Patent Application
20090020942
This application claims priority of No. 096126496 filed in Taiwan R.O.C. on Jul. 20, 2007 under 35 USC 119, the entire content of which is hereby incorporated by reference.
1. Field of Invention
The invention relates to a document ejecting mechanism and a document feeder using the same, and more particularly to a shiftable document ejecting mechanism and a document feeder using the same.
2. Related Art
In order to scan two sides of a document using a single scanning module, a conventional scanner has to be equipped with an automatic document feeder for turning the document twice or more than two times. Thus, transporting rollers have to be rotated clockwise and counterclockwise so as to transport the document in the passageways of the feeder in two opposite directions.
However, the transporting rollers which rotate clockwise and the ones which rotate counterclockwise may tug the same document at the same time in opposite directions, due to the designs of the mechanism and the structure, thereby tearing the sheet or wearing the rollers quickly. The conventional drawbacks may be clearly understood according to the advantages of the following preferred embodiments.
It is therefore an object of the invention to provide a document ejecting mechanism capable of releasing a document being transported to prevent the document from being torn up or to prevent a roller from being worn out rapidly, and a document feeder using the same.
To achieve the above-identified object, the invention provides a document ejecting mechanism including an output roller, a roller shaft, an idle roller, an idle shaft and an adjusting device. The roller shaft inserts through the output roller. The idle roller is rotated by the output roller. The idle shaft inserts through the idle roller. The adjusting device adjusts a distance between the output roller and the idle roller.
To achieve the above-identified object, the invention also provides a document feeder including a sheet input tray, a group of passageways, an image processing region and a document transporting device. The sheet input tray stores a document. The group of passageways is connected to the sheet input tray. The image processing region is disposed in the group of passageways. The document transporting device transports the document from the sheet input tray into the group of passageways with each of a front side and a back side of the document being transported across the image processing region once, and then transports the document to a sheet output tray of the document feeder. The document transporting device includes a document ejecting mechanism. The document ejecting mechanism includes an output roller, a roller shaft inserting through the output roller, an idle roller rotated by the output roller, an idle shaft inserting through the idle roller and an adjusting device for adjusting a distance between the output roller and the idle roller.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
The sheet input tray 10 stores a document D or a plurality of documents D.
The group of passageways 20 is connected to the sheet input tray 10. Specifically speaking, the group of passageways 20 includes first to fifth passageways 21 to 25. The first passageway 21 starts from point A to point B and is connected to the sheet input tray 10. The second passageway 22 starts from point B to point C and is connected to the first passageway 21. The image processing region 30 is disposed on the second passageway 22 of the group of passageways 20. In this embodiment, the image processing region 30 is a scan region, and a document being transported across the scan region is scanned by a scanning module 90. The third passageway 23 starts from point C to a sheet outlet 23A and is connected to the second passageway 22 and the sheet output tray 50. The fourth passageway 24 starts from point C to point B and is connected to the first passageway 21, the second passageway 22 and the third passageway 23. The fifth passageway 25 starts from a guiding rod 26 to a sheet outlet 25A and is connected to the third passageway 23 and the sheet output tray 50. The document is finally outputted from the sheet outlet 25A.
The document transporting device 40 transports the document D, stored in the sheet input tray 10, into the group of passageways 20 with each of a front side and a back side of the document D being transported across the image processing region 30 once or more than one time, and then transports the document D to the sheet output tray 50 of the document feeder 1.
The document transporting device 40 includes a document ejecting mechanism 41, a sheet feeding mechanism 42 and a document transporting mechanism 43. The document ejecting mechanism 41 is disposed on the third passageway 23, and includes an output roller 41A, a roller shaft 41A1, an idle roller 41B, an idle shaft 41B1 and an adjusting device 41C. The roller shaft 41A1 inserts through the output roller 41A. The idle roller 41B is rotated by the output roller 41A. The idle shaft 41B1 inserts through the idle roller 41B. The adjusting device 41C adjusts a distance L between the output roller 41A and the idle roller 41B. The sheet feeding mechanism 42 transports the document D from the sheet input tray 10 into the group of passageways 20.
The document transporting mechanism 43 includes a plurality of document transporting rollers 44 and a plurality of document transporting idle rollers 45, wherein one of the document transporting rollers 44 and the output roller 41A are driven by the same reversible power source 80. Herein, the reversible power source, such as a motor, can rotate the roller clockwise or counterclockwise.
In addition, the document feeder 1 may further include a control circuit 60 and a document detector 70. The control circuit 60 controls the overall operation of the document feeder 1 and is connected to the reversible power source and the adjusting device 41C.
The document detector 70, connected to the control circuit 60 and disposed on the group of passageways 20, detects a position of the document D and thus outputs a position signal to the control circuit 60. Thus, the control circuit 60 controls the adjusting device 41C to adjust the distance L between the output roller 41A and the idle roller 41B and controls the reversible power source to drive the output roller 41A and one of the document transporting rollers 44 to rotate clockwise or counterclockwise according to the position signal. Thus, the document D can be released at the proper timing for the following purpose.
When a duplex scanning process is being performed, the sheet feeding mechanism 42 transports the document from the sheet input tray 10 into the first passageway 21. At this time, the document transporting roller 44 and the output roller 41A are rotated counterclockwise to transport the document D from the first passageway 21 to the second passageway 22. Then, the document D pushes away a guide sheet 27 and then enters the third passageway 23. Next, it is obtained through a document detector 71 that the trailing edge of the document D has been transported past the guiding rod 26, and the document transporting roller 44 and the output roller 41A are rotated clockwise to transport the document D from the third passageway 23 to the fourth passageway 24. Then, it is obtained through the document detector 70 that the document is going to reach the document transporting idle roller 45 and the document transporting roller 44. At this time, the document transporting roller 44 and the output roller 41A have to be rotated counterclockwise. If the leading edge of the document D does not move off the output roller 41A and the idle roller 41B, and the document D is tugged by both of the output roller 41A and the document transporting roller 44 in opposite directions. Thus, the document D may be torn or the output roller 41A and the document transporting roller 44 may be worn out quickly.
According to the document ejecting mechanism of the invention, the output roller 41A and the idle roller 41B can release the document D to avoid this problem under this circumstance. The configuration of the adjustable document ejecting mechanism will be described in the following.
According to the first and second embodiments, it is obtained that a driving unit 41C1 is for moving one end of at least one of the roller shaft 41A1 and the idle shaft 41B1. In addition, the adjusting device 41C can move one end of the idle shaft 41B1 from a first position P1 to a second position P2 in the first embodiment. The document ejecting mechanism 41 may further include a torsional spring 41D, which has one end connected to the idle shaft 41B1 and the other end connected to a housing (not shown), and provides a restoring force to the idle shaft 41B1 to move the one end of the idle shaft 41B1 from the second position P2 to the first position P1. In the following embodiment, the adjusting device only drives the idle shaft. However, one of ordinary skill in the art may easily understand that the adjusting device may also drive the roller shaft.
In addition, the document ejecting mechanism 41 of this embodiment may further include a sleeve assembly 41C6 for connecting the rod 41C2 and the idle shaft 41B1. The idle shaft 41B1 inserts through a first sleeve 41C61 of the sleeve assembly 41C6. The rod 41C2 inserts through a second sleeve 41C62 of the sleeve assembly 41C6. The adjusting device 41C moves the one end of the rod 41C2 from a first position P1 to a second position P2. The document ejecting mechanism may further include a torsional spring 41D, having one end connected to the rod 41C2, for providing a restoring force to the rod 41C2 to move the one end of the rod 41C2 from the second position P2 to the first position P1.
Therefore, one end of the driving shaft or the rod may be moved to separate the output roller 41A from the idle roller 41B effectively according to the document ejecting mechanism and the document feeder of the invention. Thus, it is possible to prevent the document from being torn in the passageway.
While the invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 096126496 | Jul 2007 | TW | national |
