The present invention relates to a sheet storing device that stores a large number of sheets, a post-processing apparatus equipped with the sheet storing device and an image forming system equipped therewith, and in particular, to a sheet storing device that stores folded sheets.
A folded sheet takes a condition that plural sheets are superposed by folding operations to take an irregular shape by swelling.
Conventionally, in the post-processing apparatus connected to an image forming apparatus, sheets folded and ejected have been stored in a box-shaped storing device under the irregular condition.
Therefore, there have been problems including that a capacity of the storing device runs short and that the ejected sheets scatter.
In Patent Document 1, there is disclosed a sheet storing device that aligns folded sheets to store them.
In the sheet storing device disclosed by Patent Document 1, sheets fed into the sheet storing device continuously are stopped temporarily by a stopping roller to avoid a lift of the sheet, and then the sheet is conveyed to a sheet storing section.
Patent Document 1 discloses two types of sheet storing devices, and in the first one of them, a succeeding sheet is inserted to be under a preceding sheet, whereby, a sheet is inserted into the bottom of sheets in the sheet storing section, thus, the sheets are stacked vertically in the lying situation in the sheet storing section. In the second one of them, a succeeding sheet is supplied to the upper side of a preceding sheet, and sheets are stacked to be inclined at the storing section.
Width H of the folded sheet which is a length of the sheet in the direction perpendicular to sheet edge E formed by a fold as shown in FIG. 1 varies depending on a sheet size and on a type of folding processing.
The folded sheet is usually conveyed with its sheet edge E formed by a fold being perpendicular to the sheet conveyance direction. The conveyance method of this kind is also employed even in Patent Document 1, and in the Patent Document 1, the succeeding sheet is superposed under or over the preceding sheet, so that a large number of sheets are superposed in the prescribed order to be stored.
When width H of the folded sheet is changed as stated above, there is a problem that sheets are not superposed under the correct order and they are not aligned, when superposing preceding sheet and succeeding sheet one after another.
[Patent Document 1] Unexamined Japanese Patent Application Publication No. 11-35211