This application claims priority to Taiwanese Patent Application No. 098118821 filed on Jun. 5, 2009.
The present invention relates to a sheet stopping mechanism, and more particularly to a sheet stopping mechanism of an automatic document feeder.
With increasing industrial development, digitalized office technologies have experienced great growth and are now rapidly gaining in popularity. For example, a diversity of office machines such as copy machines, printers, fax machines and scanners (also referred as single-function peripherals) are utilized to achieve various purposes. The diverse office machines, however, occupy lots of space. Nowadays, a multifunction peripheral having multiple functions in one structural unit, for example the functions of a printer, a scanner, a fax machine and/or a copy machine, is thus developed. As a consequence, the processing capability of the multifunction peripheral is increased and the operative space thereof is reduced.
For successively and continuously feeding many paper sheets, the single-function peripheral or the multifunction peripheral usually has an automatic document feeder (ADF). After a stack of paper sheets to be scanned are placed on the sheet feeding tray, the sheet-feeding mechanism of the auto document feeder will successively fed the paper sheets into the inner portion of the office machine so as to implement associated operations such as scanning, faxing, scanning operations and the like. The automatic document feeder has a sheet separating device for separating only a single paper sheet from the stack of paper sheets, so that a single paper sheet is allowed to be fed into the inner portion of the office machine at each time. In addition, the automatic document feeder has a sheet stopping mechanism. The front edges of the paper sheets are stopped by the sheet stopping mechanism from being transported into an entrance of a sheet-guiding path before the sheet-feeding operation is done.
The sheet stopping mechanism of the conventional automatic document feeder, however, still has some drawbacks. For example, the upper cover needs to be opened if the automatic document feeder is suffered from a breakdown. During the upper cover is closed, the paper sheets are possibly pierced through. Since the stopping part is lowered to a sheet-stopping position according to the weight of the stopping part after the sheet-feeding operation is completed, the weight of the stopping part should be elaborately designed and controlled. Moreover, if the stopping part has a feathering edge resulting from the fabricating process, the stopping part fails to be normally operated.
Therefore, there is a need of providing an improved sheet stopping mechanism so as to obviate the drawbacks encountered from the prior art.
It is an object of the present invention to provide sheet stopping mechanism for avoiding the problems of piercing through the paper sheets and resulting in the feathering edge.
In accordance with an aspect of the present invention, there is provided a sheet stopping mechanism of an automatic document feeder. The automatic document feeder comprising a sheet input tray and a sheet pick-up roller. A paper sheet is placed on the sheet input tray. The sheet stopping mechanism includes a guiding element, a sheet stopping element and a guiding slot. The guiding element includes a sheathing part and an extension arm. The sheathing part is sheathed around an axle of the sheet pick-up roller. The sheet stopping element includes a stopping part, a protrusion part and a contact part. The extension arm of the guiding element is upwardly sustained against at the contact part of the sheet stopping element. The protrusion part of the sheet stopping element is accommodated within the guiding slot. When the sheet pick-up roller is moved toward the sheet input tray, the guiding element is uplifted through the transmission of the sheathing part and the sheet pick-up roller. As a result, the protrusion part of the sheet stopping element is shifted and rotated in the guiding slot, and a front edge of the paper sheet is no longer hindered by the stopping part of the sheet stopping element but permitted to be transported into a sheet-guiding path.
In accordance with another aspect of the present invention, there is provided an automatic document feeder. The automatic document feeder includes a sheet input tray, a sheet pick-up roller and a sheet stopping mechanism. The sheet input tray is used for placing thereon at least one paper sheet. The sheet pick-up roller is used for transporting the paper sheet that is placed on the sheet input tray. The sheet stopping mechanism is used for selectively hindering the paper sheet from being transported into a sheet-guiding path or allowing the paper sheet to be transported into the sheet-guiding path by the sheet pick-up roller. The sheet stopping mechanism includes a guiding element, a sheet stopping element and a guiding slot. The guiding element includes a sheathing part and an extension arm. The sheathing part is sheathed around an axle of the sheet pick-up roller. The sheet stopping element includes a stopping part, a protrusion part and a contact part. The extension arm of the guiding element is upwardly sustained against at the contact part of the sheet stopping element. The protrusion part of the sheet stopping element is accommodated within the guiding slot. When the sheet pick-up roller is moved toward the sheet input tray, the guiding element is uplifted through the transmission of the sheathing part and the sheet pick-up roller. As a result, the protrusion part of the sheet stopping element is shifted and rotated in the guiding slot, and a front edge of the paper sheet is no longer hindered by the stopping part of the sheet stopping element but permitted to be transported into a sheet-guiding path.
The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
The present invention provides a sheet stopping mechanism of an automatic document feeder for use with an office machine. An example of the office machine includes but is not limited to a printer, a scanner, a fax machine, a copy machine or a multifunction peripheral.
Please refer to
The axle 221 of the sheet separating roller 22 is directly or indirectly connected to the driving device (not shown), so that the sheet separating roller 22 is driven to rotate by the driving device. In addition, a sheet pick-up arm 25 is arranged between the sheet separating roller 22 and the sheet pick-up roller 21. The sheet pick-up arm 25 is connected to the sheet separating roller 22 and the sheet pick-up roller 21. With the axle 221 of the sheet separating roller 22 serving as a rotating shaft, the sheet pick-up arm 25 is driven by the sheet separating roller 22 or the driving device to rotate such that the sheet pick-up arm 25 is moved to be close to or distant from the sheet input tray 24. In some embodiment, the axle 211 of the sheet pick-up roller 21 is sheathed by a first gear 212, the axle 221 of the sheet separating roller 22 is sheathed by a second gear 222, and a transmission gear set 26 is arranged between the sheet pick-up roller 21 and the sheet separating roller 22. The transmission gear set 26 is engaged with the first gear 212 and the second gear 222, so that the sheet pick-up roller 21 is rotated with the sheet separating roller 22. In a case that the sheet pick-up roller 21 upon rotation is contacted with the paper sheet P, the paper sheet P is fed into the sheet-guiding path. In some embodiments, the transmission gear set 26 is replaced by a transmission belt (not shown).
The sheet stopping mechanism 23 is arranged at the entrance of the sheet-guiding path. In a case that a sheet-feeding instruction is received, the uppermost paper sheet is separated from the stack of paper sheets P and transported into the entrance of the sheet-guiding path without being stopped by the sheet stopping mechanism 23. Whereas, in a case that no sheet-feeding instruction is received, the paper sheets P on the paper input tray 24 are hindered by the sheet stopping mechanism 23 from being transported into the entrance of the sheet-guiding path.
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Hereinafter, the operations of the sheet stopping mechanism of the present invention will be illustrated with reference to
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After the sheet-feeding operation is stopped, the sheet pick-up roller 21 is ascended to its original position and thus the guiding element 232 is rotated to its original position. At the same time, the extension arm 2322 of the guiding element 232 is downwardly sustained against the sheet stopping element 231, so that the sheet stopping element 231 is returned to the original position as shown in
From the above description, the sheet stopping mechanism of the present invention is capable of hindering the front edges of the paper sheets when no sheet-feeding instruction is received. Moreover, in response to the sheet-feeding instruction, the sheet stopping element of the sheet stopping mechanism is uplifted in order to allow the paper sheets to be successively transported into the sheet-guiding path. The sheet stopping mechanism of the present invention includes a guiding element, a sheet stopping element and a guiding slot. The guiding element has a first end sheathed around the axle of the sheet pick-up roller and a second end sustained against the sheet stopping element. When the sheet pick-up roller is moved toward the sheet input tray to perform a sheet-feeding operation, the sheet stopping element is shifted and rotated in the guiding slot. As such, the front edge of the paper sheet is no longer hindered by the sheet stopping element but permitted to be transported into a sheet-guiding path. Moreover, since the sheet stopping element is shifted and rotated during the sheet pick-up roller is moved toward the sheet input tray to perform the sheet-feeding operation, the feathering edge resulting from the fabricating process has no adverse influence on the sheet stopping element. Since the sheet stopping element is returned to its original position according to the transmission of the guiding element, the weight of the sheet stopping element does not need to be elaborately designed and controlled. Moreover, since the sheet stopping element could be moved in the upward direction, the possibility of piercing through the paper sheet is avoided when the upper cover is closed.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Number | Date | Country | Kind |
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098118821 | Jun 2009 | TW | national |