configured to restrict the detachable unit inserted into the opening from being removed from the first separating portion.

8. The sheet feeding device according to claim 7, wherein, The limiting member is configured to move between a limiting position and an allowable position, wherein the limiting position is a position where the limiting member restricts the detachable unit from being removed from the first separation portion, and the allowable position is a position where the limiting member allows the detachable unit to be removed from the first separation portion.

9. The sheet feeding device according to claim 8, wherein, The limiting component covers a portion of the opening at the limiting position and increases the opening area of ​​the opening by moving from the limiting position to the allowing position.

10. The sheet feeding device according to claim 7, wherein, The limiting component is configured to be detachably fixed to the first separation portion.

11. The sheet feeding device according to claim 2, wherein, The first separating part includes an abutting part. The detachable unit includes an abutting portion, the abutting portion being configured to abut against the abutting portion, and The sheet feeding device further includes a pushing member configured to position the removable unit relative to the first separation portion by pushing the removable unit so that the abutted portion abuts the abutting portion.

12. The sheet feeding device according to claim 11, wherein, The propulsion member is configured to advance the detachable unit in the protruding direction while the detachable unit is attached to the first separation portion, and When the detachable unit is attached to the first separating part, the abutting part is located upstream of the abutting part in the protruding direction.

13. The sheet feeding device according to claim 11, wherein, The detachable unit is configured to move upstream in the protruding direction against the thrust of the propulsion member while the second separation portion is pressed by the sheet fed by the rotating feeding member.

14. The sheet feeding device according to claim 11, wherein, The abutting portion is configured to restrict the detachable unit from being removed from the first separating portion by locking it in the state where the detachable unit is inserted into the opening.

15. The sheet feeding device according to claim 2, wherein, The sheet feeding device also includes a cover configured to open and close the opening.

16. The sheet feeding device according to claim 15, wherein, The opening is the first opening. The cover includes a second opening, and When the cover is closed after the removable unit is inserted into the first opening, the second separation portion protrudes from the second opening in the protruding direction.

17. The sheet feeding device according to any one of claims 1 to 16, wherein, The coefficient of friction of at least a portion of the second separating part is higher than the coefficient of friction of the separating surface.

18. An image forming apparatus, comprising: The sheet feeding device according to claim 1, and The image forming unit is configured to form an image on a sheet fed from the sheet feeding device.

19. A sheet feeding device, comprising: Stacking section, on which sheets are stacked; A rotating feeder is configured to feed the sheet stacked on the stacked portion toward the image forming portion in a sheet feeding direction; A first separation section, the first separation section including a separation surface configured to contact the sheet fed by the rotary feeding member; as well as A detachable unit, detachably attached to the first separating portion, includes a second separating portion that contacts the sheets fed by the rotary feeding member to separate the sheets one by one together with the separating surface. The direction that intersects the sheet feeding direction, intersects the rotation axis direction of the rotating feeding component, and extends from the separation surface toward the rotating feeding component is defined as the protruding direction. With the detachable unit attached to the first separating part, the second separating part is located downstream of the separating surface in the protruding direction, and With the detachable unit attached to the first separation portion, the other part of the detachable unit, excluding the second separation portion, is configured not to contact the sheet material fed by the rotating feeding member.

20. An image forming apparatus, comprising: The sheet feeding device according to claim 19, and The image forming unit is configured to form an image on the sheet fed from the sheet feeding device.

Images