Sheet feeding or delivering – Delivering – To receiver for pack of sheets
Reexamination Certificate
1999-05-24
2001-04-03
Ellis, Christopher P. (Department: 3651)
Sheet feeding or delivering
Delivering
To receiver for pack of sheets
C270S058070, C270S058080, C270S058110
Reexamination Certificate
active
06209864
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet post-processing apparatus which is used with an image forming apparatus having copier, facsimile and/or printer functions and which performs post-processing, such as stapling, etc., for sheet-like recorded media sent from the image forming apparatus and outputs the post-processed sheets, and in particular can improve the alignment of the sheets accommodated therein.
2. Description of the Prior Art
In the recent technical field of image forming apparatuses, typified by a copier (the description hereinbelow will be described referring to a copier as an example of an image forming apparatus.), in order to automate the image forming task as well as to automate post-processing tasks for sheet-like media (to be referred to as ‘sheet’, consistently) after image formation, an automatic document feeder and sheet post-processing apparatus have been used in combination.
The sheet post-processing apparatus is one which handles copy sheets, output from a copier, on which original images are copied and performs post-processing such as stapling, hole-punching and the like for every piece of predetermined number of sheets.
As the prior art for those sheet post-processing apparatuses, Japanese Patent Application Laid-Open Hei 9 No.110,267 and Japanese Patent Application Laid-Open Hei 9 No.118,468 can be referred to.
As the first example, Japanese Patent Application Laid-Open Hei 9 No.110,267, discloses a sheet discharging apparatus. This apparatus is to deal with high-speed image formation, with a simple mechanism without the necessity of inversion conveyance, to thereby enable the sheets to be output in the collated page order when image formation is done in the order in which image data was transferred. For this purpose, this apparatus includes: a direct conveyance path for discharging sheets onto the first output tray, stacking them successively while keeping their positions the same; an inverting conveyance path that branches partway from the direct conveyance path to discharge the sheets, stacking them successively with their image-formed surface turned over with respect to that of the sheets on the first output tray; and an inversion forcing means for exerting an external force on the underside of the sheet so that the sheet can be inverted and output onto the second discharge tray.
Japanese Patent Application Laid-Open Hei 9 No.118,468 discloses another sheet post-processing apparatus having a post-processing device. This apparatus is to perform post-processing with sheets re-arranged in page order, by changing the aligned order of the sheets in the sheet storage portion when the sheets after image formation are delivered out sequentially from either the last page or the first page. For this purpose, this apparatus comprises a sheet aligning means for aligning the sheets, which are delivered to the sheet storage portion from the last page or from the first page, in the first sequential order if from the last page and in the second sequential order if from the first page; and a post-processing device for performing post-processing for the sheet stack aligned in the sheet storage portion.
In such a sheet post-processing apparatus which temporarily holds a stack of the sheets discharged from the copier within the post-processing tray therein and staples the sheets as post-processing, then discharges the stapled sheets to the output tray outside the sheet post-processing apparatus, all operations can be automated but then this device become large in its size. So if a total copying and processing system is configured, the system needs a large space, which limits the site for installation.
Various sizes of sheets are discharged from a copier. Therefore, the post-processing apparatus needs to have a post-processing tray which can hold maximum size sheets. There is a configuration in which the post-processing tray capable of handling maximum size sheets is arranged in an inclined manner, but this configuration still needs a large space for the interior structure.
For this reason, in order to reduce the installation footprint of the sheet post-processing apparatus, Japanese Patent Application Laid-Open Hei 9 Nos.110,267 and 118,468 have proposed that the post-processing tray should be arranged upright (arranged in the vertical direction).
According to the techniques disclosed in the above applications, the sheet which has been lead by the first conveyer roller into the sheet aligner is naturally dropped utilizing gravity, guided by guide pieces. Further, a sheet aligning means is configured so as to switch the sheet held direction in the storage portion, presses the sheet rear end while a regulative switching claw registers the sheet leading edge. Therefore, it is necessary to change the positional relationship between the sheet aligning means and the position of the sheet leading edge, depending upon the sheet size, which complicates the mechanism and raises the cost. Besides, when the image forming apparatus is a composite type having multiple output modes, the output is often made with different sizes, so that it takes time for the aforementioned switching, which may give rise to a speed problem. Moreover, since the sheet is naturally dropped utilizing gravity, it is also expected that the sheets cannot be stacked correctly depending upon the size and material of the sheets and/or due to the influences of humidity, dewing and the like.
Accordingly, there is still great room for improvement even with these conventional technologies, in terms of reducing the installation footprint of the sheet post-processing apparatus, regardless of the sheet size, correctly stacking the sheets discharged to the sheet post-processing tray regardless of the sheet characteristics, effecting the predetermined post-processing for an exactly aligned stack of sheets, and the like.
SUMMARY OF THE INVENTION
The present invention has been devised in view of the above problems and it is therefore an object of the present invention to provide a sheet post-processing apparatus which is minimized in its footprint regardless of the sheet size to be handled.
It is another object of the invention to provide a sheet post-processing apparatus which can stack the sheets discharged to the post-processing tray, properly regardless of the sheet characteristics and which also can effect the predetermined post-processing for an exactly aligned stack of sheets.
In order to achieve the above objects, the present invention is configured as follows:
In accordance with the first aspect of the invention, a sheet post-processing apparatus includes:
a post-processing tray for stacking the discharged sheets;
a post-processing portion for performing post-processing for the stacked sheets;
an output tray for receiving the sheets discharged after post-processing;
a conveying means for conveying sheets from the lower part of the post-processing tray arranged upright and discharging the sheets after post-processing to the output tray; and
a sheet guiding means disposed opposing the post-processing tray which presses particular portions of the sheet when the sheet is introduced into the post-processing tray so as to align the stacked sheets onto the post-processing tray, with the sheets being stacked substantially upright.
In accordance with the second aspect of the invention, the sheet post-processing apparatus having the above first feature is characterized in that the sheet guiding means can rotate about an axle located near the upper part of the post-processing tray so that the lower part of the sheet guiding means rotationally moves toward the post-processing tray; and the sheet guiding means guides the sheet upward with respect to the post-processing tray when the sheet is introduced into the post-processing tray and presses the sheet against the post-processing tray face when the sheet is discharged to the post-processing tray.
In accordance with the third aspect of the invention, the sheet post-processing apparatus having the above first feature
Fukunaga Takahiro
Kida Hiroshi
Masuda Junya
Taniguchi Tadasu
Tsuji Masaru
Bower Kenneth W
Ellis Christopher P.
Sharp Kabushiki Kaisha
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