Sheet feeding device and image forming apparatus

Abstract

To reduce possibility of generating getting caught of a sheet above a storage cabinet, when drawing the storage cabinet.SOLUTION: A sheet feeding device comprises: a storage cabinet that is attached to an opening of a device body so as to be able to be drawn, for storing a sheet; and a guide member that is provided on an upstream side of the opening in a drawing direction of the storage cabinet, for guiding a sheet toward the opening when the storage cabinet is drawn from the device body. The guide member includes a guide face, tilted downward toward the drawing direction, on which an upstream end in the drawing direction is located in an upper portion of an upper edge of the opening. A downstream end in a sheet feeding direction of the guide face is located at a lower stream than a separation nip, and an upstream end in the sheet feeding direction of the guide face is located at an upper stream than a tip position in the sheet feeding direction of a sheet stored in the storage cabinet.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a sheet feeding device that feeds a sheet, and an image forming device that forms an image on the sheet.

Background Art

[0002] An image forming apparatus such as a printer, a copier, or a multifunction peripheral includes a storage unit (also called a cassette or a deck) that stores a sheet used as a recording material, and a feeding unit that feeds the sheet from the storage unit. In this type of sheet feeding device, due to a sheet conveyance failure (jam), the sheet may stop at a position straddling the space in the storage unit and the sheet conveyance path of the apparatus main body. When the storage unit is pulled out in this state, the sheet may be torn or caught at the boundary between the storage unit and the apparatus main body, making it complicated to resolve the jam state.

[0003] Patent Document 1 describes a sheet feeding device provided in an apparatus main body, which includes an opening that opens toward the outside of the apparatus main body on the downstream side of the sheet conveyance path in the drawing-out direction of the storage unit, and a guide surface that is inclined with respect to the drawing-out direction so as to guide the sheet toward the opening. According to this document, when the storage unit is pulled out with the sheet straddling the space in the storage unit and the sheet conveyance path of the apparatus main body, the portion of the sheet located in the sheet conveyance path is guided to the opening by the guide surface, so that the possibility of the sheet being torn or caught is reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, not only when the sheet straddles the space inside the storage bin and the sheet conveyance path of the apparatus main body, but also when a part of the sheet stacked in the storage bin protrudes into the space above the storage bin inside the apparatus main body, there is a possibility that the sheet may get caught when the storage bin is pulled out. However, since the guide surface in the above-mentioned document was provided on the downstream side of the separation nip for separating the sheet sent out from the storage bin and conveying it to the sheet conveyance path, the sheet getting caught above the storage bin is not prevented.

[0006] The present invention provides a sheet feeding device capable of reducing the possibility that a sheet gets caught above a storage bin when the storage bin is pulled out, and an image forming apparatus including the same.

Means for Solving the Problems

[0007] One aspect of the present invention includes an apparatus main body provided with an opening, a storage bin for storing sheets, the storage bin being mounted on the apparatus main body and being pullable in a pulling-out direction from the apparatus main body through the opening, a pickup roller for feeding out the sheets stored in the storage bin in a sheet feeding direction orthogonal to the pulling-out direction, a separation conveyance unit having a separation nip located downstream of the pickup roller in the sheet feeding direction and conveying the sheet while separating the sheet at the separation nip, and a guide member having a guide surface for guiding the sheet wherein at least a part of the guide surface is inclined downward in the pulling-out direction, and the guide member is configured such that when the storage is pulled out from the apparatus main body, the sheet is guided downward along the inclination of the guide surface and passes below the upper edge of the opening and, the downstream end of the guide surface in the sheet feeding direction is located downstream of the separation nip in the sheet feeding direction, and the upstream end of the guide surface in the sheet feeding direction is located upstream of the leading end position of the sheets stored in the storage bin in the sheet feeding direction. The sheet feeding device is characterized by this.

Effects of the Invention

[0008] According to the present invention, it is possible to reduce the possibility that a sheet gets caught above the storage bin when the storage bin is pulled out.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0011] First, referring to FIG. 1, the printer 100 as an image forming apparatus according to the present embodiment will be described. The printer 100 is an electrophotographic laser beam printer that forms an image on a sheet S as a recording material based on image information received from an external device or image information read from a document G. The printer 100 includes an image reading device 200 that reads image information of the document G stacked on the document tray 221, and an apparatus main body 10 that forms the image read by the image reading device 200 on the sheet S. Further, the printer 100 includes a control unit 50 that controls the image reading device 200 and the apparatus main body 10.

[0012] The image reading device 200 includes a first reading unit 211 and a second reading unit 251, a scanner unit 210 that reads the image of the document G, and an automatic document feeder (ADF) 220 that automatically feeds the document G one by one toward the scanner unit 210. The image information read by the first reading unit 211 and the second reading unit 251 is transferred to the control unit 50 after being subjected to image processing and is used for the image forming operation described later.

[0013] The apparatus main body 10 has an image forming unit 20 as an image forming means for forming an image on the sheet S, and a sheet feeding device 30 for feeding the sheet S loaded inside the apparatus main body 10 to the image forming unit 20. The configuration and operation of the sheet feeding device 30 will be described later. The apparatus main body 10 also has a discharge roller pair 46 for discharging the sheet S on which the image is formed to the outside of the apparatus main body 10, and a discharge tray 45 on which the discharged sheet S is loaded.

[0014] The image forming unit 20 has a photosensitive drum 22 as an image carrier (also called an electrophotographic photoreceptor) that carries a toner image, a charging device 26, a laser scanner unit 21 as an exposure device, a developing device 23, and a transfer device 24. The photosensitive drum 22 is, for example, a cylindrical aluminum substrate with a photosensitive layer such as an organic photoreceptor formed on the outer peripheral portion, and is rotationally driven in the clockwise direction in the figure. The charging device 26 can be a corona discharge type having a wire for charging the surface of the photosensitive drum 22 by corona discharge, but for example, one using a roller close to the photosensitive drum 22 may also be used. The developing device 23 houses a developer containing toner, and carries the developer on a developing roller as a developer carrier facing the photosensitive drum 22 and supplies it to the photosensitive drum 22. The transfer device 24 forms a transfer portion between the photosensitive drum 22. Upstream of the transfer device 24 in the conveyance path of the sheet S, a registration roller pair 11 is arranged.

[0015] Further, the image forming unit 20 includes a fixing device 25 disposed downstream of the transfer device 24 in the sheet conveyance direction. The fixing device 25 has a fixing roller pair that sandwiches and conveys the sheet S, and heating means such as a halogen lamp or an induction heating unit for heating the toner image on the sheet S.

[0016] Next, an example of an image forming operation of the printer 100 will be described in the case of forming an image on a sheet S fed from the sheet feeding device 30 based on the image information of the document G read by the scanner unit 210. When the image forming operation is started, the photosensitive drum 22 rotates, and the surface of the photosensitive drum 22 is uniformly charged by the charging device 26. Further, based on the image information of the document G read by the scanner unit 210, a laser beam is irradiated from the laser scanner unit 21 onto the photosensitive drum 22, so that an electrostatic latent image is formed on the surface of the photosensitive drum 22. This electrostatic latent image is developed by the developing device 23 and visualized as a toner image.

[0017] In parallel with the creation of the toner image on the photosensitive drum 22, sheets S are fed one by one from the sheet feeding device 30 and conveyed toward the registration roller pair 11. The sheet S is abutted against the leading end of the stationary registration roller pair 11 for skew correction, and then sent to the transfer unit at a timing synchronized with the creation of the toner image on the photosensitive drum 22.

[0018] In the transfer unit, the toner on the photosensitive drum 22 is transferred to the sheet S by the transfer device 24. Next, the sheet S undergoes an image fixing process by being heated and pressed by the fixing device 25. In the case of single-sided printing where an image is formed on one side of the sheet S, the sheet S that has passed through the fixing device 25 is discharged from the apparatus main body 10 by the discharge roller pair 46 and stacked on the discharge tray 45. In the case of double-sided printing where images are formed on both sides of the sheet S, the sheet S on which an image has been formed on the first side and has passed through the fixing device 25 is guided to the reverse conveyance path 12 and conveyed again toward the registration roller pair 11 with the first side and the second side reversed. Then, the sheet S on which an image has been formed on the second side in the same process as the first side is discharged from the apparatus main body 10 by the discharge roller pair 46 and stacked on the discharge tray 45.

[0019] (Sheet Feeding Device) Next, the outline of the sheet feeding device 30 according to the present embodiment will be described. As shown in FIG. 1, the sheet feeding device 30 is provided below the apparatus main body 10 of the printer 100, and the frame of the apparatus main body 10 also serves as the frame of the sheet feeding device 30.

[0020] FIG. 2 is a schematic view of the sheet feeding device 30 as seen from the front side of the printer 100. The sheet feeding device 30 includes a storage bin 1 in which the sheet S is stored in a stacked state, and a conveyance mechanism including a pickup roller 2, a feed roller 3, and a retard roller 4 for feeding the sheet S stacked in the storage bin 1 one by one. In each figure after FIG. 2, a unitized form of the main components of the sheet feeding device 30 other than the storage bin 1, the main body frame 101, the conveyance guides 17 and 18, and the jam processing guide 7 is shown as a feeding unit 30U. The feeding unit 30U includes a holding member that holds the pickup roller 2 and the feed roller 3, a holding member that holds the retard roller 4, a drive gear train that transmits driving force to each roller, and a feeding frame that supports these members.

[0021] In the following description and drawings, the arrow "Z" represents the vertical direction when the printer 100 is installed on a horizontal plane. The arrows "X" and "Y" intersect the vertical direction and intersect each other in a top view, preferably in a direction perpendicular to each other in a top view. Among these, the direction in which the sheet S is fed out from the storage 1 is defined as the sheet feeding direction X, and the direction in which the storage 1 is pulled out from the apparatus main body 10 is defined as the pulling-out direction Y. Note that the pulling-out direction Y is also a direction along the sheet width direction (a direction perpendicular to the sheet feeding direction X) of the sheet S stored in the storage 1.

[0022] As shown in FIG. 2, the storage 1 has a storage main body 1A that forms a rectangular parallelepiped-shaped sheet storage space 1s with an open top. At the bottom of the storage main body 1A, a support plate 31 for supporting the sheet S stored in the sheet storage space 1s is provided. Also, as shown in the top view of FIG. 5, the storage 1 includes a pair of side regulating members 32F and 32R that are movable along the sheet width direction (pulling-out direction Y) with respect to the storage main body 1A, and a rear end regulating member 33 that is movable along the sheet feeding direction X with respect to the storage main body 1A.

[0023] The rear end (upstream end) of the sheet S stored in the storage 1 in the sheet feeding direction X abuts against the rear end regulating member 33, and the front end (downstream end) of the sheet S in the sheet feeding direction X abuts against the side wall 1D of the storage main body 1A in the sheet feeding direction X, whereby the sheet is positioned with respect to the sheet feeding direction. X Therefore, in the present embodiment, the surface of the side wall 1D on the sheet storage space 1s side defines the front end position of the sheet S stored in the storage 1 in the sheet feeding direction X. Also, the sheet S stored in the storage 1 is positioned with respect to the sheet width direction by abutting both side ends in the pulling-out direction Y, which is the sheet width direction, against the side regulating members 32F and 32R.

[0024] The pickup roller 2 is disposed above the sheet storage space 1s (above the support plate 31) and is rotatably held by a holding member (not shown). The pickup roller 2 is movable between a feeding position where it contacts the uppermost sheet S of the sheet bundle loaded on the support plate 31 and a standby position where it is spaced upward from the uppermost sheet S by the swinging of the holding member. The pickup roller 2 rotates counterclockwise in the drawing at the feeding position by the driving force transmitted from the motor in the apparatus main body 10, thereby feeding out the uppermost sheet S toward the separation nip N1.

[0025] The feed roller 3 and the retard roller 4 form a separation nip N1 as a nip portion in contact with each other and function as a separation conveyance unit that conveys the sheet S one by one while separating it at the separation nip N1. The feed roller 3 rotates counterclockwise in the drawing by the driving force transmitted from the motor in the apparatus main body 10, thereby applying a conveyance force (frictional force) in the sheet feeding direction X to the sheet S received from the pickup roller 2.

[0026] The retard roller 4 is connected via a torque limiter to a shaft that rotates by the driving force transmitted from the motor in the apparatus main body 10, and a driving force in a direction opposite to the conveyance of the sheet S in the sheet feeding direction X (counterclockwise in the drawing) is input thereto. When only one sheet S enters the separation nip N1, the torque limiter slips and the retard roller 4 rotates in a direction following the feed roller 3 (clockwise in the drawing). When a plurality of sheets S enter the separation nip N1, the retard roller 4 rotates in the reverse direction by the driving force transmitted via the torque limiter, and pushes back the sheets S other than the uppermost sheet S in contact with the feed roller 3 to the upstream side in the sheet feeding direction X. Note that the retard roller 4 is an example of a separating member, and a roller member connected via a torque limiter to a shaft fixed to the apparatus main body 10 or a pad-shaped elastic member that presses against the feed roller 3 may be used as the separating member.

[0027] When the storage bin 1 is pulled out from the apparatus main body 10, the retard roller 4 is separated from the feed roller 3 by a moving mechanism (not shown), and the separation nip N1 is opened. Since the separation nip N1 is opened when the storage bin 1 is pulled out, it is possible to prevent the sheet S from being torn when the storage bin 1 is pulled out with a part of the sheet S being held by the separation nip N1. As the moving mechanism, a mechanism can be used that moves a holding member that holds the retard roller 4 in conjunction with the movement of the storage bin 1 in the pulling-out direction Y by a cam mechanism that is actuated by being pressed against a protrusion provided on the storage bin 1. Not limited to this, the moving mechanism may move the holding member of the retard roller 4 so that the separation nip N1 is in an open state during a period when the sheet S is not fed by the pickup roller 2 by a driving force such as a motor or a solenoid.

[0028] Downstream of the separation nip N1 in the sheet feeding direction X, a sheet conveyance path P1 inside the apparatus main body 10 is formed as a space between the conveyance guides 17 and 18 facing each other. The sheet conveyance path P1 is a conveyance path along which the sheet S fed by the sheet feeding device 30 is conveyed toward the registration roller pair 11 (FIG. 1). On either side of the conveyance guides 17 and 18 with respect to the sheet conveyance path P1, a sheet sensor 19 (FIG. 1) is disposed as detection means for detecting a jam of the sheet in the sheet conveyance path P1. As the sheet sensor 19, a photointerrupter that detects that a swingable flag protruding into the sheet conveyance path P1 has been swung by being pressed against the sheet S, or a photoreflector that emits light toward the sheet conveyance path P1 and detects reflected light from the sheet S can be used.

[0029] The control unit 50 (Fig. 1) of the printer 100 monitors the occurrence of a sheet jam based on the detection signal of the sheet sensor 19. For example, when the sheet sensor 19 does not detect the passage of the leading edge of the sheet even after a predetermined time has elapsed since the feeding of the sheet S was started by rotating the pickup roller 2 at the feeding position, the control unit 50 determines that a jam has occurred upstream of the detection position of the sheet sensor 19. When a jam occurs, the control unit 50 interrupts the ongoing image forming operation and notifies the user of the occurrence of the jam by means such as displaying a warning screen on the liquid crystal panel of the operation unit provided in the printer 100, voice alerts, or notifications to an external computer. The notification content at the time of jam occurrence includes information prompting the user to open the storage unit 1 and remove the jammed sheet.

[0030] (Opening of the apparatus main body) Using Fig. 3, the positional relationship between the storage unit 1 and the main body frame 101 which is the frame of the apparatus main body 10 will be described. Fig. 3 is a schematic view seen from the front side of the printer 100 of the positional relationship between the storage unit 1 and the main body frame 101 when the storage unit 1 is attached to the apparatus main body 10.

[0031] The main body frame 101 has a main opening 5 for enabling the pulling out and attachment of the storage unit 1. That is, the storage unit 1 is detachably attached to the opening of the apparatus main body. The main opening 5 is formed by support columns 101L, 101R extending vertically on both sides of the storage unit 1 in the sheet feeding direction X and beam members 101T, 101B extending substantially horizontally so as to connect the support columns 101L, 101R when viewed from the front side of the printer 100. The main opening 5 of the present embodiment is substantially rectangular when viewed from the front side of the printer 100. The support columns 101L, 101R and the beam members 101T, 101B can preferably use metal members having rigidity such as stainless steel, and are frame members constituting the main body frame 101 in a state of being fixed to each other. In the present embodiment, the main opening 5 is described as being formed by the main body frame 101, but the main opening 5 may be formed by other members fixed to the main body frame 101.

[0032] The storage compartment 1 can be pulled out in the pulling direction Y with respect to the apparatus main body 10 and inserted in the opposite direction by gripping and operating a gripping portion provided on a front plate 1F (FIG. 5) exposed on the front side of the printer 100. As shown in FIG. 5, in a state where the storage compartment 1 is mounted at a predetermined mounting position of the apparatus main body 10, the sheet storage space 1s of the storage compartment 1 is located inside the apparatus main body 10 with respect to the main opening 5. As shown in FIGS. 6(a) to 6(c), when the storage compartment 1 is pulled out from the mounting position in the pulling direction Y, at least a part of the sheet storage space 1s moves outside the apparatus main body 10 with respect to the main opening 5, and the sheet storage space 1s is exposed when viewed from above. The user can access the sheet storage space 1s with the storage compartment 1 pulled out from the apparatus main body 10 to replace or replenish the sheet S.

[0033] Note that the upper end height of the sheet storage space 1s in the storage compartment 1 is set to be the higher one of the upper end height of the side regulating member 32R on the upstream side (the back side of the printer 100) in the pulling direction Y or the upper end height of the side wall 1R on the upstream side of the storage compartment main body 1A in the pulling direction Y. The beam member 101T constituting the upper edge of the main opening 5 is located above the upper end height of the sheet storage space 1s. Therefore, when the storage compartment 1 is pulled out from the mounting position in the pulling direction Y, normally, the sheet S stored in the storage compartment 1 passes below the beam member 101T without contacting the beam member 101T.

[0034] Further, the main body frame 101 is provided with a sheet extraction opening 6 that is located near the feed roller 107 and opens downstream in the extraction direction Y. When viewed from the extraction direction Y with the storage compartment 1 pulled out, the sheet extraction opening 6 is arranged at a position and with a size such that at least a part of the separation nip N1 and the sheet conveyance path P1 on the downstream side of the separation nip N1 is exposed. The sheet extraction opening 6 is located outside the movement locus when the storage compartment 1 is pulled out and installed. That is, the opening of the apparatus main body 10 of the present embodiment includes a main opening 5 as a first part for enabling the attachment and extraction of the storage compartment 1, and a sheet extraction opening 6 as a second part protruding from the first part to expose a part of the sheet conveyance path P1. The sheet extraction opening 6 is provided continuously with the main opening 5 of the apparatus main body 10 that enables the extraction of the storage compartment 1, and functions as an opening for jam processing that facilitates the removal of the sheet stopped straddling the sheet storage space 1s and the sheet conveyance path P1 in the apparatus main body 10.

[0035] The sheet extraction opening 6 of the present embodiment is formed in a concave shape in which a part of the support column 101L on the downstream side in the sheet feeding direction X is notched toward the sheet feeding direction X. The sheet extraction opening 6 is continuous with the main opening 5 for extracting the storage compartment 1, and forms a space protruding from the main opening 5 in the sheet feeding direction X. The sheet extraction opening 6 is exposed when viewed from the extraction direction Y with the storage compartment 1 pulled out from the apparatus main body 10, but is covered by the front plate 1F (FIG. 5) and not exposed when viewed from the extraction direction Y with the storage compartment 1 attached to the apparatus main body 10. This prevents foreign matter from entering the sheet conveyance path P1 from the sheet extraction opening 6 in the state where the storage compartment 1 is attached.

[0036] Note that, depending on the positional relationship between the size of the main opening 5 and the sheet conveyance path P1, a configuration without providing the sheet extraction opening 6 may be adopted. For example, in a configuration where the main opening 5 is enlarged in the sheet feeding direction X up to the position of the side edge portion 6x of the sheet extraction opening 6 of the present embodiment, there is no need to provide the sheet extraction opening 6.

[0037] (Jam Processing Guide) Next, the jam processing guide 7 as a guide member provided in the sheet drawing opening 6 will be described with reference to FIGS. 4, 5, and 7. FIG. 4 is a perspective view of the jam processing guide 7 viewed from the inside of the apparatus main body 10 with respect to the sheet drawing opening 6. FIG. 5 is a top view of the sheet feeding apparatus 30, showing a cross section of the printer 100 in the X-Y plane passing through the jam processing guide 7 as viewed from above. FIG. 7 is a cross-sectional view of the sheet feeding apparatus 30, showing a cross section of the printer 100 in the Y-Z plane passing through the jam processing guide 7 as viewed in the sheet feeding direction X.

[0038] The jam processing guide 7 is disposed on the upstream side (inside the apparatus main body 10) in the drawing direction Y with respect to the sheet drawing opening 6 and is fixed to the main body frame 101. The jam processing guide 7 has a first guide surface 7b and a second guide surface 7a extending in different directions from each other.

[0039] As shown in FIG. 5, the jam processing guide 7 is provided downstream of the sheet feeding apparatus 30 in the drawing direction Y and upstream of the sheet drawing opening 6 of the main body frame 101. In particular, the jam processing guide 7 is located on the downstream side in the drawing direction Y with respect to the region (hereinafter referred to as the conveyance region Ym) through which the sheet S having the largest length in the sheet width direction among the sheets S that can be fed by the sheet feeding apparatus 30 passes. Therefore, before the storage 1 is pulled out during jam processing, usually, the jam processing guide 7 is located on the downstream side in the drawing direction Y with respect to the sheet S.

[0040] As shown in FIGS. 4 and 7, at least a part of the first guide surface 7b is an inclined surface inclined downward in the drawing direction Y. The upstream end 7b1 of the first guide surface 7b in the drawing direction Y is located above the upper edge portion 6z of the sheet drawing opening 6. The downstream end 7b2 of the first guide surface 7b in the drawing direction Y is located at substantially the same position as the upper edge portion 6z of the sheet drawing opening 6 in the vertical direction or below the upper edge portion 6z. That is, the downstream end 7b2 of the first guide surface 7b in the drawing direction Y is arranged so that the sheet S passing through the first guide surface 7b when the storage 1 is pulled out does not get caught on the upper edge portion 6z of the sheet drawing opening 6.

[0041] Also, as will be described later, the first guide surface 7b extends upstream of the separation nip N1 in the sheet feeding direction X. The upstream end 7b1 of the first guide surface 7b in the drawing-out direction Y is located above the upper edge portion 5z of the main opening 5. The downstream end 7b2 of the first guide surface 7b in the drawing-out direction Y is located at substantially the same position as the upper edge portion 5z of the main opening 5 in the vertical direction, or below the upper edge portion 5z. That is, the downstream end 7b2 of the first guide surface 7b in the drawing-out direction Y faces both the main opening 5 and the sheet drawing-out opening 6.

[0042] As shown in FIGS. 4 and 5, the second guide surface 7a is located downstream of the separation nip N1 in the sheet feeding direction X. At least a part of the second guide surface 7a is an inclined surface inclined upstream in the sheet feeding direction X toward the drawing-out direction Y. The upstream end 7a1 of the second guide surface 7a in the drawing-out direction Y is located downstream of the side edge portion 6x, which is the edge in the sheet feeding direction X of the sheet drawing-out opening 6. The downstream end 7a2 of the second guide surface 7a in the drawing-out direction Y is located at substantially the same position as the side edge portion 6x of the sheet drawing-out opening 6 in the sheet feeding direction X, or upstream of the side edge portion 6x in the sheet feeding direction X. The downstream end 7a2 of the second guide surface 7a in the drawing-out direction Y is located at substantially the same position as the side edge portion 6x of the sheet drawing-out opening 6 in the sheet feeding direction X, or upstream of the side edge portion 6x in the sheet feeding direction X. That is, the downstream end 7a2 of the second guide surface 7a in the drawing-out direction Y is arranged so that the sheet S that has passed through the second guide surface 7a when the storage 1 is pulled out does not get caught on the side edge portion 6x of the sheet drawing-out opening 6.

[0043] Furthermore, as shown in FIG. 4, the jam processing guide 7 of the present embodiment has a third guide surface 7c below the first guide surface 7b in the vertical direction. The third guide surface 7c at least partially overlaps the first guide surface 7b when viewed from above, and is another guide surface facing the first guide surface 7b in the vertical direction. At least a part of the third guide surface 7c is an inclined surface that slopes upward in the drawing direction Y. The upstream end of the third guide surface 7c in the drawing direction Y is located below the lower edge of the sheet drawing opening 6. The downstream end of the third guide surface 7c in the drawing direction Y is located at substantially the same position as the lower edge of the sheet drawing opening 6 in the vertical direction, or above the lower edge. That is, the downstream end of the third guide surface 7c in the drawing direction Y is arranged so that the sheet S that has passed through the third guide surface 7c when the storage 1 is drawn out is not caught by the lower edge of the sheet drawing opening 6.

[0044] In the jam processing guide 7 of the present embodiment, the downstream ends of the first guide surface 7b and the third guide surface 7c in the sheet feeding direction X are connected to the second guide surface 7a, so that in a cross section perpendicular to the drawing direction Y, the upstream side in the sheet feeding direction X is open, having a U-shaped cross-sectional shape. Also, the jam processing guide 7 has portions where the first guide surface 7b, the second guide surface 7 a and the third guide surface 7c are inclined surfaces, and on the downstream side in the drawing direction Y with respect to these portions, the first guide surface 7b, the second guide surface 7 a and the third guide surface 7c have portions that extend substantially parallel to the drawing direction Y.

[0045] Here, the inclination angles of the first guide surface 7b, the second guide surface 7 a and the third guide surface 7c are not particularly limited, but if the inclination angle is small, the range capable of receiving the sheet when the storage 1 is drawn out becomes narrow. If the inclination angle is too large, there is a possibility that the sheet may be caught by the jam processing guide 7 itself and fall into the apparatus main body 10 or the jam sheet may be torn when the storage 1 is drawn out. The inclination angles of the respective guide surfaces of the jam processing guide 7 and the length in the drawing direction Y should be appropriately set according to the specific configuration such as the positional relationship between the column 101L of the main body frame 101, the separation nip N1, and the sheet conveyance path P1.

[0046] Note that the directions of the inclinations of the first guide surface 7b and the third guide surface 7c shall refer to the inclinations with respect to the pulling-out direction Y in a plane perpendicular to the sheet feeding direction X. The first guide surface 7b and the third guide surface 7c may have an inclination when viewed from a direction different from the sheet feeding direction X. For example, the first guide surface 7b may be inclined with respect to the pulling-out direction Y in a plane perpendicular to the sheet feeding direction X and may also be inclined on the upstream side of the sheet feeding direction X with respect to the pulling-out direction Y in a plane perpendicular to the vertical direction. Similarly, the direction of the inclination of the second guide surface 7a shall refer to the inclination with respect to the pulling-out direction Y in a plane perpendicular to the vertical direction, and the second guide surface 7a may have an inclination when viewed from a direction different from the vertical direction.

[0047] (Function of jam processing guide) The function of the jam processing guide 7 will be described according to the position of the sheet when a jam of the sheet occurs. First, using FIGS. 6(a) to 6(c), the function of the jam processing guide 7 when the storage case 1 is pulled out with the sheet S stopped at a position straddling the sheet storage space 1s in the storage case 1 and the sheet conveyance path P1 of the apparatus main body 10 will be described.

[0048] FIG. 6(a) shows a state in which the sheet S1 being fed has stopped at a position straddling the sheet storage space 1s in the storage case 1 and the sheet conveyance path P1 of the apparatus main body 10. That is, the leading end of the sheet S protrudes downstream of the separation nip N1 in the sheet feeding direction X, and the trailing end of the sheet S remains in the storage case 1.

[0049] When the storage compartment 1 is pulled out in the pulling-out direction Y to remove the sheet S1 in this state, as shown in FIG. 6(b), the sheet S1 moves in the pulling-out direction Y together with the storage compartment 1, and the leading end portion of the sheet S1 contacts the second guide surface 7a. When the storage compartment 1 is further pulled out, as shown in FIG. 6(c), the sheet S1 is guided to the upstream side in the sheet feeding direction X along the inclination of the second guide surface 7a, passes through the sheet pulling-out opening 6, and moves to the outside of the apparatus main body 10. At this time, the sheet S is pressed against the second guide surface 7a, and while being bent inside the region surrounded by the first guide surface 7b and the third guide surface 7c, it passes inside the side edge portion 6x of the sheet pulling-out opening 6 in the sheet feeding direction X.

[0050] As described above, when the sheet S1 stops at a position straddling the sheet storage space 1s in the storage compartment 1 and the sheet conveyance path P1 of the apparatus main body 10, the sheet S1 is pushed back to the upstream side in the sheet feeding direction X by the second guide surface 7a up to the opening range of the sheet pulling-out opening 6. Further, regardless of the state of curling or bending of the sheet S1, the first guide surface 7b guides the sheet S1 from above so that the leading end portion of the sheet S1 passes through the opening range of the sheet pulling-out opening 6 without being caught by the upper edge portion of the sheet pulling-out opening 6. That is, the portion of the first guide surface 7b downstream of the separation nip N1 in the sheet feeding direction X has a function of guiding the sheet S1 from above so that the leading end portion of the sheet S1 protruding from the separation nip N1 can pass through the opening of the apparatus main body 10. Further, regardless of the state of curling or bending of the sheet S1, the third guide surface 7c guides the sheet S1 from below so that the leading end portion of the sheet S1 passes through the opening range of the sheet pulling-out opening 6 without being caught by the lower edge portion of the sheet pulling-out opening 6.

[0051] Next, with reference to FIGS. 8(a) to 8(c), the function of the jam processing guide 7 when the storage compartment 1 is pulled out with the sheet S2 stopped at a position straddling the sheet storage space 1s in the storage compartment 1 and the space above the storage compartment 1 in the apparatus main body 10 will be described.

[0052] Examples of the occurrence of such jam sheets include, for example, when the sheet S is loaded beyond the maximum loading height preset for the storage bin 1, or when there is bending (curl) or folding of the sheet S stored in the storage bin 1 that exceeds the allowable range. In such cases, during feeding, the sheet S2 may get caught on the members around the conveyance path, and a part of the sheet S2 may be wrinkled or turned up, causing it to protrude above the storage bin 1 as shown in Fig. 8(a). Note that when viewed from above, it is assumed that the sheet S2 remains inside the sheet storage space 1s of the storage bin 1.

[0053] In the state of Fig. 8(a), a part of the sheet S2 protrudes above the sheet storage space 1s in the storage bin 1 and is located above the upper edge 5z of the main opening 5 and the upper edge 6z of the sheet extraction opening 6. That is, if the sheet S2 moves in the extraction direction Y in its current state, it may come into contact with the upper edge 6z of the sheet extraction opening 6.

[0054] When the storage bin 1 is pulled out in the extraction direction Y from the state of Fig. 8(a), the end of the sheet S2 in the extraction direction Y comes into contact with the first guide surface 7b as shown in Fig. 8(b). When the storage bin 1 is further pulled out, the sheet S2 is guided downward along the inclination of the first guide surface 7b and moves outside the apparatus main body 10 through the sheet extraction opening 6 as shown in Fig. 8(c). That is, the first guide surface 7b guides the sheet S2 from above so that the sheet S2 passes through the opening range of the main opening 5 without getting caught on the upper edge 5z of the main opening 5 of the main body frame 101. Thereby, when the storage bin 1 is pulled out, the possibility that the sheet S2 gets caught on the upper edge 5z of the main opening 5 and falls into the apparatus main body 10 or is pinched between the side regulating member 32R and the upper edge 5z to prevent the pulling out of the storage bin 1 can be reduced.

[0055] Here, the installation range of the first guide surface 7b of the jam processing guide 7 will be described. Fig. 9 is a top view of the sheet feeding device 30 and shows a cross-section of the printer 100 in the X - Y plane passing through the jam processing guide 7 as viewed from above.

[0056] As shown in FIG. 9, in the present embodiment, the first guide surface 7b extends upstream in the sheet feeding direction X from the leading end position X2 of the sheet S in the storage 1 (see also FIG. 2). That is, with respect to the sheet feeding direction X, the upstream end 7b4 of the first guide surface 7b (see also FIG. 4) is located upstream of the leading end position X2 of the sheet S in the storage 1. With such a configuration, even if the sheet S2 is curled or wrinkled in the storage 1, the possibility that the sheet S2 is caught by the upper edge portion 5z (beam member 101T) of the main opening 5 when the storage 1 is pulled out can be reduced.

[0057] Further, the downstream end 7b3 of the first guide surface 7b in the sheet feeding direction X is located downstream of the position X3 of the separation nip N1 (see also FIGS. 2 and 4). Thereby, as described above with reference to FIGS. 6(a - c), the possibility that the sheet S1 stopped at a position protruding from the separation nip N1 is caught by the upper edge portion 6z (beam member 101T) of the sheet drawing opening 6 when the storage 1 is pulled out can be reduced. That is, the jam processing guide 7 can correspond to both the jam sheet (S1) straddling the storage and the sheet conveyance path of the apparatus main body, and the jam sheet (S2) straddling the storage and the space above the storage in the apparatus main body, by having the first guide surface 7b.

[0058] In particular, in the present embodiment, the upstream end 7b4 of the first guide surface 7b is located further upstream than the contact position X1 (see also FIG. 2) where the pickup roller 2 contacts the sheet S when feeding the sheet S in the storage 1. Thereby, the possibility that the jam sheet (S2) straddling the storage and the space above the storage in the apparatus main body is caught by the upper edge portion 5z of the main opening 5 when the storage 1 is pulled out can be further reduced. This is because the wrinkling or curling of the sheet in the storage 1 basically occurs on the downstream side in the sheet feeding direction X from the contact position X1 of the pickup roller 2 with respect to the sheet S.

[0059] As described above, according to this embodiment, it is possible to reduce the possibility that the sheet S gets caught when the drawer of the storage 1 is pulled out, and to provide a sheet feeding device with good operability that allows the user to smoothly perform jam processing, and an image forming apparatus including the same.

[0060] (Modification) In this embodiment, the jam processing guide 7 having a U-shaped cross-sectional shape has been described. However, the shape and arrangement of the jam processing guide 7 can be appropriately changed according to the positional relationship between the sheet conveyance path P1 and the sheet extraction opening 6, etc. For example, when it is less necessary to push back the leading end of the sheet S1 (FIG. 6(a)) stopped in the sheet conveyance path P1 to the upstream side in the sheet feeding direction X, a jam processing guide 7 omitting the second guide surface 7a may be used.

[0061] Also, in this embodiment, the jam processing guide 7 attached to the main body frame 101 of the apparatus main body 10 has been described. However, the jam processing guide 7 may be attached to either of the conveyance guides 17, 18, or may be formed integrally with either of the conveyance guides 17, 18.

[0062] (Other Embodiments) In the above-described embodiment, the sheet feeding device incorporated as part of the printer 100 has been described. However, this technology is also applicable to a sheet feeding device independent of the image forming apparatus. For example, this technology may be applied to a device (also called an optional feeder) that is connected to the printer 100 and feeds sheets toward the printer 100. Further, this technology may be applied to a sheet feeding device that feeds sheet materials one by one in fields other than image forming apparatuses.

Description of Reference Numerals

[0063] 1: Storage / 2: Pickup roller / 3, 4: Separation conveyance unit (feed roller, retard roller) / 5, 6: Opening / 7: Guide member / 7a: Second guide surface / 7b: Guide surface (first guide surface) / 7c: Third guide surface / 10: Apparatus main body / 100: Image forming apparatus (printer)

Claims

1. A device body provided with an opening, A storage for storing a sheet, which is attached to the device body and can be pulled out from the device body in a pulling-out direction through the opening, A pickup roller for feeding out the sheet stored in the storage in a sheet feeding direction orthogonal to the pulling-out direction, A separation conveyance unit having a separation nip located downstream of the pickup roller in the sheet feeding direction and conveying the sheet while separating the sheet at the separation nip, A guide member having a guide surface for guiding the sheet, at least a part of the guide surface being inclined downward toward the pulling-out direction, and configured such that when the storage is pulled out from the device body, the sheet is guided downward along the inclination of the guide surface and passes below the upper edge of the opening, comprising The downstream end of the guide surface in the sheet feeding direction is located downstream of the separation nip in the sheet feeding direction, The upstream end of the guide surface in the sheet feeding direction is located upstream of the leading end position of the sheet stored in the storage in the sheet feeding direction in the sheet feeding direction, A sheet feeding device characterized by the above.

2. The upstream end of the guide surface in the sheet feeding direction is located upstream of the contact position where the pickup roller contacts the sheet stored in the storage in the sheet feeding direction, The sheet feeding device according to claim 1, characterized by the above.

3. The guide surface is a first guide surface, The guide member is a second guide surface inclined upstream in the sheet feeding direction toward the pulling-out direction, and has a second guide surface for guiding the sheet such that when the storage is pulled out from the device body, the sheet passes upstream of the downstream end of the opening in the sheet feeding direction, The sheet feeding device according to claim 1 or 2, characterized by the above.

4. The guide member is a third guide surface facing the first guide surface in the vertical direction and has a third guide surface inclined upward toward the pulling-out direction, The sheet feeding device according to claim 3, characterized by the above.

5. The upstream end of the second guide surface in the pulling-out direction is located downstream of the downstream end of the opening in the sheet feeding direction in the sheet feeding direction, The downstream end of the second guide surface in the sheet extraction direction is located at the same position as the downstream end of the opening in the sheet feeding direction or upstream of the downstream end of the opening. The sheet feeding device according to claim 3 or 4, characterized in that.

6. The upstream end of the guide surface in the sheet extraction direction is located above the upper edge of the opening. The downstream end of the guide surface in the sheet extraction direction is located at the same position as the upper edge of the opening in the vertical direction or below the upper edge of the opening. The sheet feeding device according to any one of claims 1 to 5, characterized in that.

7. The opening includes a first part for receiving the storage in the device body, and a second part located downstream of the first part in the sheet feeding direction. When viewed from the downstream in the sheet extraction direction, at least a part of the conveyance path on the downstream side of the separation nip in the sheet feeding direction is exposed. A part of the position of the guide surface in the sheet feeding direction overlaps with the position of the first part in the sheet feeding direction, and another part of the position of the guide surface in the sheet feeding direction overlaps with the position of the second part in the sheet feeding direction. The sheet feeding device according to claim 1 or 2, characterized in that.

8. The guide surface is a first guide surface. The guide member further has a second guide surface extending downward from the downstream end of the first guide surface in the sheet feeding direction, and a third guide surface extending in the sheet feeding direction from the lower end of the second guide surface and facing the first guide surface in the vertical direction. The sheet feeding device according to claim 7, characterized in that.

9. When viewed from the downstream in the extraction direction, the device body has a first frame extending vertically downstream of the storage in the sheet feeding direction, a second frame extending vertically upstream of the storage in the sheet feeding direction, a third frame connecting the first frame and the second frame above the storage, and a fourth frame connecting the first frame and the second frame below the storage. The first part of the opening is an area surrounded by the first frame, the second frame, the third frame, and the fourth frame. The second part of the opening has a concave shape in which a part of the first frame is recessed downstream in the sheet feeding direction. The sheet feeding device according to claim 7 or 8, characterized in that.

10. The guide member is positioned downstream in the drawing direction with respect to a region through which a sheet having the greatest length in the drawing direction among the sheets that can be fed by the sheet feeding device passes when the sheet is fed, and at least a part of the guide member is positioned upstream in the drawing direction with respect to the opening. The sheet feeding device according to any one of claims 1 to 9, characterized in that.

11. A sheet feeding device according to any one of claims 1 to 10, and an image forming means for forming an image on a sheet fed from the sheet feeding device. An image forming apparatus, characterized by comprising.

Images