Sheet feeding device, image reading device, and image forming device

Abstract

To make skewing of a sheet difficult.SOLUTION: This sheet feeder comprises: a mounting unit in which first and second grooves are formed; a feeding member; a first regulating member having a first regulation surface, a first engagement part, and a first rack part and movable along the first groove in a sheet width direction; a second regulating member having a second regulation surface, a second engagement part, and a second rack part and movable along the second groove in the sheet width direction; a pinion gear engaged with the first and second rack parts; and a rotation regulation unit that abuts against the first rack part at a position farther from the first engagement part than the pinion gear in the sheet width direction to regulate movement of the tip of the first rack part downstream in a sheet feeding direction which causes rotation of the first regulating member in a direction where the downstream end of the first regulation surface in the sheet feeding direction is farther from the second regulation surface.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a sheet feeding device that feeds sheets, an image reading device that reads an image from a sheet, and an image forming apparatus that forms an image on a recording material. [Background technology]

[0002] Patent document 1 describes a document feeding device that has a first regulating plate and a second regulating plate that are movable in conjunction with each other via gears and that regulate the widthwise position of a document supported on a document tray. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-54431 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above document, even if the first and second regulating plates are moved to match the width of the document, tilting of the first or second regulating plate may occur due to play between the first or second regulating plate and the gears or play in the support mechanisms for the first and second regulating plates. Then, tilting of the first or second regulating plate may create a gap between the side edge of the document and the first or second regulating plate, which may cause the document to be fed at an angle.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sheet feeding device, an image reading device, and an image forming apparatus in which skewed feeding of sheets is less likely to occur. [Means for solving the problem]

[0006] One aspect of the present invention is a sheet placement section on which a sheet is placed, the sheet placement section having a first groove and a second groove formed therein extending in a sheet width direction perpendicular to a sheet feeding direction; a feeding member that feeds the sheet placed on the sheet placement section in the sheet feeding direction; a first regulating surface that regulates one end of the sheet placed on the sheet placement section in the sheet width direction; a first engaging portion that is engaged with the first groove below the first regulating surface; and a first rack portion that extends from the first engaging portion in the sheet width direction, the first regulating member being movable in the sheet width direction along the first groove; a second restricting member having a second restricting surface that restricts the other end of the seat in the seat width direction, a second engaging portion that is engaged with the second groove portion below the second restricting surface, and a second rack portion that extends from the second engaging portion in the seat width direction and is movable in the seat width direction along the second groove portion; a pinion gear that meshes with the first rack portion and the second rack portion and is configured so that the first restricting member and the second restricting member move in the seat width direction in conjunction with each other; and a pinion gear that abuts against the first rack portion at a position farther from the first engaging portion than the pinion gear in the seat width direction. death The leading end of the first rack portion moves downstream in the sheet feeding direction. By restricting a rotation regulating portion that regulates the first regulating member from rotating in a direction in which a downstream end of the first regulating surface in the sheet feeding direction moves away from the second regulating surface. When the distance between the first regulating surface and the second regulating surface in the sheet width direction is equal to or less than a predetermined length, the rotation regulating portion abuts against the first rack portion, and when the distance is wider than the predetermined length, the rotation regulating portion does not abut against the first rack portion. The sheet feeding device is characterized by the above. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a sheet feeding device, an image reading device, and an image forming apparatus in which skewed sheets are less likely to occur. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 2] 1A is a perspective view of an image forming apparatus according to a first embodiment, and FIG. 1B is a schematic view of an image reading apparatus according to the first embodiment. [Figure 3]FIG. 1 is a perspective view of an image reading apparatus according to a first embodiment. [Figure 4] 1A is an enlarged perspective view of a rear regulating member according to the first embodiment, and FIG. 1B is an enlarged perspective view of a front regulating member according to the first embodiment. [Figure 5] FIG. 2 is a bottom view of the document tray according to the first embodiment. [Figure 6] 4 is a perspective view showing a front regulating member, a rear regulating member, and a pinion gear when viewed through the document tray according to the first embodiment. FIG. [Figure 7] FIG. 11 is a view of the document tray according to the second embodiment, seen from the opposite side to the support surface. [Figure 8] 10 is a perspective view showing a front regulating member, a rear regulating member, and a pinion gear in a document tray according to the second embodiment. FIG. [Figure 9] FIG. 11 is a view of the document tray according to the second embodiment, seen from the opposite side to the support surface. [Figure 10] An enlarged view of a portion of Figure 9. [Figure 11] FIG. 10 is an enlarged view of another part of FIG. 9. [Figure 12] 1A and 1B are a perspective view and a top view of a document tray according to a reference example. [Figure 13] 10A and 10B are explanatory diagrams of a document tray according to a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] (Image forming device) The overall configuration of an image forming apparatus 1 according to the first embodiment will be described with reference to Figures 1 and 2(a). Figure 1 is a schematic diagram of the image forming apparatus 1. Figure 2(a) is a perspective view of the image forming apparatus 1.

[0011] 1 and subsequent drawings respectively represent the left-right direction, depth direction (front-rear direction), and up-down direction (height direction) of image forming apparatus 1. When image forming apparatus 1 is viewed from the front (-Y direction), the direction toward one side along the horizontal direction (rightward) is the direction of arrow X, and the direction toward the opposite side (leftward) is the opposite direction of arrow X. When image forming apparatus 1 is viewed from the front (-Y direction), the direction toward the opposite side (leftward) is the direction opposite to arrow Y. When image forming apparatus 1 is installed on a horizontal surface, the vertically upward direction is the direction of arrow Z, and the vertically downward direction (direction of gravity) is the direction opposite to arrow Z.

[0012] 1, the image forming apparatus 1 is a tandem-type full-color multifunction machine in which process units PY, PM, PC, and PK are arranged along an intermediate transfer belt 12. The image forming apparatus 1 has an apparatus main body 3 that houses an image forming unit 3A (electrophotographic engine) as an image forming means, an image reading device 4 provided above the apparatus main body 3, and an operation unit 11 as a user interface.

[0013] The image forming section 3A includes process units PY to PK, an exposure device 13, an intermediate transfer belt 12, and a fixing device 14. Each of the process units PY to PK has a photosensitive drum as an image carrier, a charging roller acting on the photosensitive drum, a developing unit, a cleaning unit, etc.

[0014] The device main body 3 also has a cassette 2 in which sheets as recording material are loaded and stored, a manual feed tray 9 on which a user can manually place sheets, a pair of discharge rollers 15 as a discharge means, and a discharge tray 5 on which sheets as the finished product are loaded.

[0015] This section describes a series of operations (image forming operations) in which image forming apparatus 1 forms an image on a sheet while conveying the sheet. Image forming apparatus 1 starts the image forming operation, for example, when a user inputs an instruction to perform the image forming operation via operation unit 11 with a document set in document tray 8 of image reading device 4.

[0016] During image formation, the photosensitive drums of each process unit PY to PK and the intermediate transfer belt 12 are rotated at a predetermined peripheral speed (process speed). In each process unit PY to PK, a charging roller charges the surface of the photosensitive drum. The exposure device 13 is driven based on image information received from the image reading device 4 or an external host device, and exposes the surface of the photosensitive drum to light to write an electrostatic latent image. The development unit of each process unit PY to PK uses toner as a developer to develop the electrostatic latent image into a single-color toner image. These single-color toner images are transferred onto the intermediate transfer belt 12 so that they are superimposed on each other. As a result, a full-color toner image (hereinafter simply referred to as a toner image) is formed on the intermediate transfer belt 12. The toner image carried on the intermediate transfer belt 12 is transported toward the secondary transfer unit T2 by the rotation of the intermediate transfer belt 12.

[0017] Meanwhile, sheets are fed one by one from one of the cassettes 2 or the manual feed tray 9 and transported to the secondary transfer section T2. ​​At the secondary transfer section T2, a toner image is transferred from the intermediate transfer belt 12 to the sheet. The sheet that has passed through the secondary transfer section T2 is heated and pressed by the fixing device 14, thereby fixing the toner image to the sheet. The sheet that has passed through the fixing device 14 is discharged outside the device main body 3 by a pair of discharge rollers 15 and stacked on the discharge tray 5.

[0018] (Image reader overview) An overview of the image reading device 4 will be described. Fig. 2(b) is a schematic diagram showing a cross section of the image reading device 4. As shown in Figs. 1 and 2(a), the image reading device 4 has a reader unit 6 attached to the top surface of the device main body 3, and an automatic document feeder 7 (hereinafter referred to as ADF) supported by the reader unit 6.

[0019] The reader unit 6 has a configuration similar to that of a flatbed scanner. That is, the reader unit 6 has a platen glass 6a and a surface reading unit 36, and can acquire image information by optically scanning a stationary document placed on the platen glass 6a with the surface reading unit 36. The ADF 7 is provided so as to be openable (rotatable) relative to the reader unit 6. A user can place a document on the platen glass 6a by lifting the ADF 7.

[0020] 2(a) and 2(b), the ADF 7 has a document tray 8, a discharge tray 10, a plurality of transport members for transporting documents, and a back surface reading unit 37. In this embodiment, the plurality of transport members include a pickup roller 30 as a feeding member, a separation roller pair 31, a pull-out roller pair 32, a first read roller pair 33, a second read roller pair 34, and a discharge roller pair 35 as a discharge member.

[0021] The front surface reading unit 36 ​​and the back surface reading unit 37 are both examples of reading means for reading image information from a sheet. The front surface reading unit 36 ​​and the back surface reading unit 37 may be a CCD type or CMOS type image sensor (line sensor).

[0022] When using the ADF 7 to read image information from a document, the user places the document in the document tray 8 and then operates the operation unit 11 to input the black-and-white or color reading mode, document size, and other settings. When the user inputs a command to execute scanning, the ADF 7 transports the document one sheet at a time. Specifically, the pickup roller 30 rotates while contacting the top document on the document tray 8, thereby advancing the top document from the document tray 8. The separation roller pair 31 applies friction to the document, separating the document one sheet at a time and further transporting the document. The document that passes through the separation roller pair 31 is conveyed by passing through the pull-out roller pair 32, the first read roller pair 33, and the second read roller pair 34 in this order, and image information is read from the first and second sides of the document by the front side reading unit 36 ​​and the back side reading unit 37. The document from which the image information has been read is discharged by the discharge roller pair 35 and stacked on the discharge tray 10.

[0023] (Document tray) The document tray 8 of the ADF 7 will be described in detail with reference to Figs. 3 to 6. Fig. 3 is a perspective view of the image reading device 4. Fig. 4(a) is an enlarged perspective view showing the rear regulating member 22. Fig. 4(b) is an enlarged perspective view showing the front regulating member 21. Fig. 5 is a view seen from the opposite side (underside) of the support surface 80 (document placement surface) that supports the document tray 8. Fig. 6 is a view showing the front regulating member 21, rear regulating member 22, and pinion gear 23 when seen through the document tray 8.

[0024] In the following description, the direction in which the document is fed from the document tray 8 by the pickup roller 30 is referred to as the sheet feeding direction Df. The direction along the document and perpendicular to the sheet feeding direction Df is referred to as the sheet width direction Dw. The sheet width direction Dw is parallel to the arrow Y in Figures 1 and 2(a). One side of the sheet width direction Dw is referred to as the front side or simply the "front side" of the image reading device 4. The other side of the sheet width direction Dw is referred to as the rear side or simply the "rear side" of the image reading device 4. In addition, the direction perpendicular to both the sheet feeding direction Df and the sheet width direction Dw is referred to as the height direction.

[0025] As shown in FIGS. 3 and 6, the ADF 7 includes a front regulating member 21, a rear regulating member 22, and a pinion gear 23.

[0026] The front regulating member 21 and the rear regulating member 22 are supported by the document tray 8 and are movable in the sheet width direction Dw relative to the document tray 8. The front regulating member 21 and the rear regulating member 22 can regulate the position of the document in the sheet width direction Dw by abutting the first regulating surface 21a and the second regulating surface 22a against both side edges of the document placed on the document tray 8. The front regulating member 21 and the rear regulating member 22 are a pair of regulating members (side regulating plates) that cooperate to regulate the position of the document in the sheet width direction Dw. The front regulating member 21 is an example of a first regulating member, and the rear regulating member 22 is an example of a second regulating member.

[0027] The document tray 8 is an example of a loading section on which documents are placed. The document tray 8 has a support surface 80 that supports the placed documents, and two grooves (a first groove 8a and a second groove 8b) formed in the support surface 80. The first groove 8a and the second groove 8b are each formed to penetrate the support surface 80 from top to bottom and extend along the sheet width direction Dw.

[0028] As shown in FIGS. 4(b), 5, and 6, the front-side regulating member 21 has a first regulating surface 21a, a first support surface 21f, a first rack portion 21b, and a tray groove engaging portion 21d as a first engaging portion. The first regulating surface 21a and the first support surface 21f are disposed above the support surface 80 of the document tray 8, and the first rack portion 21b is disposed below the support surface 80. The tray groove engaging portion 21d is engaged with the first groove portion 8a below the first regulating surface 21a. The front-side regulating member 21 is movable relative to the document tray 8 along the first groove portion 8a by having the tray groove engaging portion 21d guided by the first groove portion 8a.

[0029] The first restricting surface 21a is configured to restrict one end of the document in the sheet width direction Dw. The first restricting surface 21a is a surface that extends upward in the height direction relative to the support surface 80 and extends in the sheet feeding direction Df. The first support surface 21f is configured to support one end of the document in the sheet width direction Dw. The first support surface 21f is a surface that is parallel to the support surface 80 of the document tray 8 and perpendicular to the first restricting surface 21a. The tray groove engaging portion 21d extends from the upper side to the lower side of the support surface 80 through the first groove portion 8a. The tray groove engaging portion 21d functions as a first connecting portion that connects the first restricting surface 21a and the first rack portion 21b via the first groove portion 8a. The first rack portion 21b extends rearward from the tray groove engaging portion 21d (toward the rear restricting member 22 in the sheet width direction Dw). The first rack portion 21b has a plurality of teeth 21b1 that mesh with a pinion gear 23, which will be described later. The plurality of teeth 21b1 are provided on a downstream side of the first rack portion 21b in the sheet feeding direction Df, and are aligned in the sheet width direction Dw.

[0030] As shown in FIGS. 4(a), 5, and 6, the rear regulating member 22 has a second regulating surface 22a, a second support surface 22f, a second rack portion 22b, and a tray groove engaging portion 22d as a second engaging portion. The second regulating surface 22a and the second support surface 22f are disposed above the support surface 80 of the document tray 8, and the second rack portion 22b is disposed below the support surface 80. The tray groove engaging portion 22d is engaged with the second groove portion 8b below the second regulating surface 22a. The rear regulating member 22 is movable relative to the document tray 8 along the second groove portion 8b by having the tray groove engaging portion 22d guided by the second groove portion 8b.

[0031] The second restricting surface 22a is configured to restrict the other end of the document in the sheet width direction Dw. The second restricting surface 22a is a surface that extends upward in the height direction relative to the support surface 80 and extends in the sheet feeding direction Df. The second support surface 22f is configured to support the other end of the document in the sheet width direction Dw. The second support surface 22f is a surface that is parallel to the support surface 80 of the document tray 8 and perpendicular to the second restricting surface 22a. The tray groove engaging portion 22d extends from above the support surface 80 to below the support surface 80 through the second groove portion 8b. The tray groove engaging portion 22d functions as a second connecting portion that connects the second restricting surface 22a and the second rack portion 22b via the second groove portion 8b. The second rack portion 22b extends frontward from the tray groove engaging portion 22d (toward the front restricting member 21 in the sheet width direction Dw). The second rack portion 22b has a plurality of teeth 22b1 that mesh with a pinion gear 23, which will be described later. The plurality of teeth 22b1 are provided on an upstream side of the second rack portion 22b in the sheet feeding direction Df, and are aligned in the sheet width direction Dw.

[0032] The pinion gear 23 is arranged to mesh with both the first rack portion 21b of the front regulating member 21 and the second rack portion 22b of the rear regulating member 22. In this embodiment, the pinion gear 23 is arranged downstream of the first rack portion 21b and upstream of the second rack portion 22b in the sheet feeding direction Df. The pinion gear 23 is rotatably supported by the document tray 8 and rotates around a rotation center 23a. The rotation center 23a is located on a conveyance center Wc, which will be described later.

[0033] The front regulating member 21 and the rear regulating member 22 are connected via a pinion gear 23 and move in conjunction with each other in the sheet width direction Dw. That is, the first rack portion 21b of the front regulating member 21, the second rack portion 22b of the rear regulating member 22, and the pinion gear 23 configure a rack-and-pinion mechanism as an interlocking mechanism that interlocks the front regulating member 21 and the rear regulating member 22.

[0034] In this embodiment, the front regulating member 21 and the rear regulating member 22 move while maintaining a symmetrical positional relationship with respect to the conveyance center Wc (FIG. 5). That is, even when the front regulating member 21 and the rear regulating member 22 move, the distance from the first regulating surface 21a to the conveyance center Wc in the sheet width direction Dw and the distance from the second regulating surface 22a to the conveyance center Wc in the sheet width direction Dw are maintained equal.

[0035] The conveyance center Wc is a reference for the position of the document conveyed by the ADF 7 in the sheet width direction Dw. The ADF 7 is a center-referenced sheet conveying device that conveys the document so that the center of the document in the sheet width direction Dw coincides with the conveyance center Wc. To further prevent the document from skewing, the pickup roller 30 is preferably positioned so that the area where the pickup roller 30 contacts the document is symmetrical with respect to the conveyance center Wc.

[0036] In this embodiment, the document tray 8 can accommodate sheets (hereinafter referred to as small-sized documents) such as business cards that have a short length in the sheet width direction Dw (hereinafter referred to as sheet width), and the ADF 7 can transport the small-sized documents. A small-sized document is a sheet that is smaller than the paper size for general documents, such as an A6 size or smaller (a sheet width of 105 mm or smaller). Small-sized documents include documents with a sheet width of 55 mm and a sheet length of 91 mm, which is the size of a general business card. The front and rear restricting members 21 and 22 can restrict the position of small-sized documents such as business cards (i.e., they can be moved to positions where they abut against both side edges of the small-sized document). Note that FIGS. 3 to 6 show the front and rear restricting members 21 and 22 moved to positions corresponding to an LTR-sized document, which has the largest sheet width among documents that can be placed on the document tray 8.

[0037] (Rotation restriction part) Next, a description will be given of a configuration for restricting the rotation of the front regulating member 21 and the rear regulating member 22. As shown in Fig. 5, the document tray 8 has a first wall portion 81 for restricting the rotation of the front regulating member 21 and a second wall portion 82 for restricting the rotation of the rear regulating member 22.

[0038] In this embodiment, the first wall portion 81 and the second wall portion 82 are both examples of a “rotation restricting portion.” When the first wall portion 81 is the first rotation restricting portion, the second wall portion 82 is the second rotation restricting portion.

[0039] In this embodiment, the first wall portion 81 and the second wall portion 82 have a rib shape that protrudes from the surface of the document tray 8 opposite the support surface 80. The first wall portion 81 and the second wall portion 82 are formed integrally with the support surface 80 by a method such as injection molding using the same resin material as the support surface 80. However, the first wall portion 81 and the second wall portion 82 may be separate members from the support surface 80 that is fixed to the document tray 8.

[0040] The first rack portion 21b of the front-side regulating member 21 is provided with a first protrusion 21e as a contact portion (first contact portion) that contacts the first wall portion 81. The first protrusion 21e is provided on a tip end 21c, which is an end of the first rack portion 21b farther from the first regulating surface 21a in the sheet width direction Dw. The first protrusion 21e protrudes downstream in the sheet feeding direction Df further than the teeth 21b1 of the first rack portion 21b, whose tips are formed to face downstream in the sheet feeding direction Df. In other words, the teeth 21b1 of the first rack portion 21b are retracted from the first protrusion 21e. Therefore, as will be described later, the clearance between the first rack portion 21b and the pinion gear 23 can more reliably regulate the first rack portion 21b from moving downstream in the sheet feeding direction Df. Furthermore, when the first protrusion 21e abuts against the first wall portion 81, the teeth 21b1 can be prevented from contacting the first wall portion 81.

[0041] The second rack portion 22b of the rear regulating member 22 is provided with a second protrusion 22e as a contact portion (second contact portion) that contacts the second wall portion 82. The second protrusion 22e is provided on a side surface of the second rack portion 22b facing the downstream side in the sheet feeding direction Df, and extends in the sheet width direction Dw. The second protrusion 22e protrudes toward the downstream side in the sheet feeding direction Df, opposite to the teeth 22b1 of the second rack portion 22b that are formed so that the tooth tips face upstream in the sheet feeding direction Df.

[0042] (Advantages of this embodiment) The advantages of this embodiment will be explained by comparing it with a reference example shown in Figures 12(a) and 12(b) and 13(a) and 13(b). Figures 12(a) and 12(b) are a perspective view and a top view of the document tray 8 according to the reference example. Figures 13(a) and 13(b) are a perspective view and a top view showing the front regulating member 21', the rear regulating member 22', and the pinion gear 23 when seen through the document tray 8.

[0043] The ADF according to the reference example differs from the first embodiment in that it does not have the first wall portion 81 and the second wall portion 82 of the document tray 8, the first convex portion 21e of the front regulating member 21, and the second convex portion 22e (FIG. 5) of the rear regulating member 22. The other configurations of the reference example are the same as those of the first embodiment.

[0044] The front regulating member 21' and the rear regulating member 22' are moved to positions that correspond to the width of the document placed on the document tray 8, whereby the first regulating surface 21a and the second regulating surface 22a regulate the position of the document in the sheet width direction Dw. However, when the first regulating surface 21a or the second regulating surface 22a is separated from the side edge of the document, skew of the document may occur. In particular, when the vicinity of the downstream end of the first regulating surface 21a or the vicinity of the downstream end of the second regulating surface 22a in the sheet feeding direction Df is separated from the side edge of the document, skew of the document is likely to occur.

[0045] Here, there is a predetermined clearance (backlash, apex gap, and backlash) between the teeth of the first rack portion 21b of the front regulating member 21' and the teeth of the pinion gear 23. Providing an appropriate clearance allows the first rack portion 21b and the pinion gear 23 to operate smoothly. On the other hand, when the front regulating member 21' is positioned to match the width of the document, the presence of the clearance allows the first rack portion 21b to move in a direction A1 approaching the rotation center 23a of the pinion gear 23.

[0046] 13(a) and 13(b), the first rack portion 21b is allowed to move in the direction A1, which allows the front regulating member 21' to rotate so that the downstream end 21a1 of the first regulating surface 21a in the sheet feeding direction Df moves away from the second regulating surface 22a. Specifically, the front regulating member 21' is allowed to rotate in a counterclockwise direction R1 in FIG. 13(b) around the tray groove engaging portion 21d (first engaging portion) supported by the first groove 8a of the document tray 8 as a fulcrum. This direction R1 is a rotation direction in which the tip portion 21c of the first rack portion 21b moves downstream in the sheet feeding direction Df and the downstream end 21a1 of the first regulating surface 21a in the sheet feeding direction Df moves away from the second regulating surface 22a.

[0047] When such rotation of the front regulating member 21' occurs, the vicinity of the downstream end of the first regulating surface 21a in the sheet feeding direction Df moves away from the side edge of the document, making it more likely that the document will skew.

[0048] Furthermore, if there is a gap between the downstream surface 22b2 of the rear regulating member 22' in the sheet feeding direction Df and a member facing the surface 22b2 of the rear regulating member 22', the second rack portion 22b is permitted to move in the direction A2 away from the rotation center 23a of the pinion gear 23. The "member facing the surface 22b2 of the rear regulating member 22'" is, for example, a wall portion 83 provided at the same position as the rotation center 23a of the pinion gear 23 to maintain the meshing of the second rack portion 22b and the pinion gear 23. In this case, the wall portion 83 restricts the movement of the second rack portion 22b in the sheet feeding direction Df, thereby preventing tooth jumping of the second rack portion 22b and the pinion gear 23. On the other hand, the backlash between the second rack portion 22b and the wall portion allows the second rack portion 22b to move in the direction A2 away from the rotation center 23a of the pinion gear 23 of the rear regulating member 22'.

[0049] 13(a) and 13(b), the second rack portion 22b is allowed to move in the direction A2, which allows the rear regulating member 22' to rotate so that the downstream end 22a1 of the second regulating surface 22a in the sheet feeding direction Df moves away from the first regulating surface 21a. Specifically, the rear regulating member 22' is allowed to rotate in a clockwise direction R2 in FIG. 13(b) around the tray groove engaging portion 22d (second engaging portion) supported by the second groove portion 8b of the document tray 8 as a fulcrum. This direction R2 is a rotation direction in which the tip portion 22c of the second rack portion 22b moves downstream in the sheet feeding direction Df and the downstream end 22a1 of the second regulating surface 22a in the sheet feeding direction Df moves away from the first regulating surface 21a.

[0050] When such rotation of the rear regulating member 22' occurs, the vicinity of the downstream end of the second regulating surface 22a in the sheet feeding direction Df moves away from the side edge of the document, making it more likely that the document will skew.

[0051] Furthermore, the narrower the width of the document set in the document tray 8, the more easily the front regulating member 21' and the rear regulating member 22' rotate. This is because, if the clearance between the first rack portion 21b and the pinion gear 23 is constant, the shorter the distance L1 in the sheet width direction Dw from the tray groove engaging portion 21d to the rotation center 23a of the pinion gear 23, the larger the rotation angle of the front regulating member 21' that is allowed by the clearance. Also, if the distance that the second rack portion 22b can be separated from the pinion gear 23 is constant, the shorter the distance L2 in the sheet width direction Dw from the tray groove engaging portion 22d to the rotation center 23a of the pinion gear 23, the larger the rotation angle of the rear regulating member 22' that is allowed. Therefore, with small-sized documents, skewing of the document caused by misalignment in the rotational direction of the front regulating member 21' and the rear regulating member 22' is more likely to become apparent, while with documents other than small sizes (e.g., A4 size), skewing of the document tends to be relatively less likely to occur.

[0052] In contrast, according to the present embodiment, the first protrusion 21e of the front regulating member 21 abuts against the first wall portion 81 at a position farther from the tray groove engaging portion 21d in the sheet width direction Dw than the pinion gear 23 is from the tray groove engaging portion 21d (FIG. 5). That is, a distance L3 in the sheet width direction Dw from the tray groove engaging portion 21d to the first protrusion 21e (first abutment portion) is longer than a distance L1 in the sheet width direction Dw from the tray groove engaging portion 21d to the rotation center 23a of the pinion gear 23.

[0053] The first wall portion 81 abuts against the first protrusion 21e, restricting the first rack portion 21b from moving in the direction A1 toward the rotation center 23a of the pinion gear 23 (FIG. 6). In other words, the amount of movement of the first rack portion 21b in the direction A1 allowed in this embodiment is smaller than the amount of movement of the first rack portion 21b permitted by the clearance between the first rack portion 21b and the pinion gear 23 in the absence of the first wall portion 81 and the first protrusion 21e. Restricting the movement of the first rack portion 21b restricts the front-side restricting member 21 from rotating in the counterclockwise direction R1 in FIG. 6 around the tray groove engaging portion 21d as a fulcrum. This makes it difficult for the downstream end 21a1 of the first restricting surface 21a to separate from the side edge of the document. As a result, the document is less likely to skew in this embodiment than in the reference example.

[0054] Furthermore, according to this embodiment, the second protrusion 22e of the rear regulating member 22 abuts against the second wall portion 82 at a position farther from the tray groove engagement portion 22d in the sheet width direction Dw than the pinion gear 23 is (FIG. 5). That is, a distance L4 in the sheet width direction Dw from the tray groove engagement portion 22d to the end of the second protrusion 22e farther from the tray groove engagement portion 22d is longer than a distance L2 in the sheet width direction Dw from the tray groove engagement portion 22d to the rotation center 23a of the pinion gear 23.

[0055] The abutment of the second wall portion 82 with the second protrusion 22e restricts the movement of the second rack portion 22b in the direction A2 away from the rotation center 23a of the pinion gear 23 (FIG. 6). That is, the amount of movement of the second rack portion 22b in the direction A2 allowed in this embodiment is smaller than the amount of movement of the second rack portion 22b allowed in the absence of the second wall portion 82 and the second protrusion 22e. For example, compared to the case where the movement of the second rack portion 22b is restricted by the wall portion 83 (FIG. 13(b)) provided at the same widthwise position as the pinion gear 23, the amount of movement of the second rack portion 22b allowed in the direction A2 in this embodiment is smaller. Restricting the movement of the second rack portion 22b restricts the rear regulating member 22 from rotating in the clockwise direction R2 in FIG. 6 around the tray groove engaging portion 22d as a fulcrum. This makes it difficult for the downstream end 22a1 of the second regulating surface 22a to separate from the side edge of the document. As a result, in this embodiment, skew of the document can be made less likely to occur than in the reference example.

[0056] As described above, according to the present embodiment, it is possible to provide a sheet feeding device, an image reading device, and an image forming device in which skew of sheets is less likely to occur. In particular, according to the present embodiment, when using small-sized originals that are short in the sheet width direction Dw, it is possible to make skew of the originals less likely to occur.

[0057] In this embodiment, the first wall portion 81 (rotation restricting portion) abuts against the first rack portion 21b over the entire range in which the front restricting member 21 (first restricting member) can move in the sheet width direction Dw. Similarly, the second wall portion 82 abuts against the second rack portion 22b over the entire range in which the rear restricting member 22 can move in the sheet width direction Dw. In other words, the first wall portion 81 can restrict the rotation of the front restricting member 21 both when a small-sized document is set in the document tray 8 and when a document of the maximum size (for example, LTR size) is set in the document tray 8. Therefore, it is possible to make it difficult for the document to skew, regardless of the size of the document set in the document tray 8.

[0058] (Variation) In the present embodiment, a configuration has been exemplified in which both a first wall portion 81 (first rotation restricting portion) that restricts the rotation of the front restricting member 21 and a second wall portion 82 (second rotation restricting portion) that restricts the rotation of the rear restricting member 22 are provided. However, the present invention is not limited to this, and a configuration may be provided in which only one of the first wall portion 81 and the second wall portion 82 is provided. For example, if it is known that the rotation of the rear restricting member 22 is less likely to occur than that of the front restricting member 21 and falls within an allowable range, a configuration may be provided in which only the first wall portion 81 is provided. Furthermore, in a configuration in which only the second wall portion 82 that restricts the rotation of the rear restricting member 22 is provided, the second wall portion 82 corresponds to the "rotation restricting portion."

[0059] In this embodiment, the distance from the tray groove engaging portion 21d of the front regulating member 21 to the downstream end 21a1 of the first regulating surface 21a is longer than the distance from the tray groove engaging portion 22d of the rear regulating member 22 to the downstream end 22a2 of the second regulating surface 22a. In this case, even if the amounts of change in the rotation angles of the front regulating member 21 and the rear regulating member 22 are the same, the downstream end 21a1 of the first regulating surface 21a moves a larger distance in the sheet width direction Dw. Therefore, it is preferable to provide a rotation regulating portion (first wall portion 81) that regulates the rotation of at least the front regulating member 21.

[0060] Second Embodiment The second embodiment will be described using Figures 7 and 8. The ADF 7 according to this embodiment differs from the first embodiment in the range in which the first wall portion and the second wall portion serving as the rotation restricting portion are provided. Hereinafter, elements with the same reference symbols as those in the first embodiment will be considered to have basically the same configurations and functions as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0061] Fig. 7 is a view of the document tray 8 as seen from the opposite side to the support surface 80. Fig. 8 is a view showing the front regulating member 21, the rear regulating member 22, and the pinion gear 23 when viewed through the document tray 8. Note that Figs. 7 and 8 show a state in which the front regulating member 21 and the rear regulating member 22 have been moved to positions that align with an A6-sized document, which is an example of a small-sized document.

[0062] The document tray 8 has a first wall portion 181 for restricting the rotation of the front-side restricting member 21 and a second wall portion 182 for restricting the rotation of the rear-side restricting member 22 (FIG. 7). The first wall portion 181 can come into contact with the first protrusion 21e of the front-side restricting member 21, and the second wall portion 182 can come into contact with the second protrusion 22e of the rear-side restricting member 22.

[0063] Both the first wall portion 181 and the second wall portion 182 are an example of a “rotation restricting portion.” When the first wall portion 181 is a first rotation restricting portion, the second wall portion 182 is a second rotation restricting portion.

[0064] The first wall portion 181 of this embodiment has a shorter length in the seat width direction Dw than the first wall portion 81 (FIG. 5) of the first embodiment. Also, the second wall portion 182 of this embodiment has a shorter length in the seat width direction Dw than the second wall portion 82 (FIG. 5) of the first embodiment.

[0065] In this embodiment, the first wall portion 181 and the second wall portion 182 come into contact with the first convex portion 21e and the second convex portion 22e only when a small-sized document with a sheet width of A6 size or less (105 mm or less) is set. When a document with a sheet width wider than A6 size is set, the first wall portion 181 and the second wall portion 182 do not come into contact with the first convex portion 21e and the second convex portion 22e.

[0066] In other words, when the distance between the first and second restriction surfaces 21a and 22a in the sheet width direction Dw is equal to or less than a predetermined length, the first wall portion 181 (rotation restriction portion) abuts against the first rack portion 21b. Furthermore, when the distance is greater than the predetermined length, the first wall portion 181 (rotation restriction portion) does not abut against the first rack portion 21b. In this embodiment, the predetermined length is 105 mm. In other words, when the first and second restriction surfaces 21a and 22a are in contact with the side edges of a sheet (e.g., A6 size or business card size) whose length in the sheet width direction Dw is a first length, the first wall portion 181 (rotation restriction portion) abuts against the first rack portion 21b. Furthermore, when the first regulating surface and the second regulating surface are in contact with the side edge of a sheet (e.g., an A4-sized document) whose length in the sheet width direction Dw is a second length longer than the first length, the first convex portion 21e and the second convex portion 22e do not abut.

[0067] As in the first embodiment, when a small-sized original document is set, the rotation of the front regulating member 21 and the rear regulating member 22 is restricted by the first wall portion 181 and the second wall portion 182, thereby making it less likely for the original document to skew.

[0068] That is, a distance L3 in the sheet width direction Dw from the tray groove engagement portion 21d to the first protrusion 21e is longer than a distance L1 in the sheet width direction Dw from the tray groove engagement portion 21d to the rotation center 23a of the pinion gear 23. Also, a distance L4 in the sheet width direction Dw from the tray groove engagement portion 22d to the end of the second protrusion 22e farther from the tray groove engagement portion 22d is longer than a distance L2 in the sheet width direction Dw from the tray groove engagement portion 22d to the rotation center 23a of the pinion gear 23. Therefore, movement of the first rack portion 21b and the second rack portion 22b in the directions A1 and A2 is restricted, and rotation (R1, R2) of the front regulating member 21 and the rear regulating member 22 is restricted. As a result, skew of the document can be made less likely to occur compared to the above-described reference example.

[0069] As described above, according to the present embodiment, it is possible to provide a sheet feeding device, an image reading device, and an image forming device in which skew of sheets is less likely to occur. In particular, according to the present embodiment, when using small-sized originals that are short in the sheet width direction Dw, it is possible to make skew of the originals less likely to occur.

[0070] Furthermore, in this embodiment, when a document with a sheet width wider than that of a small-sized document is set, the first wall portion 181 and the second wall portion 182 do not come into contact with the first protrusion portion 21e and the second protrusion portion 22e. In other words, the range in which friction occurs between the first wall portion 181 and the second wall portion 182 and the first protrusion portion 21e and the second protrusion portion 22e is limited to a part of the entire range in which the front-side regulating member 21 and the rear-side regulating member 22 can move in the sheet width direction Dw. This reduces the operating force required to slide the front-side regulating member 21 and the rear-side regulating member 22, improving operability.

[0071] As described above, skew of the document caused by misalignment in the rotational direction of the front regulating member 21 and the rear regulating member 22 is likely to become apparent with small-sized documents, whereas skew of the document tends to be relatively unlikely to occur with documents other than small sizes (e.g., A4 size). Therefore, according to this embodiment, by providing the first wall portion 181 and the second wall portion 182 only in the range where skew of the document is relatively likely to occur, it is possible to achieve both suppression of skew of the document and improved operability.

[0072] (Inclined surface of rotation restriction part) 9 to 11, the tapered shapes provided on the first wall portion 181 and the second wall portion 182 will be further described. FIG. 9 is a view of the document tray 8 as seen from the opposite side to the support surface 80. FIG. 9 shows the state just before the first convex portion 21e and the second convex portion 22e come into contact with the first wall portion 181 and the second wall portion 182 when the front regulating member 21 and the rear regulating member 22 are narrowed from their maximum widened state. FIG. 10 is an enlarged view of a part of FIG. 9 (the periphery of the second wall portion 182), and FIG. 11 is an enlarged view of another part of FIG. 9 (the periphery of the first wall portion 181).

[0073] As shown in FIGS. 10 and 12, the first wall portion 181 has a flat portion 181a extending in the seat width direction Dw and an inclined portion 181b inclined with respect to the seat width direction Dw.

[0074] The flat portion 181a is an abutting surface that abuts against the first convex portion 21e of the first rack portion 21b when the distance between the first restricting surface 21a and the second restricting surface 22a is equal to or less than a predetermined length (105 mm in this embodiment). The inclined portion 181b is provided upstream of the flat portion 181a in the movement direction Dw1 of the first rack portion 21b when narrowing the distance between the front restricting member 21 and the rear restricting member 22, and is inclined toward the upstream side in the sheet feeding direction Df toward the movement direction Dw1. In other words, the inclined portion 181b is inclined so as to approach the first convex portion 21e in the sheet feeding direction Df as it moves downstream in the movement direction Dw1. The movement direction Dw1 is the movement direction of the first rack portion 21b when the front restricting member 21 and the rear restricting member 22 are moved to narrow the distance between the first restricting surface 21a and the second restricting surface 22a from a state in which the distance is wider than a predetermined length.

[0075] As shown in FIGS. 10 and 11, the second wall portion 182 has a flat portion 182a extending in the seat width direction Dw and an inclined portion 182b inclined with respect to the seat width direction Dw.

[0076] The flat portion 182a is an abutting surface that abuts against the second convex portion 22e of the second rack portion 22b when the distance between the first restricting surface 21a and the second restricting surface 22a is equal to or less than a predetermined length (105 mm in this embodiment). The inclined portion 182b is provided upstream of the flat portion 182a in the movement direction Dw2 of the second rack portion 22b when narrowing the distance between the front restricting member 21 and the rear restricting member 22, and is inclined toward the upstream side in the sheet feeding direction Df toward the movement direction Dw2. In other words, the inclined portion 182b is inclined so as to approach the second convex portion 22e in the sheet feeding direction Df as it moves downstream in the movement direction Dw2. The movement direction Dw2 is the movement direction of the second rack portion 22b when the front restricting member 21 and the rear restricting member 22 are moved to narrow the distance between the first restricting surface 21a and the second restricting surface 22a from a state in which the distance is wider than a predetermined length.

[0077] By providing the inclined portions 181b, 182b on the first wall portion 181 and the second wall portion 182, when narrowing the gap between the front regulating member 21 and the rear regulating member 22, the first protrusion 21e and the second protrusion 22e are less likely to get caught on the ends of the first wall portion 181 and the second wall portion 182. This allows the front regulating member 21 and the rear regulating member 22 to be slid more smoothly, further improving operability.

[0078] When viewed in the height direction, the angle θ1 between a line extending along the sheet feeding direction Df and a line extending along the inclined portion 181b is set to, for example, 45° to 80°. When viewed in the height direction, the angle θ2 between a line extending along the sheet feeding direction Df and a line extending along the inclined portion 182b is set to, for example, 45° to 80°. As an example, it is preferable that θ1 and θ2 are set to about 70°.

[0079] (Other embodiments) In the above-described embodiments, a configuration example has been described in which the present technology is applied to the ADF 102, which is a sheet conveying device that conveys documents in the image reading device 101. However, the present technology is not limited to this, and may be applied to, for example, a sheet conveying device that conveys sheets used as recording materials in an image forming device. [Explanation of symbols]

[0080] 8...Placement portion (document tray) / 8a...First groove portion / 8b...Second groove portion / 21...First regulating member (front regulating member) / 21a...First regulating surface / 21b...First rack portion / 21d...First engagement portion (tray groove engagement portion) / 22...Second regulating member (rear regulating member) / 22a...Second regulating surface / 22b...Second rack portion / 22d...Second engagement portion (tray groove engagement portion) / 23...Pinion gear / 30...Feeding member (pickup roller) / 81, 82, 181, 182...Rotation regulating portion (first wall portion, second wall portion)

Claims

1. a loading section on which a sheet is loaded, the loading section having a first groove section and a second groove section formed therein and extending in a sheet width direction perpendicular to a sheet feeding direction; a feeding member that feeds the sheets placed on the sheet placement section in the sheet feeding direction; a first restricting member having a first restricting surface that restricts one end in the sheet width direction of the sheet placed on the placement portion, a first engaging portion that is engaged with the first groove portion below the first restricting surface, and a first rack portion that extends from the first engaging portion in the sheet width direction, and that is movable in the sheet width direction along the first groove portion; a second regulating member having a second regulating surface that regulates the other end in the sheet width direction of the sheet placed on the placement portion, a second engaging portion that is engaged with the second groove portion below the second regulating surface, and a second rack portion that extends from the second engaging portion in the sheet width direction, and that is movable in the sheet width direction along the second groove portion; a pinion gear configured to mesh with the first rack portion and the second rack portion, and to move the first regulating member and the second regulating member in the sheet width direction in conjunction with each other; a rotation regulating portion that abuts against the first rack portion at a position farther from the first engagement portion than the pinion gear in the sheet width direction and regulates a tip end of the first rack portion from moving downstream in the sheet feeding direction, thereby regulating rotation of the first regulating member in a direction in which a downstream end of the first regulating surface in the sheet feeding direction moves away from the second regulating surface; Equipped with When the distance between the first regulating surface and the second regulating surface in the sheet width direction is equal to or less than a predetermined length, the rotation regulating portion abuts against the first rack portion, When the gap is wider than the predetermined length, the rotation restricting portion does not come into contact with the first rack portion. A sheet feeding device characterized by:

2. the first restricting member has a first contact portion provided at a tip end of the first rack portion on a side farther from the first engaging portion in the seat width direction, The rotation restricting portion abuts against the first abutment portion.

2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

3. The teeth of the first rack portion are formed so that the tooth tips face the downstream side in the sheet feeding direction, the first contact portion protrudes downstream in the sheet feeding direction beyond the teeth of the first rack portion; 3. The sheet feeding device according to claim 2, wherein the sheet feeding device is a sheet feeding device.

4. When the rotation restricting portion is a first rotation restricting portion, a second rotation regulating portion that abuts against the second rack portion at a position farther from the second engaging portion than the pinion gear in the sheet width direction and regulates the tip of the second rack portion from moving downstream in the sheet feeding direction, thereby regulating the second regulating member from rotating in a direction in which the downstream end of the second regulating surface in the sheet feeding direction moves away from the first regulating surface; 2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

5. The teeth of the second rack portion are formed so that the tooth tips face the upstream side in the sheet feeding direction, the second regulating member has a second contact portion that is provided on a side surface portion downstream of the second rack portion in the sheet feeding direction and that extends in the sheet width direction, the second rotation restricting portion abuts against the second abutting portion; 5. The sheet feeding device according to claim 4.

6. The rotation restricting portion is a contact surface extending in the sheet width direction and contacting the first rack portion when the interval is equal to or less than the predetermined length; an inclined surface provided upstream of the contact surface in a moving direction of the first rack portion when the first regulating member and the second regulating member are moved so that the gap narrows from a state in which the gap is wider than the predetermined length, the inclined surface being inclined toward the upstream side of the sheet feeding direction toward the moving direction; 2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

7. the first regulating member and the second regulating member are capable of regulating a sheet having a length of 105 mm or less in the sheet width direction, When the first and second restricting surfaces are in contact with a side edge of a sheet having a length of 105 mm or less in the sheet width direction, the rotation restricting portion abuts against the first rack portion.

2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

8. the placement portion has a support surface that supports a sheet, the rotation restricting portion has a rib shape that is integrally formed with the support surface so as to protrude from a surface of the placement portion opposite to the support surface.

2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

9. The sheet feeding device according to any one of claims 1 to 8, a reading means for reading image information from the sheet fed by the sheet feeding device; An image reading device comprising:

10. The image reading device according to claim 9 ; an image forming means for forming an image on a recording material based on the image information read by the image reading device; An image forming apparatus comprising:

Images