JP2024018745A - Paper feeding device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device capable of suppressing contact of a sheet with a part other than a paper feeding roller even when the sheet to be fed is corrugated.

SOLUTION: A paper feeding device 3 comprises: a paper feeding tray 10; a paper feeding roller 32; and a sheet loading device 11 which can be lifted and lowered between a first position for enabling paper feeding of a sheet S with the paper feeding roller 32 and a second position, lower than the first position, for loading the sheet S, and has a first loading plate 12 having a first loading surface 121 supporting the sheet S and a second loading plate 13 having a second loading surface 131 supporting the sheet S and arranged lower than the first loading plate 12 when the sheet loading device 11 is positioned at the second position. The first loading plate 12 has a notch part 123 at a position facing the paper feeding roller 32 in a front end. In a state where the sheet loading device 11 is positioned at the first position, the second loading surface 131 is protruded from the notch part 123 and positioned upper than the first loading surface 121.

SELECTED DRAWING: Figure 6

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a paper feeding device and an image forming apparatus.

Conventionally, as disclosed in Patent Document 1, a paper feed roller that feeds sheets, a separation roller that separates the fed sheets one by one, and a drive connection between the paper feed roller and the separation roller are connected. However, an image forming apparatus is known that includes a gear train disposed adjacent to one side in the axial direction of a paper feed roller and a separation roller.

In such an image forming apparatus, when a sheet being fed is undulated, the deformed sheet may come into contact with a gear in a gear train located on one side of the sheet feeding roller.

Japanese Patent Application Publication No. 2017-065819

When the deformed sheet and the gear come into contact as described above, the load on the sheet is divided into the load from the paper feed roller and the load due to friction between the sheet and the gear, resulting in the nip being applied to the sheet during paper feeding. The load may decrease and paper feeding errors may occur.

Therefore, the present invention provides a paper feeding device and an image forming apparatus that can suppress the sheet from coming into contact with parts other than the paper feeding roller even when the fed sheet is undulated.

A paper feeding device and an image forming apparatus that solve the above problems have the following features.

That is, the paper feeding device includes a paper feeding tray that supports sheets, and a paper feeding roller that feeds the sheets supported by the paper feeding tray toward an image forming section, and has a first axis that extends in the axial direction. A rotatable paper feed roller, and a sheet stacker that can be raised and lowered between a first position that allows the paper feed roller to feed sheets and a second position that stacks sheets below the first position. The device has a flat first stacking member having a first stacking surface that supports sheets, and a second stacking surface that supports sheets, and when the sheet stacking device is located at a second position, a sheet stacking device having a flat second stacking member disposed below the first stacking member, the first stacking member facing the paper feed roller at a downstream end in the sheet conveyance direction; the second loading surface protrudes from the notch and is located above the first loading surface when the sheet stacking device is located at the first position; .

As a result, when feeding paper with the sheet stacking device raised to the first position, the second stacking surface, which is the portion of the sheet stacking device that faces the paper feed roller, is positioned above the other portions. , it is possible to suppress the sheet from coming into contact with parts other than the paper feed roller.

Further, in a state where the sheet stacking device is located at the second position, the first stacking member is configured such that the first stacking surface is at the same height as the second stacking surface, or the first stacking surface is at the same height as the second stacking surface. It is positioned above the loading surface.

As a result, when the sheet stacking device is located at the second position, the second stacking surface does not protrude upward from the notch of the first stacking member, and the second stacking surface does not stack sheets on the sheet stacking device. It is possible to suppress the interference when doing so.

The first stacking member is a first bent portion extending downward from a downstream end in the sheet conveyance direction, and the first stacking member is a first bent portion that abuts the paper feed tray when the sheet stacking device is located at a second position. It has one bend.

Thereby, the first bent portion of the first stacking member comes into contact with the paper feed tray, so that the first stacking member can be positioned.

Further, the sheet feeding tray is a convex portion located at a downstream end in the sheet conveyance direction and at both ends in the axial direction, and the sheet feeding tray is a convex portion located at the first bent portion when the sheet stacking device is located at the second position. It has a convex part that comes into contact with.

Thereby, the first bent portion of the first stacking member and the convex portion of the paper feed tray come into contact with each other, so that the first stacking member can be positioned.

Further, the second stacking member is a pressing surface extending parallel to the second loading surface, and includes a pressing surface facing the first loading member and an upper portion of the pressing surface from a downstream end in the sheet conveyance direction. The second stacking surface extends from the upper end of the second bending section in the sheet conveyance direction and is located above the pressing surface.

This allows the second stacking surface to easily protrude upward from the notch while the sheet stacking device is located at the first position.

Further, the paper feed tray has a rotating shaft portion that is located upstream of the notch portion in the sheet conveying direction and at both ends in the axial direction, and that supports the first stacking member and the second stacking member. The first loading member and the second loading member are rotatable about the rotation shaft.

Thereby, the space occupied by the portions that support the first stacking member and the second stacking member and the number of parts of the supporting members of the first stacking member and the second stacking member can be reduced.

Further, the paper feed tray is movable in the axial direction and includes a pair of side regulating plates that regulate end portions of the sheets in the axial direction, and the rotating shaft portion is configured to be movable in the axial direction. It is located upstream of the plate in the sheet conveyance direction.

As a result, the rotation shafts that support the first stacking member and the second stacking member are arranged at a position away from the paper feed roller in the sheet conveyance direction, so that the paper feed roller for the sheets stacked on the sheet stacking device It is possible to reduce the entry angle with respect to the paper feed roller, and the sheet can be stably fed by the paper feed roller.

The invention further includes an elevating member that moves up and down by a driving force from a drive source, the elevating member pressing the second loading member from below to raise it, and the second loading member lifting the first loading member from below. Press down to raise it.

Thereby, the first stacking member and the second stacking member can be raised and lowered simultaneously by the lifting member.

Further, the elevating member contacts the second stacking member at a position overlapping the paper feed roller in the vertical direction.

This makes it possible to reliably raise the portion of the second stacking member that faces the paper feed roller, and it is possible to secure the nip load from the paper feed roller against the sheet supported by the second stacking surface.

Further, the second loading member has a pressing surface extending parallel to the second loading surface and facing the first loading member, and the first loading member has a pressing surface extending parallel to the second loading surface, and the first loading member and has a pressed surface opposite to the pressing surface, and there is a gap between the pressing surface and the pressed surface when the sheet stacking device is located at the second position. is formed and the sheet stacking device is located at the first position, the pressing surface and the pressed surface are in contact with each other.

Thereby, when feeding a sheet, the sheet can be stably supported by the two members, the second stacking member and the first stacking member.

The invention further includes an elevating member that moves up and down by a driving force from a drive source, and when the sheet stacking device moves up from the second position to the first position, the elevating member presses the second stacking member. , after the second loading surface protrudes upward from the notch, the pressing surface of the second loading member presses the pressed surface of the first loading member, causing the first loading member to rise. starts.

This can prevent the sheet supported by the first stacking surface from entering the notch and being bent or damaged during the process of the sheet stacking device rising from the second position to the first position.

Further, the paper feed roller gear is rotatable about the first shaft and is located on one side of the paper feed roller in the axial direction, and the cutout portion is configured to include: It is located closer to the paper feed roller than the paper feed roller gear.

This can effectively prevent the sheet from coming into contact with the paper feed roller gear.

Further, the first loading member and the second loading member are made of sheet metal.

Thereby, it is possible to suppress the first stacking member and the second stacking member from bending, and the sheet can be stably supported by the first stacking member and the second stacking member.

Further, the image forming apparatus includes the paper feeding device according to any one of claims 1 to 13, and an image forming section that forms an image on a sheet sent out from the paper feeding device.

As a result, in an image forming apparatus equipped with a paper feeding device, when feeding paper with the sheet stacking device raised to the first position, the second stacking surface, which is the portion of the sheet stacking device that faces the paper feeding roller, is By locating it above other parts, it is possible to suppress the sheet from coming into contact with parts other than the paper feed roller.

According to the present invention, even if a fed sheet is undulated, the sheet can be prevented from coming into contact with parts other than the paper feeding roller.

FIG. 2 is a central sectional view showing the image forming apparatus. (a) is a perspective view showing the paper feed roller, and (b) is a front view showing the paper feed roller. FIG. 3 is a perspective view showing a paper feed tray. FIG. 3 is a plan view showing a paper feed tray. FIG. 3 is a side view showing the paper feed tray. FIG. 3 is a side cross-sectional view showing the paper feed tray in a state where the sheet stacking device is located at the first position. FIG. 7 is a side cross-sectional view showing the paper feed tray with the sheet stacking device located at the second position. (a) is a plan view showing the first stacking plate, and (b) is a perspective view showing the first stacking plate. (a) is a plan view showing the second stacking plate, and (b) is a perspective view showing the second stacking plate. FIG. 3 is a side cross-sectional view showing a first bent portion of the first stacking plate and a convex portion of the paper feed tray. FIG. 7 is a side cross-sectional view showing the sheet stacking device in a second position, with a gap formed between the pressing surface of the second stacking plate and the pressed surface of the first stacking plate. From the state where the sheet stacking device is located in the second position, the second stacking plate is pressed by the elevating plate and rises, and the second stacking surface of the second stacking plate projects upward from the notch of the first stacking plate. FIG. 3 is a side sectional view showing the situation. FIG. 3 is a side cross-sectional view showing the sheet stacking device in a first position, where the pressing surface of the second stacking plate and the pressed surface of the first stacking plate are in contact with each other. FIG. 7 is a front sectional view showing the paper feed tray with the sheet stacking device located at the second position. FIG. 3 is a front sectional view showing the paper feed tray with the sheet stacking device located at the first position.

Next, embodiments for carrying out the present invention will be described using the accompanying drawings.

[Image forming device]
An image forming apparatus 1 shown in FIG. 1 is an embodiment of an image forming apparatus equipped with a paper feeding device according to the present invention, and is a color laser printer that forms images in multiple colors on a sheet S using an electrophotographic method. .

In the following description, the right side in FIG. 1 is defined as the front side of the image forming apparatus 1, the left side in FIG. 1 is defined as the rear side of the image forming apparatus 1, and the front side in FIG. The back side of the page is defined as the right side of the image forming apparatus 1. Further, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

The image forming apparatus 1 includes an apparatus main body 2, a paper feeding device 3 having a paper feeding tray 10 that supports sheets S, and a paper feeding unit 30 that feeds the sheets S, and It includes an image forming section 5 that forms an image and a motor 90. Motor 90 is an example of a drive source.

The apparatus main body 2 is formed into a substantially rectangular parallelepiped shape, and accommodates a paper feeder 3 and an image forming section 5. An upper opening 2A is opened on the upper surface of the apparatus main body 2, and the apparatus main body 2 has a top cover 23 that can open and close the upper opening 2A. A front opening 2B is open at the front of the apparatus main body 2, and the apparatus main body 2 has an MP tray 24 that can open and close the front opening 2B.

The top cover 23 is configured to be rotatable around a rotation axis 23a at the rear end, and by rotating around the rotation axis 23a, the top cover 23 is placed in a closed position (see FIG. ) and an open position in which the upper opening 2A is opened. The top cover 23 of the apparatus main body 2 is formed with a paper discharge tray 23b that slopes downward from the front side toward the rear side.

The MP tray 24 rotates about the rotation axis 24a, and can be moved between a closed position (the position indicated by the two-dot chain line in FIG. 1) where the front opening 2B is closed and an open position (where the front opening 2B is opened). It is possible to move between the positions shown by solid lines in FIG. The MP tray 24 can support a plurality of stacked sheets S when it is in the open position.

The paper feeder 3 is disposed at the lower part of the apparatus main body 2, and feeds the sheet S supported by the paper feed tray 10 toward the image forming section 5 using the paper feeder 30. The paper feed tray 10 is configured to be slidable in the front-back direction, and is configured to be movable between an accommodation position where it is accommodated in the apparatus main body 2 and a separation position where it is pulled out forward from the accommodation position.

The paper feeding device 3 is a sheet stacking device 11 that is provided on the paper feeding tray 10 and stacks sheets S, and is a sheet stacking device that can be raised and lowered by rotating around the rotating shaft portion 106 of the paper feeding tray 10. The sheet stacking device 11 includes a device 11 and a lifting mechanism 14 including a lifting plate 145 for lifting and lowering the sheet stacking device 11. The elevating plate 145 is made of a flat metal plate.

The elevating plate 145 can be moved up and down by rotating about the pivot point 145a by the driving force from the motor 90. The elevating plate 145 can move the sheet stacking device 11 up and down by rotating about the rotation fulcrum 145a. The elevating plate 145 is an example of an elevating member.

The paper feed section 30 includes a paper feed roller 32, a separation roller 33, and a separation pad 33a. A conveying roller 34a and a registration roller 35a are arranged between the paper feeding section 30 and the image forming section 5. The paper feed roller 32, separation roller 33, separation pad 33a, conveyance roller 34a, and registration roller 35a are driven by a motor 90. Inside the apparatus main body 2, there is configured a transport path P for sheets S from the paper feed tray 10 to the paper output tray 23b via the paper feed section 30, transport rollers 34a, registration rollers 35a, and image forming section 5. ing.

The sheets S supported by the paper feed tray 10 are separated one by one by a paper feed roller 32, a separation roller 33, and a separation pad 33a, and sent out to a conveyance path P. The paper feed roller 32 is a roller that feeds the sheet S supported by the paper feed tray 10 toward the image forming section 5 . The separation roller 33 is a roller that separates the sheets S fed by the paper feed roller 32 one by one. The separation roller 33 and the separation pad 33a constitute separation means that separates the sheets S supported by the paper feed tray 10 one by one.

The sheet S sent out to the conveyance path P is transferred to the image forming section 5 by the conveyance roller 34a and the rollers 34b arranged opposite to the conveyance roller 34a, and the registration rollers 35a and the registration rollers 35b arranged opposite to the registration roller 35a. transported towards the The registration rollers 35a restrict the movement of the leading end of the sheet S being conveyed and once stop the sheet S, and then convey the sheet S toward the image forming section 5 at a predetermined timing.

The paper feeding device 3 includes a feeding mechanism 36 that transports the sheet S supported by the MP tray 24 to the image forming section 5. The supply mechanism 36 includes a supply roller 361, a separation roller 362, a separation pad 363, and a holder 364 that rotatably supports the supply roller 361 and separation roller 362. The sheets S supported by the MP tray 24 are separated one by one by a supply roller 361, a separation roller 362, and a separation pad 363, and sent out to a conveyance path P. The sheet S sent out to the conveyance path P is conveyed toward the image forming section 5 by the registration rollers 35a.

The image forming section 5 is arranged above the paper feeding device 3, and includes four process cartridges 50 arranged in parallel in the front-back direction. Each process cartridge 50 is provided corresponding to each color of black, yellow, magenta, and cyan. The process cartridge 50 is removably attached to the apparatus main body 2. The process cartridge 50 includes a photosensitive drum 51, a developing roller 52, a supply roller 53, and a charger 54. The photosensitive drum 51 is an example of a drum on which a toner image is formed.

The process cartridge 50 is attached to the apparatus main body 2 with the drum axis of the photosensitive drum 51 aligned in the left-right direction. The developing roller 52 is configured to be movable between a contact position where it contacts the photosensitive drum 51 and a separate position where it separates from the photosensitive drum 51. The supply roller 53 supplies the toner contained in the process cartridge 50 to the developing roller 52 .

The apparatus main body 2 has an exposure head 59 that exposes the surface of the photosensitive drum 51. The exposure head 59 is supported by the top cover 23. Four exposure heads 59 are provided corresponding to each photosensitive drum 51, and each exposure head 59 is arranged in parallel in the front-back direction. The exposure head 59 extends downward from the top cover 23 and has an exposure section 59a at its lower end. The exposure section 59a is arranged above and close to the photosensitive drum 51 when the top cover 23 is closed. The exposure section 59a is constituted by an LED array including a plurality of LED elements arranged in parallel in the left-right direction.

A transfer belt 41 is disposed below the photosensitive drum 51 across the conveyance path P therebetween. The transfer belt 41 is stretched between a drive roller 42 and a driven roller 43 arranged in front of the drive roller 42 . A belt device 40 is composed of a transfer belt 41, a driving roller 42, and a driven roller 43. Transfer rollers 44 are arranged at positions facing each photosensitive drum 51 with the transfer belt 41 in between. The transfer roller 44 is an example of a transfer member disposed facing the drum.

In the image forming section 5, the photosensitive drums 51 uniformly charged by the charger 54 are selectively exposed by the exposure heads 59, respectively. Through this exposure, charges are selectively removed from the surface of the photosensitive drum 51, and an electrostatic latent image is formed on the surface of the photosensitive drum 51.

The toner contained in the process cartridge 50 is positively charged between the supply roller 53 and the developing roller 52 and carried on the surface of the developing roller 52 . A developing bias is applied to the developing roller 52, and when the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52, the potential difference between the electrostatic latent image and the developing roller 52 causes the developing roller 52 to toner is supplied to the electrostatic latent image. As a result, a toner image is formed on the surface of the photosensitive drum 51.

When the sheet S conveyed toward the image forming section 5 reaches the transfer belt 41, it is conveyed by the transfer belt 41 and sequentially passes between the transfer belt 41 and each photosensitive drum 51. The toner image on the surface of the photosensitive drum 51 is transferred onto the sheet S by a transfer bias applied to the transfer roller 44 when the photosensitive drum 51 faces the sheet S.

Note that the transfer belt 41 in this embodiment is configured as a conveyor belt that conveys the sheet S onto which the toner image is transferred, but the toner image is transferred to the belt itself, and the toner image transferred to the belt is further transferred to the sheet. It is also possible to configure an intermediate transfer belt that transfers images to S.

The sheet S onto which the toner image has been transferred is conveyed to a fixing device 60. The fixing device 60 includes a heating roller 61 and a pressure roller 62 that is in pressure contact with the heating roller 61, and the sheet S conveyed to the fixing device 60 passes between the heating roller 61 and the pressure roller 62. The toner image is thermally fixed.

The sheet S on which the toner image has been thermally fixed is conveyed from the fixing device 60 to the downstream side in the conveyance direction, and is further conveyed to an intermediate sheet discharge roller pair 63 and a sheet discharge roller disposed downstream of the intermediate sheet discharge roller pair 63 in the conveyance direction. The sheet is conveyed by the pair 64 and discharged onto the paper discharge tray 23b.

[Paper feed roller]
As shown in FIG. 2, the paper feeding device 3 includes a first shaft 321 extending in the left-right direction, and the paper feeding roller 32 is configured to be rotatable about the first shaft 321. The left-right direction is an example of the axial direction. The paper feeding device 3 includes a paper feeding roller gear 322 that is rotatable about a first shaft 321 . The paper feed roller gear 322 is located to the left of the paper feed roller 32. The left side is an example of one side in the axial direction.

The driving force from the motor 90 is input to the paper feed roller gear 322, and by inputting the driving force from the motor 90 to the paper feed roller gear 322, the paper feed roller gear 322, the first shaft 321, and the paper feed roller 32 are rotated. rotates as one. The paper feed roller gear 322 is formed to have a smaller diameter than the paper feed roller 32.

[Paper feed tray]
As shown in FIGS. 3 to 5, the paper feed tray 10 includes a bottom wall 101, a left wall 102, a right wall 103, a front wall 104, a rear wall 105, a rotating shaft portion 106, and a side regulation member. A plate 107 is provided.

The paper feed tray 10 is capable of stacking sheets S in a space surrounded by a bottom wall 101, a left wall 102, a right wall 103, a front wall 104, and a rear wall 105. The sheets S stacked on the paper feed tray 10 are fed along the front-rear direction by a paper feed roller 32. Specifically, the sheet S is fed forward by the paper feed roller 32.

A pair of side regulating plates 107 are provided on the left and right, and are supported by the bottom wall 101 so as to be movable in the left-right direction. The side regulation plate 107 can regulate the ends of the sheets S in the left-right direction by moving in the left-right direction according to the size of the sheets S loaded on the paper feed tray 10 .

A pair of rotation shafts 106 are provided on the left and right, the left rotation shaft 106 is located at the left end of the bottom wall 101, and the right rotation shaft 106 is located at the right end of the bottom wall 101. are doing. Further, the rotation shaft portion 106 is located on the rear side of the side regulating plate 107. The rear side is an example of the upstream side in the sheet conveyance direction.

[Lifting mechanism]
The lifting mechanism 14 includes an input gear 141, a first transmission gear 142, a second transmission gear 143, a drive gear 144, and a lifting plate 145. Input gear 141 , first transmission gear 142 , second transmission gear 143 , and drive gear 144 are supported by left wall 102 of paper feed tray 10 .

The driving force from the motor 90 is input to the input gear 141 . The first transmission gear 142 meshes with the input gear 141. The second transmission gear 143 is coaxially and integrally rotatably provided with the first transmission gear 142. The drive gear 144 meshes with the second transmission gear 143. The elevating plate 145 is a plate-like member extending in the left-right direction, and the left end portion of the elevating plate 145 is connected to the drive gear 144.

The driving force from the motor 90 that is input to the input gear 141 is transmitted to the drive gear 144 via the first transmission gear 142 and the second transmission gear 143. The drive gear 144 to which the driving force is transmitted drives the elevating plate 145, and the elevating plate 145 driven by the driving gear 144 rotates about a rotation fulcrum 145a.

[Sheet loading device]
As shown in FIG. 6, the sheet stacking device 11 is moved to a first position where the elevating plate 145 rotates upward about the rotation fulcrum 145a, thereby allowing the sheet S to be fed by the paper feed roller 32. Rise. On the other hand, as shown in FIG. 7, the elevating plate 145 rotates downward about the pivot point 145a, so that the sheet stacking device 11 moves to the second position where the sheets S are stacked below the first position. descend. In this way, the sheet stacking device 11 is raised and lowered between the first position and the second position by the lifting plate 145.

The sheet stacking device 11 has a first stacking plate 12 and a second stacking plate 13. The first stacking plate 12 is an example of a first stacking member, and the second stacking plate 13 is an example of a second stacking member.

As shown in FIGS. 3 and 6 to 8, the first stacking plate 12 is made of a flat metal plate, and has a first stacking surface 121 that supports the sheets S and a rotating surface of the paper feed tray 10. It has a rotation support part 122 rotatably supported by the shaft part 106.

A pair of rotation support parts 122 are provided on the left and right, and are located at the left and right ends of the rear end of the first loading surface 121, respectively. The first stacking plate 12 is rotatably attached to the paper feed tray 10 about the rotation shaft 106 because the rotation support portion 122 is supported by the rotation shaft 106 .

A notch 123 is formed in the left and right center portions of the front end of the first loading surface 121, and is cut out in a rectangular shape from the front end toward the rear. The front end is an example of the downstream end in the sheet conveyance direction. The cutout portion 123 is formed at a position facing the paper feed roller 32 in the vertical direction. However, the notch 123 does not have to be formed by cutting out the front end of the first stacking surface 121 as long as it is formed at a position facing the paper feed roller in the vertical direction. The cutout portion 123 may be formed by cutting out a portion of the first stacking surface 121 that faces the paper feed roller 32. The rotation shaft portion 106 of the paper feed tray 10 is located on the rear side of the notch portion 123.

A through hole 124 is formed in the first loading surface 121 in front of the rotation support portion 122 . A pair of through holes 124 are provided on the left and right sides. In the paper feed tray 10 , the side regulating plate 107 projects upward from below the first stacking surface 121 through the through hole 124 .

The first loading plate 12 has a first bent portion 125 extending downward from the front end of the first loading surface 121 . A pair of first bent portions 125 are provided on the left and right at the front end of the first stacking plate 12 . The front end is an example of the downstream end in the sheet conveyance direction. The first loading plate 12 has a pressed surface 126 that is a surface opposite to the first loading surface 121 . The first loading surface 121 faces upward, and the pressed surface 126 faces downward.

As shown in FIGS. 4, 6, 7, and 9, the second loading plate 13 is made of a flat sheet metal, and includes a second loading surface 131, a pressing surface 132, and a second bent portion. 133 and a rotation support part 134.

The second stacking surface 131 is a surface that supports the sheets S, and is located at the front end of the second stacking plate 13. The pressing surface 132 is a surface extending parallel to the second loading surface 131 and is located behind the second loading surface 131. The second loading surface 131 and the pressing surface 132 face upward.

The second bent portion 133 extends upward from the front end of the pressing surface 132. The upper end of the second bent portion 133 is connected to the rear end of the second loading surface 131. The second loading surface 131 extends from the upper end of the second bent portion 133 along the front-rear direction. Specifically, the second loading surface 131 extends forward from the upper end of the second bent portion 133. That is, the second loading surface 131 is located above the pressing surface 132, and the second bent portion 133 connects the front end of the pressing surface 132 and the rear end of the second loading surface 131.

A pair of rotation support parts 134 are provided on the left and right, and are located at the left and right ends of the rear end of the pressing surface 132, respectively. The rotation support portion 134 is rotatably supported by the rotation shaft portion 106 of the paper feed tray 10 . The second stacking plate 13 is rotatably attached to the paper feed tray 10 about the rotation shaft 106 because the rotation support portion 134 is supported by the rotation shaft 106 . The second loading plate 13 has a contact surface 135 that is a surface opposite to the second loading surface 131. The contact surface 135 faces downward. A friction member 136 made of cork or the like is attached to the front end of the second loading surface 131 of the second loading plate 13 . When the sheet stacking device 11 is located at the first position, the friction member 136 is located at a position overlapping the paper feed roller 123 in the vertical direction.

As shown in FIG. 3, FIG. 4, FIG. 6, and FIG. They are stacked vertically so as to be located above 132. When the first stacking plate 12 and the second stacking plate 13 are stacked, the notch 123 of the first stacking plate 12 and the second stacking surface 131 of the second stacking plate 13 are located at a position where they overlap in the vertical direction. It is located. Further, in the state in which the first stacking plate 12 and the second stacking plate 13 are stacked, the pressed surface 126 of the first stacking plate 12 and the pressing surface 132 of the second stacking plate 13 are opposed to each other.

As shown in FIG. 7, when the sheet stacking device 11 is located at the second position, the first stacking plate 12 and the second stacking plate 13 rotate downward and are substantially parallel to the bottom wall 101 of the paper feed tray 10. It is in the position of Further, when the sheet stacking device 11 is located at the second position, the second stacking plate 13 is arranged below the first stacking plate 12. The elevating plate 145 is located below the second stacking plate 13 and has a contact portion 145b that can contact the contact surface 135 of the second stacking plate 13.

As shown in FIGS. 4 and 10, the paper feed tray 10 has protrusions 101a that are located at the front end and both left and right ends of the bottom wall 101 and project upward from the bottom wall 101. As shown in FIGS. The first bent portion 125 of the first stacking plate 12 and the convex portion 101a of the paper feed tray 10 are in contact with each other when the sheet stacking device 11 is located at the second position, and the first bent portion 125 and the convex portion 101a, the vertical position of the first loading plate 12 is determined.

In this way, by providing the convex portion 101a on the paper feed tray 10, the first bent portion 125 of the first stacking plate 12 and the convex portion 101a of the paper feed tray 10 are brought into contact with each other, and the first stacking plate 12 is It is possible to position up and down.

As shown in FIGS. 4 and 11, when the sheet stacking device 11 is located at the second position, the first stacking plate 12 has the first stacking surface 121 at the same height as the second stacking surface 131, or the first stacking plate 12 The loading surface 121 is positioned above the second loading surface 131. When the sheet stacking device 11 is located at the second position, the sheets S are mainly supported by the first stacking surface 121. Note that in FIG. 11, the first loading surface 121 and the second loading surface 131 are located at the same height.

In this manner, when the sheet stacking device 11 is located at the second position, the first stacking plate 12 is arranged so that the first stacking surface 121 that supports the sheets S is at the same height as the second stacking surface 131, or It is positioned at a height above the loading surface 131. As a result, when the sheet stacking device 11 is located at the second position, the second stacking surface 131 does not protrude upward from the notch 123 of the first stacking plate 12, and the second stacking surface 131 does not stack the sheets. It is possible to prevent the sheet S from becoming a hindrance when stacking the sheets S on the device 11.

When the sheet stacking device 11 is located at the second position, the pressing surface 132 of the second stacking plate 13 is located below the first stacking surface 121 and the pressed surface 126 of the first stacking plate 12. Further, when the sheet stacking device 11 is located at the second position, a gap is formed between the pressing surface 132 of the second stacking plate 13 and the pressed surface 126 of the first stacking plate 12.

Further, when the sheet stacking device 11 is located at the second position, a gap is formed between the contact surface 135 of the second stacking plate 13 and the contact portion 145b of the elevating plate 145. Note that in FIG. 11, a gap is formed between the contact surface 135 and the contact portion 145b, but when the sheet stacking device 11 is in the second position, the contact portion 145b is in contact with the contact surface 135 and the contact portion 145b. It may be in contact with surface 135.

When the sheet stacking device 11 located at the second position is raised to the first position, the elevating plate 145 is rotated upward about the rotation fulcrum 145a by the driving force from the motor 90. When the lifting plate 145 rotates upward, the contact portion 145b of the lifting plate 145 contacts the contact surface 135 of the second loading plate 13, and the lifting plate 145 presses the second loading plate 13 from below and rises. let

As shown in FIG. 12, when the second loading plate 13 is pressed by the lifting plate 145 and rises, the second loading surface 131 of the second loading plate 13 protrudes upward from the notch 123 of the first loading plate 12. , located above the first loading surface 121. After the second loading surface 131 protrudes upward from the notch 123, when the second loading plate 13 is further raised by the elevating plate 145, the pressing surface 132 of the second loading plate 13 becomes the pressed surface of the first loading plate 12. 126 is pressed from below, and the first loading plate 12 starts to rise.

After the second stacking surface 131 protrudes upward from the notch 123, the first stacking plate 12 starts to rise, so that in the process of the sheet stacking device 11 rising from the second position to the first position, the first stacking plate 12 It is possible to prevent the sheet S supported by the stacking surface 121 from entering the notch 123 and being bent or damaged.

In this way, when the sheet stacking device 11 is raised from the second position to the first position, the elevating plate 145 presses the second stacking plate 13 from below to raise it, and the second stacking plate 13 Press from below to raise it. The second stacking plate 13 and the first stacking plate 12 are raised by the lifting plate 145 until the sheet stacking device 11 is located at the first position.

As shown in FIG. 13, when the second stacking plate 13 and the first stacking plate 12 are raised by the elevating plate 145 and the sheet stacking device 11 is located at the first position, the pressing surface 132 of the second stacking plate 13 and the pressed surface 126 of the first loading plate 12 are in contact with each other.

In addition, when the sheet stacking device 11 is located at the first position, the second stacking surface 131 of the second stacking plate 13 protrudes upward from the notch 123 of the first stacking plate 12 and extends beyond the first stacking surface 121. is also located above. In this case, since the second stacking surface 131 is located above the pressing surface 132, the second stacking surface 131 can be easily moved upward from the notch 123 while the sheet stacking device 11 is located at the first position. It is possible to make it stick out.

When the sheet stacking device 11 is located at the first position, the sheet S is supported by the first stacking surface 121 and the second stacking surface 131 located above the first stacking surface 121. In this case, the second stacking surface 131 that projects upward from the notch 123 of the first stacking plate 12 faces the paper feed roller 32 in the vertical direction.

As shown in FIG. 14, when the sheets S are stacked on the paper feed tray 10 with the sheet stacking device 11 located at the second position, the sheets S are wavy and the sheet S is placed in a position higher than other parts. There may be a protruding portion Sa that protrudes.

In such a case, especially if the protrusion Sa is located below the paper feed roller gear 322, the protrusion Sa may remain in the same state when the sheet stacking device 11 rises to the first position where paper can be fed. If the protrusion Sa is present, there is a risk that the protrusion Sa will come into contact with the paper feed roller gear 322, and the nip load from the paper feed roller 32 applied to the sheet S will decrease, resulting in a paper feeding error.

However, in the paper feeding device 3, as shown in FIG. 15, when feeding sheets with the sheet stacking device 11 raised to the first position, The sheet S is supported by the second stacking surface 131 located at , and the portion of the sheet S facing the paper feed roller 32 is lifted by the second stacking surface 131 more than the other portion.

Therefore, the amount of protrusion Sa of the sheet S lifted by the second stacking surface 131 can be kept small, and the protrusion Sa of the sheet S to be fed is connected to the paper feed roller 32 such as the paper feed roller gear 322. Contact with other parts can be suppressed. Thereby, the nip load applied to the sheet S by the paper feed roller 32 can be ensured, and the occurrence of paper feeding mistakes can be suppressed.

In this case, in the left-right direction, the notch 123 of the first stacking plate 12 is located to the right of the paper feed roller gear 322, that is, closer to the paper feed roller 32 than the paper feed roller gear 322. The portion adjacent to the paper feed roller gear 322 can be lifted by the second stacking surface 131, making it possible to effectively suppress the amount of protrusion of the protrusion Sa. Thereby, it is possible to effectively prevent the protruding portion Sa of the sheet S from coming into contact with the paper feed roller gear 322.

Further, when the second stacking plate 13 and the first stacking plate 12 are raised by the lifting plate 145, the lifting plate 145 is in contact with the second stacking plate 13 at a position overlapping with the paper feed roller 32 in the vertical direction. This makes it possible to reliably raise the portion of the second stacking plate 13 that faces the paper feed roller 32, ensuring the nip load from the paper feed roller 32 on the sheet S supported by the second stacking surface 131. can do.

Furthermore, when the sheet stacking device 11 is raised to the first position, the pressing surface 132 of the second stacking plate 13 and the pressed surface 126 of the first stacking plate 12 are in contact with each other, so that the sheet S is not fed. At this time, it is possible to stably support the sheet S by the two members, the second stacking plate 13 and the first stacking plate 12.

Further, since the first loading plate 12 and the second loading plate 13 are made of sheet metal, it is possible to suppress the first loading plate 12 and the second loading plate 13 from bending, and the first loading plate 12 and the second loading plate 13 can be prevented from bending. The sheet S can be stably supported by the stacking plate 13.

Further, the rotation shaft portion 106 that supports the first stacking plate 12 and the second stacking plate 13 is located at the rear of the side regulating plate 107, and is separated from the paper feed roller 32 in the front-rear direction, which is the sheet conveyance direction. It is placed in the same position. As a result, the angle at which the sheets S stacked on the sheet stacking device 11 enter the paper feed roller 32 can be reduced, and the sheet S can be stably fed by the paper feed roller 32.

In addition, in the paper feeding device 3, since both the first stacking plate 12 and the second stacking plate 13 are supported by the rotation shaft portion 106, the first stacking plate 12 and the second stacking plate 13 are supported. It is possible to reduce the space occupied by the parts and the number of parts of the supporting members of the first loading plate 12 and the second loading plate 13.

In addition, in the paper feeding device 3, the elevating plate 145 presses the second stacking plate 13 from below to raise it, and the second stacking plate 13 presses the first stacking plate 12 from below to raise it, so the first The loading plate 12 and the second loading plate 13 can be raised and lowered simultaneously by the lifting plate 145.

1 Image forming device 3 Paper feeding device 5 Image forming unit 10 Paper feeding tray 11 Sheet stacking device 12 First stacking plate 13 Second stacking plate 32 Paper feeding roller 101 Bottom wall 101a Convex portion 106 Rotation shaft portion 107 Side regulating plate 121 First loading surface 123 Notch portion 125 First bent portion 126 Pressed surface 131 Second loading surface 132 Pressing surface 133 Second bent portion 145 Elevating plate 321 First shaft 322 Paper feed roller gear S sheet

Claims (14)

a paper feed tray that supports sheets;
a paper feed roller that feeds sheets supported by the paper feed tray toward an image forming section, the paper feed roller being rotatable about a first axis extending in the axial direction;
A sheet stacking device that is movable up and down between a first position that allows the sheet feeding roller to feed sheets and a second position that stacks sheets below the first position,
a flat first stacking member having a first stacking surface that supports the sheet;
a second stacking member having a flat plate shape and having a second stacking surface that supports sheets and being disposed below the first stacking member when the sheet stacking device is located at the second position; a device;
Equipped with
The first stacking member has a notch at a position facing the paper feed roller at a downstream end in the sheet conveyance direction,
A sheet feeding device characterized in that, when the sheet stacking device is located at the first position, the second stacking surface protrudes from the notch and is located above the first stacking surface. With the sheet stacking device located at the second position, the first stacking member is configured such that the first stacking surface is at the same height as the second stacking surface, or the first stacking surface is at the same height as the second stacking surface. The paper feeding device according to claim 1, wherein the paper feeding device is positioned at a position located above. The first stacking member is a first bent portion that extends downward from the downstream end in the sheet conveyance direction, and has a first bent portion that abuts the paper feed tray when the sheet stacking device is located at the second position. 3. The paper feeding device according to claim 2, further comprising: The paper feed tray is a convex portion located at a downstream end in the sheet conveyance direction and at both ends in the axial direction, and the sheet feeding tray is a convex portion located at both ends in the axial direction, and is in contact with the first bent portion when the sheet stacking device is located at the second position. The paper feeding device according to claim 3, further comprising a convex portion that contacts the convex portion. The second stacking member is a pressing surface that extends parallel to the second loading surface, and includes a pressing surface that faces the first loading member, and a pressing surface that extends upward from a downstream end of the pressing surface in the sheet conveyance direction. a second bent portion;
The sheet feeding device according to claim 1, wherein the second stacking surface extends from the upper end of the second bending portion in the sheet conveyance direction and is located above the pressing surface. The paper feed tray is located upstream of the notch in the sheet conveyance direction and at both ends in the axial direction, and has a rotating shaft part that supports the first stacking member and the second stacking member. death,
The paper feeding device according to claim 1, wherein the first stacking member and the second stacking member are rotatable about the rotation shaft. The paper feed tray is movable in the axial direction and includes a pair of side regulating plates that regulate the ends of the sheets in the axial direction,
7. The paper feeding device according to claim 6, wherein the rotation shaft portion is located upstream of the pair of side regulating plates in the sheet conveyance direction. Further comprising an elevating member that moves up and down by driving force from the driving source,
The elevating member presses the second loading member from below to raise it;
The paper feeding device according to claim 1, wherein the second stacking member presses the first stacking member from below to raise it. The paper feeding device according to claim 8, wherein the elevating member contacts the second stacking member at a position overlapping the paper feeding roller in the vertical direction. The second loading member has a pressing surface that extends parallel to the second loading surface and faces the first loading member,
The first loading member has a pressed surface opposite to the first loading surface and facing the pressing surface,
When the sheet stacking device is located at the second position, a gap is formed between the pressing surface and the pressed surface,
The sheet feeding device according to claim 1, wherein the pressing surface and the pressed surface are in contact with each other when the sheet stacking device is located at the first position. Further comprising an elevating member that moves up and down by driving force from the driving source,
When the sheet stacking device ascends from the second position to the first position,
After the elevating member presses the second stacking member and the second stacking surface protrudes upward from the notch,
The paper feeding device according to claim 10, wherein the pressing surface of the second stacking member presses the pressed surface of the first stacking member, and the first stacking member starts to rise. further comprising a paper feed roller gear rotatable about the first shaft, the paper feed roller gear being located on one side of the paper feed roller in the axial direction;
The paper feeding device according to claim 1, wherein the cutout portion is located closer to the paper feed roller than the paper feed roller gear in the axial direction. The paper feeding device according to claim 1, wherein the first stacking member and the second stacking member are made of sheet metal. A paper feeding device according to any one of claims 1 to 13,
An image forming apparatus comprising: an image forming section that forms an image on a sheet fed out from the paper feeding device.

Images