Patent Grant
11745966
This application is based on and claims the benefit of Japanese Patent Application No. 2020-102826 filed on Jun. 15, 2020, the contents of which are hereby incorporated by reference.
The present disclosure relates to a sheet feeding device for inserting a cover sheet, a slip sheet, or the like among a plurality of sheets having images formed on them by an image forming apparatus such as a copier, facsimile machine, or printer. The present disclosure also relates to an image forming system that employs such a sheet feeding device.
A known image forming system includes an image forming apparatus, a sheet feeding apparatus connected downstream of the image forming apparatus, and a sheet post-processing apparats connected downstream of the sheet feeding apparatus. In this image forming system, among a plurality of output sheets having images formed on them by the image forming apparatus, insertion sheets to become cover sheets or slip sheets are inserted to produce a bundle of sheets that includes output sheets and insertion sheets, and the bundle of sheets is subjected to predetermined post-processing by the sheet post-processing apparatus to produce a booklet.
According to one aspect of the present disclosure, a sheet feeding apparatus includes a sheet stacking portion, a lift plate, an actuating segment, a driving unit, a sheet feeding portion, a first detecting portion, and a remaining amount detection portion. On the sheet stacking portion, sheets are stacked the lift plate is disposed on the bottom surface of the sheet stacking portion, and is ascendable-descendable about an upstream end part of the lift plate in the sheet feed direction. The actuating segment is disposed between the bottom surface and the lift plate, and pivots about a driving shaft extending in the direction orthogonal to the sheet feed direction so as to raise and lower a downstream end part of the lift plate with respect to the sheet feed direction. The driving unit is coupled to the driving shaft, and raises and lowers the actuating segment via the driving shaft. The sheet feeding portion is disposed over the lift plate so as to face it, and feeds sheets raised to a feeding portion by the lift plate. The first detecting portion senses the top surface of the sheets located at the feeding portion. The remaining amount detection portion senses as a remaining quantity level whether or not the remaining quantity of sheets stacked on the feeding portion is more or less than a predetermined quantity. The remaining amount detection portion includes a detection piece, a link mechanism, a second detecting portion, and a controller. The detection piece has a base end part of it pivoted on the driving shaft, and is provided so as to be pivotable about the driving shaft. The link mechanism couples together the driving shaft and the detection piece at a coupling position attained by pivoting the lift plate through a predetermined angle from the lower limit position in the rotation direction, so as to let the driving shaft and the detection piece rotate together. The second detecting portion senses whether or not, with the lift plate located at the feeding portion, the detection piece is present. The controller determines the remaining quantity level of the stacked sheets according to whether or not, with the first detecting portion detecting the top surface of the sheets, the second detecting portion is detecting the detection piece being present.
This and other objects of the present disclosure, and the specific benefits obtained according to the present disclosure, will become apparent from the description of embodiments which follows.
Hereinafter, with reference to the accompanying drawings, an embodiment of a sheet feeding apparatus according to the present disclosure and an image forming system employing it will be described.
First with reference to
The image forming apparatus 1 includes the sheet storage portion 4, which is provided in a lower part of the image forming apparatus 1; a sheet conveyance passage 6, which is disposed at a side of the sheet storage portion 4 and which extends downstream in the sheet conveyance direction; a sheet feeding portion 5, which is provided between the sheet conveyance passage 6 and the sheet storage portion 4; an image recording portion 7, which is disposed so as to face the sheet conveyance passage 6 in the height direction; and a reversing conveyance portion 8, which branches off the sheet conveyance passage 6 to extend over the image recording portion 7.
In the sheet storage portion 4, a plurality of (here three) sheet feeding cassettes 4a are removably provided, on which bundles of output sheets P1 are placed. The sheet feeding portion 5 feeds the output sheets P1 stored in the sheet storage portion 4 to the sheet conveyance passage 6 by the action of a pair of feed rollers 5a provided downstream of each of the sheet feeding cassette 4a.
Under the image recording portion 7, a conveying belt 6a is provided, which is endless and which is stretched around a plurality of rollers including a driving roller. The conveying belt 6a has formed in it a large number of ventilation holes (not illustrated) for air suction. An output sheet P1 fed out from the sheet feeding portion 5 passes, in a state held on the conveying belt 6a under suction by a sheet suction portion provided inside the loop of the conveying belt 6a, under the image recording portion 7.
The image recording portion 7 includes a plurality of inkjet heads, which eject ink toward the output sheet P1 conveyed in the state held on the conveying belt 6a under suction. The inkjet heads are supplied respectively with ink of four colors (cyan, magenta, yellow, and black) stored in ink tanks.
When recording is performed on both sides of an output sheet P1, the reversing conveyance portion 8 switches the conveyance direction of (switches back) the output sheet P1 having recording on one side finished, and turns over the output sheet P1 reverse side up; the reversing conveyance portion 8 then conveys the output sheet P1, with the side having no image recorded on it yet facing up, once again to the image recording portion 7. Output sheets P1 having predetermined images recorded on them by the image recording portion 7 are discharged one by one via a pair of discharge rollers 9.
The output sheets P1 discharged from the image forming apparatus 1 are introduced one by one into the sheet feeding apparatus 2. Among the plurality of output sheets P1 so introduced, the sheet feeding apparatus 2 inserts, with predetermined timing, insertion sheets P2, such as front covers and back covers (cover sheets) used in binding and slip sheets (insertion sheets) for indexing. That is, the sheet feeding apparatus 2 is an inserter that inserts insertion sheets P2 into a bundle of sheets comprising output sheets P1. The sheet feeding apparatus 2 then conveys those output sheet P1 and insertion sheet P2 to the sheet post-processing apparatus 3.
The sheet feeding apparatus 2 includes the sheet stacking portion 10. On the sheet stacking portion 10, insertion sheets P2 are stacked. Below the sheet stacking portion 10, there are provided a sheet inlet port 12, through which output sheets P1 discharged from the image forming apparatus 1 are introduced, and a relay conveyance passage 11, along which they are conveyed from the sheet inlet port 12 to the sheet post-processing apparatus 3. On the relay conveyance passage 11, a relay conveying roller 15 is disposed. The relay conveying roller 15 conveys downstream the output sheet P1 it has received.
Over the relay conveyance passage 11, an insertion conveyance passage 16 is provided. An upstream end opening 19 of the insertion conveyance passage 16 is adjacent to the sheet stacking portion 10 in the sheet conveyance direction. A downstream end part of the insertion conveyance passage 16 forms a confluence portion 13 that meets the relay conveyance passage 11. The insertion conveyance passage 16 forms a passage through which the sheet stacking portion 10 and the relay conveyance passage 11 communicate with each other. Over the upstream end opening 19 of the relay conveyance passage 11, a sheet feeding portion 14 is provided. The sheet feeding portion 14 includes a sheet feed roller 51, which is provided adjacent to the upstream end opening 19 of the insertion conveyance passage 16 in the sheet conveyance direction. The sheet feeding portion 14 feeds, by the action of the sheet feed roller 51, insertion sheets P2 from the sheet stacking portion 10 to the insertion conveyance passage 16. Midway along the insertion conveyance passage 16 in the sheet conveyance direction, a pair of conveying rollers 17 is provided. An insertion sheet P2 fed into the insertion conveyance passage 16 is conveyed by the pair of conveying rollers 17 to the confluence portion 13. The insertion sheet P2 conveyed to the confluence portion 13 is inserted into the relay conveyance passage 11 to be conveyed to the sheet post-processing apparatus 3.
The sheet post-processing apparatus 3 performs predetermined post-processing, such as punch hole formation or binding, on a bundle of sheets that includes a plurality of output sheets P1 output from the image forming apparatus 1 as well as insertion sheets P2 inserted among those output sheets P1.
The sheet post-processing apparatus 3 includes a sheet inlet port 21 through which it receives the output sheets P1 and insertion sheets P2 that are conveyed from the sheet feeding apparatus 2. The sheet post-processing apparatus 3 includes, inside it, a punch hole forming device 22, which forms punch holes in the output sheets P1 and insertion sheets P2 introduced through the sheet inlet port 21; an end binding unit 23, which stacks the introduced output sheets P1 and insertion sheets P2 to form a bundle of sheets, aligns an end part of it, and binds it with staples; and a middle-binding middle-folding unit 25, which staples a bundle of sheets at the middle and then folds it about the stapled part into the form of a booklet. On a side surface of the sheet post-processing apparatus 3, there is provided a main tray 24a, which is ascendable-descendable to a position suitable for discharge of a bundle of sheets, and a subsidiary tray 24b, which is fixed to an upper part of the sheet post-processing apparatus 3.
The punch hole forming device 22 is disposed in an upper part of the sheet post-processing apparatus 3. The output sheets P1 and insertion sheets P2 that have passed through the relay conveyance passage 11 in the sheet feeding apparatus 2 are fed in via the sheet inlet port 21, which is provided in an upper right part of the sheet post-processing apparatus 3, and pass through the punch hole forming device 22. When these output sheets P1 and insertion sheets P2 do to need stapling, they are discharged as they are onto the subsidiary tray 24b; when those sheets need stapling, they are conveyed to the end binding unit 23 or to the middle-binding middle-folding unit 25, either being disposed under the punch hole forming device 22.
The end binding unit 23 includes a stapler, a processing tray, etc. (none of which is illustrated). Output sheets P1 and insertion sheets P2 are stacked on the processing tray to be formed into a bundle of sheets. The bundle of sheets is, with the leading end of the bundle aligned, bound in an end part of it by the stapler, and is then discharged along the processing tray onto the main tray 24a.
Disposed under the end binding unit 23, the middle-binding middle-folding unit 25 for middle binding and middle folding includes a middle-binding stapler, a middle-folding device, and sheet guides (none of which is illustrated). The middle-binding stapler staples a middle part of a bundle of sheets stacked inside the sheet guides. The bundle of sheets stapled by the middle-binding stapler is folded about the stapled part by the middle-folding device into the form of a booklet, and is then discharged onto a booklet tray 26.
In the sheet feeding apparatus 2, one sheet feeding apparatus 2 may be provided, or a plurality of sheet stacking portions 10 may be provided as shown in
Next the sheet feeding apparatus 2 according to the present disclosure will be described in detail with reference to
On the bottom surface 30 of the sheet stacking portion 10, surrounded by the upright wall portion 33 and the pair of side surfaces 31, a lift plate 34 is disposed. The insertion sheets P2 in the sheet stacking portion 10 are stacked on the lift plate 34. The lift plate 34 is adjacent to the upright wall portion 33 of the sheet stacking portion 10 in the sheet conveyance direction. An upstream end part of the lift plate 34 in the sheet conveyance direction is pivotably supported on the shaft projections 32. Thus the lift plate 34 pivots about the shaft projections 32. As the lift plate 34 pivots about the shaft projections 32, a downstream end part of the lift plate 34 in the sheet conveyance direction ascends and descends in the height direction (the up-down direction in
Between the bottom surface 30 of the sheet stacking portion 10 and the lift plate 34, a lift mechanism 35 is provided, which raises and lowers the downstream end part of the lift plate 34. The lift mechanism 35 includes a driving unit 36 and a plurality of (here two) actuating segments 38. The driving unit 36 includes a driving source (not illustrated) such as a motor, which generates a driving force, and a driving shaft 37, which is rotatably connected to the driving source. The driving shaft 37 is located under the lift plate 34 and extends in the sheet width direction so as to bridge between the pair of side surfaces 31. The driving shaft 37 is located downstream of the shaft projections 32 in the sheet conveyance direction. The actuating segments 38 are rectangular plate-form members elongate in the sheet conveyance direction. Upstream end parts of the actuating segments 38 are fixed to the driving shaft 37. The actuating segments 38 are disposed at an interval from each other in the sheet width direction. As the driving shaft 37 rotates, the actuating segments 38 rotate about the driving shaft 37. Thu, downstream end parts of the actuating segments 38 swing in the ascent-descent direction (in the up-down direction in
Since as mentioned above the driving shaft 37 is disposed under the lift plate 34, also the actuating segments 38, which are fixed to the driving shaft 37, are located under the lift plate 34. Here, as shown in
Referring back to
The detection piece 39 is provided on the driving shaft 37 so as to be adjacent to the actuating segments 38 in the sheet width direction. The detection piece 39 is a small segment elongate in the sheet conveyance direction. In a base end part 39a (an upstream end part in the sheet conveyance direction) of the detection piece 39, a through hole 40 (bearing portion) is formed, which penetrates the detection piece 39 in the sheet width direction. Through the through hole 40, the driving shaft 37 is inserted, so that the detection piece 39 is supported on the driving shaft 37 so as to be pivotable about the driving shaft 37. As the detection piece 39 pivots about the driving shaft 37, a downstream end part of the detection piece 39 swings in the ascent-descent direction. The downstream end part of the detection piece 39 descends, under its own weight, until it makes contact with the bottom surface 30 of the sheet stacking portion 10. In the downstream end part of the detection piece 39, a light-shielding portion 41 is formed, which is in the shape of a rectangular plate and which extends downstream in the sheet conveyance direction.
The detection piece 39 and the driving shaft 37 are coupled together via the link mechanism 42. The link mechanism 42 has an engagement segment 43, which projects from the driving shaft 37 in its radial direction, and an engagement hole 44, which is formed in the base end part 39a of the detection piece 39 and in which the engagement segment 43 is fitted. The engagement hole 44 is a recess-like hole depressed in the direction in which the engagement segment 43 projects. Of the inner circumferential surface of the engagement hole 44, a top part is formed as an engagement surface 45, which faces the outer circumferential surface of the engagement segment 43 in the circumferential direction of the driving shaft 37.
As shown in
Here the detection piece 39, as the driving shaft 37 rotates clockwise in the illustration, descends under its own weight so as to follow the swinging of the actuating segments 38. Even after the detection piece 39 has descended until it makes contact with the bottom surface 30, as the driving shaft 37 rotates as illustrated, a gap A1 reappears between the outer circumferential surface of the engagement segment 43 and the engagement surface 45.
As shown in
As shown in
From this state, when as described above the driving shaft 37 rotates until the light-shielding portion 41 ascends to a position higher than the light-emitting portion 49 (see
As shown in
At a position facing the device body 20 in the sheet width direction, an ascent-descent sensor 54 is provided. The ascent-descent sensor 54 has a light-emitting portion 56 and a light-receiving portion (not illustrated), which face each other in the sheet width direction. The light-receiving portion of the ascent-descent sensor 54 receives the light emitted from the light-emitting portion 56. The ascent-descent sensor 54 and the light-shielding segment 52 constitute a top surface detecting mechanism 53 (first detecting portion). The top surface detecting mechanism 53 can sense the insertion sheets P2 being in contact with the sheet feed roller 51 and the device body 20 being at a position higher than a predetermined height.
As shown in
As shown in
While from the state shown in
Here the sheet feeding apparatus 2 includes a controller 90 (see
Specifically, when as described above the device body 20 descends until the light-shielding segment 52 intercepts the light emitted from the light-emitting portion 56 of the ascent-descent sensor 54, the controller 90 raises the lift plate 34. Thus the top surface of the insertion sheets P2 ascends and the device body 20 ascends back. When the light-shielding segment 52 rises until it moves away from between the light-emitting portion 56 and the light-receiving portion of the ascent-descent sensor 54, the light-receiving portion of the ascent-descent sensor 54 receives the light emitted from the light-emitting portion 56. Then the controller 90 stops raising the lift plate 34. The controller 90 raises and lowers the lift plate 34 by controlling the driving source.
From this state, as the sheet feed roller 51 rotates in the sheet conveyance direction and feeds out the insertion sheets P2 one by one, as described above, the top surface of the insertion sheets P2 lowers. In response the controller 90 controls the driving source to rotate the driving shaft 37. Thus the engagement segment 43 pivots counter-clockwise about the driving shaft 37, and the gap A1 between the outer circumferential surface of the engagement segment 43 and the engagement surface 45 narrows. When the driving shaft 37 rotates further until the gap A1 disappears and the outer circumferential surface of the engagement segment 43 makes contact with the engagement surface 45, the rotation of the driving shaft 37 is transmitted to the detection piece 39. From this state, as the driving shaft 37 rotates further, the detection piece 39 gradually pivots counter-clockwise about the driving shaft 37. When the remaining quantity of insertion sheets P2 becomes less than a predetermined quantity, the light-shielding portion 41 of the detection piece 39 reaches a position higher than the light-emitting portion 49 of the detection sensor 48. Now the light-receiving portion 50 of the detection sensor 48 receives the light emitted from the light-emitting portion 49. In this way the detection sensor 48 senses the ascent of the downstream end part (light-shielding portion 41) of the detection piece 39.
The sheet feeding apparatus 2 includes a transmission device (not illustrated) that transmits the detecting result of the detection sensor 48 to the image forming apparatus 1 and the sheet post-processing apparatus 3. Usable as the transmission device is, for example, an information communication device of a wired or wireless type. When the detection sensor 48 senses the ascent of the light-shielding portion 41 of the detection piece 39 (i.e., when it senses the remaining quantity of insertion sheets P2 becoming lower than the predetermined quantity), the transmission device transmits the detecting result to the image forming apparatus 1. In response the image forming apparatus 1 controls the sheet feeding portion 5 to adjust the timing with which output sheets P1 are fed from the sheet feeding cassette 4a, so as not to produce a booklet without a front cover.
The embodiment described above is in no way meant to limit the scope of the present disclosure, which can thus be implemented with many modifications made without departure from the spirit of the present disclosure. For example, a construction is also possible where the lift mechanism 35 has a recess-like engagement hole 44 formed so as to be depressed in a radial direction from the outer circumferential surface of the driving shaft and a boss-like engagement segment 43 extending from the detection piece 39 toward the driving shaft and fitted in the engagement hole 44.
A construction is also possible where as shown in
The present disclosure finds applications in sheet feeding apparatuses for inserting, with predetermined timing, insertion sheets among a plurality of output sheets output from a image forming apparatus. Based on the present disclosure, it is possible to provide, for image forming systems comprising an image forming apparatus, a sheet feeding apparatus, and a sheet post-processing apparatus, a sheet feeding apparatus that can sense a low remaining quantity of insertion sheets and thereby prevent production of a booklet without a front cover or the like with a simple construction without requiring complicate software.
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| 2020-102826 | Jun 2020 | JP | national |
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| Number | Date | Country | |
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| 20210387822 A1 | Dec 2021 | US |
