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

Abstract

To reduce occurrence of conveying failure and skew of a sheet having small size in a width direction.SOLUTION: An ADF comprises a document tray, a pickup roller for feeding a document, and a first side regulation plate 31 and a second side regulation plate 32 arranged on a top surface of the document tray so as to be moved in a width direction of the document. The first side regulation plate 31 includes a first regulation surface 31Aa for regulating a position of the document in the width direction, and a first bottom plate part 31B slid with respect to the top surface of the document tray. The second side regulation plate 32 includes a second regulation surface 32Aa for regulating the position of the document in the width direction, and a second bottom plate part 32B slid with respect to the top surface of the document tray. A part of the first bottom plate part 31B is positioned on the side of the second regulation surface 32Aa beyond a middle position B in a state where the first regulation surface 31Aa and the second regulation surface 32Aa are brought closest to each other in the width direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a sheet feeding device, an image reading device, and an image forming apparatus, in which a stacking tray for stacking sheets is provided with a first regulating portion and a second regulating portion for regulating the position of the sheet in the width direction. [Background technology]

[0002] For example, some image forming apparatuses, such as copiers and multifunction peripherals, are equipped with an automatic document feeder (hereinafter referred to as "ADF") that transports sheet-like documents to an image reading unit. In general, such an ADF is provided with a document tray on which documents (sheets) are stacked, and two side regulating plates (side guide mechanisms) that abut on both sides of the widthwise edges of the documents to regulate the widthwise position of the documents (see Patent Document 1). A user places a document on the document tray and slides the two side regulating plates so that they abut against the widthwise edges of the documents. This regulates the widthwise position of the documents set on the stacking tray, thereby ensuring a good posture of the documents when they are subsequently fed and their images are read by an image reading device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-8766 Summary of the Invention [Problem to be solved by the invention]

[0004] The side regulating plate has a regulating portion formed with a regulating surface that abuts against the widthwise end of the document, and a bottom plate portion that is slidably provided on the top surface of the stacking tray and is integral with the regulating portion. . bottom The plate portion is provided on the side of the restricting surface of the restricting portion, that is, on the inner side in the width direction of the two side restricting plates.

[0005] On the other hand, in recent years, there has been a demand for documents with a small width, such as business cards, to be fed and read using the ADF. In order to configure the scanner to be able to load documents with a small width, such as business cards, the restriction portions of the two side restriction plates must be moved closer to each other in the width direction. To be able to There is a need It was.

[0007] Therefore, the present invention provides a sheet having a small width. Compatible with It is an object of the present invention to provide a sheet feeding device, an image reading device, and an image forming apparatus that are capable of doing so. [Means for solving the problem]

[0008] One aspect of the present invention provides a sheet feeding device including a stacking tray having a stacking surface on which sheets are stacked, a feeding unit that feeds the sheets stacked on the stacking tray, and first and second regulating units that are movable in a width direction perpendicular to a sheet feeding direction and that regulate a position of the sheets stacked on the stacking surface in the width direction, wherein the stacking surface has a first slit extending in the width direction and a second slit that is disposed at a position different from the first slit in the feeding direction and that extends in the width direction, and the first regulating unit has a first regulating surface that abuts against one end in the width direction of the sheets stacked on the stacking surface, a first bottom plate that slides against an upper surface of the stacking tray and supports the sheets together with the stacking surface, and a first protrusion that moves inside the first slit, and the second regulating unit has a second regulating surface that abuts against the other end in the width direction of the sheets stacked on the stacking surface, the first bottom plate portion has a first inclined portion inclined with respect to the feeding direction such that an outer edge of the first regulating surface side in the width direction moves away from the first regulating surface toward the downstream side in the feeding direction when viewed from above, the second bottom plate portion has a second inclined portion inclined with respect to the feeding direction such that an outer edge of the first regulating surface side in the width direction moves closer to the second regulating surface toward the downstream side in the feeding direction when viewed from above, a first tip end portion of the first regulating portion located closest to the second regulating surface in the width direction and a second tip end portion of the second regulating portion located closest to the first regulating surface in the width direction are disposed at mutually different positions in the feeding direction, and the first regulating surface and the second regulating surface Mutually Closest to In a state where , the first tip The portion in the width direction a center position between the first and second restriction surfaces; the second tip portion is located on the side of the first restriction surface with respect to the center position between the first restriction surface and the second restriction surface in the width direction, The sheet feeding device is characterized by the above. [Effects of the Invention]

[0010] According to the present invention, a sheet having a small size in the width direction Compatible with It is possible. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view showing a printer according to a first embodiment. [Figure 2] 1A is a schematic cross-sectional view showing an image reading device equipped with an ADF according to a first embodiment, and FIG. 1B is a schematic view showing an image engine. [Figure 3] 1A is a perspective view showing the entire ADF according to the first embodiment with the first and second side regulating plates closed, and FIG. 1B is a perspective view showing the entire ADF according to the first embodiment with the first and second side regulating plates opened. [Figure 4] 1A is a perspective view showing only the first and second side regulating plates according to the first embodiment, and FIG. 1B is an enlarged perspective view showing the first and second side regulating plates according to the first embodiment when they are attached to a stacking tray. [Figure 5] 1A is an enlarged perspective view showing a state in which a first side regulating plate and a second side regulating plate according to the first embodiment are provided on a stacking tray, and FIG. [Figure 6] 1A is a perspective view showing the side regulating mechanism in a state where the first and second side regulating plates are open, and FIG. 1B is a perspective view showing the side regulating mechanism in a state where the first and second side regulating plates are closed. [Figure 7] 1A is a schematic cross-sectional view showing the relationship between the component tolerances of the second side regulating plate, the inclination of the regulating surface, and the positional tolerance of the regulating surface in the first embodiment, and FIG. 1B is a schematic top view showing the relationship between the positional tolerances of the first and second regulating surfaces and the document to be set in the first embodiment. [Figure 8] 10A is a perspective view showing an entire ADF with a first side regulating plate and a second side regulating plate closed according to a second embodiment, and FIG. 10B is a perspective view showing only the first side regulating plate and the second side regulating plate according to the second embodiment. [Figure 9]10A is a perspective view showing an entire ADF with a first side regulating plate and a second side regulating plate closed according to a third embodiment, and FIG. 10B is a perspective view showing only the first side regulating plate and the second side regulating plate according to the third embodiment. [Figure 10] 10A is a perspective view showing an entire ADF with a first side regulating plate and a second side regulating plate closed according to a fourth embodiment, and FIG. 10B is a perspective view showing only the first side regulating plate and the second side regulating plate according to the fourth embodiment. [Figure 11] 1A is a perspective view showing the ADF in a state where the first and second side regulating plates are closed and the first and second bottom plate portions are shortened, and FIG. 1B is a perspective view showing the ADF in a state where the first and second side regulating plates are opened and the first and second bottom plate portions are shortened. [Figure 12] 1A is a schematic cross-sectional view showing the relationship between the component tolerances, the inclination of the regulating surface, and the positional tolerance of the regulating surface in the second side regulating plate when the second bottom plate portion is shortened, and FIG. 1B is a schematic top view showing the relationship between the positional tolerances of the first and second regulating surfaces and the document to be set when the first and second bottom plate portions are shortened. DETAILED DESCRIPTION OF THE INVENTION

[0012] First Embodiment [Overall configuration] A first embodiment will be described below. A printer 100 serving as an image forming apparatus according to this first embodiment is an electrophotographic laser beam printer. As shown in FIG. 1, the printer 100 includes a printer main body 70, an image reading device 10 attached to the top of the printer main body 70, and an operation unit 90 having a display unit 91 and operation keys 92 for various notifications and operations. As shown in FIG. 2(b), the printer main body 70 includes an image forming engine 60. In the following description, the term "sheet" refers to not only plain paper but also special paper such as cardboard and coated paper, recording materials in special shapes such as envelopes and index paper, and plastic film or cloth for overhead projectors, and a manuscript is also an example of a sheet.

[0013] As shown in FIG. 2(b), the image forming engine 60 as an image forming section includes an image forming unit PU as an electrophotographic image forming means, and a fixing device 7. When a command to start an image forming operation is issued, the photosensitive drum 1, which is a photosensitive member, rotates, and the drum surface is uniformly charged by the charging device 2. Then, the exposure device 3 modulates and outputs laser light based on image data transmitted from the image reading device 10 or an external computer, and scans the surface of the photosensitive drum 1 to form an electrostatic latent image. This electrostatic latent image is visualized (developed) into a toner image by toner supplied from the developing device 4.

[0014] In parallel with this image forming operation, a feeding operation is performed to feed sheets loaded on a cassette or manual feed tray (not shown) toward the image forming engine 60. The fed sheets are transported in accordance with the progress of the image forming operation by the image forming unit PU. The toner image carried on the photosensitive drum 1 is then transferred onto the sheet by the transfer roller 5. Any toner remaining on the photosensitive drum 1 after the toner image has been transferred is collected by a cleaning device 6. The sheet onto which the unfixed toner image has been transferred is passed to a fixing device 7, where it is sandwiched between a pair of rollers and heated and pressurized. The sheet on which the toner has melted and adhered to the sheet and the image has been fixed is discharged by a discharge means such as a pair of discharge rollers.

[0015] [Image reader] Next, the image reading device 10 will be described in detail. As shown in FIG. 2(a), the image reading device 10 includes an ADF (automatic document feeder) 20 that feeds documents loaded on a document tray 121 as a loading tray and discharges them onto a discharge tray 122, and a reading unit 40 that reads the documents transported by the ADF 20. That is, the ADF 20 constitutes a sheet feeding device that transports sheets as documents to the reading unit 40. The reading unit 40 has a front surface reading unit 104 as a reading section that reads an image on the front surface of the document. The ADF 20 is rotatably supported relative to the reading unit 40 by a hinge (not shown) so that a document table glass 101 can be opened. Furthermore, the document, which is an example of a sheet, may be blank paper or may have an image formed on one or both sides.

[0016] The ADF 20 has a pickup roller 111 as a feeding section, and a separation drive roller 112 and a retard roller 113 that form a separation roller pair. The ADF 20 also has a registration roller pair 114, a read roller pair 115, a conveyance roller pair 117, and a discharge roller pair 119. The ADF 20 also has a back side reading unit 105 as a reading section. Meanwhile, the reading unit 40 has a platen glass 102, a document table glass 101, and a front side reading unit 104 as image reading means. The front side reading unit 104 is configured to be slidable, that is, configured to be movable in the sub-scanning direction of a reading sensor (not shown).

[0017] As shown in FIGS. 3A and 3B, the document tray 121 also includes a side restriction mechanism 30, which serves as a width restriction means on the document loading surface. The side restriction mechanism 30 is movable in a width direction perpendicular to the feeding direction and contacts the widthwise edges of the documents to restrict the widthwise position of the documents. The side restriction mechanism 30 is composed of a pair (two) of first and second restriction members, a first side restriction plate 31 and a second side restriction plate 32, which are movable in the width direction. The first and second side restriction plates 31 and 32 are connected to an interlocking mechanism 50 (see FIGS. 6A and 6B), which is a rack-and-pinion mechanism (described later in detail). As a result, movement of one of the first side restriction plate 31 and the second side restriction plate 32 interlocks with and moves the other in the width direction. That is, the center of transport of the document is at the center in the width direction, and these side regulating plates 31, 32 are configured to approach or move away from the center in the width direction, that is, configured so that the center of the document is at the same position as the center of transport regardless of the size of the document.

[0018] Next, the operation of reading a document will be described with reference to Fig. 2(a). The image reading device 10 reads image information from a document in a flow reading mode in which the document image is scanned while the document loaded on the document tray 121 is transported by the ADF 20, and in a fixed reading mode in which the document placed on the document glass 101 is scanned. The flow reading mode is selected when a document presence / absence sensor (not shown) detects the document loaded on the document tray 121, or when the user explicitly instructs it via the operation unit 90 or the like.

[0019] When the flow-reading mode is executed, the pickup roller 111 descends and abuts against the topmost document on the document tray 121. The document is then transported by the pickup roller 111 and separated one by one at a separation nip formed by the separation drive roller 112 and the retard roller 113. A torque limiter is provided in the rotation support structure of the retard roller 113, so that the retard roller 113 rotates along with the separation drive roller 112 when a single document is transported, but does not rotate when two or more documents are transported. This allows the document to be separated one by one. Note that a drive force in the opposite direction to the sheet transport direction may be input to the retard roller 113. Meanwhile, the front surface reading unit 104 is moved below the platen glass 102 to read the document being transported simultaneously with the descent of the pickup roller 111. The transported document is transported toward the platen glass 102 by a registration roller pair 114 and a lead roller pair 115.

[0020] In the case of front side reading, the image on the front side of the document is read by the front side reading unit 104 through the platen glass 102. The reading surface is illuminated by a light source of the front side reading unit 104, and the light reflected from the document surface is photoelectrically converted line by line by a light receiving element of a reading sensor (not shown). The photoelectrically converted image information is transferred to an image memory of a control unit (not shown). Then, the document that has passed through the platen glass 102 is guided by a pair of conveying rollers 117 and discharged onto a discharge tray 122 by a pair of discharge rollers 119.

[0021] In the case of double-sided reading, the front side is read by the front side reading unit 104 as described above, and the image on the back side of the document is read by the back side reading unit 105. Similarly, the reading surface is illuminated by the light source of the back side reading unit 105, and the light reflected from the document surface is photoelectrically converted line by line by the light receiving element of the reading sensor (not shown). The photoelectrically converted image information is transferred to the image memory of the control unit.

[0022] On the other hand, the fixed reading mode is selected when the device detects a document placed on the document glass 101 or when the user explicitly instructs this via the operation unit 90. In this case, the document on the document glass 101 does not move, and the front surface reading unit 104 is moved along the document glass 101 to scan the document. Similarly, image information photoelectrically converted by the light receiving element of the reading sensor of the front surface reading unit 104 is transferred to the image memory of the control unit.

[0023] [Detailed configuration of side regulation mechanism] Next, the detailed configuration of the side regulating mechanism 30 will be described using FIGS. 4(a), 4(b), 5(a), 5(b), 6(a), and 6(b). As shown in FIGS. 4(a) and 6(a), the side regulating mechanism 30 is roughly configured to include a first side regulating plate 31, a second side regulating plate 32, and an interlocking mechanism 50 that interlocks their movement in the width direction. In the following description, with a center position B between the first side regulating plate 31 and the second side regulating plate 32 as a reference, the side facing the center position B is referred to as the inside, and the opposite side is referred to as the outside. In addition, in describing the first bottom plate portion 31B and the second bottom plate portion 32B described below, the portions that are integrally connected to the first regulating portion 31A and the second regulating portion 32A in the width direction of the seat are referred to as the root, and the opposite side is referred to as the tip, and are referred to as the root side and the tip side, respectively.

[0024] In the first embodiment, as shown in FIGS. 4(a) and 6(a), the first side regulating plate 31 has a first regulating portion 31A, a first bottom plate portion 31B, and a first slider portion 31C. As shown in FIGS. 4(a) and 4(b), the first regulating portion 31A is disposed so as to protrude upward from the document stacking surface 121a of the document tray 121. The first regulating portion 31A is formed with a first regulating surface 31Aa that abuts against an edge of a document in the width direction loaded on the document tray 121 to regulate its position. The first regulating surface 31Aa is disposed facing inward between the first side regulating plate 31 and the second side regulating plate 32 so as to face a second regulating surface 32Aa of the second side regulating plate 32 (described later).

[0025] Furthermore, the first bottom plate portion 31B is formed at two locations for one first restricting portion 31A. Each first bottom plate portion 31B is formed in a rectangular shape when viewed from above, with its base portion formed integrally with the first restricting portion 31A and extending in the width direction toward its tip. The upper surface 31Ba of the first bottom plate portion 31B is disposed so as to be substantially flush with the document loading surface 121a of the document tray 121, and forms the document loading surface. The widthwise length of the first bottom plate portion 31B will be described in detail later.

[0026] As shown in FIGS. 6(a) and 6(b), the first slider portion 31C is integrally formed with the first restricting portion 31A and the first bottom plate portion 31B so as to protrude downward from the side opposite the upper surface 31Ba of the first bottom plate portion 31B. Meanwhile, as shown in FIG. 5(a), the document tray 121 is formed with a groove-shaped (slit-shaped) guide groove 121c with the width direction as the longitudinal direction. The document tray 121 is also formed with a plurality of ribs 121b protruding upward parallel to the guide groove 121c. As shown in FIGS. 5(b), 6(a), and 6(b), the plurality of ribs 121b slide on a base-side sliding portion 31Ab located at the end of the width direction below the first restricting portion 31A and a tip-side sliding portion 31Bb located at the tip of the width direction below the first bottom plate portion 31B. Therefore, the first side regulating plate 31 is arranged to be movable (slidable) in the width direction relative to the document tray 121 by sliding on the upper surfaces of the multiple ribs 121b and the first slider portion 31C being guided by the guide groove portion 121c.

[0027] Similarly, as shown in FIGS. 4(a) and 6(a), the second side regulating plate 32 has a second regulating portion 32A, a second bottom plate portion 32B, and a second slider portion 32C. As shown in FIGS. 4(a) and 4(b), the second regulating portion 32A is disposed so as to protrude upward from the document stacking surface 121a of the document tray 121. The second regulating portion 32A is formed with a second regulating surface 32Aa that abuts against an edge of a document in the width direction loaded on the document tray 121 to regulate its position. The second regulating surface 32Aa is disposed facing inward between the first side regulating plate 31 and the second side regulating plate 32 so as to face the first regulating surface 31Aa of the first side regulating plate 31 described above.

[0028] The second bottom plate portion 32B is formed so as to be located at one position for one second restricting portion 32A and between the two second bottom plate portions 31B of the first restricting portion 31A in the feeding direction. The second bottom plate portion 32B is formed in a rectangular shape when viewed from above, with its base portion formed integrally with the second restricting portion 32A and extending in the width direction toward its tip. The upper surface 32Ba of the second bottom plate portion 32B is positioned so as to be substantially flush with the document loading surface 121a of the document tray 121, thereby forming the document loading surface. The widthwise length of the second bottom plate portion 32B will be described in detail later.

[0029] As shown in FIGS. 6(a) and 6(b), the second slider portion 32C is integrally formed with the second restricting portion 32A and the second bottom plate portion 32B so as to protrude downward from the side opposite the upper surface 32Ba of the second bottom plate portion 32B. As described above, the document tray 121 is formed with the guide groove portion 121c and a plurality of ribs 121b. As shown in FIGS. 5(b), 6(a), and 6(b), the base-side sliding portion 32Ab at the lower end of the second restricting portion 32A in the width direction and the tip-side sliding portion 32Bb at the lower tip of the second bottom plate portion 32B in the width direction slide on the plurality of ribs 121b. Therefore, the second side restricting plate 32 is arranged to be movable (slidable) in the width direction relative to the document tray 121 by the second slider portion 32C being guided by the guide groove portion 121c while sliding on the upper surfaces of the plurality of ribs 121b.

[0030] As shown in FIGS. 5(b), 6(a), and 6(b), the interlocking mechanism 50 is configured as a rack-and-pinion mechanism disposed inside the document tray 121. The interlocking mechanism 50 includes a first rack 51, a second rack 52, a pinion 53, and a support plate 54. The first rack 51 is connected to one of the first slider portions 31C of the first side regulating plate 31, and the second rack 52 is connected to the second slider portion 32C of the second side regulating plate 32. The first rack 51 and the second rack 52 are disposed on the rear side of the document tray 121 because the first slider portion 31C and the second slider portion 32C each pass through the guide groove portion 121c. The pinion 53 has a central axis supported by a support plate 54 fixed to the rear side of the document tray 121 and is engaged with the first rack 51 and the second rack 52. As a result, as described above, moving one of the first side regulating plate 31 and the second side regulating plate 32 moves the other in the width direction in conjunction with the first regulating surface 31Aa and the second regulating surface 32Aa so that the center of the document, both ends of which are regulated by the first regulating surface 31Aa and the second regulating surface 32Aa, is positioned at the same position as the conveyance center.

[0031] [Regarding position tolerance of control surfaces due to component tolerances] Next, we will explain the inclination of the first and second restriction surfaces 31Aa and 32Aa and the positional tolerance at their upper ends, which arise due to component tolerances in the first and second side restriction plates 31 and 32. First, we will explain a case where the widthwise lengths of the first and second bottom plate portions are formed to be half the width of a business card, so that both widthwise ends of a business card can be restricted by the first and second restriction surfaces of the first and second side restriction plates. Note that in the following explanation, for parts that are similar between the first and second side restriction plates, we will explain the second side restriction plate as an example, and will omit explanation of the first side restriction plate.

[0032] 11(a) and 11(b) show an ADF that can accommodate a size such as a business card. The ADF 10 includes a side restriction mechanism 530, which includes a first side restriction plate 531 and a second side restriction plate 532, mounted on the document tray 121. To load a business card onto the document tray 121, the first and second side restriction plates 531 and 532 must be moved from their separate widthwise positions shown in FIG. 11(b) to the width of the business card shown in FIG. 11(a). Therefore, the widthwise lengths of the first and second bottom plate portions 531B and 532B of the first and second side restriction plates 531 and 532 are extended to a central position (center line) B, which is the center of their widthwise lengths. In other words, they are formed to be half the width of a business card. The length of the first and second side restriction plates 531 and 532 in the feeding direction is a typical length L1 (see FIG. 12(b)).

[0033] However, if the widthwise lengths of the first bottom plate portion 531B and the second bottom plate portion 532B are short, the following problem occurs. As shown in FIG. 12A, the second side regulating plate 532 has a base-side sliding portion 532Ab at the second regulating portion 532A that slides against the document tray 121, and a tip-side sliding portion 532Bb at the tip of the bottom plate portion 532B that slides against the document tray 121. Assume that a component tolerance d12 occurs in the height direction between the base-side sliding portion 532Ab and the tip-side sliding portion 532Bb. Then, when the widthwise length of the second bottom plate portion 532B is W11, the second regulating surface 532Aa of the second regulating portion 532A is inclined at an angle θ11, resulting in a position error d11 at the upper end of the second regulating surface 532Aa.

[0034] Similarly, if the tip-side sliding portion of the first side regulating plate 531 has a component tolerance d12 relative to the base-side sliding portion, a position error d11 also occurs at the upper end of the first regulating surface 531Aa shown in FIG. 12B. Suppose a stack of A4-sized original documents S1, each having a length LS1 in the feeding direction and a width WS1 in the width direction, is set. With respect to the width WS1 of the original documents S1, the widthwise distance between the upper ends of the first regulating surface 531Aa and the second regulating surface 532Aa is "WS1 + d11 × 2." Therefore, even though the original documents S1 set between the first side regulating plate 531 and the second side regulating plate 532 are regulated by the length L1 of the first regulating surface 531Aa and the second regulating surface 532Aa, a gap of position error d11 × 2 occurs. Therefore, the angle θ12 of the original S1 is inclined at a maximum of tan θ=d11×2 / L1, which means that the skew (initial skew) that occurs from the start of feeding becomes large.

[0035] In addition, there may be cases where the component tolerances of the leading-edge sliding portions of the first and second side regulating plates 531 and 532 are reversed relative to the component tolerances of the root-edge sliding portions, i.e., the leading-edge sliding portion 532Bb is lower than the root-edge sliding portion 532Ab (component tolerance -d12). In this case, the position error of the upper ends of the first regulating surface 531Aa and the second regulating surface 532Aa is the position error -d11, meaning that the upper ends are tilted inward. In this case, if the user presses the first and second side regulating plates 531 and 532 inward strongly when setting the stack of originals S1, the upper originals S1 of the stack are tightly clamped, creating a transport load. This may result in a transport failure in which the pickup roller 111 cannot transport the originals. Furthermore, if the user does not press the first side regulating plate 531 and the second side regulating plate 532 inward strongly when setting the stack of originals S1, the position error of the lower ends of the first regulating surface 531Aa and the second regulating surface 532Aa becomes the position error d11. Therefore, as described above, the skew (initial skew) that occurs from the start of feeding below the stack of originals S1 becomes large.

[0036] Next, we will explain the inclination of the first and second restricting surfaces 31Aa and 32Aa and the positional tolerance at their upper ends, which are caused by component tolerances in the first and second side restricting plates 31 and 32 in this first embodiment. The width direction lengths of the first and second bottom plate portions 31B and 32B of the first and second side restricting plates 31 and 32 in this first embodiment are formed to a length W1, which is the width of a business card, as shown in FIG. 7(a). In other words, they are formed to a length twice the length of the second bottom plate portion 532B shown in FIG. 12(a).

[0037] That is, the first bottom plate portion 31B and the second bottom plate portion 32B are alternately formed at different positions in the feeding direction. Therefore, when the first side regulating plate 31 and the second side regulating plate 32 are closest to each other, the leading edge of the first bottom plate portion 31B abuts against the second regulating surface 32Aa, and the leading edge of the second bottom plate portion 32B abuts against the first regulating surface 31Aa. In other words, the first bottom plate portion 31B and the second bottom plate portion 32B are formed so that a portion (approximately half) thereof extends beyond the center position B, which is the center in the width direction, when the first side regulating plate 31 and the second side regulating plate 32 are closest to each other. Therefore, when the first side regulating plate 31 and the second side regulating plate 32 are closest to each other, the first bottom plate portion 31B and the second bottom plate portion 32B are configured to overlap each other when viewed from the feeding direction.

[0038] In the second side regulating plate 32 configured as above, as shown in FIG. 7A, a component tolerance d2 occurs in the height direction between the base-side sliding portion 32Ab, which is the portion that slides against the document tray 121, and the tip-side sliding portion 32Bb, which is the portion that slides against the document tray 121. Since the width direction length of the second bottom plate portion 32B is W1, the second regulating surface 32Aa of the second regulating portion 32A is inclined at an angle θ1. Only a position error d1 occurs at the upper end of the second regulating surface 32Aa, which has a height direction length W2. That is, assume that the component tolerance d2 is the same as the component tolerance d12 (see FIG. 12A) and the height direction length W2 is also the same. Since the width direction length W1 of the second bottom plate portion 32B is double the length W11, the angle θ1 is half the angle θ11, and the position error d1 is also half the position error d11.

[0039] Similarly, even if the tip-side sliding portion 31Bb (see FIG. 5B) of the first side regulating plate 31 has a component tolerance d12 relative to the base-side sliding portion 31Ab, the position error occurring at the upper end of the first regulating surface 31Aa shown in FIG. 7B is a position error d1. Assume that a stack of A4-sized original documents S1, each having a length LS1 in the feeding direction and a width WS1 in the width direction, is set. With respect to the width WS1 of the original documents S1, the widthwise distance between the upper ends of the first regulating surface 31Aa and the second regulating surface 32Aa is "WS1+d1×2," which is half of the distance "WS1+d11×2." Therefore, when the original documents S1 are set between the first side regulating plate 31 and the second side regulating plate 32, a gap of a position error d1×2 occurs while the original documents S1 are regulated by the length L1 of the first regulating surface 31Aa and the second regulating surface 32Aa, but this is half of the position error d11×2. Therefore, the angle θ2 of the original S1 is at most tan θ=d11×2 / L1, which means that the skew (initial skew) that occurs from the start of feeding is reduced.

[0040] Furthermore, in the first and second side regulating plates 31 and 32, the component tolerances of the leading-edge sliding portions may be reversed relative to the base-edge sliding portions, i.e., the leading-edge sliding portion 32Bb may be lower than the base-edge sliding portion 32Ab (component tolerance -d2). Even in this case, the position error of the upper ends of the first and second regulating surfaces 31Aa and 32Aa is the position error -d1, meaning that the upper ends tilt inward. However, even if the user presses the first and second side regulating plates 31 and 32 inward strongly when setting a stack of originals S1, the distance over which the upper originals S1 of the stack are tightly clamped is halved, thereby reducing the transport load. This also reduces the occurrence of transport failures in which the pickup roller 111 is unable to transport the originals. Furthermore, if the user does not press the first and second side regulating plates 31 and 32 inward strongly when setting the stack of documents S1, the position error of the lower ends of the first and second regulating surfaces 31Aa and 32Aa will be the position error d1. Even in this case, the gap that occurs in the width direction of the documents S1 below the stack will be the position error d1 × 2, and the skew that occurs below the stack of documents S1 from the start of feeding will be reduced.

[0041] As described above, the first bottom plate portion 31B and the second bottom plate portion 32B are formed so as to extend beyond the center position B (see FIG. 4(b)) between the first and second restricting surfaces 31Aa, 32Aa when the first and second restricting surfaces 31Aa, 32Aa are closest to each other. That is, the tip of the first bottom plate portion 31B extends beyond the center position B and is positioned on the side of the second restricting surface 32Aa, and the tip of the second bottom plate portion 32B extends beyond the center position B and is positioned on the side of the first restricting surface 31Aa.

[0042] As a result, the length W1 is defined as the length between the base sliding portions 31Ab, 32Ab and the tip sliding portions 31Bb, 32Bb at both ends of the portions of the first and second side regulating plates 31, 32 that slide against the document tray 121. The length W1 can be longer than half the length W11, which is the length when the first and second regulating surfaces 31Aa, 32Aa are closest to each other. Therefore, even if there is a component tolerance d2 between the base sliding portions 31Ab, 32Ab and the tip sliding portions 31Bb, 32Bb, the inclination angle θ1 of the first and second regulating surfaces 31Aa, 32Aa can be reduced. This reduces the position error d1 of the upper ends of the first and second regulating surfaces 31Aa, 32Aa. Therefore, when the first and second regulating surfaces 31Aa, 32Aa are inclined inward, the transport resistance of the placed document can be reduced, reducing the occurrence of transport failures. Furthermore, when the first and second restricting surfaces 31Aa and 32Aa are inclined outward, the inclination of the set document relative to the feeding direction can be reduced, and the occurrence of skew during feeding can be reduced. This reduces the inclination of the image read by the front surface reading unit 104 and the back surface reading unit 105, and prevents a decrease in reading quality.

[0043] <Second embodiment> Next, a second embodiment, which is a partial modification of the first embodiment, will be described with reference to Figures 8(a) and 8(b). In the description of the second embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0044] In the second embodiment, the shapes of the first and second bottom plates are changed compared to the first embodiment. Specifically, as shown in FIGS. 8(a) and 8(b), the side regulating mechanism 130 in the second embodiment has a first side regulating plate 131 and a second side regulating plate 132, similar to the first embodiment. Similarly, the first side regulating plate 131 has a first regulating portion 131A having a first regulating surface 131Aa and a first bottom plate portion 131B, and the second side regulating plate 132 has a second regulating portion 132A having a second regulating surface 132Aa and a second bottom plate portion 132B.

[0045] In the second embodiment, the first bottom plate portion 131B and the second bottom plate portion 132B are each formed as a single unit, rectangular in shape when viewed from above, and positioned at different positions in the feeding direction. When the first restricting surface 131Aa and the second restricting surface 132Aa are closest to each other, the leading ends of the first bottom plate portion 131B and the second bottom plate portion 132B extend beyond the center position B and have widthwise lengths that allow them to abut against the first restricting surface 131Aa and the second restricting surface 132Aa, respectively. In other words, when the first restricting surface 131Aa and the second restricting surface 132Aa are closest to each other, the first bottom plate portion 131B and the second bottom plate portion 132B overlap when viewed from the feeding direction but do not overlap when viewed from the widthwise direction. Therefore, as in the first embodiment, the inclination of the first restricting surface 131Aa and the second restricting surface 132Aa caused by component tolerances is reduced, and positional errors at their upper ends are also reduced.

[0046] The other configurations, actions, and effects of the second embodiment are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0047] <Third embodiment> Next, a third embodiment, which is a partial modification of the first embodiment, will be described with reference to Figures 9(a) and 9(b). In the description of the third embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0048] In the third embodiment, the shapes of the first and second bottom plates are modified compared to the first embodiment. Specifically, as shown in Figures 9(a) and 9(b), the side regulation mechanism 230 in the third embodiment has a first side regulation plate 231 and a second side regulation plate 232, similar to the first embodiment. Similarly, the first side regulation plate 231 has a first regulation portion 231A having a first regulation surface 231Aa and a first bottom plate portion 231B, and the second side regulation plate 232 has a second regulation portion 232A having a second regulation surface 232Aa and a second bottom plate portion 232B.

[0049] In the third embodiment, the first bottom plate portion 231B and the second bottom plate portion 232B are each composed of two (or more) pieces, each rectangular when viewed from above, and alternately arranged at different positions in the feeding direction, forming a so-called comb-like shape. When the first restricting surface 231Aa and the second restricting surface 232Aa are closest to each other, the leading ends of the first bottom plate portion 231B and the second bottom plate portion 232B extend beyond the center position B and have widthwise lengths that allow them to abut against the first restricting surface 231Aa and the second restricting surface 232Aa, respectively. In other words, when the first restricting surface 231Aa and the second restricting surface 232Aa are closest to each other, the first bottom plate portion 231B and the second bottom plate portion 232B overlap when viewed from the feeding direction but do not overlap when viewed from the widthwise direction. Therefore, similarly to the first embodiment, the inclination of the first restriction surface 231Aa and the second restriction surface 232Aa caused by component tolerances is reduced, and the positional error at their upper ends is also reduced.

[0050] The other configurations, actions, and effects of the third embodiment are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0051] <Fourth embodiment> Next, a fourth embodiment, which is a partial modification of the first embodiment, will be described with reference to Figures 10(a) and 10(b). In the description of the fourth embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0052] In the fourth embodiment, the shapes of the first and second bottom plates are modified compared to the first embodiment. Specifically, as shown in Figures 10(a) and 10(b), a side regulating mechanism 330 in the fourth embodiment has a first side regulating plate 331 and a second side regulating plate 332, similar to the first embodiment. Similarly, the first side regulating plate 331 has a first regulating portion 331A having a first regulating surface 331Aa and a first bottom plate portion 331B, and the second side regulating plate 332 has a second regulating portion 332A having a second regulating surface 332Aa and a second bottom plate portion 332B.

[0053] In the fourth embodiment, the first bottom plate portion 331B and the second bottom plate portion 332B are each formed as a single piece and are formed in a triangular shape with the first restriction surface 331Aa or the second restriction surface 332Aa as the base when viewed from above. That is, the first bottom plate portion 331B and the second bottom plate portion 332B are formed in a so-called tapered shape, in which the width in the feeding direction decreases toward the leading end in the width direction. When the first restriction surface 331Aa and the second restriction surface 332Aa are closest to each other, the leading ends of the first bottom plate portion 331B and the second bottom plate portion 332B extend beyond the center position B and have widthwise lengths that allow them to abut against the first restriction surface 331Aa and the second restriction surface 332Aa, respectively. That is, the first bottom plate portion 331B and the second bottom plate portion 332B are shaped so that they overlap when viewed from the feeding direction with the first restriction surface 331Aa and the second restriction surface 332Aa closest to each other. Therefore, similar to the first embodiment, the inclination of the first restriction surface 331Aa and the second restriction surface 332Aa caused by component tolerances is reduced, and the positional error at their upper ends is also reduced.

[0054] The other configurations, actions, and effects of the fourth embodiment are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0055] <Possibilities for other embodiments> In the above first to fourth embodiments, the first and second bottom plate portions both exceed the center position B when the first and second side regulating plates are closest to each other. However, this is not limiting, and only the first bottom plate portion (or the second bottom plate portion) may exceed the center position B. Even in this case, there is an effect of reducing the position error of the side that exceeds the center position B.

[0056] In the first to fourth embodiments, the leading edge of the first bottom plate abuts against the second restriction surface and the leading edge of the second bottom plate abuts against the first restriction surface when the first and second side restriction plates are closest to each other. However, the leading edge of the first or second bottom plate may be slightly beyond the center position B when the first and second side restriction plates are closest to each other. Even in this case, there is an advantage in that positional errors are reduced compared to when the leading edge does not exceed the center position B. In other words, as long as at least a portion of the first and second bottom plate exceeds the center position B when the first and second side restriction plates are closest to each other, there is an advantage in that positional errors are reduced compared to when the leading edge does not exceed the center position B. In this case, the portion where the first and second side restriction plates abut against each other when the first and second side restriction plates are closest to each other is not limited to the leading edge of the first or second bottom plate. For example, it is conceivable to abut any part of the first bottom plate portion of the first side regulating plate (the second bottom plate portion of the second side regulating plate) against a predetermined part, such as a protrusion, of the document tray.It is also conceivable to abut the first rack (second rack) fixed to the first side regulating plate (second side regulating plate) against a predetermined part, such as a protrusion, of the document tray.

[0057] In the first to third embodiments, the first and second bottom plate portions are rectangular when viewed from above, and in the fourth embodiment, the first and second bottom plate portions are triangular when viewed from above. However, the present invention is not limited to this. Any shape may be used as long as the first and second side regulating plates are not hindered when moved in the width direction and the leading edge of the first or second bottom plate portion extends beyond the center position B. For example, the boundary between the first and second bottom plate portions when the first and second side regulating plates are closest to each other may be arc-shaped or stepped, or there may be a gap between the first and second bottom plate portions.

[0058] In the first to fourth embodiments, the inclination of the first and second restricting surfaces and the positional error of their upper ends due to component tolerances between the base-side sliding portion and the tip-side sliding portion of the first and second bottom plates have been described. However, this is not limiting. For example, the sliding portions of the first and second bottom plates that slide with the top surface of the document tray may have a planar shape that allows for surface contact. In other words, the present invention can be applied to any shape that causes a difference in the vertical height between the base and tip sides of the sliding portions of the first and second bottom plates due to component tolerances.

[0059] In the first to fourth embodiments, a rack-and-pinion mechanism is used as the interlocking mechanism for interlocking the first and second side regulating plates. However, the present invention is not limited to this, and any mechanism that functions as an interlocking mechanism, such as a belt and pulley, may be used.

[0060] In the first to fourth embodiments, the sheet feeding device is described as being provided in an image reading device. However, the present invention is not limited to this, and may be a manual feed tray or paper feed cassette equipped with first and second side regulating plates on which sheets as recording materials can be set. Even in this case, sheet skew can be reduced, and deterioration in positional accuracy when an image is formed on the sheet by the image forming engine 60 can be reduced, and transport failures can be reduced. [Explanation of symbols]

[0061] 10...image reading device / 20...sheet feeding device (ADF) / 31...first regulating portion (first side regulating plate) / 31Aa...first regulating surface / 31B...first bottom plate portion / 32...second regulating portion (second side regulating plate) / 32Aa...second regulating surface / 32B...second bottom plate portion / 60...image forming portion (image forming engine) / 100...image forming device (printer) / 104, 105...reading portion (front side reading unit, back side reading unit) / 111...feeding portion (pickup roller) / 121...loading tray (document tray)

Claims

1. a loading tray having a loading surface for loading sheets; a feeding section that feeds the sheets stacked on the stacking tray; a first regulating portion and a second regulating portion that are movable in a width direction perpendicular to a sheet feeding direction and that regulate a position in the width direction of the sheets stacked on the stacking surface, the loading surface has a first slit extending in the width direction and a second slit disposed at a position different from the first slit in the feeding direction and extending in the width direction, the first regulating portion has a first regulating surface that abuts against one end in the width direction of the sheets loaded on the loading surface, a first bottom plate portion that slides against the upper surface of the loading tray and supports the sheets together with the loading surface, and a first protruding portion that moves inside the first slit, the second regulating portion has a second regulating surface that abuts against the other end in the width direction of the sheets loaded on the loading surface, a second bottom plate portion that slides against the upper surface of the loading tray and supports the sheets together with the loading surface, and a second protruding portion that moves inside the second slit, the first bottom plate portion has a first inclined portion inclined with respect to the feeding direction such that an outer edge on the second regulating surface side in the width direction becomes more distant from the first regulating surface toward the downstream side in the feeding direction when viewed from above, the second bottom plate portion has a second inclined portion inclined with respect to the feeding direction so that an outer edge on the first regulating surface side in the width direction approaches the second regulating surface toward downstream in the feeding direction when viewed from above, a first tip end portion of the first restricting portion that is located closest to the second restricting surface in the width direction and a second tip end portion of the second restricting portion that is located closest to the first restricting surface in the width direction are disposed at positions different from each other in the feeding direction, When the first restriction surface and the second restriction surface are positioned at positions closest to each other, the first tip end is positioned on the second restriction surface side with respect to a central position between the first restriction surface and the second restriction surface in the width direction, and the second tip end is positioned on the first restriction surface side with respect to the central position between the first restriction surface and the second restriction surface in the width direction. A sheet feeding device characterized by:

2. a linking mechanism that links and moves the first restricting portion and the second restricting portion in opposite directions in the width direction, 2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

3. the interlocking mechanism includes a first rack portion connected to the first restricting portion via the first slit, a second rack portion connected to the second restricting portion via the second slit, and a pinion gear meshing with the first rack portion and the second rack portion.

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

4. the loading surface has a plurality of ribs extending in the width direction and sliding on the first bottom plate portion and the second bottom plate portion; 4. The sheet feeding device according to claim 1, wherein the sheet feeding device comprises: a first feeding unit;

5. The sheet feeding device according to any one of claims 1 to 4, a reading unit that reads an image on the sheet fed by the sheet feeding device, An image reading device characterized by:

6. The image reading device according to claim 5 ; an image forming unit that forms the image read by the image reading device on another sheet, An image forming apparatus characterized by:

7. The sheet feeding device according to any one of claims 1 to 4, an image forming unit that forms an image on the sheet fed by the sheet feeding device, An image forming apparatus characterized by:

Images