a) is a plane view of a stacker, while
a) and 5(b) are cross-sectional views showing placement of the paddle-wheels.
The embodiments of the present invention will now be detailed, while referring to the drawings.
Stacker 10 includes sheet stacking tray 11 which receives sheets S and stacks sheets S, stopping member 12 which stops the top edges of sheets S and align sheets S, alignment members 13A and 13B which align sheets S perpendicular to a sheet conveyance direction, paddle-wheels 16A and 16B, a paddle-wheel position shifting member, and a transmission member for the paddle-wheels.
Motor M1, mounted on side plate 14A of stacker 10, rotates paddle-wheels 16A and 16B via the transmission member. The transmission member is structured of gears G1, G2, G3, G4A, G4B and G5A. Motor M1 rotates gear G3, which has long and straight teeth parallel to the rotation shaft, via gears G1 and G2. Both ends of the rotation shaft, extending from both ends of gear G3, are rotatably supported between side plate 14A and side plate 14B of stacker 10. That is, gear G3 is mounted perpendicular to the sheet conveyance direction.
Adjacent to both ends of gear G3, gear G4A and gear G4B are engaged, and movably supported in the direction of the rotation shaft of gear G3 by the position shifting member 15A, which will be detailed later. Gear G4A rotates gear G5A which is supported by position shifting member 15A, and rotates paddle-wheel 16A which is mounted on the same rotation shaft as gear G5A. Further, gear G4B rotates gear G5B which is supported by position shifting member 15B, and rotates paddle-wheel 16B which is mounted on the same rotation shaft as gear G5B.
Rotating paddle-wheels 16A and 16B come into contact with the front surface of sheet S which is to be conveyed onto sheet stacking tray 11, so that sheet S is conveyed and pushed against stopping member 12. Further rotating paddle-wheels 16A and 16B press the surface of curled sheet S to flatten it. Both sides of flattened sheet S are pressed by alignment members 13A and 13B, and sheets S are aligned perpendicular to the sheet conveyance direction.
In addition, since the height of stacked sheets S varies in accordance with the number of stacked sheets S, the height of paddle-wheels 16A and 16B varies by a driving device, which is not illustrated.
Paddle-wheel 16 is structured of paddle shaft 161, supporting member 162 provided on paddle shaft 161, and blades 163 provided on supporting member 162.
As shown in
Blades 163 are formed of thin elastic plates, and for example, are made of resin plates such as polyurethane rubber, whose thickness is 1 mm.
As another example of paddle-wheel 16, paddle shaft 161, supporting member 162 and blades 163 can be integrally molded.
As shown in
Since position shifting members 15A and 15B are moved in accordance with the sheet size of sheet S, the position of paddle-wheels 16A and 16B changes, whereby, even while rotating, paddle-wheels 16A and 16B press against both edges of sheet S, and curled sheets S is flattened.
Based on the size of sheet which is stacked in stacker 10, control section 100 shifts the position of paddle-wheels 16A and 16B in direction perpendicular to the sheet conveyance direction via position shifting members 15A and 15B, respectively, after which control section 100 allows rotating blades 163 to press against the surface of sheet S, and to flatten curled sheet S.
a) is a cross-section, showing the positions of paddle-wheels 16A and 16B which flatten curling generated at the both edges of sheet S, while
In
In addition, it is possible to provide control section 100 either on image forming apparatus A or post-finishing section FS.
The structure of the image forming system will now be detailed while referring to
Image forming apparatus A includes electro-charging device 2, image exposure device 3, developing device 4, transfer device 5A, electro-discharging member 5B, sheet separating member 5C, and cleaning device 6, each mounted around rotating image conductor 1. After the surface of image conductor 1 is electrically and evenly charged by electro-charging device 2, based on an image data which is read from the document via laser beams emitted from image exposure device 3, a latent image is generated via the exposure scan, which is developed in reverse via developing device 4, whereby a toner image is formed on the surface of image conductor 1.
Further, sheet S, supplied from sheet supply section 7A, is conveyed to a transfer position. The toner image is transferred, via transfer device 5A, onto sheet S at that transfer position. After sheet S is electrically discharged by discharging device 5B, sheet S is separated from image conductor 1 by sheet separating member 5C, and is conveyed by intermediate conveyance section 7b. the sheet carrying the transferred toner image is heated and fixed by fixing device 8, and is ejected from image forming apparatus A by paired sheet ejecting rollers 7C.
Any remaining toner on the surface of image conductor 1 is removed by cleaning device 6 downstream of separating crew 5C after image formation, and image conductor 1 waits for the next image formation cycle.
In case of double-sided image formation on sheet S, conveyance route switching plate 7D is switched, after the heat-fix by fixing device 8, sheet S is conveyed downward, and is switched back by paired flipping rollers 7E1, and is returned to the transfer position, where a new toner image is transferred onto the reverse side of sheet S. Next, sheet S, carrying the new toner image on the revere side, is heated and the image is fixed by fixing device 8. After sheet S, carrying the fixed image on the reverse, passes through conveyance switching plate 7D, said sheet S is ejected from image forming apparatus A by paired ejecting rollers 7C.
Still further, as will be described later, post-finishing processes, such as folding process or stitching process, are conducted, after conveyance route switching plate 7D is switched, sheet S, carrying the fixed image fixed by fixing device 8, is conveyed downward, and sheet S is switched back to be flipped by paired flipping rollers 7E2, after which said sheet S is ejected from image forming apparatus A by paired ejecting rollers 7C.
Post-finishing apparatus FS, shown in
At the left of post-finishing apparatus FS shown in
Sheet S, ejected from paired ejecting rollers 7C of image forming apparatus A, is introduced to paired conveyance rollers 21 which are mounted near inlet conveyance section 20 of post-finishing apparatus FS. In addition, paired conveyance rollers 21 are positioned in close proximity to paired ejecting rollers 7C of image forming apparatus A.
Further, paired conveyance rollers 21 convey not only sheets S conveyed from image forming apparatus A, but also interleaving sheets K, such as cover sheets, or inserting sheets, conveyed from sheet supply tray 30. Interleaving sheets K are separately conveyed by sheet paired supply rollers 31, and sent to paired conveyance rollers 12 via paired conveyance rollers 32 and 33, as well as paired conveyance rollers 21. Hereinafter, interleaving sheet K is also generically referred to as sheet S.
Switching gates Y1 and Y2 are driven by solenoids, which are not illustrated, to select any one of three conveyance routes, which are first conveyance route r1 directing to fixed sheet-ejecting tray 81, second conveyance route r2 directing to sheet shifting section 40, and third conveyance route r3 directing to sheet stitching device 60.
When no post-finishing process is selected for sheet S, switching gates Y1 and Y2 are open only for first conveyance route r1, and cut off second and third conveyance routes r2 and r3. Sheet S is conveyed upward through first conveyance route r1, and stacked on fixed sheet-ejection tray 81.
Further, when the sheet shifting process is selected, switching gates Y1 and Y2 are open only for second conveyance route r2, and cut off first and third conveyance routes r1 and r3. Sheet S passes through second conveyance route r2, and is shifted perpendicular to the sheet conveyance direction by sheet shifting section 40. That is, sheet shifting section 40 changes the ejecting position of sheet S perpendicular to the sheet conveyance direction, for every predetermined number of sheets S. Shifted sheet S is ejected onto elevating sheet ejection tray 82, and stacked.
Still further, when either the sheet stitching process or the sheet folding process is selected, switching gates Y1 and Y2 are open only for third conveyance route r3, and cut off first and second conveyance routes r1 and r2. Sheet S passes through third conveyance route r3, and is stopped when the leading edge of sheet S comes into contact with paired registration rollers 61, whereby the leading edge of sheet S is aligned. After the trailing edge of sheet S is ejected from paired registration rollers 61, sheet S is released upward by inertial force along slanted sheet stacking section 62A. Next, sheet S goes down by its own weight, while slipping on the slope of slanted sheet stacking section 62A, and is stopped by stopping member 63A.
Near stopping member 63A, downstream of sheet stacking section 62A, a first stacker is provided, including paddle-wheel 65A, a position shifting member, and alignment member 64A, which together function to flatten and align curled sheet S.
When the predetermined number of sheets have been stacked on sheet stacking section 62A, the stacked sheets are aligned by paired stacking members 64A provided on both sides of sheet stacking section 62A, and sheets are stitched into booklet Sa at one or two positions by stitching device 60, whereby the stitching process is completed. Stitched booklet SA is conveyed upward by conveyance belt 66 on the slope of sheet stacking section 62A, and is ejected onto elevating sheet ejection tray 82.
Still further, when the saddle stitching-folding process is selected, stopping member 63A, to stop the side stitching sheets, is displaced from the conveyance route, and sheet S goes down by its own weight, while slipping on the slope of slanted sheet stacking section 62A, and is stopped by stopping member 63B to stop saddle stitching sheets, whereby sheet S is stacked on sheet stacking section 62B.
Near stopping member 63B, further downstream of sheet stacking section 62B, a second stacker is provided, including paddle-wheel 65B, a position shifting member, and alignment member 64B, which together function to flatten and align curled sheets S.
After sheets S are aligned, stitching pins are driven into the center of sheets S by sheet stitching device 60. Sheet folding device 70, which includes folding plate 71, plural folding rollers 72, folds saddle stitched booklet Sb at its center, and ejects said booklet Sb onto fixed sheet-ejection tray 83.
Based on the stacker, the post-finishing apparatus, and the image forming system of the present invention, the effects described below will be obtained.
1. The sheets are properly aligned, independent of the sheet size, the sheet type, and the amount of curl.
2. Sheets are properly aligned by the paddle-wheels of the stacker, whereby a booklet can be produced to the optimal style by the book binding operation, such as saddle stitching, side stitching or pasting.
3. Curls, generated on the various sheets in the fixing device of the image forming apparatus, are flattened by the paddle-wheels of the stacker of the post-finishing apparatus, whereby the sheets are properly aligned.
Number | Date | Country | Kind |
---|---|---|---|
JP2006-171144 | Jun 2006 | JP | national |
JP2007-061608 | Mar 2007 | JP | national |